JP2001140610A - Directly striking type valve system - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To prevent the roundness of the outer peripheral surface of a valve lifter from deteriorating due to the attachment of a rotation preventing member, and to easily reduce the roundness of the outer peripheral surface of a valve lifter. Providing a direct-acting valve train that can correct the deterioration. An engagement groove (20e) is formed on a valve lifter (20a) side.
It is not attached to 0a, but attached to the lifter bore 20b side. Since the rotation preventing member 36 is engaged with the engagement groove 20e on the valve lifter 20a side, the valve lifter 20a can reciprocate in the axial direction of the lifter bore 20b without rotating in the lifter bore 20b. For this reason, deterioration of the roundness of the outer peripheral surface 20d of the valve lifter 20a due to the attachment of the rotation preventing member 36 can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a direct-acting valve train for an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, there has been known a variable valve timing mechanism for varying the opening / closing valve timing of an intake valve or an exhaust valve of an internal combustion engine in accordance with the operation state of the internal combustion engine. FIG. 8 shows one type of the variable valve timing mechanism.
The opening / closing valve timing is adjusted by making the lift amount of a valve 1018 variable by using a three-dimensional cam 1011 movable in the direction of the rotation axis (the Z direction shown in the figure) as shown in FIG. It has been known.

In the variable valve timing mechanism using such a three-dimensional cam, the inclination angle of the cam surface 1011a changes according to the rotation. For this reason, the cam follower 1023 is swingably disposed on the upper surface 1019a of the valve lifter 1019 to cope with a change in the inclination angle of the cam surface 1011a. A guide groove 1021 extending in parallel with the rotation direction of the three-dimensional cam 1011 is formed on the upper surface 1019a of the valve lifter 1019. By disposing the semi-cylindrical cam follower 1023 in the guide groove 1021, the cam follower 1023 swings. Supported as possible. In this manner, a sufficient contact state between the three-dimensional cam 1011 and the valve lifter 1019 is maintained to improve the durability.

Further, in this configuration, it is necessary to always keep the semi-cylindrical cam follower 1023 in the swinging axis direction (the direction of arrow S in the drawing) parallel to the rotation direction of the three-dimensional cam 1011. For this reason, the valve lifter 1 is used as a detent mechanism.
A projection 1025 is provided on an outer peripheral surface 1019b of the cylinder 019, and a guide groove (not shown) is formed in the inner peripheral surface of the lifter bore 1029 on the cylinder head 1027 side in the axial direction. By engaging the projection 1025 with the guide groove on the lifter bore 1029 side, rotation of the valve lifter 1019 is prevented while allowing movement in the axial direction.

[0005]

The above-mentioned valve lifter 10
19 has a corresponding lifter bore 102
The roundness of several μm level is required together with the inner peripheral surface of No. 9. However, when the protrusion 1025 described above is formed on the valve lifter 1019 in order to form a rotation preventing mechanism, the outer peripheral surface 1019b of the valve lifter 1019 formed accurately.
Roundness may be significantly deteriorated.

Further, even if the roundness is to be corrected by cutting or grinding after forming the protrusion 1025, the protrusion 102
5 makes cutting and grinding itself impossible, and as a result, it becomes difficult to manufacture a valve lifter 1019 having an outer peripheral surface 1019b with high roundness.

According to the present invention, it is possible to suppress the deterioration of the roundness of the outer peripheral surface of the valve lifter due to the attachment of the rotation preventing member, and even if the roundness of the outer peripheral surface of the valve lifter deteriorates, the deterioration can be easily reduced. It is an object of the present invention to provide a direct-acting type valve train capable of correcting the above.

[0008]

The means for achieving the above object and the effects thereof will be described below. A direct-acting valve train according to claim 1, wherein a valve lifter is slidably inserted into a lifter bore formed in a cylinder head of the internal combustion engine, wherein the lifter bore is disposed adjacent to the lifter bore in the cylinder head. On the other hand, a shaft insertion hole extending in a direction substantially perpendicular to the shaft is formed, a shaft is inserted into the shaft insertion hole, and a rotation preventing mechanism for preventing rotation of the valve lifter is provided between the valve lifter and the shaft.

A rotation preventing mechanism is provided between the shaft inserted into the shaft insertion hole and the valve lifter in the lifter bore, and the rotation preventing mechanism prevents the valve lifter from rotating in the lifter bore.

As described above, the non-rotating member is not attached to the valve lifter side, and the deterioration of the roundness of the outer peripheral surface of the valve lifter due to the mounting of the non-rotating member can be avoided. Therefore, the valve lifter used in the present direct-acting valve train can be formed on the outer peripheral surface with high roundness.

Further, even if the roundness of the outer peripheral surface of the valve lifter once formed is deteriorated for some reason, the rotation preventing member is not attached to the outer peripheral surface, so that it does not hinder cutting or grinding, and is easy to perform. Thus, the roundness can be corrected, and the outer peripheral surface of the valve lifter can be returned to a state of high roundness.

Further, even if it is necessary to correct the inner peripheral surface of the lifter bore once formed for some reason, the shaft inserted into the shaft insertion hole is removed and rotated together with the rotation preventing mechanism to retract. I just need. Since the shaft insertion hole after the shaft and rotation prevention mechanism are in the retracted state does not hinder cutting or grinding, the inner peripheral surface of the lifter bore can be easily modified, and the inner peripheral surface of the lifter bore can be made to the required shape. it can.

The lifter bore is not provided with a vertical groove, and a shaft insertion hole is formed adjacent to the lifter bore and extends in a direction substantially perpendicular to the lifter bore. For this reason, there is no need for a dedicated processing machine for processing the vertical groove in the lifter bore. Further, such a troublesome cutting operation by the dedicated processing machine becomes unnecessary, and the operation for opening the shaft insertion hole is sufficient, so that the cutting time can be shortened. Therefore, productivity can be improved.

According to a second aspect of the present invention, there is provided a direct-acting type valve train, wherein a plurality of lifter bores are formed in a line in the cylinder head, and a common shaft insertion hole is provided next to the plurality of lifter bores. And a common shaft is inserted through the shaft insertion hole.

By sharing a shaft insertion hole for a plurality of lifter bores in this way, it is not necessary to form shaft insertion holes for several lifter bores. Therefore, together with the operation and effect described in the first aspect, the operation of opening the shaft insertion hole is reduced, and the productivity can be further improved. In addition, since the shaft inserted into the shaft insertion hole can be shared, the number of parts can be reduced and the manufacturing cost can be reduced.

According to a third aspect of the present invention, there is provided a direct-acting type valve train, wherein the shaft insertion hole is formed substantially parallel to the camshaft. In addition to the functions and effects described in the first or second aspect, the shaft insertion hole is formed substantially parallel to the camshaft, so that even when the shaft insertion hole is long, the cylinder head can be easily formed without increasing the size of the cylinder head. Can be formed.

According to a fourth aspect of the present invention, there is provided a direct-acting valve operating mechanism according to the first, second or third aspect, wherein the shaft insertion hole is formed so as to partially overlap an inner peripheral surface of the lifter bore. A vertical hole or a vertical groove provided in a side wall portion of the valve lifter and a guide portion provided in the shaft so as to be slidably engaged with the vertical hole or the vertical groove. It is characterized by comprising a blocking mechanism.

A vertical hole or a vertical groove is provided in a side wall portion of the valve lifter, and a rotation preventing member is not attached. For this reason, it is possible to avoid deterioration of the roundness of the outer peripheral surface of the side wall of the valve lifter due to the attachment of the rotation preventing member. Therefore, the valve lifter used in the present direct-acting valve train can be formed on the outer peripheral surface with high roundness.

Further, even if the roundness of the outer peripheral surface in the side wall portion of the valve lifter once formed is deteriorated for some reason, the elongated hole or the elongated groove is recessed from the outer peripheral surface. No. For this reason, the roundness can be easily corrected, and the outer peripheral surface of the valve lifter can be returned to a state of high roundness.

Even if it is necessary to correct the inner peripheral surface of the lifter bore once formed for some reason, if the shaft inserted into the shaft insertion hole is removed or rotated together with the guide portion and retracted, the shaft is retracted. Good. Since the shaft insertion hole after the shaft and the guide portion are in the retracted state does not hinder cutting or grinding, the inner peripheral surface of the lifter bore can be easily modified, and the inner peripheral surface of the lifter bore can be formed into a required shape. .

According to a fifth aspect of the present invention, in the direct-acting type valve train according to the first, second or third aspect, the shaft insertion hole is formed so as to partially overlap an inner peripheral surface of the lifter bore. And a guide provided on the shaft so as to slidably hold the side wall protrusion, the side wall protrusion being formed by a pair of vertically long recesses provided on the side wall of the valve lifter. And the portion constitutes the rotation preventing mechanism.

As described above, a pair of vertically long concave portions is formed on the side wall portion of the valve lifter to relatively form a side wall convex portion. The projection of the side wall is slidably held by a guide portion provided on the shaft to prevent rotation of the valve lifter in the lifter bore. As described above, the side wall convex portion is formed on the side wall portion of the valve lifter, which is relatively formed by forming a pair of vertically long concave portions, and protrudes from the outer peripheral surface of the side wall portion of the valve lifter. Not. That is, the side wall projection does not hinder cutting or grinding.

For this reason, even if the roundness of the outer peripheral surface on the side wall portion of the valve lifter once formed is not sufficient, the roundness can be easily corrected, and the outer peripheral surface of the valve lifter can be brought into a state of high roundness. it can.

According to a sixth aspect of the present invention, there is provided a direct-acting type valve train, wherein the guide portion is provided on the shaft so as not to exceed the inner diameter of the shaft insertion hole toward the outer peripheral side. It is characterized by the following.

Therefore, the operation of inserting or removing the shaft into or from the shaft insertion hole can be performed because the guide portion does not exceed the inner diameter of the shaft insertion hole toward the outer peripheral side. It is easy, and production and repair are easy and highly efficient.

According to a seventh aspect of the present invention, there is provided a direct-acting valve train according to any one of the first to sixth aspects, wherein the cam profile is continuously formed in the axial direction from the first cam profile to the second cam profile. And a displacement device for continuously or stepwise displacing the three-dimensional cam in the axial direction is provided on the top wall of the valve lifter to prevent a change in the contact line angle accompanying the rotation of the three-dimensional cam. A cam follower that contacts the three-dimensional cam while following is provided.

By providing such a three-dimensional cam, a displacement device, and a cam follower, the three-dimensional cam can be brought into contact with the valve lifter over a wide area by the cam follower, thereby improving the wear resistance and the durability. Further, by the displacement device displacing the three-dimensional cam continuously or stepwise in the axial direction, it is possible to realize a suitable valve lift and opening / closing valve timing according to the operation state of the internal combustion engine.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [First Embodiment] FIG. 1 is a schematic structural explanatory view of an engine 11 incorporating a valve lifter detent mechanism to which the above-mentioned invention is applied.

