CN1312382C - Valve driving device for internal combustion engine - Google Patents

Abstract

A valve driving device in which a lifter is disposed between a cam and a poppet valve, the valve driving device comprising: a guide hole formed in a cylinder head; and a direct drive having a tappet portion and a guide portion placed in the guide hole Type valve lifter, which slides freely in the axial direction of the lift valve in an interlocking state as the pushing action of the tappet part by the cam, the diameter of the guide part is made smaller than the diameter of the tappet part; the valve lifter is relatively The cylinder head screw is inclined, and the valve lifter is inclined relative to the axis of the cylinder; the valve lifter is arranged adjacent to the cylinder head screw in a plan view; the diameter of the screw bearing surface of the cylinder head screw and the passage along the suction valve The virtual cylinders obtained by extending the diameter of the tappet part with the axis of the shaft overlap in the top view; and satisfy the following relational formula: P+R>pd; on the suction side and the exhaust side, the tappet part is set On the outside of the nose of the cylinder head screw.

Description

Valve drives for internal combustion engines

This case is a divisional application of the Chinese patent application number: 00109043.7, the application date is June 7, 2000, and the invention name is "valve driving device for internal combustion engine".

technical field

The present invention relates to a valve driving device for driving a valve which opens and closes an intake port or an exhaust port in an internal combustion engine, and more particularly, the present invention relates to a valve driving device using a direct drive type valve lifter, Use of the lifter enables miniaturization and weight reduction of the valve while protecting a sufficient lift amount to improve its working efficiency.

Background technique

A valve driving device using a poppet of a direct drive type valve has been disclosed, for example, in Japanese Unexamined Patent Publication No. Hei 10-331709. A direct drive type valve lifter comprising a lifter portion in contact with a cam provided on the cylinder head of an internal combustion engine and a guide portion slidably placed in the cylinder head, the valve lifter is positioned between the cam and the valve in such a state It is provided that when the cam rotates to slide the guide portion along the cylinder head, the tappet portion is pushed by the protruding portion of the cam, so that the valve moves integrally with the valve lifter in the direction of its axis thereby opening and closing the suction valve on which the valve is set. port or exhaust port.

The tappet portion that the protruding portion of the cam contacts is made into a substantially circular flat plate, thereby realizing line contact with the protruding portion of the cam, and the profile of the cam is designed so that the tappet portion contacts the protruding portion of the cam without contacting the cam protruding portion. Deviate from the tappet diameter range and obtain allowable contact loads on the tappet section.

For example, in order to improve the output of the internal combustion engine with the increase of the air intake amount, it is necessary to increase the opening area of the valve. Since the lift amount of the valve needs to be increased in order to increase the opening area of the valve, the tappet portion should be designed so as to have a sufficient The diameter of the lift.

In order to ensure the lift amount required for the valve, the diameter of the lifter part must be determined according to the lift amount. However, since the diameter of the lifter part is set larger, the diameter of the guide rail part becomes larger. As a result, the valve The size of the lifter becomes larger. On the other hand, since there are various mechanisms and structures near the cylinder head of the internal combustion engine, the position where the valve lifter is installed is limited, so the maximum size of the valve lifter is limited, and therefore when installing the valve in a limited space It is a problem to ensure the required valve lift amount during the lifter, and such a problem is relatively harsh for a small-sized internal combustion engine.

When the size of the valve lifter is simply made larger, the inertial weight of the valve drive system becomes larger, so it is feared that it will become difficult to ensure the performance required by the engine. Further, when the inertial weight of the valve drive system becomes larger As it increases, the elastic force of the spring system required to push the valve to close increases, thus causing a problem that the tappet portion and the cam are worn because the contact pressure between the tappet portion and the cam becomes higher.

Conventional valve actuators also suffer from lubricity problems, and such a problem will be described with reference to FIGS. 25 and 26 . Figures 25 and 26 show a schematic diagram of a conventional valve actuator using a direct drive valve lifter, with Figure 25 showing a state where the valve lifter is not pushed down and Figure 26 showing a state where the valve lifter is pushed down.

As shown in these figures, a cam 902 is provided on the upper side of an internal combustion engine cylinder head 901, and a guide hole 903 is defined inside the cylinder head 901, and a cylindrical portion (guide portion) of a cylindrical valve lifter 904 is slidably provided in the guide hole 903. In this case, the cam 902 abuts against the upper surface (the tappet portion) of the valve lifter 904 , and the valve 905 (suction valve or exhaust valve) is arranged opposite to the cam 902 with respect to the valve lifter 904 .

As the cam 902 rotates, the valve lifter 904 is pushed down and reciprocally moves in the guide hole 903, thereby repeatedly opening and closing the valve 905. An oil pool 906 in which lubricating oil 907 is stored is formed around the upper portion of the guide hole 903, so that when the valve lifter 904 is pushed down by the cam 902, both the tappet portion and the protruding portion of the cam 902 are submerged in the oil pool 906. Lubricating oil 907.

In most internal combustion engines, a predetermined gap is defined between the pilot hole 903 and the valve lifter 904, so that the valve lifter 904 is operable even at extremely low temperatures, so the lubricating oil 907 in the oil pool 906 due to The rotation of the cam 902, the vertical reciprocation of the valve lifter 904, the self-weight of the lubricating oil 907, etc., enter the gap, thereby lubricating the relevant parts.

As described above, the protruding portion of the cam 902 is in line contact with the tappet portion of the valve lifter 904, and since the contact portion between the protruding portion of the cam 902 and the tappet portion moves within the diameter of the tappet, the movement from the cam 902 A position of the tappet portion upon which a load is applied thus changes as counter torque is applied to the valve lifter 904 during reciprocation.

Therefore, when the lubricating oil 907 is at a high temperature, the gap between the valve lifter 904 and the guide hole 903 becomes larger and the viscosity of the lubricating oil becomes lower, so noise is generated due to the discontinuous oil film at the gap and the friction at the gap becomes larger , on the other hand, when the lubricating oil 907 is at a low temperature, the gap between the valve lifter 904 and the guide hole 903 becomes smaller, so it is difficult for the lubricating oil 907 to flow along the side wall of the guide hole 903 while the frictional force becomes stronger. Large, therefore, may reduce the output efficiency and fuel consumption of the internal combustion engine and may cause wear of the valve lifter 904 and the like.

Further, in most internal combustion engines, the cylinder head is made of aluminum and the valve lifter is made of iron. Valve lifter 904 is operational at temperature. At high temperature, the gap between the valve lifter 904 and the guide hole 903 becomes larger, so under the action of the above-mentioned torque on the valve lifter 904, the valve lifter 904 is inclined at a larger angle relative to the guide hole 903; otherwise , since the tappet portion of the valve lifter 904 is made in a plate shape, the rigidity of its peripheral portion is high, so the tappet portion is difficult to deform.

Therefore, when the lift amount is the largest, the attitude of the valve lifter 904 changes to a large range, and at the same time, when the valve lifter 904 hits the inner surface of the guide hole 903, the oil film at the gap is pushed to one side, thereby generating a large The metal noise, further, may reduce the output efficiency and fuel consumption of the internal combustion engine due to the greater degree of friction and wear.

The present invention is made to solve the above-mentioned various problems of the conventional valve driving apparatus using a direct drive type valve lifter for an internal combustion engine.

Contents of the invention

An object of the present invention is to provide a valve driving device using a direct drive type valve lifter which can be miniaturized and reduced in weight while maintaining a sufficient lift amount of a valve in a limited space to improve work efficiency.

According to the valve driving apparatus of the present invention using a direct drive type valve lifter, the valve lifter is provided between a cam formed on a camshaft and a poppet valve provided in a passage formed at a cylinder head of an internal combustion engine and move toward the axial direction of the valve to open or close the passage, the valve driving device includes: a guide hole formed on the cylinder head; Pressed by the cam, and also has a guide portion coupled with the tappet portion at one end and placed in the guide hole, so as to slide freely therein in an interlocking state toward the axis of the poppet valve as a result of the tappet portion operated by the push of the cam; wherein the diameter of the guide hole is made smaller than that of the tappet portion; the valve lifter is relative to the The cylinder head screw of the cylinder head is inclined, and the valve lifter is arranged in a state of being inclined relative to the axis of the cylinder; the valve lifter is arranged adjacent to the cylinder head screw in a plan view; the The valve lifter and the cylinder head screw are arranged such that the diameter of the screw bearing surface of the cylinder head screw and the virtual cylindrical shape obtained by extending the diameter of the tappet part along the axis of the suction valve are superimposed in plan view. and satisfy the following relationship: P+R>p-d, where P is the pitch of the tappet part, R is the diameter of the tappet part, p is the pitch of the cylinder head screw, and d is the screw support of the cylinder head screw The diameter of the surface; on the suction side and the exhaust side, the tappet part is arranged on the outside of the convex head of the cylinder head screw.