The engine 11 is an in-cylinder four-cylinder direct injection gasoline engine, and is mounted on the vehicle to drive the vehicle with its output. This engine 11
The cylinder block 13 includes a reciprocating piston 12, an oil pan 13 a provided below the cylinder block 13, and a cylinder head 14 provided above the cylinder block 13.

A crankshaft 15 as an output shaft is rotatably supported below the engine 11, and a piston 12 is connected to the crankshaft 15 via a connecting rod 16. The reciprocating motion of the piston 12 is converted by the connecting rod 16 into a rotational motion of the crankshaft 15. A combustion chamber 17 is provided above the piston 12, and an intake port 18 and an exhaust port 19 are connected to the combustion chamber 17.
The intake port 18 and the combustion chamber 17 are connected to the intake valve 2
0, the exhaust port 19 and the combustion chamber 17
Is communicated and shut off by the exhaust valve 21.

As shown in the cross section of the cylinder head 14 shown in FIG. 2, the two intake ports 18 are straight type intake ports extending substantially linearly. An ignition plug 17a is arranged at the center of the inner wall surface of the cylinder head 14. Further, a fuel injection valve 17b is disposed around the inner wall surface of the cylinder head 14 near the intake valve 20 so that fuel can be directly injected into the combustion chamber 17.

FIG. 3 is a plan view of the top surface of the piston 12, FIG. 4 is a sectional view taken along line XX in FIG. 2, and FIG. 5 is a sectional view taken along line YY in FIG. As shown in the figure, a recess 12a having a dome-shaped profile extending from below the fuel injection valve 17b to below the ignition plug 17a is formed on the top surface of the piston 12 formed in a substantially mountain shape.

As shown in FIG. 2, two intake ports 18 of each cylinder are connected to a surge tank 18c via two intake passages 18a and 18b formed in an intake manifold.
It is connected to the. An airflow control valve 18d is disposed in one of the intake passages 18a. These airflow control valves 18d are connected via a common shaft 18e, and are opened and closed by an actuator 18f via the shaft 18e in accordance with the operation state of the engine 11. When the airflow control valve 18d is closed, a strong swirling flow A is generated in the combustion chamber 17 by the intake air sucked from only one intake port 18.

As shown in FIG. 1, the cylinder head 14
, An intake side camshaft 22 and an exhaust side camshaft 23 are arranged in parallel. Intake side camshaft 2
2 is a cylinder head that is rotatable and movable in the axial direction.
The exhaust-side camshaft 23 is rotatable but not movable in the axial direction.
Supported above.

At one end of the intake camshaft 22, a variable valve characteristic device 24 having a timing sprocket 24a is provided. Also, the exhaust side camshaft 2
A timing sprocket 25 is attached to one end of the third sprocket. The timing sprocket 25 and the timing sprocket 24a of the variable valve characteristic device 24
Are connected via a timing chain 26 to a sprocket 15a attached to the crankshaft 15. And, a crankshaft 15 as an output shaft
Is transmitted to the timing sprockets 24a and 25 via the sprocket 15a and the timing chain 26. This allows the intake side camshaft 22
And the exhaust side camshaft 23 is the crankshaft 15
It rotates in synchronization with the rotation of.

The variable valve characteristic device 24 acts on the intake camshaft 22 to adjust the position of the intake camshaft 22 in the direction of the rotation axis. The adjustment of the position of the intake side camshaft 22 in the rotation axis direction is performed by supplying hydraulic pressure from an oil control valve 70 that is driven and controlled by an electronic control unit (not shown) in accordance with the operation state of the engine 11.

The intake camshaft 22 is provided with an intake cam 27 that contacts a valve lifter 20a provided at the upper end of the intake valve 20. The exhaust camshaft 23 is provided with an exhaust cam 28 which comes into contact with a valve lifter 21a provided at the upper end of the exhaust valve 21. When the intake camshaft 22 rotates in synchronization with the crankshaft 15, the intake valve 20 is opened and closed according to the cam profile of the intake cam 27, and when the exhaust camshaft 23 rotates, the cam profile of the exhaust cam 28 rotates. The exhaust valve 21 is driven to open and close according to.

Here, the cam profile of the exhaust cam 28 is a flat cam that is constant in the direction of the rotation axis of the exhaust-side camshaft 23. However, the cam profile of the intake cam 27 continuously changes in the rotation axis direction (the direction of the arrow S) of the intake camshaft 22. That is, the intake cam 27
Is configured as a three-dimensional cam. The target lift pattern of the intake valve 20 is realized by adjusting the position of the intake cam 27 in the rotation axis direction by the variable valve characteristic device 24.

The electronic control unit is separately provided with the engine 1
According to the operation state of 1, the fuel is injected at the end of the compression stroke and stratified combustion in which the fuel is burned with a fuel smaller than the stoichiometric air-fuel ratio. Weak stratified combustion in which the fuel is burned with a smaller amount of fuel, and homogeneous combustion in which the fuel is injected in the intake stroke and burned with a stoichiometric air-fuel ratio or a fuel larger than the stoichiometric air-fuel ratio is performed.

FIG. 6 is a perspective view showing the structure around two intake cams 27 for one cylinder. FIG. 7 is an exploded perspective view of the configuration of FIG. The cylinder head 14 is provided with two lifter bores 20 b for the intake valve 20. A cylindrical valve lifter 20a is housed in the lifter bore 20b so as to be able to reciprocate while sliding in the axial direction. The valve lifter 20a has an engagement groove 20e extending from the top surface 20c to the outer peripheral surface 20d in the reciprocating direction of the valve lifter 20a.

Between two adjacent lifter bores 20b,
A journal bearing 30 is formed. The journal bearing 30 supports the intake side camshaft 22 together with the bearing cap 32 between two intake cams 27 of the same cylinder. The journal bearing 30 and the bearing cap 32 support the intake-side camshaft 22 so as to be slidable in the rotation axis direction.
2 can be smoothly moved in the rotation axis direction.

In the center of the journal bearing 30, a storage groove 34 having a deep notch shape is formed in the rotation axis direction of the intake side camshaft 22. A plate-shaped detent member 36 is inserted into the storage groove 34. The detent member 36 is shown in a perspective view (A), a plan view (B), a left side view (C), a front view (D) and a right side view (E) of FIG.
As shown, the rotation preventing member 36 has legs 36a on both sides of the lower side, and is disposed so as to straddle the bottom of the storage groove 34 with the legs 36a. The rotation preventing member 36 has a lubricating oil supply groove 36 on one side (the rear side in FIG. 7).
b is formed from the vicinity of the center to the upper side. The lubricating oil supply groove 36b is formed in the cylinder head 14 and opened in the storage groove 34 as shown in the sectional view of FIG. 9 when the rotation preventing member 36 is stored in the storage groove 34. It is formed at a position communicating with the oil supply passage 38. As a result, the lubricating oil supplied from the lubricating oil supply passage 38 is supplied to the lubricating oil supply groove 36 of the detent member 36.
Through b, the air can be supplied between the intake side camshaft 22 located immediately above the detent member 36, the journal bearing 30 and the bearing cap 32.

As shown in the perspective view of FIG. 10 in which the cylinder head 14 is cut in the arrangement direction of the lifter bores 20b, the detent member 36 disposed in the storage groove 34 has two side portions 36c having two lifter bores 20b. It protrudes into. Thereby, each side portion 36c of the rotation preventing member 36 is slidably engaged with the engagement groove 20e of each valve lifter 20a.

Storage groove 34 in journal bearing 30
Is formed as follows. First, as shown in the perspective view of FIG. 11, the disc-shaped cutter M is arranged so that the cut surface is located on the arrangement line L of the lifter bore 20b. And
The journal bearing 30 is cut in the axial direction of the lifter bore 20b, that is, in the driving direction of the intake valve 20. Thereby, the storage groove 34 is formed as shown in FIG. Also, when the storage groove 34 is formed, at the same time, the lifter bore 20b has two grooves 4 formed by the disc-shaped cutter M depending on the dimensions.
Although 0 is formed extra, it does not hinder the functions of the lifter bore 20b and the cylinder head 14.

The thus formed cylinder head 14
Each of the two lifter bores 20b of FIG.
Is inserted. At this time, the stem 44 (FIG. 7) of the intake valve 20 penetrating through the intake port 18 is provided in the valve lifter 20a.
(FIG. 7), the spring 48 (FIG. 7), and the like are already assembled, and the stem end 50 (FIG. 7) comes into contact with the inside of the top surface 20c of the valve lifter 20a from inside. This state is shown in FIG.

As shown in FIG. 15, a detent member 36 is inserted and disposed in the storage groove 34 formed in the journal bearing 30 with the leg portion 36a facing downward. At this time, from the top surface 20c of the valve lifter 20a to the outer peripheral surface 20d
The rotation preventing member 36
Of each side 36c is inserted. As a result, the rotation of the valve lifter 20a around the axis in the lifter bore 20b is prevented, and only the axial movement is allowed.

A guide groove 52 is formed on the top surface 20c of the valve lifter 20a. The guide groove 52 is composed of a semi-cylindrical large-diameter groove 52a having a large diameter in the center and a semi-cylindrical small-diameter groove 52b having a small diameter on both sides thereof. A cam follower 54 is arranged in the guide groove 52 as shown in FIG. FIG. 16 shows this state.

FIG. 17 is a perspective view (A), a front view (B), a plan view (C), and a left side view (D) of the cam follower 54.
And the right side view (E). As shown in the figure, the cam follower 54 has a semi-cylindrical large-diameter portion 54 having a large diameter in the center.
a and a semi-cylindrical small-diameter portion 54b having a small diameter on both sides thereof. The large diameter portion 54a of the cam follower 54 is accommodated in the large diameter groove 52a of the guide groove 52, and the small diameter portion 54b of the cam follower 54 is accommodated in the small diameter groove 52b of the guide groove 52. As a result, the small diameter portion 54b of the cam follower 54 and the small diameter groove 52b of the guide groove 52 slide, so that the cam follower 54 can swing around the axis.
Since the large-diameter portion 54a of the cam follower 54 is inserted into the large-diameter groove 52a of the guide groove 52, the entire cam follower 54 is prevented from moving in the axial direction.

Next, the intake side camshaft 22 is disposed on the journal bearing 30, and the rotation preventing member 36 is
4 is prevented from leaving. Then, the bearing cap 32 is bolted to the journal bearing 30 so that the intake camshaft 2 is attached to the journal bearing 30.
2 is mounted so as to be rotatable and slidable in the axial direction. Thus, the state shown in FIG.
The cam surface 27 a formed on the outer periphery of the intake cam 27 attached to the cam follower 2 is a cam sliding surface 54 of the cam follower 54.
c.