According to the valve driving device thus arranged, since the diameter of the tappet portion capable of securing the required lifting amount and the diameter of the guide portion can be made small, the valve lifter can be miniaturized and reduced in weight, and therefore, it is possible High output efficiency of the engine is ensured while reducing the area occupied by valve-related components near the cylinder head. Further, since the valve-related components can be placed in a small space, the degree of freedom in the arrangement of other components can be Improved, moreover, since the valve lifter is miniaturized and reduced in weight, the valve drive can be adapted to the high speed of the engine.

Preferably, when the poppet valve driven by the valve driving device according to the present invention is provided at the intake passage of the engine, it is possible to increase the amount of intake air by using the valve lifter which is miniaturized and reduced in weight, thus Can improve the working efficiency of the engine.

In the case of the state in which the engine is arranged such that the camshaft is arranged on the upper side of the cylinder head, while the intake passage opens to the combustion chamber of the internal combustion engine at its one end and to the upper surface of the cylinder head at its other end, when having this The use of the valve lifter in the cylinder head of an intake passage is restricted in its proper position, however, the valve driving device according to the present invention can ensure a sufficient amount of lift except for this restriction.

In the case where two or more poppet valves provided in each of the cylinder heads of the engine are driven so as to be opened and closed by the valve lifters, the valve lifters are also limited in their positions due to the large number of valve lifters However, the valve driving device according to the present invention can ensure a sufficient lifting amount except for this limitation.

When using the valve drive device according to the present invention, it is possible to arrange the cylinder head screws in a sufficient space, and even better, even in the case where it is necessary to arrange the cylinder head screws close to the valve lifter, when the valve lifter is provided so as to be relatively When the axis of the engine cylinder is tilted, the screw can be tightened without affecting the valve lifter.

In the valve driving device according to the present invention, the guide hole is provided at its opening edge and has an oil pool storing lubricating oil therein, the diameter of the tappet portion is at least partially larger than the diameter of the guide portion while the tappet portion has a The protruding portion whose outer peripheral surface protrudes toward the outer diameter of the guide portion, according to such an arrangement, the protruding portion moves in the oil pool when the valve lifter is lifted, so that the valve lifter can be miniaturized and lightened, and further, the oil The lubricating oil in the pool is sent to the required part due to the movement of the protruding part, so the lubricating oil can be actively supplied to the relevant part of the valve lifter. Therefore, since the friction becomes smaller, the noise caused by the striking action when the valve lifter changes its attitude can be reduced and the degree of wear caused by the striking action can also be reduced. Therefore, the output efficiency and fuel consumption of the engine are improved, and further, the durability and reliability of the engine are also improved.

In such a valve driving device according to the present invention, it is preferable to provide a gap between the outer peripheral surface of the oil pool and the edge portion of the tappet portion, so that lubricating oil can splash out of the gap, so when the valve lifter is pushed down At this time, lubricating oil is forcibly sent into between the guide part and the guide hole by the lower surface of the tappet part. Simultaneously, further, lubricating oil is splashed from the gap, so lubricating oil is introduced into the upper surface of the tappet portion.

Further, when the gap is provided in such a state that its width toward the axis perpendicular to the cam rotation center and its vicinities are larger than the remainder thereof, lubricating oil can be actively splashed to the sides of the cam.

This technical advantage can also be obtained only in the case where a gap is provided toward and near the portion toward the axis direction perpendicular to the center of rotation of the cam.

Similar technical advantages can also be obtained in the case where the valve lifter is arranged so as to be inclined relative to the vertical direction towards the axis perpendicular to the center of rotation of the cam, while only in the downward direction of the two directions perpendicular to the axis of rotation of the cam. Set gaps in and around the part.

In the valve driving device having the aforementioned oil pool according to the present invention, when the diameter of the tappet portion is smaller than that of the substantially circular portion of the cam, splashed lubricating oil can be directly introduced into the cam.

In the direct drive type valve lifter used in the valve driving device according to the present invention, it is preferable to provide an elastic deformation promoting portion to promote elastic deformation of the guide portion when the guide portion is placed in the guide hole. In this arrangement, when the valve lifter changes its attitude during its lifting action, the elastic deformation of the guide portion can be promoted, and therefore, the noise caused by the striking action can be suppressed while the valve lifter changes its attitude. An increase in friction can be avoided, so the durability of the valve lifter can be improved, and further, the output efficiency and fuel consumption of the engine can be improved.

Preferably, the elastic deformation promoting portion is provided at the guide portion near the boundary between the tappet portion and the guide portion, so that the guide portion can be easily elastically deformed along the guide hole when the valve lifter changes its attitude.

Further, it is preferable that the elastic bending promoting portion provided near the boundary between the tappet portion and the guide portion is a groove provided at the peripheral portion of the guide portion, in this case, since the groove can be used as a rear surface of the tappet portion. The recessed part is required during the grinding process with the outer peripheral surface of the guide hole, so the valve lifter can be easily machined.

Description of drawings

1 is a front view showing the form of a valve driving device according to a first embodiment of the present invention;

Fig. 2 is a front view showing a main part of an internal combustion engine to which the valve driving device shown in Fig. 1 is applied;

Fig. 3 is a plan view showing the main part of Fig. 2 shown from the axial direction of a cylinder of the internal combustion engine;

4 is a front view schematically showing the form of a valve driving device according to a second embodiment of the present invention;

5 is a front view schematically showing the form of a valve driving device according to a second embodiment of the present invention;

6 is a front view schematically showing the form of a valve driving device according to a third embodiment of the present invention;

7 is a front view showing the form of a valve driving device according to a fourth embodiment of the present invention;

8 is a side view showing the form of a valve driving device according to a fourth embodiment of the present invention;

9 is a front view showing the form of a valve driving device according to a fourth embodiment of the present invention;

10 is a side view showing the form of a valve driving device according to a fourth embodiment of the present invention;

Fig. 11 is a view showing the valve driving device taken along line VIII-VIII in Figs. 7 and 9;

12 is a front view showing the form of a valve driving device according to a fifth embodiment of the present invention;

13 is a front view showing the form of a valve driving device according to a fifth embodiment of the present invention;

Fig. 14 is a view taken along the line XI-XI in Fig. 12 to represent the valve actuator;

15 is a front view showing the form of a valve driving device according to a sixth embodiment of the present invention;

16 is a front view showing the form of a valve driving device according to a sixth embodiment of the present invention;

Fig. 17 is a view taken along the line XIV-XIV in Fig. 15 to represent the valve actuator;

18 is a front view showing the form of a valve driving device according to a seventh embodiment of the present invention;

Fig. 19 is a view taken along the line XVI-XVI in Fig. 18 to represent the valve actuator;

20 is a front view showing the form of a valve driving device according to an eighth embodiment of the present invention;

21 is a front view showing the form of a valve driving device according to an eighth embodiment of the present invention;

Fig. 22 is a view taken along line III-III in Fig. 21 to represent the valve driving device;

23 is a front view showing the form of a valve driving device according to an eighth embodiment of the present invention;

Fig. 24 is a view taken along the line V-V in Fig. 23 to represent the valve actuator;

Fig. 25 is a front view showing the form of a conventional valve driving device;

Fig. 26 is a front view showing the form of a conventional valve driving device.

Detailed ways

Now, a more detailed description of a preferred embodiment of the present invention will be given with reference to the accompanying drawings.

A valve driving device according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 3 .

1, the valve lifter 101 includes a lifter portion 103 in contact with a cam 102 provided on a cylinder head 111 of an internal combustion engine, and a portion of the lifter portion 103 in contact with the protruding portion of the cam 102 is made substantially Flat disc shape, the protruding part of the cam 102 is in line contact with the tappet part 103, the valve lifter 101 includes a hollow cylindrical guide part 104 continuous to the lower part of the tappet part 103, the guide part 104 is slidably placed on In the guide hole 123 of the cylinder head 111 , the diameter r of the guide portion 104 is set to be smaller than the diameter R of the tappet portion 103 .

Using the above form, the diameter R of the tappet portion is set so as to ensure the required lifting amount of the valve lifter 101, that is, the lifting amount of this valve lifter 101 ensures a predetermined value or a larger drop ratio and the required flow. In addition, since the diameter of the guide portion 104 is made small, the valve lifter 101 is designed to be compact and lightweight, in other words, it becomes possible to provide the tappet portion 103 having such a diameter R so as to obtain a High engine performance boost, while at the same time reducing the footprint of the valve-related components in the vicinity of the cylinder head 111 . Further, since the components related to the valve can be placed in a small space, the degree of freedom in the arrangement of other components can be improved with superior conditions in space, and in addition, since the valve lifter 101 is miniaturized and light in weight, the valve driving device is suitable for due to the high speed of the internal combustion engine.