FIG. 1 is a plan view corresponding to FIG.
As shown in FIG. 8, the guide groove 52 is formed in the journal bearing 3.
It is formed so as to be offset from the center of the valve lifter 20a in a direction away from zero. This is because the guide groove 52 is provided to secure the axial movement amount of the intake cam 27 when the distance between the centers of the two lifter bores 20b is not sufficiently large.
Must be spaced apart and are offset outward.

In the drive mechanism of the intake valve 20 thus configured, when the intake side camshaft 22 rotates as indicated by the arrow C shown in FIG. 6, the valve lifter via the cam follower 54 according to the position of the cam surface 27a. 20a moves in the lifter bore 20b in the axial direction. Thus, the intake valve 20 is lifted according to the lift pattern of the cam surface 27a. For example, FIG. 19 shows a state in which the valve lifter 20a is pressed down most by the cam nose 27b which indicates the peak of the lift. Cam nose 27
b, a gradient is formed with respect to the rotation axis of the intake side camshaft 22.
And the cam sliding surface 54c corresponds to the inclination of the cam nose 27b.

The variable cam characteristic device 24 moves the intake camshaft 22 in the direction of the rotation axis indicated by the arrow S as necessary. For example, the intake side camshaft 22
20 and 21 show the state in which the arrow has moved the maximum amount in the direction R within the arrow S. In the present embodiment, since the cam nose 27b is higher on the direction F side of the intake cam 27 than on the direction R side, the case of the intake valve 20 in FIGS. The lift peak increases, and the operating angle in which the intake valve 20 is in the open state increases.

Since the moving position in the direction of arrow S by the variable valve characteristic device 24 can be continuously adjusted, the engine 11 is moved between the lift pattern in the state shown in FIGS. 6 and 19 and the lift pattern in the state shown in FIGS. It is possible to adjust steplessly according to the operating state.

As described above, most of the cam surface 27a is inclined with respect to the rotation axis of the intake camshaft 22. In particular, the cam nose 27b is in a state of maximum inclination. When the cam surface 27a slides on the cam sliding surface 54c other than the center of the cam follower 54 in the state where the cam surface 27a is tilted in this manner, the valve lifter 20
a is supplied with a rotational force about the axis from the intake cam 27 via the cam follower 54. However, since the rotation preventing member 36 disposed in the storage groove 34 of the journal bearing 30 is engaged with the engaging groove 20e formed from the top surface 20c to the outer peripheral surface 20d of the valve lifter 20a, the rotation of the valve lifter 20a is prevented. Is blocked. As a result, the axial direction of the cam follower 54 is maintained in the direction in which the intake cam 27 slides, that is, the direction which always coincides with the rotational direction of the intake camshaft 22, and a desired valve lift can be accurately realized.

According to the first embodiment described above, the following effects can be obtained. (I). An engagement groove 20e is formed on the valve lifter 20a side.
Are mounted on the lifter bore 20b side. Since the rotation preventing member 36 is engaged with the engagement groove 20e on the valve lifter 20a side, the valve lifter 20a can reciprocate in the axial direction of the lifter bore 20b without rotating in the lifter bore 20b.

As described above, it is possible to realize a rotation preventing mechanism for the valve lifter 20a which avoids deterioration of the roundness of the outer peripheral surface 20d of the valve lifter 20a due to the attachment of the rotation preventing member 36. Therefore, the valve lifter 20a can be formed on the outer peripheral surface 20d having a high roundness.

Even if the roundness of the outer peripheral surface 20d of the once formed valve lifter 20a deteriorates for some reason, the engagement groove 20e does not hinder cutting or grinding, so that the roundness can be easily corrected and the valve lifter can be easily corrected. 20a outer peripheral surface 2
0d can be returned to a state of high roundness.

Further, the engagement groove 20 is formed in the valve lifter 20a side.
By forming e, the secondary effect that the valve lifter 20a as a reciprocating component can be reduced in weight and the durability of the engine 11 can be improved is produced.

(B). A storage groove 34 is opened in the inner peripheral surface of the lifter bore 20b. The central portion of the rotation preventing member 36 is stored in the storage groove 34, and the rotation preventing member 36
Side 36c is engaged with the engagement groove 20e on the valve lifter 20a side.
The valve lifter 20a is allowed to slide in the axial direction, but is prevented from rotating.

As described above, with respect to the lifter bore 20b on the cylinder head 14 side, the storage groove 34 is opened on the inner peripheral surface thereof, and the central portion of the detent member 36 is stored in the storage groove 34. 36 is attached. For this reason, the detent member 36 can be easily attached, and the detent mechanism of the valve lifter 20a can be easily realized. Therefore, by adopting such a configuration, the productivity of the rotation stopping mechanism of the valve lifter 20a can be increased.

(C). The storage groove 34 is provided in the lifter bore 2
The cylinder head 14 of the portion 0b is formed by cutting the cylinder head 14 with a disk-shaped cutter M in the axial direction of the lifter bore 20b. Thus, the storage groove 34 can be easily formed by machining in the axial direction of the lifter bore 20b. Therefore, the productivity of the detent mechanism of the valve lifter 20a can be further increased.

(D). Further, the storage groove 34 is formed by cutting the journal bearing 30 for the intake-side camshaft 22 in the axial direction of the lifter bore 20 b with a disk-shaped cutter M, and the rotation preventing member 36 stored in the storage groove 34.
Is prevented from being detached from the storage groove 34 by the intake side camshaft 22 disposed on the journal bearing 30.
Therefore, it is not necessary to provide a special member for fixing the rotation preventing member 36 on the cylinder head 14, so that the number of parts is reduced and an increase in the weight of the engine 11 can be prevented.

Even if it is necessary to correct the inner peripheral surface of the once formed lifter bore 20b for some reason, the detent member 36 housed in the housing groove 34 may be removed. Since the lifter bore 20b itself is not a reciprocating component, the lifter bore 20b is formed with a simple configuration and mounting as described above, so that it can be easily removed.

Since the storage groove 34 from which the rotation preventing member 36 has been removed does not hinder cutting or grinding, the inner peripheral surface can be easily modified, and the inner peripheral surface of the lifter bore 20b can be formed into a shape requiring the inner peripheral surface. it can.

(E). Further, the storage groove 34 is formed by cutting the arrangement line L of the lifter bores 20b in the cylinder head 14 between the adjacent lifter bores 20b with the disk-shaped cutter M in the axial direction of the lifter bores 20b. The arrangement line L of the lifter bores 20b between the adjacent lifter bores 20b can be easily cut in the axial direction of the lifter bores 20b to form cut grooves even with the disk-shaped cutter M. Therefore, the storage groove 34 can be easily and quickly formed by ordinary processing without using a special machine tool, and the productivity of the detent mechanism of the valve lifter 20a can be further increased.

(F). The adjacent lifter bore 20b
The storage groove 3 on the arrangement line L of the lifter bore 20b between
4 to form one detent member 36 into 2
The two valve lifters 20a are engaged with the engagement grooves 20e. Therefore, the number of parts can be reduced and productivity can be improved.

(G). Further, a lubricating oil supply passage 38 is opened in the storage groove 34, and lubricating oil is supplied to the peripheral surface of the intake side camshaft 22 via a lubricating oil supply groove 36 b formed in the detent member 36. .

If the lubricating oil supply passage 38 is opened at the portion where the journal bearing 30 is in contact with the intake camshaft 22, and the lubricating oil is supplied directly to the peripheral surface of the intake camshaft 22. Conversely, the lubricating oil may be immediately discharged from the storage groove 34 in which the rotation preventing member 36 is stored, and the lubricating oil on the peripheral surface of the intake camshaft 22 may be insufficient. In the present embodiment, the lubricating oil supply passage 3
8 is opened in the storage groove 34, and the lubricating oil is supplied to the peripheral surface of the intake side camshaft 22 through the lubricating oil supply groove 36 b of the detent member 36. Shortage of lubricating oil is prevented. The supply of the lubricating oil can simultaneously serve as the supply of the lubricating oil between the valve lifter 20a and the detent member 36 and between the valve lifter 20a and the lifter bore 20b.

[Second Embodiment] FIG. 22 is a perspective view showing a configuration around two intake cams 127 for one cylinder in a second embodiment. FIG. 2 is an exploded perspective view of the configuration of FIG.
3 is shown. In the second embodiment, a storage hole 134 and a columnar detent member 136 shown in FIG. 23 are used instead of the combination of the storage groove 34 and the detent member 36 in the first embodiment. Other configurations are basically the same as the first embodiment. Unless otherwise specified, in the second embodiment, configurations having the same functions as those of the first embodiment are described in the corresponding first embodiment.
Are added to the reference numerals assigned to the above configuration and “100” is added.

As shown in the perspective view of the cylinder head 114 in FIG. 24, a cylindrical storage hole 134 is formed below the journal bearing 130 between two adjacent lifter bores 120b. The storage hole 134 is a hole formed by drilling from the outer peripheral surface 114 a of the cylinder head 114 in a direction substantially orthogonal to the axial direction of the lifter bore 120 b by 90 °. Since the diameter of the storage hole 134 is formed larger than the interval between the inner peripheral surfaces of the lifter bore 120b,
The storage hole 134 partially overlaps the lifter bore 120b. For this reason, the storage hole 134 is formed in the lifter bore 120b.
Through an opening 134a.

A cylindrical detent member 136 is inserted into the storage hole 134. Detent member 1
36 is a perspective view (A), a plan view (B), a bottom view (C), a front view (D), a rear view (E), and a left side view (F) of FIG.
And a right side view (G). As shown in the drawing, the rotation preventing member 136 has a short cylindrical head 136a formed at the distal end, and a cylindrical base 136 having the same diameter as the head 136a at the proximal end.
b is formed. These head 136a and base 13
The diameter of 6b is substantially the same as the diameter of the storage hole 134.

The head 136a and the base 136b are connected by a columnar neck 136c having a smaller diameter than the head 136a and the base 136b. This small neck 136c
Is formed to have a smaller diameter than the interval between the inner peripheral surfaces of the lifter bore 120b. Then, the neck 136c is shown in FIG.
As shown in (2), when the rotation preventing member 136 is stored in a regular position in the storage hole 134, it is arranged at a position facing the opening 134a. At this time, the head 136a and the base 136b are not arranged at positions facing the opening 134a.

The neck 136c is formed with two columnar engaging projections 136d so as to project radially and in opposite directions. The distal end surface 136e of the engagement projection 136d is included in a cylindrical surface common to the outer peripheral surfaces of the head 136a and the base 136b. That is, the engagement protrusion 136
As for d, the protrusion amount is made the same as the diameter of the head 136a and the base 136b. Therefore, the detent member 136
Is inserted into the storage hole 134, the engagement protrusion 136d is in a state of protruding into the lifter bore 120b from the opening 134a by the amount of the storage hole 134 overlapping the lifter bore 120b.

The base 136b has a rotation stopping hole 136f formed in a direction orthogonal to the direction in which the engaging projection 136d projects. In addition, the base end face 136g of the base 136b
Has a slit 1 in the same direction as the projection direction of the engagement protrusion 136d.
36h are formed.