The end of the rod portion of the poppet valve 105 (hereinafter referred to simply as "valve") is disposed in the guide portion 104 of the valve lifter 101 so as to abut against the lower surface of the tappet portion 103, while the valve 105 is held by an unshown The spring pushes up. That is, the valve lifter 101 is provided between the cam 102 and the valve 105 . The protruding portion of the cam 102 comes into contact with the tappet portion 103 due to the rotation of the cam 102 to push down the valve lifter 101, so the valve 105 is pushed down together with the valve lifter 101 against the urging force of the spring, thereby opening the valve 105 Since the inertial mass of the valve driving system is made smaller due to the miniaturization and light weight of the valve lifter 101, there is no need to make a larger spring force, thereby making it difficult to wear the cam 102 and the tappet portion 103.

An internal combustion engine using the valve driving apparatus according to the first embodiment will be described with reference to FIGS. 2 and 3. As shown in FIG. A concave cavity 114a is defined on the top surface of the piston 114, so the cavity 114a produces such a reverse downflow that the suction air in the cylinder 113 almost just flows on it, and the suction valve seat 115 and the exhaust valve seat 116 are arranged on In the combustion chamber 110 of the cylinder 113, the intake valve seat 115 can be opened and closed by the intake valve (valve 105), while the exhaust valve seat 116 can be opened and closed by the exhaust valve 118 (valve 105).

The cylinder block 112 is connected to the cylinder head 111 by means of cylinder head screws 109, the valve lifter 101 is arranged obliquely along the axis of the suction valve 117 (or exhaust valve 118) in the cylinder head 111, and the guide part 104 is slidably moved by the cylinder. Supported by the cover 111, the suction valve 117 (or exhaust valve 118) is set in the valve lifter 101 in such a state that it is pushed in the direction of closing the valve 117 (or 118) by the retainer 119 and the spring 120, every An intake valve 117 and an exhaust valve 118 are disposed on the cylinder head 111 at a predetermined angle θ with respect to the axis of the cylinder 113, and the angle θ of the intake valve 117 may be the same as or different from the angle θ of the exhaust valve 118.

The valve lifter 101 is arranged in such a state that the diameter r of the guide portion 104 (see FIG. 1) is smaller than the diameter R of the tappet portion 103 (see FIG. 1), while the valve lifter 101 is arranged in an inclined state. Therefore, the space in the plan view can be arbitrarily guaranteed to increase the degree of freedom of the angle θ of the suction valve 117 and the exhaust valve 118, such as the exhaust valve 118 shown in FIG. Gaskets 131 may be provided between 118 (or suction valve 117).

The cylinder head 111 is provided along the axial direction of the cylinder 113 or vertically with a suction port 121 communicating with the suction valve seat 115 and an exhaust port 122 communicating with the exhaust valve seat 116 . Since the suction port 121 is arranged along the axis of the cylinder or vertically, and the suction valve 117 is provided at a given angle θ with respect to the cylinder axis, the air sucked from the suction port 121 flows into the cylinder 113 just downwards, and therefore, the piston 114 The cavity 114a can produce such a reverse downflow that the intake air of the cylinder 113 flows almost exactly upwards. Fuel is injected directly into the combustion chamber 110, while stratified combustion can be performed due to the reverse downflow of the intake air.

As shown in FIG. 3 , the tappet portion 103 of the valve lifter 101 and the cylinder head screw 109 are arranged in such a state that the diameter d of the screw bearing surface of the cylinder head screw 109 and the diameter R by axially extending the suction The virtual cylindrical shape obtained by the tappet portion 103 of the air valve 117 (or exhaust valve 118) is superimposed when viewed from the plane of the screw bearing surface. When the lifting amount of the valve is 0, when viewed along the axis of the cylinder head screw 109, the cylinder head screw 109 does not overlap with the tappet part 103, that is, the following relationship is satisfied:

P+R>p-d

where p is the pitch of the cylinder head screw 109 and P is the pitch of the lifter portion 103 .

Since the valve lifter 101 is provided in a state of inclination with respect to the axis of the cylinder 113, even when the diameter d of the screw bearing surface of the cylinder head screw 109 overlaps with a virtual column when viewed from the plane of the screw bearing surface, the cylinder head screw can be tightened. 109 without affecting the valve lifter 101. Further, since the diameter d of the screw bearing surface of the cylinder head screw 109 overlaps with a virtual cylinder when viewed from the plane of the screw bearing surface, the pitch p of the cylinder head screw 109 can be made Small in order to obtain sufficient valve lift (large lift) to guarantee high engine performance, even if the displacement of the internal combustion engine is small.

In the first embodiment described above, an example of the type of application of the present invention to an internal combustion engine was given in which the valve lifter 101 is inclined relative to the axis of the cylinder 113 (i.e., rotates perpendicular to the cam relative to the vertical direction). axis direction of the center), and the fuel is directly injected into the combustion chamber 110. However, the present invention is not limited to the structure of the first embodiment but can be applied to other forms of internal combustion engines. More specifically, the present invention can be applied to internal combustion engines in which the valve lifter 101 is arranged vertically, that is, parallel to the axis of the cylinder 113, or as long as the tappet portion of the valve lifter 101 is pushed down by the cam 102, the air-fuel mixture into the combustion chamber 110. Also, the relationship between the pitch P of the valve lifter 101 and the pitch p of the cylinder head screw 109 is not limited to the example described above, but other relationships can be adopted, so that when viewed from the plane of the screw bearing surface, the cylinder The screw bearing surface of the cover screw 109 does not overlap the virtual cylinder.

The valve lifter 101 is provided between a cam 102 formed at the camshaft and an intake valve 117 (or exhaust valve 118) provided in a suction valve 117 (or exhaust valve 118) formed in the cylinder head 110 of the internal combustion engine. At the gas port 121 (or exhaust port 122), and move along the stem of the valve 117 (or 118) to open and close the suction port 121 (or exhaust port 122), the valve driving device using the valve lifter 101 is set at Defined in the pilot bore 123 in the cylinder head 111, and in the direct drive valve lifter. The direct-drive valve lifter includes a tappet portion 103 that contacts the cam 102 and is pushed down by the cam 102, and a guide portion 104 that is connected to the tappet portion 103 at one end and placed in a guide hole 123, so that There slides along the axis of the intake valve 117 (or exhaust valve 118 ) in an interlocking state, ie the action of the tappet portion 103 being pushed down by the cam 102 . Further, the diameter r of the guide portion 104 is made smaller than the diameter R of the tappet portion 103 . According to the above configuration, the diameter of the tappet portion 103 is set to such a value as to ensure the lift amount of the valve lifter 101 necessary to obtain a drop rate of a predetermined value or more and a required flow rate. Further, since the diameter of the guide portion 104 is made small, the valve lifter 101 can be miniaturized and reduced in weight.

Thus, it is possible to reduce the occupied area of the valve-related components in the vicinity of the cylinder head 111 while ensuring high engine performance. Also, since the valve-related components can be placed in a small space, the degree of freedom in arrangement for other components can be improved. In addition, since the valve lifter 101 is miniaturized and light in weight, the valve driving device can be adapted to high speed of the internal combustion engine.

Since the valve lifter 101 is inclined with respect to the axis of the cylinder 113, the cylinder head screw 109 can be be fastened without affecting the tappet portion 103. Further, since the intake valve 117 is arranged at an angle θ with respect to the axis of the cylinder 113, but the present invention can be applied to an internal combustion engine having a vertical intake port that generates a reverse gas flow almost at the portion directly above the combustion chamber 110. Downstream while directly injecting fuel within the combustion chamber 110 . Needless to say that a large lift amount of the valve lifter is not required in an internal combustion engine, the lifter can be further miniaturized and reduced in weight without changing the lift amount.

A valve driving device according to a second embodiment of the present invention will be described with reference to FIGS. 4 and 5 .

FIG. 4 shows a state where the valve lifter is not pushed down, and FIG. 5 shows a state where the valve lifter is pushed down.

Referring to these figures, the cam 212 is arranged on the upper side of the cylinder head 211 of the internal combustion engine and the cylinder head 211 defines a guide hole 213, and the cylindrical guide portion 215 of the valve lifter 214 is slidably disposed along and juxtaposed in the guide hole 213, and the tappet portion 216 is arranged on the top of guide part 215, and tappet part 216 protrudes from its circumferential part toward the outer diameter direction of guide part 215 to form protruding part 230, and tappet part 216 continues to the top of guide part 215 to form an umbrella shape, very The rod portion 216 constitutes a substantially flat disc shape at its portion in contact with the protruding portion of the cam 212, which is in line contact with the tappet portion 216, and the entirety of the outer peripheral portion of the tappet portion 216 may not be guided from the guide portion 215. protrudes, but only a part of the outer peripheral portion of the tappet portion 216 can protrude from the guide portion 215 by changing its diameter.