FIG. 2 shows the arrangement of the rotation preventing member 136 and the valve lifter 120a in the cylinder head 114.
6 and a plan view of FIG. FIGS. 26 and 27 show a state in which the cylinder head 114 is cut perpendicular to the axis of the valve lifter 120a at the shaft portion of the storage hole 134. Also, FIG. 28 shows a state of being cut perpendicularly to the cut surface of FIGS.

Of the rotation preventing member 136, only the engagement protrusion 136d existing in the portion where the storage hole 134 and the lifter bore 120b overlap is engaged with the engagement groove 120e of the valve lifter 120a. This allows the valve lifter 120a to move in the axial direction, but prevents rotation of the valve lifter 120a.

The two bolts 1 for fixing the bearing cap 132 to the journal bearing 130 are provided in the rotation stopping hole 136f formed in the base 136b.
The tip of one of the bolts 132a of 32a and 132b is inserted. As a result, the detent member 136
Is prevented from rotating, and the engagement protrusion 136 is
d is prevented from coming off from the engagement groove 120e.

When the valve lifter 120a is removed for some reason such as replacement of parts, the following steps are performed. First, the bearing cap 132 is removed from the journal bearing 130 by removing the bolts 132a and 132b. Further, the intake camshaft 122 is removed from the journal bearing 130. Since the rotation stopping hole 136f is opened by removing the bolt 132a, the rotation preventing member 136 becomes rotatable about the axis.

Next, after removing the cam follower 154,
Using the slit 136h formed in the base end face 136g, the jig is used to axially rotate the rotation preventing member 136 with a jig. By this rotation, as shown in FIGS. 29, 30, and 31 (corresponding to FIGS. 26, 27, and 28, respectively), the engagement protrusion 136d comes out of the engagement groove 120e of the valve lifter 120a. As a result, the valve lifter 120a becomes rotatable. Further, when the valve lifter 120a is pulled out upward, the bottom surface 120f of the engagement groove 120e does not collide with the engagement protrusion 136d.
Can be easily removed from the lifter bore 120b.

Conversely, when the valve lifter 120a is mounted, the valve lifter 120a is connected to the lifter bore 120b.
After that, the rotation preventing member 136 is rotated by 90 ° using the slit 136h to engage the engagement protrusion 136d with the engagement groove 120e. Then, the cam follower 154 is attached, the intake camshaft 122 is arranged on the journal bearing 130, and the bearing cap 132 is attached to the journal bearing 130 with bolts 132a and 132b. Thus, the configuration returns to the configuration shown in FIG.

According to the second embodiment described above, the following effects can be obtained. (I). An engagement groove 120e is formed on the valve lifter 120a side, but the detent member 136 is not attached. The detent member 136 is attached to the storage hole 134 on the cylinder head 114 side. This storage hole 13
4 is a hole having an axis not existing on the same plane as the axis of the lifter bore 120b;
The cylinder head 114
Is formed. The rotation preventing member 136 is provided with an engagement protrusion 136d, and the lifter bore 120b and the storage hole 134.
Is formed so as to protrude to an overlapping portion with the above. As a result, portions other than the engagement protrusion 136d of the rotation preventing member 136 do not project into the lifter bore 120b, and only the engagement protrusion 136d projects. In this way, only the engagement protrusion 136d of the rotation preventing member 136 can be engaged with the engagement groove 120e on the valve lifter 120a side.

As described above, since the detent member 136 is not attached to the valve lifter 120a side, the roundness of the outer peripheral surface 120d of the valve lifter 120a can be prevented from deteriorating. Therefore, the valve lifter 120a can be formed on the outer peripheral surface 120d having a high roundness.

Even if the roundness of the outer peripheral surface 120d of the once formed valve lifter 120a is deteriorated for some reason, the roundness can be easily corrected because the engagement groove 120e does not hinder cutting or grinding. The outer peripheral surface 120d of 120a can be returned to a state of high roundness.

Further, the engagement groove 1 is formed on the valve lifter 120a side.
Due to the formation of 20e, the side effect that the valve lifter 120a as a reciprocating component can be reduced in weight and the durability of the engine can be improved is produced.

Further, a storage hole 134 formed in the cylinder head 114 for storing the rotation preventing member 136 is provided.
Are simply holes having an axis that does not lie on the same plane as the axis of the lifter bore 120b.
b in a state where a part of the cylinder head 11 overlaps in the radial direction.
4, it can be easily formed by drilling or the like. In addition, the engagement projection 136d of the rotation preventing member 136 can be easily formed because it only has to be formed so as to protrude to an overlapping portion between the lifter bore 120b and the storage hole 134. Further, the engagement groove 120e of the valve lifter 120a is formed on the outer peripheral surface 120d of the valve lifter 120a.
In this case, it can be easily formed because it may be formed in the reciprocating direction.

Therefore, without using a special machine tool,
The storage hole 134, the detent member 136, and the engagement groove 120e can be easily and quickly formed by ordinary processing, and the productivity of the detent mechanism of the valve lifter 120a can be increased.

Even if it is necessary to correct the inner peripheral surface of the once formed lifter bore 120b for some reason,
The detent member 136 housed in the storage hole 134 is removed or the detent member 136 is rotated to engage the engagement protrusion 136.
What is necessary is just to evacuate d. Since the storage hole 134 after the retreat of the engagement protrusion 136d does not hinder cutting or grinding, the inner peripheral surface can be easily modified, and the inner peripheral surface of the lifter bore 120b can be formed into a shape that requires the inner peripheral surface.

(B). The rotation preventing member 136 is rotated about the axis to retract the engagement protrusion 136d from the overlapped portion between the lifter bore 120b and the storage hole 134, so that the valve lifter 120 formed by the engagement protrusion 136d.
a can be released from engagement with the engagement groove 120e. As a result, before the valve lifter 120a is assembled, the detent member 136 can be stored in the storage hole 134 in advance, and the detent member 136 can be engaged with the engagement groove 120e of the valve lifter 120a simply by rotating the detent member 136. The protrusion 136d can be engaged. Therefore, the work of assembling the detent mechanism of the valve lifter 120a is also facilitated, and the productivity of the detent mechanism of the valve lifter can be further increased.

(C). In addition, when the valve lifter 120a is mounted, simply rotating the detent member 136 causes the bottom 120f of the engagement groove 120e and the detent member 1 to rotate.
The engagement projections 136d of 36 are in contact with each other. This allows the valve lifter 120a to resist the urging force of the spring 148.
Can be temporarily fixed, and the arrangement of the cam follower 154 to be performed next and the intake side camshaft 122 can be
The work of assembling into is more efficient.

Third Embodiment FIG. 32 is a perspective view showing a configuration around two intake cams 227 for one cylinder in a third embodiment. FIG. 3 is an exploded perspective view of the configuration of FIG.
3 is shown. In the third embodiment, instead of the combination of the storage groove 34 and the detent member 36 in the first embodiment, a storage hole 234 and a columnar detent member 236 shown in FIG. 33 are used. Further, the valve lifter 22
A guide surface 220e is formed in Oa instead of the engagement groove.

The other structure is basically the same as that of the first embodiment. Unless otherwise specified, in the third embodiment, components having the same functions as those of the first embodiment are denoted by reference numerals obtained by adding “200” to the reference numerals assigned to the corresponding configurations of the first embodiment. Is shown.

As shown in the perspective view of the cylinder head 214 in FIG. 34, a cylindrical storage hole 234 is formed in the cylinder head 214 along the direction in which the two adjacent lifter bores 220b are arranged. The storage hole 234 is drilled from outside the cylinder head 214 using a lifter bore 220.
The hole is formed in a direction substantially different from the axial direction of b by 90 ° and along the arrangement direction of the lifter bores 220b. The storage hole 234 passes directly below one of the bolt holes 230a of the journal bearing 230. Unlike the second embodiment, a common storage hole 234 is formed for all four cylinders by a single drilling process.
Since the distance from the axial position of the storage hole 234 to the inner peripheral surface of the lifter bore 220b is shorter than the radius of the storage hole 234, the storage hole 234 partially overlaps the lifter bore 220b. For this reason, the storage hole 234 communicates with the lifter bore 220b at the opening 234a.

A cylindrical detent member 236 is inserted into the storage hole 234 as shown in FIG.
Here, the detent member 236 is shown in a perspective view (A) of FIG.
A plan view (B), a front view (C), a rear view (D) and a bottom view (E) are shown. In FIG. 36, the detent member 236 is shown.
1 partially shows one cylinder. Detent member 2
The actual length of 36 is the length of four cylinders that penetrate the cylinder head 214 in the direction of the intake camshaft 222.
The diameter of the cylindrical portion of the rotation preventing member 236 is equal to the diameter of the storage hole 23.
The diameter is almost the same as the diameter of No. 4.

As shown in the figure, two semi-cylindrical portions 236a and 236b are formed in each cylinder portion of the detent member 236. A rotation stopping hole 236c is formed in the column between the semi-columns 236a and 236b.

Then, the semi-cylindrical portions 236a and 236b are
As shown in FIG. 35, the rotation preventing member 236 is
In the state where it is stored in a regular position in
a, and the cylindrical portion is not located at the opening 234a. Accordingly, the semi-cylindrical portions 236a and 236b are formed by an amount corresponding to the storage hole 234 overlapping the lifter bore 220b.
It is in a state of being inserted into the lifter bore 220b from the opening 234a.

FIG. 3 shows the arrangement of the detent member 236 and the valve lifter 220a in the cylinder head 214.
7 and a plan view of FIG. FIGS. 37 and 38 show a state in which the cylinder head 214 is cut perpendicular to the axis of the valve lifter 220a at the shaft portion of the storage hole 234. FIG. 39 shows a state where the cylinder head 214 is cut in the shaft portion of the storage hole 234 in parallel to the axis of the valve lifter 220a.

Here, the valve lifter 220a is
Are formed as shown in a perspective view (A), a plan view (B), a front view (C) and a right side view (D). A guide surface 220e parallel to the reciprocating direction of the valve lifter 220a is formed on the outer peripheral surface of the valve lifter 220a by partially removing the outer peripheral surface by cutting or the like. This guide surface 220e is cut perpendicular to the axis of the rotation preventing member 236 at the axis of the valve lifter 220a.
As shown in the cross-sectional view of FIG. 1, the cylindrical member 236 contacts the cylindrical surfaces 236d of the semi-cylindrical portions 236a and 236b of the detent member 236 existing at the overlapping portion of the lifter bore 220b and the storage hole 234. As a result, the valve lifter 220a is guided, and the valve lifter 220a can move in the axial direction, but the rotation of the valve lifter 220a is prevented. In addition,
The valve lifter 220a shown in FIG. 40 shows the configuration of the valve lifter 220a on the left side in FIG. The configuration of the valve lifter 220a on the right side in FIG.
The configuration is the same as that shown in FIG. 40 except that the position of 52 is shifted to the right in FIG. 40 (C).