The stem portion of the valve 217 (suction valve or exhaust valve) is set in the guide portion 215 of the valve lifter 214 in such a state that the end of the stem portion abuts against the lower surface of the tappet portion 216, and the valve 217 is The unrepresented spring pushes up, that is, the valve lifter 214 is arranged between the cam 212 and the valve 217, and the protruding portion of the cam 212 contacts the tappet portion 216 by the rotation of the cam 212 to push the valve lifter 214 downward, so The valve 217 is pushed down together with the valve lifter 214 against the urging force of the spring, thus opening the valve 217 .

The oil sump 218 in which the lubricating oil 219 is stored is used as an oil sump portion formed around the upper portion (the tappet 216 side) of the guide hole 213, and the tappet portion 216 is arranged in the oil sump 218 so as to be outside the tappet portion 216. A small gap is formed between the periphery and the inner wall of the oil pool 218, which is arranged so that when the valve lifter 214 is lifted, the tappet portion 216 moves in the oil pool 218, as shown in Figure 4, the oil pool 218 is set The depth d so as to satisfy the following expression:

d≥D-S,

where D is the length from the upper surface of the tappet portion 216 to the bottom surface of the oil pool 218 when the lifter 214 is not pushed down, and S represents the valve lift amount.

Like the valve driving device of the third embodiment shown in FIG. 6, the valve driving device is arranged in such a state that when the valve 317 is inclined relative to the axis of the cylinder (that is, toward the center of rotation of the cam perpendicular to the vertical direction direction of the axis), at least a portion of the rear of the lifter portion 316 is below the oil level when the valve lifter 314 is lifted.

According to the valve driving device arranged in the aforementioned state, the load is applied from the cam to the right side face of the tappet portion 216 (316) in FIG. 5 (FIG. 6) until after the valve lifter 214 (314) lifting action starts. The lift reaches its maximum value. Therefore, a torque acting on the valve lifter 214 (314) in the same direction as the rotation direction of the cam 212 (312) is generated. As a result, the valve lifter 214 (314) is inclined to the left in FIG. 5 (FIG. 6), and thus the gap between the guide portion 215 (315) on the left side and the guide hole 213 (313) becomes larger than that in the left side. The upper one is larger. In this state, when the upper gap became larger, the lubricating oil 219 (319) in the oil pool 218 (318) was pushed down (towards Fig. 5 (Fig. ) in the direction indicated by the arrow A), thus the lubricating oil 219 (319) is filled into the gap.

Simultaneously, the lubricating oil 219 (319) is pushed out of the gap between the outer peripheral portion of the tappet portion 216 (316) and the oil pool 218 (318) (in the direction of arrow B in FIG. 5 (FIG. 6 ), and the lubricating oil 219 (319) is introduced to the side of the cam 212 (312). The lubricating oil 219 (319) in the oil pool 218 (318) is agitated by the umbrella-shaped tappet portion 216 (316) while slag and the like are discharged by the lifting action of the valve lifter 214 (314).

After the valve lifter reaches the uppermost position to achieve the maximum lift amount of the valve lifter, the torque acts on the valve lifter 214 (314) in the opposite direction to that which has been applied to it, so that the valve lifter 214 (314) moves toward The left side in Fig. 5 (Fig. 6) is slanted. In this case, although the gap between the guide portion 215 (315) and the guide hole 213 (313) on the left side becomes smaller at its upper part, since the lubricating oil 219 (319) filling the gap realizes the extrusion action, the valve Lifter 214 (314) does not change its attitude very quickly.

In the above valve driving device, when the valve lifter 214 (314) is lifted, the lubricating oil 219 (319) in the oil 218 (318) is pushed into the guide portion 215 (315) by the back of the tappet portion 216 (316). and the guide hole 213 (313), in this state, lubricating oil 219 (319) is supplied to the gap between the guide portion 215 (315) and the guide hole 213 (313) regardless of the lubricating oil 219 ( 319) viscosity. Further, since the lubricating oil 219 (319) is pushed out of the gap between the outer peripheral portion of the tappet portion 216 (316) and the oil pool 218 (318), while the lubricating oil 219 (319) is introduced into the side of the cam 212 (313), Lubricating oil 219 (319) is supplied to the contact surface between the cam 212 (312) and the tappet portion 216 (316).