Further, as shown in FIG.
The two bolts 232a, 2 that fix the bearing cap 232 to the journal bearing 230 are provided in the rotation stopping hole 236c formed between the journal bearings 230a, 236b.
The tip of one of the bolts 232a out of 32b is inserted. As a result, the rotation preventing member 236 is prevented from rotating around the shaft, and the rotation preventing member 236 is prevented from rotating during the operation of the engine.
36 rotates and the cylindrical surface 2 of the semi-cylindrical portions 236a and 236b
36d is prevented from coming off the guide surface 220e.

When the valve lifter 220a is removed for some reason such as replacement of parts, the following steps are performed. First, the bolts 232a and 232b are removed, and the bearing cap 232 is removed from the journal bearing 230. Further, the intake camshaft 222 is removed from the journal bearing 230. Since the rotation stopping hole 236c of the rotation preventing member 236 is opened by removing the bolt 232a, the rotation preventing member 236 becomes rotatable about the shaft.

Next, the cam follower 254 is removed from the valve lifter 220a. Then, the 180 ° detent member 236 is axially rotated by a jig or the like. 42, 43, 44 and 45 (FIGS. 37, 38 and 3 respectively).
9 and 41), as shown in FIG.
a and 236b are excluded from the portion where the storage hole 234 and the lifter bore 220b overlap. This allows
The guide surface 220e of the valve lifter 220a is a semi-cylindrical portion 2
Since it is no longer guided by the cylindrical surface 236d of the cylinders 36a and 236b, the valve lifter 220a can be rotated around the axis. Further, when the valve lifter 220a is pulled upward, the lower cylindrical portion 220f of the uncut cylindrical portions 220f existing at the upper and lower ends of the guide surface 220e does not collide with the semi-cylindrical portions 236a and 236b. Can be easily removed from the lifter bore 220b.

On the contrary, when the valve lifter 220a is mounted, the valve lifter 220a is connected to the lifter bore 220b.
Then, the rotation preventing member 236 is rotated by 180 °, and is brought into contact with the guide surface 220e of the valve lifter 220a at the cylindrical surface 236d of the semi-cylindrical portions 236a and 236b to rotate the valve lifter 220a and the lifter bore 22.
0b is prevented. And Cam Follower 254
, The intake camshaft 222 is arranged on the journal bearing 230, and the bearing cap 232 is attached to the journal bearing 230 with bolts 232a and 232b. Thus, the configuration returns to the configuration shown in FIG.

According to the third embodiment described above, the following effects can be obtained. (I). The valve lifter 220a is formed with a guide surface 220e having a shape in which the outer peripheral surface 220d is partially removed, but the detent member 236 is not attached. The detent member 236 is attached to the storage hole 234 on the cylinder head 214 side. The storage hole 234 is formed in the cylinder head 214 as a hole having an axis that does not exist on the same plane as the axis of the lifter bore 220b and partially overlapping the lifter bore 220b. Then, the semi-cylindrical portions 236a and 236b of the detent member 236
Exist in the overlapping portion between the lifter bore 220b and the storage hole 234.

As a result, the semi-cylindrical portions 236a, 23
The cylindrical surface 236d of 6b projects into the lifter bore 220b at the guide surface 220e of the valve lifter 220a. The cylindrical surface 236d of each of the semi-cylindrical portions 236a and 236b corresponds to the guide surface 22 of the valve lifter 220a.
By guiding the valve lifter 0e, the entire valve lifter 220a can reciprocate in the axial direction of the lifter bore 220b without rotating.

As described above, since the rotation preventing member 236 is not attached to the valve lifter 220a side, it is possible to prevent the roundness of the outer peripheral surface 220d of the valve lifter 220a from deteriorating.

As described above, the rotation preventing member 236 is not attached to the valve lifter 220a side, so that the deterioration of the roundness of the outer peripheral surface 220d of the valve lifter 220a due to the mounting of the rotation preventing member 236 can be avoided. Therefore, the valve lifter 220a can be formed on the outer peripheral surface with high roundness.

Further, even if the roundness of the outer peripheral surface 220d of the valve lifter 220a once formed is deteriorated for some reason, the guide surface 2 having a shape in which the outer peripheral surface 220d is partially removed is used.
20e does not hinder cutting or grinding, so the roundness can be easily corrected and the outer peripheral surface 220d of the valve lifter 220a
Can be returned to a state of high roundness.

The outer peripheral surface 22 is attached to the valve lifter 220a.
A guide surface 220e formed by partially removing Od is formed. This has the secondary effect of reducing the weight of the valve lifter 220a, which is a reciprocating component, and improving engine durability.

Furthermore, a storage hole 234 formed in the cylinder head 214 for storing the rotation preventing member 236 is provided.
Is simply a hole having an axis that does not lie on the same plane as the axis of the lifter bore 220b.
Since it is sufficient to form the cylinder head 214 in a state where a part thereof is overlapped with b, it can be easily formed by drilling or the like. Further, the detent member 236 can be connected to the lifter bore 220b and the storage hole 2 without specially forming an engagement protrusion or the like.
Since it is only necessary to arrange the semi-cylindrical portions 236a and 236b so as to be present in the overlapping portion with the portion 34, it can be easily formed. The guide surface 22 of the valve lifter 220a
Since 0e may be formed by partially removing the outer peripheral surface 220d of the valve lifter 220a, 0e can be easily formed.

Therefore, without using a special machine tool,
The storage hole 234, the detent member 236, and the guide surface 220e can be easily and quickly formed by ordinary processing, and the productivity of the detent mechanism of the valve lifter can be increased.

Even if it is necessary to correct the inner peripheral surface of the once formed lifter bore 220b for some reason,
The detent member 236 stored in the storage hole 234 may be removed or the detent member 236 may be rotated to retract the semi-cylindrical portion 236a. Since the storage hole 234 after retreating the semi-cylindrical portion 236a does not hinder cutting or grinding, the inner peripheral surface can be easily modified, and the inner peripheral surface of the lifter bore 220b can be formed into a required shape.

(B). The rotation preventing member 236 rotates the semicircular column portions 236a and 236b of the rotation preventing member 236 with the lifter bore 220b and the storage hole 23 by rotating about the axis.
4, the guide of the valve lifter 220a with respect to the guide surface 220e can be released. Thus, before the valve lifter 220a is assembled, the detent member 236 can be stored in the storage hole 234 in advance, and the guide to the guide surface 220e of the valve lifter 220a can be executed only by rotating the detent member 236. Can be done. Therefore, the work of assembling the detent mechanism of the valve lifter 220a is also facilitated, and the productivity of the detent mechanism of the valve lifter can be further increased.

(C). In addition, when the valve lifter 220a is attached, the edge of the cylindrical portion 220f below the guide surface 220e and the semi-cylindrical portions 236a and 236b of the detent member 236 are merely rotated by the detent member 236.
Abuts against the urging force of the spring 248 to temporarily stop the valve lifter 220a, and the same effect as (c) of the second embodiment can be obtained.

[Fourth Embodiment] FIGS. 46 to 49 show a direct-acting valve train as a fourth embodiment. The other configuration is basically the same as that of the first embodiment unless otherwise specified.

In FIG. 47, the camshaft 301 has a low-rotation cam profile (corresponding to the first cam profile) on the lower right side and a high-rotation cam profile (corresponding to the second cam profile) on the upper left. A three-dimensional cam 302 having a cam profile continuously changed in the axial direction.
Are formed. The three-dimensional cam 302 has a base circle portion 302
a and a nose portion 302b, and a base circular portion 302a
Has the same radius in both the low-rotation cam profile and the high-rotation cam profile. However, the nose portion 302b is inclined like a conical surface because the valve opening operation angle and the lift amount are small in the low rotation cam profile and the valve opening operation angle and the lift amount are large in the high rotation cam profile. .

The end of the camshaft 301 is provided with a camshaft 30 according to the engine operating condition such as the engine speed.
1 and a variable valve characteristic device 303 as a displacement device for continuously displacing the three-dimensional cam 302 in the axial direction. The variable valve characteristic device 303 includes, for example, a guide portion of the camshaft 301 using a spline and a driving portion of the camshaft 301 using a hydraulic pressure (both not shown), and an engine speed sensor and an accelerator opening sensor. Are controlled by a control device (not shown) such as a microcomputer that operates based on the above.

Below the camshaft 301, a direct-acting valve lifter (hereinafter, this embodiment) that opens and closes a valve (here, an intake valve) 304 by reciprocating up and down based on the cam profile of the three-dimensional cam 302. 4 simply referred to as a “valve lifter” 310). The stem 304 a of the valve 304 is guided by being inserted into a valve guide 325 fixed to the cylinder head 307.

The valve lifter 310 has a cylindrical side wall 3.
13, a disc-shaped top wall 311 provided at the upper end of the side wall 313, a semi-cylindrical inner seat 319 as a seat provided on the top surface of the top wall 311, and a semi-cylindrical inner seat 319
Cam follower 3 fitted to be able to swing (roll)
21.

In the cylinder head 307, a plurality of lifter bores 308 are formed in a row (in the direction perpendicular to the plane of FIG. 46, and in the direction of the two-dot chain line in FIG. 47). For example, in the case of an in-line four-cylinder internal combustion engine having two intake valves and two exhaust valves per cylinder, eight lifter bores 308 are formed in a row on the intake side, and eight lifter bores 308 are formed in a row on the exhaust side. . The valve lifter 310 is vertically slidably inserted into the lifter bore 308 and is guided by the side wall 313. The three-dimensional cam 302 is provided at two places around the lifter bore 308 of the cylinder head 307.
An escape recess 315 is formed to allow the rotation locus to escape.

The center of the lower surface of the top wall 311 is the valve 304
And a shim 309 for adjusting valve clearance is provided between the pressing portion 312 and the end of the valve 304 (when not provided as described later). There is also). An upper end of a valve spring 306 for urging the valve 304 toward the valve lifter 310 is in contact with a valve retainer 305 attached near the upper end of the valve 304. A spring recess 326 for holding the lower end of the valve spring 306 is provided in the cylinder head 307 directly below the lifter bore 308, and a spring seat 327 is applied to the recess 326.

The semi-cylindrical inner seat 319 and the cam follower 321 constituting the follow-up contact mechanism 317 will be described in detail. The semi-cylindrical inner seat 31 extending in the same direction
9 is recessed. An engagement recess 320 is provided at a substantially central portion in the longitudinal direction of the semicylindrical inner seat 319.

The cam follower 321 has a semi-cylindrical inner surface seat 31.
9 and the three-dimensional cam 3
02 and a flat contact surface 323 that comes into contact with 02. A fan-shaped engaging protrusion 324 is integrally provided at the center in the longitudinal direction of the semi-cylindrical surface 322, and the engaging protrusion 324 is engaged with the engaging recess 320. The cam follower 321 swings at a small angle to follow the change in the contact line angle accompanying the rotation of the three-dimensional cam 302,
3 comes in contact with the three-dimensional cam 302. At this time, the three-dimensional cam 302 is in contact with the contact surface 3 of the cam follower 321.
23 is slid in the longitudinal direction, but the engagement convex portion 324
Are engaged with the engaging recesses 320 to restrict the movement of the cam follower 321 in the longitudinal direction.
1 does not come off the semi-cylindrical inner seat 319.

In the fourth embodiment, the valve lifter 310
The following structure is employed to prevent the rotation of the motor. Next to the plurality of lifter bores 308 in the cylinder head 307, a common shaft insertion hole 330 extending in a direction substantially orthogonal to the plurality of lifter bores 308 (in the above-described example, common to the eight lifter bores 308) is provided. The lifter bore 308 is formed so as to overlap a part of the inner peripheral surface thereof in parallel with the lifter bore 308 and communicates with the lifter bore 308. Round hole-shaped shaft insertion hole 33
0 has an inner diameter of 10 to 15 mm, and has a shaft insertion hole 33.
The overlap width of 0 and the lifter bore 308 is 1.5 to 4 mm
It is.

The shaft insertion hole 330 is shared (in the above-described example, shared with the eight valve lifters 310).
The shaft 331 is inserted. The shaft 331 is
A round bar-shaped fitting portion 332 having an outer diameter substantially equal to the inner diameter of the shaft insertion hole 330 and fitted in the shaft insertion hole 330.
And a reduced diameter portion 333 reduced in diameter so as not to contact the side wall portion 313 of each valve lifter 310, and a guide portion 334 provided in the middle of each reduced diameter portion 333. Guide part 3
Reference numeral 34 denotes a rectangular section having a small width and height, and
The projection 33 protrudes in two directions perpendicular to the axis, and its protruding end surface 334 a has a curved surface substantially equal to the outer diameter of the fitting portion 332. That is, the guide portion 334 is connected to the shaft insertion hole 33.
The shaft 331 is provided so as not to exceed the inner diameter of 0 toward the outer peripheral side.

On the other hand, the side wall 313 of the valve lifter 310
Is provided with a vertically long hole 340, and the guide portion 334 is engaged with the vertically long hole 340 so as to be relatively slidable. In short, the rotation preventing mechanism of the valve lifter 310 is constituted by the vertically long hole 340 and the guide portion 334. Vertical hole 34
The inner surface of 0 may be a simple cut as shown in FIG. 48 (a). However, as shown in FIG. 48 (b), the cut edge 313a of the side wall 313 is bent inward, or a forging or other method is used. It is preferable to increase the area of the inner surface by forming the inner surface. In addition, as shown in FIG. 48 (c), the vertically long hole 340 can be changed to a vertically long groove 341 formed by recessing the side wall 313.

The vertical length of the vertical hole 340 is larger than the maximum stroke of the valve lifter 310 by the three-dimensional cam 302.
The guide portion 334 does not come into contact with Oa.
The elongated hole 340 has a shape that allows centerless polishing in a valve lifter outer diameter grinding step. In FIG. 49, a guide portion 334 indicated by a solid line and a guide portion 334 indicated by a two-dot chain line are shown.
Is the maximum stroke. The upper and lower edges 340a
May be rounded as shown in FIG. 49 (a), but may be processed into a semicircle as shown in FIG.
As shown in FIG. 49 (c), it is easier to process by releasing the corner.

Shaft 331 to cylinder head 307
The assembly of the valve lifter 310 and the rotation prevention of the valve lifter 310 are performed as follows. (1) The shaft 331 is inserted into the shaft insertion hole 330, and each guide portion 334 is positioned at a communication portion between the lifter bore 308 and the shaft insertion hole 330. At this time, since the guide portion 334 as well as the reduced diameter portion 333 has a size that does not exceed the inner diameter of the shaft insertion hole 330 toward the outer peripheral side, it does not hinder insertion. At the time of this insertion (or after the insertion), the guide portion 334 is set in the vertical position as shown by a solid line in FIG. 47 so as not to interfere with the side wall portion 313 of the valve lifter 310 in the next step.

(2) The valve lifter 310 is inserted into each of the lifter bores 308, and the vertically long holes 340 are located at the communicating portions between the lifter bores 308 and the shaft insertion holes 330. The side wall portion 313 around the vertically elongated hole 340 enters the shaft insertion hole 330 by the overlap width of the shaft insertion hole 330 and the lifter bore 308. However, since the guide portion 334 is in the vertical position as described above, there is an obstacle to insertion. Does not.

It should be noted that depending on how the fitting portion 332 is provided,
The order of steps (1) and (2) can be reversed. (3) By rotating the shaft 331 by 90 °, the guide portion 33
4 is set in the horizontal position as shown by the two-dot chain line in FIG. 47 and is engaged with the vertically long hole 340 of the valve lifter 310. Thereafter, the shaft 331 is fixed to the cylinder head 307 by fixing means (not shown) such as a screw or an adhesive so that the shaft 331 does not rotate.

In the structure for preventing rotation of the valve lifter 310, the lifter bore 3 in the cylinder head 307 is provided.
When the shaft insertion hole 330 extending in a direction substantially orthogonal to the lifter bore 308 is formed next to the lifter bore 308, a simple shaft insertion hole 330 is sufficient, so that a small number of processing steps, a simple processing method, and a high processing accuracy are achieved. can get. Moreover, a common shaft insertion hole 330 (one per row in the fourth embodiment) is formed next to the plurality of lifter bores 308,
Since the common shaft 331 (one per line in the fourth embodiment) is inserted into the shaft insertion hole 330, the number of processing steps and the number of parts are further reduced. Therefore, it contributes to practical application and mass production.

The direct-acting valve train with the continuously variable mechanism according to the fourth embodiment operates as follows. First, when the engine is running at a low speed, the camshaft 301 is displaced in the upper left direction in FIG.
The low-rotation cam profile on the lower right side of the three-dimensional cam 302 corresponds to the cam follower 321. And the contact surface 3
23 and the nose portion 3
Since the cam follower 321 swings by a small angle when it comes into contact with 02b, the contact surface 323 contacts the three-dimensional cam 302 while following the change in the contact line angle, and is pressed by the nose portion 302b. Therefore, the valve lifter 310 reciprocates up and down based on the cam profile for low rotation, opens and closes one or both valves 304 on the exhaust side and the intake side with a small valve opening angle and lift amount, and increases low-speed torque. Improve fuel economy. In addition, the vertically long hole 340
Since the movement in the circumferential direction is regulated by the guide portion 334 while sliding relative to the guide portion 334 engaged therein, the rotation of the valve lifter 310 is prevented, and the direction of the cam follower 321 relative to the three-dimensional cam 302 is maintained. Is done.

When the engine is running at high speed, the camshaft 301 is displaced in the lower right direction in FIG. 47 by the variable valve characteristic device 303, and the high rotation cam profile on the upper left side of the three-dimensional cam 302 corresponds to the cam follower 321. I do. Since the cam follower 321 swings at a small angle as described above, the contact surface 323 contacts the three-dimensional cam 302 while following the change in the contact line angle, and the nose portion 302b
Is pressed. Therefore, the valve lifter 310 reciprocates up and down based on the cam profile for high rotation, opens and closes one or both of the valves 304 on the exhaust side and the intake side with a large valve opening angle and lift amount, increases the intake amount, and increases the intake amount. Increase output.

During the period from low rotation to high rotation, the camshaft 301 is continuously displaced by the variable valve characteristic device 303 in accordance with the engine operation state such as the engine speed and the accelerator opening. Cam 302
The cam profile of the middle part is cam follower 32
Corresponds to 1. Therefore, the valve lifter 310 reciprocates up and down based on the cam profile, and the valve 3
04 is opened and closed with an intermediate valve opening angle and lift amount,
Generates torque and output according to the operating state of the engine.

In the above-described example, the cam profile of the three-dimensional cam 302 having a small valve opening operating angle and a lift amount is used as the low-rotation cam profile of the engine.
Although the cam profile portion having the large valve opening angle and the lift amount is defined as the cam profile for high rotation of the engine, this does not have to be the case for the engine operating state. For example, in the three-dimensional cam 302, a cam profile portion in which valve overlap does not occur with a small valve opening angle and a lift amount in the three-dimensional cam 302 is defined as a start / idle cam profile (corresponding to a first cam profile), and a large valve opening effect. The cam profile portion where the valve overlap is the largest in terms of the angle and the lift amount may be a high-load medium-speed low-speed rotation cam profile (second cam profile). In this case, the camshaft 301 is controlled by the variable valve characteristic device 303 in other operating regions of the engine according to the engine speed and the engine load.
, So that the cam profile of the intermediate portion of the three-dimensional cam 302 corresponds to the cam follower 321. Therefore, the valve lifter 310 reciprocates up and down based on its cam profile, and the valve 304
Is opened and closed with an intermediate valve opening duration, lift amount and valve overlap to generate torque and output according to the operating state of the engine.

According to the fourth embodiment described above, the following effects can be obtained. (I). Shaft 3 inserted in shaft insertion hole 330
Between the valve lifter 31 and the valve lifter 310 in the lifter bore 308, a rotation preventing mechanism including a guide portion 334 and a vertically long hole 340 is provided.
In FIG. 8, the valve lifter 310 is prevented from rotating.

As described above, the rotation preventing member is not attached to the valve lifter 310 side, so that the roundness of the outer peripheral surface of the valve lifter 310 due to the mounting of the rotation preventing member can be prevented from being deteriorated. Therefore, the valve lifter 310 used in the fourth embodiment can be formed on the outer peripheral surface with high roundness.

Further, even if the roundness of the outer peripheral surface of the side wall portion 313 of the valve lifter 310 once formed is deteriorated for some reason, since the vertically long hole 340 is recessed from the outer peripheral surface, it is difficult to cut or grind. No. For this reason, the roundness can be easily corrected, and the outer peripheral surface of the valve lifter 310 can be returned to a state in which the roundness is high.

Even if it is necessary to correct the inner peripheral surface of the once formed lifter bore 308 for some reason, the shaft 331 inserted into the shaft insertion hole 330 is removed together with the guide portion 334 or the shaft 331 is removed. What is necessary is just to rotate by 90 degrees and make it a retracted state. By doing so, the guide portion 334 of the shaft 331 and the shaft insertion hole 330 do not hinder cutting or grinding, so that the inner peripheral surface of the lifter bore 308 can be easily modified and the inner peripheral surface of the lifter bore 308 has a required shape. be able to.

In addition, no vertical groove is provided in the lifter bore 308,
Next to the lifter bore 308, a shaft insertion hole 330 extending in a direction substantially perpendicular to the lifter bore 308 is formed.
For this reason, a dedicated processing machine for processing the vertical groove in the lifter bore 308 is not required. Further, the complicated cutting work by such a dedicated processing machine becomes unnecessary, and the shaft insertion hole 33 is not required.
Since the work of opening 0 with a drill or the like is sufficient, the cutting time can be shortened. Therefore, productivity can be improved.

(B). A plurality, for example, eight lifter bores 3
08, the shaft insertion hole 330 is shared, so that the number of shaft insertion holes 33 equal to the number of lifter bores 308 is increased.
It is not necessary to form 0. Therefore, the work of opening the shaft insertion hole 330 is reduced, and the productivity can be further improved. Further, since the shaft 331 inserted into the shaft insertion hole 330 can be shared, the number of parts can be reduced and the manufacturing cost can be reduced.

(C). By forming the shaft insertion hole 330 substantially parallel to the camshaft 301, even when the shaft insertion hole 330 is long, it can be easily formed in the cylinder head 307 without increasing the size of the cylinder head 307.

(D). Guide part 334 of shaft 331
Does not exceed the inner diameter of the shaft insertion hole 330 to the outer peripheral side. This facilitates the work of inserting or removing the shaft 331 into or from the shaft insertion hole 330, thereby facilitating production and repair and increasing the efficiency.

(E). By providing the three-dimensional cam 302, the variable valve characteristic device 303, and the cam follower 321, the three-dimensional cam 302 can come into contact with the valve lifter 310 over a wide area by the cam follower 321, thereby improving wear resistance and durability. Further, the variable valve characteristic device 303 displaces the three-dimensional cam 302 continuously or stepwise in the axial direction, so that a suitable valve lift can be realized according to the operating state of the engine.

That is, precise control according to the operating state of the engine is performed by continuously changing the operating angle and the lift amount, and continuously changing the valve timing and valve overlap according to the operating angle. Therefore, various characteristics such as torque, output, fuel efficiency, and emission can be maximized over the entire operation range. In addition, the change can be performed smoothly and quietly by the displacement of the camshaft 301.

[Fifth Embodiment] FIGS. 50 to 52 show a direct-acting valve train as a fifth embodiment. Particularly, a point different from the fourth embodiment is a rotation preventing mechanism. The other configuration is basically the same as that of the fourth embodiment unless otherwise specified. In addition, except for a configuration that is particularly described,
In the fifth embodiment, components having the same functions as those of the fourth embodiment are denoted by reference numerals obtained by adding “100” to the reference numerals assigned to the corresponding configurations of the fourth embodiment.

A side wall convex portion 443 (formed in a vertical concave portion 442) formed by a pair of vertical concave portions 442 provided on a side wall portion 413 of a direct hit type valve lifter (hereinafter, simply referred to as “valve lifter” in the fifth embodiment) 410. Is convex on the outer peripheral surface of the side wall portion 413).
The rotation preventing mechanism is constituted by the guide portion 435 provided on the shaft 431 so as to hold the 43 slidably. Both sides of the side wall convex portion 443 are a pair of thrust surfaces 44.
4 and a relief 4 is provided at the back of the thrust surface 444.
45 is recessed. The guide portion 435 is a recess formed in the shaft 431 having a round bar shape, and includes a pair of guide surfaces 436 that are in sliding contact with the pair of thrust surfaces 444.

Shaft 431 to cylinder head 407
The assembly of the valve lifter 410 and the rotation prevention of the valve lifter 410 are performed as follows. (1) The shaft 431 is inserted into the shaft insertion hole 430, and each guide portion 435 is positioned at a communication portion between the lifter bore 408 and the shaft insertion hole 430. At this time, since the guide portion 435 has a size that does not exceed the inner diameter of the shaft insertion hole 430 toward the outer peripheral side, it does not hinder insertion.

(2) The valve lifter 410 is inserted into each lifter bore 408, and the side wall protrusion 443 is inserted into the guide portion 435 and held. After that, if necessary,
The shaft 431 is fixed to the cylinder head 407 by fixing means (not shown) such as a screw or an adhesive so that the shaft 31 does not rotate.
Fixed to.

According to the fifth embodiment described above, the following effects can be obtained. (I). By forming a pair of vertically long concave portions 442 on the side wall portion 413 of the valve lifter 410, the side wall convex portions 443 are relatively formed. Then, this side wall convex portion 443 is
The rotation of the valve lifter 410 in the lifter bore 408 is prevented by holding the guide 435 provided on the shaft 431 so as to be relatively slidable. As described above, the side wall protrusion 443 is formed on the side wall 413 of the valve lifter 410, which is relatively formed by forming a pair of vertically long recesses 442, and the side wall 413 of the valve lifter 410 is formed. Does not protrude from the outer peripheral surface. That is, the side wall protrusion 443 does not hinder cutting or grinding.

For this reason, the valve lifter 41 formed once is
Even if the roundness of the outer peripheral surface of the 0 side wall portion 413 is not sufficient, the roundness can be easily corrected, and the outer peripheral surface of the valve lifter 410 can be in a state of high roundness.

Even if the roundness of the outer peripheral surface of the side wall portion 413 of the valve lifter 410 once formed is deteriorated for some reason, the side wall convex portion 443 protrudes from the outer peripheral surface of the side wall portion 413 of the valve lifter 410 as described above. Absent. For this reason, since the side wall convex portion 443 does not hinder cutting or grinding, the roundness can be easily corrected, and the outer peripheral surface of the valve lifter 410 can be returned to a state of high roundness.

Even if it is necessary to correct the inner peripheral surface of the once formed lifter bore 408 for some reason, the shaft 431 inserted in the shaft insertion hole 430 may be removed. When the retracted state is set as described above, the guide portion 435 of the shaft 431 and the shaft insertion hole 430 do not hinder cutting or grinding.
08 can be modified, and the inner peripheral surface of the lifter bore 408 can be formed into a required shape.

Further, without providing a vertical groove in the lifter bore 408,
Next to the lifter bore 408, a shaft insertion hole 430 extending in a direction substantially orthogonal to the lifter bore 408 is formed.
Therefore, there is no need for a dedicated processing machine for processing the vertical groove in the lifter bore 408. Further, the complicated cutting work by such a dedicated processing machine becomes unnecessary, and the shaft insertion hole 43
Since the work of opening 0 with a drill or the like is sufficient, the cutting time can be shortened. Therefore, productivity can be improved.

(B). (B) of the fourth embodiment,
The effects (c) and (d) are produced. (C). According to the fifth embodiment, the fourth embodiment is also applicable.
The same operation and effect as described in (e) can be obtained. In addition, in the fifth embodiment, even if a large rotational moment is generated in the valve lifter 410 by the contact between the pair of guide surfaces 436 and the pair of thrust surfaces 444, the fifth embodiment can sufficiently receive the rotation. From this, especially the three-dimensional cam 40
2 is more effective when used in a high-speed engine (sport-oriented engine) or the like that generates a large rotational moment in the valve lifter 410 due to a large difference between the minimum lift and the maximum lift.

[Other Embodiments] In the third embodiment, a part of the detent member 236 is rotated by rotating the detent member 236 so that the lifter bore 2
Evacuation from the overlapping portion of the storage hole 234 and the storage hole 234,
Or the other way around. Alternatively, the detent member may be moved in the axial direction, and a part of the detent member may be retracted or arranged from the overlapping portion between the lifter bore and the storage hole.

In the first to third embodiments, examples of the mechanism for preventing the rotation of the valve lifter of the intake valve have been described. Instead of this, or together with the intake valve, the exhaust valve camshaft can be moved in the axial direction at the exhaust valve, and a variable valve characteristic device is attached to the exhaust camshaft. May be employed.

In the first and second embodiments, the two cylinders
Although the shaft rotation is prevented by one detent member for one valve lifter, the shaft rotation may be prevented by one detent member for one valve lifter.

In the third embodiment, the shaft rotation is prevented by one detent member with respect to the valve lifters of the intake valves of all cylinders. The rotation of the shaft may be prevented, or the rotation of the shaft may be prevented by one detent member for one valve lifter.

In the second and third embodiments, the axial direction of the lifter bore and the axial direction of the storage hole are different by 90 °, but the difference between the directions may be smaller than 90 °. It is sufficient that a part of the storage hole in the radial direction crosses the lifter bore.

In the fourth and fifth embodiments, the shaft 3
31 and 431 are arranged over all the cylinders, respectively.
Although the book corresponds to the eight valve lifters 310 and 410, each of the shaft insertion holes 330 and 430 has two
The shafts may be inserted from both ends so that each shaft corresponds to four valve lifters. The same applies to the third embodiment.

In the fourth and fifth embodiments, the cam followers 321 and 421 have slightly different thicknesses without providing the valve clearance adjusting shims 309 and 409 (the semi-cylindrical surfaces 322 and 422 have slightly smaller radii). A first embodiment in which the thickness is different due to the difference;
2, 422 has a constant radius, but the contact surfaces 323, 423 have slightly different heights and thus have different thicknesses, and the valve clearance is appropriately selected and replaced. Adjustments may be made.

The embodiments of the present invention have been described above. However, it should be added that the embodiments of the present invention include the following various embodiments. (1). 13. The valve lifter detent mechanism according to claim 1, wherein the cam is a three-dimensional cam having a different profile in a rotation axis direction.

[Brief description of the drawings]

FIG. 1 is a schematic structural explanatory view of an engine incorporating a valve lifter rotation preventing mechanism according to a first embodiment.

FIG. 2 is a configuration explanatory view of a cross section of a cylinder head and a periphery thereof according to the first embodiment;

FIG. 3 is a plan view of a piston top surface according to the first embodiment.

FIG. 4 is a sectional view taken along line XX in FIG. 2;

FIG. 5 is a sectional view taken along line YY in FIG. 2;

FIG. 6 is a perspective view showing a configuration around two intake cams for one cylinder according to the first embodiment;

FIG. 7 is an exploded perspective view of the configuration of FIG. 6;

FIG. 8 is a perspective view of (A), a plan view of (B), a left side view of (C), a front view of (D), and a right side view of (E) of the detent member according to the first embodiment. FIG.

FIG. 9 is a longitudinal sectional view showing an arrangement state of a rotation preventing member according to the first embodiment.

FIG. 10 is a perspective view showing the cylinder head in the configuration shown in FIG.

FIG. 11 is an explanatory diagram of processing for forming a storage groove in the first embodiment.

FIG. 12 is an explanatory diagram of processing for forming a storage groove in the first embodiment.

FIG. 13 is a perspective view showing a configuration of a valve lifter and a cam follower according to the first embodiment.

FIG. 14 is an explanatory diagram of an assembly process of the valve lifter rotation preventing mechanism according to the first embodiment.

FIG. 15 is an explanatory diagram of an assembling process of the valve lifter rotation preventing mechanism according to the first embodiment.

FIG. 16 is an explanatory diagram of an assembling process of the valve lifter rotation preventing mechanism according to the first embodiment.

FIG. 17 shows a cam follower according to the first embodiment (A).
FIG. 2 is a perspective view of FIG. 1, a front view of (B), a plan view of (C), a left side view of (D), and a configuration explanatory view represented by a right side view of (E).

FIG. 18 is a plan view of the configuration in FIG. 16;

FIG. 19 is an explanatory diagram of an operation state of the valve lifter rotation preventing mechanism according to the first embodiment.

FIG. 20 is an explanatory diagram of an operation state of the valve lifter rotation preventing mechanism according to the first embodiment.

FIG. 21 is an explanatory diagram of an operation state of the valve lifter rotation preventing mechanism according to the first embodiment.

FIG. 22 is a perspective view showing a configuration around two intake cams for one cylinder according to the second embodiment.

FIG. 23 is an exploded perspective view of the configuration of FIG. 22;

FIG. 24 is a perspective view showing an arrangement state of a rotation preventing member with respect to a cylinder head according to the second embodiment.

FIG. 25A shows a detent member according to the second embodiment.
, A plan view of (B), a bottom view of (C), a front view of (D), a rear view of (E), a left side view of (F), and a right side view of (G). FIG.

FIG. 26 is a perspective view showing an arrangement state of a rotation preventing member according to the second embodiment.

FIG. 27 is a plan view of the configuration shown in FIG. 26;

FIG. 28 is a longitudinal sectional view showing an arrangement state of a rotation preventing member according to the second embodiment.

FIG. 29 is a functional explanatory view of the rotation preventing member according to the second embodiment.

FIG. 30 is a plan view of the configuration shown in FIG. 29;

FIG. 31 is a functional explanatory view of the rotation preventing member according to the second embodiment shown in a vertical section.

FIG. 32 is a perspective view showing a configuration around two intake cams for one cylinder according to the third embodiment.

FIG. 33 is an exploded perspective view of the configuration of FIG. 32;

FIG. 34 is a perspective view showing a state in which a storage hole is formed in the cylinder head according to the third embodiment.

FIG. 35 is a perspective view showing an arrangement state of a rotation preventing member with respect to a cylinder head according to a third embodiment.

FIG. 36 shows a detent member according to the third embodiment (A).
FIG. 2 is a perspective view of FIG. 1, a plan view of (B), a front view of (C), a rear view of (D), and a configuration explanatory view represented by a bottom view of (E).

FIG. 37 is a perspective view showing an arrangement state of a rotation preventing member according to the third embodiment.

FIG. 38 is a plan view of the configuration shown in FIG. 37.

FIG. 39 is a perspective view showing an arrangement state of a rotation preventing member according to the third embodiment.

FIG. 40 shows a valve lifter according to Embodiment 3 (A).
FIG. 3 is a perspective view of FIG. 1, a plan view of FIG. 3B, a front view of FIG.

FIG. 41 is a longitudinal sectional view in the configuration of FIG. 39;

FIG. 42 is an explanatory view of the function of the rotation preventing member according to the third embodiment.

FIG. 43 is a plan view of the configuration shown in FIG. 42;

FIG. 44 is a functional explanatory view of the rotation preventing member according to the third embodiment.

FIG. 45 is a longitudinal sectional view in the configuration of FIG. 44;

FIG. 46 is a longitudinal sectional view of a direct-acting valve train according to a fourth embodiment.

FIG. 47 is a perspective view of a direct-acting valve train according to a fourth embodiment.

FIG. 48 is a partial cross-sectional view showing a relationship between a vertically long hole of a valve lifter and a guide portion of a shaft in a direct-acting type valve train according to a fourth embodiment.

FIG. 49 is a front view showing a relationship between a vertically long hole of a valve lifter and a guide portion of a shaft in a direct-acting valve train according to a fourth embodiment.

FIG. 50 is a longitudinal sectional view of a direct-acting valve train according to a fifth embodiment.

FIG. 51 is a perspective view of a direct-acting valve train according to a fifth embodiment.

FIG. 52 is a partial cross-sectional view showing a relationship between a side wall convex portion of a valve lifter and a guide portion of a shaft in a direct-acting type valve train according to a fifth embodiment.

FIG. 53 is a configuration explanatory view of a conventional valve lifter rotation preventing mechanism.

[Description of Signs] 11 ... Engine, 12 ... Piston, 12a ... Recess, 13
... Cylinder block, 13a ... Oil pan, 14 ... Cylinder head, 15 ... Crankshaft, 15a ... Sprocket, 16 ... Connecting rod, 17 ... Combustion chamber, 17a ... Spark plug, 17b ... Fuel injection valve, 18 ... Intake port, 1
8a, 18b: intake passage, 18c: surge tank, 18
d ... air flow control valve, 18e ... shaft, 18f ... actuator, 19 ... exhaust port, 20 ... intake valve, 20a
... valve lifter, 20b ... lifter bore, 20c ... top surface,
20d: outer peripheral surface, 20e: engagement groove, 21: exhaust valve,
21a: valve lifter, 22: intake side camshaft, 2
3. Exhaust side camshaft, 24 ... Variable valve characteristic device,
24a, 25: timing sprocket, 26: timing chain, 27: intake cam, 27a: cam surface, 27
b: cam nose, 28: exhaust cam, 30: journal bearing, 32: bearing cap, 34: storage groove, 36
.., Rotation preventing member, 36 a, leg portion, 36 b, lubricating oil supply groove, 36 c, side portion, 38, lubricating oil supply passage, 40, groove,
44: stem, 46: retainer, 48: spring, 50: stem end, 52: guide groove, 52a: large diameter groove, 52b
... Small diameter groove, 54 ... Cam follower, 54a ... Large diameter part, 54
b: small diameter portion, 54c: cam sliding surface, 70: oil control valve, 114: cylinder head, 114a: outer peripheral surface, 120: intake valve, 120a: valve lifter,
120b ... lifter bore, 120d ... outer peripheral surface, 120e ...
Engaging groove, 120f bottom surface, 122 intake camshaft, 127 intake cam, 130 journal bearing, 1
32: Bearing cap, 132a, 132b: Bolt, 134: Storage hole, 134a: Opening, 136: Detent member, 136a: Head, 136b: Base, 136c
... neck, 136d ... engagement projection, 136e ... tip surface, 13
6f: hole, 136g: base end face, 136h: slit,
148: spring, 154: cam follower, 214: cylinder head, 220a: valve lifter, 220b: lifter bore, 220d: outer peripheral surface, 220e: guide surface, 220
f: cylindrical portion, 222: intake camshaft, 227: intake cam, 230: journal bearing, 230a: bolt hole, 232: bearing cap, 232a, 232b
... bolts, 234 ... storage holes, 234a ... openings, 236
... detent members, 236a, 236b ... semi-cylindrical portions, 23
6c: hole, 236d: cylindrical surface, 248: spring, 252
... Guide groove, 301 ... Camshaft, 302 ... Solid cam, 302a ... Base circular part, 302b ... Nose part, 30
3. Variable valve characteristic device, 304 Valve, 304a
Stem 305 Valve retainer 306 Valve spring 307 Cylinder head 308 Lifter bore 309 Shim 310 Valve lifter 311 Top wall 312 Pressing part 313 Side wall part 313a Cutting edge 315: concave portion, 317: follow-up contact mechanism, 318: raised portion, 319: semi-cylindrical inner surface seat, 320: engaging concave portion, 32
DESCRIPTION OF SYMBOLS 1 ... Cam follower, 322 ... Semi-cylindrical surface, 323 ... Contact surface, 324 ... Engagement convex part, 325 ... Valve guide, 327
... Spring seat, 330 ... Shaft insertion hole, 331
... shaft, 332 ... fitting part, 333 ... reduced diameter part, 334
... Guide part, 340 ... Vertical hole, 340a ... Top and bottom edges, 40
2 ... solid cam, 408 ... lifter bore, 409 ... shim, 4
10: Valve lifter, 413: Side wall, 421: Cam follower, 422: Semi-cylindrical surface, 423: Contact surface, 430 ...
Shaft insertion holes, 431: shaft, 435: guide portion, 442: vertically long concave portion, 443: side wall convex portion, 444: thrust surface.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Shuji Nakano 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (72) Inventor Katsuhiko Motosu 10 Hamada Shimo, Nakahatacho, Nishio City, Aichi Prefecture Inside Otics Corporation (72) Inventor Hiromichi Oda 10 Hamadashita, Nakahata-machi, Nishio-shi, Aichi Pref. In OTICS Co., Ltd. AA02 AA06 AA19 BA27 BA36 BB04 BB05 BB06 BB07 CA02 CA04 CA06 CA08 CA16 CA43 CA44 CA50 CA57 DA12 GA01 3G018 AB07 BA04 BA24 DA03 DA17 DA18 DA69 FA01 FA06 FA08 GA17

Claims (7)

[Claims] 1. A direct-acting valve train in which a valve lifter is slidably inserted into a lifter bore formed in a cylinder head of an internal combustion engine, wherein a shaft insertion extending in a direction substantially orthogonal to the lifter bore next to the lifter bore in the cylinder head. A direct-acting valve train, wherein a hole is formed, a shaft is inserted through the shaft insertion hole, and a rotation preventing mechanism for preventing rotation of the valve lifter is provided between the valve lifter and the shaft. 2. A plurality of lifter bores are formed in a line in said cylinder head, a common shaft insertion hole is formed next to said plurality of lifter bores, and a common shaft is inserted through said shaft insertion hole. Direct-acting valve train. 3. The direct-acting valve train according to claim 1, wherein the shaft insertion hole is formed substantially parallel to the camshaft. 4. The shaft insertion hole is formed so as to overlap a part of the inner peripheral surface of the lifter bore, communicates with the lifter bore, and has a vertical hole or a vertical groove provided in a side wall of the valve lifter. 4. The direct-acting valve mechanism according to claim 1, wherein the rotation preventing mechanism is constituted by a guide portion provided on the shaft so as to be slidably engaged with the vertically long hole or the vertically long groove. 5. The shaft insertion hole is formed so as to overlap a part of the inner peripheral surface of the lifter bore, communicates with the lifter bore, and is relatively formed by a pair of vertically long recesses provided on a side wall portion of the valve lifter. 4. The direct-acting type moving mechanism according to claim 1, wherein the rotation preventing mechanism comprises a side wall protruding portion and a guide portion provided on the shaft so as to slidably hold the side wall protruding portion. Valve mechanism. 6. The direct-acting valve mechanism according to claim 4, wherein the guide portion is provided on the shaft so as not to exceed an inner diameter of the shaft insertion hole toward an outer peripheral side. 7. A three-dimensional cam in which a cam profile is continuously changed in an axial direction from a first cam profile to a second cam profile, and a displacement device for continuously or stepwise displacing the three-dimensional cam in an axial direction. 7. A straight follower according to claim 1, wherein a cam follower is provided on a top wall portion of the valve lifter to contact the three-dimensional cam while following a change in a contact line angle accompanying rotation of the three-dimensional cam. Punching valve mechanism.