Therefore, since the friction and contact surface at the gap becomes smaller, the noise caused by the striking action when the valve lifter 214 (314) changes its attitude can be reduced and the degree of wear caused by the striking action can also be reduced. Therefore, the output efficiency and fuel consumption of the engine are improved, and the durability and reliability of the engine are further improved.

A valve driving device according to a fourth embodiment of the present invention will be described with reference to FIGS. 7 to 11 .

Figures 7 and 8 show a state where the valve lifter is not pushed down and Figures 9 and 10 show the state where the valve lifter is pushed down, and Figure 11 shows that the valve drive is cut along the VIII-VIII line of Figures 7 and 9 An illustration of a part of the device.

As shown in these figures, the tappet portion 416 protrudes from its circumferential portion toward the outer diameter direction of the guide portion 415 to form a protrusion (430), and the oil pool 421 serves as an oil pool portion in which lubricating oil 419 is stored in the guide hole. 413 is formed at the periphery of the upper part. As shown in Figures 7, 9 and 11, the oil pool 421 is provided with a portion 422 with a notch, which forms a pair of axial directions perpendicular to the center of rotation of the cam 412 (in the figure) by partially removing the opposite part of the inner peripheral wall of the oil pool. left and right direction) convex shape. As shown in FIGS. 8 and 10 , the portion of the oil pool 421 (ie, the portion mainly along the axis of the rotation center of the cam 412 ) faces the tappet portion 416 with a small gap therebetween except the notched portion 422 .

According to the valve driving device arranged in this state, when the valve lifter 414 is lifted, the lubricating oil 419 in the oil pool 421 is pushed into the gap between the guide portion 415 and the guide hole 413 by the rear surface of the tappet portion 416, Therefore, the lubricating oil 419 is supplied to the gap between the guide portion 415 and the guide hole 413, and further, the lubricating oil 419 is supplied from the gap between the outer peripheral portion of the tappet portion 416 and the oil pool 421 mainly along the axis of the rotation center of the cam 412. Push out and lead on the side of cam 412. The lubricating oil 419 in the oil pool 421 is stirred by the umbrella-shaped tappet portion 416 and at the same time the slag etc. are discharged by the lifting action of the valve lifter 414. When the valve lifter 414 is lifted, the lubricating oil 419 is pushed out from the notch portion 422 to the tappet At the same time, a lot of lubricating oil 419 is introduced onto the contact surface between the cam 412 and the tappet portion 416, so that the contact surface between the cam 412 and the tappet portion 416 is sufficiently lubricated.

Therefore, since the gap and the friction at the contact surfaces become smaller, the noise caused by the striking action when the valve lifter 414 changes its posture can be reduced and the degree of wear caused by the striking action can also be reduced. Therefore, the output efficiency and fuel consumption of the engine are improved, and further, the durability and reliability of the engine are also improved.

A valve driving device according to a fifth embodiment of the present invention will be described with reference to FIGS. 12 to 14 .

Fig. 12 shows the situation that the valve lifter is not pushed down and Fig. 13 shows the situation that the valve lifter is pushed down, and Fig. 14 is a diagram showing that a part of the valve driving device is cut away along line XI-XI in Fig. 12 .

As shown in this phase diagram, the valve 517 is arranged obliquely with respect to the axis of the cylinder (that is, toward the axis direction perpendicular to the rotation center of the cam with respect to the vertical direction), and the tappet rod portion 516 extends from its peripheral portion toward the direction of the guide portion 515. The outer diameter protrudes to form a protrusion (530). An oil pool 526 serving as an oil pool portion storing lubricating oil 519 is formed at an upper peripheral portion of the guide hole 513 . The oil pool 526 is provided with a notch portion 527 formed by partially removing a part of the inner peripheral wall of the oil pool in a convex shape on the inclined inner side (left side in the figure) toward a direction perpendicular to the rotation center axis of the cam 512, A portion of the oil pool 526 faces the tappet portion 516 except for the notch portion 527 with a small gap therebetween.

According to the valve driving device arranged in this state, when the valve lifter 514 is lifted, the lubricating oil 519 is pushed out from the notch portion 527 to the upper surface of the tappet portion 516, while the lubricating oil 519 is introduced between the cam 512 and the tappet portion 516. on the contact surface. Further, particularly, when the engine rotates in a high speed range, the lubricating oil in the notch portion 527 is squeezed by the tappet portion 516 under high pressure, and therefore, the lubricating oil 519 is splashed toward the wall surface of the cylinder head 511 or the like. Then, the lubricating oil 519 splashed in this way collides with the wall surface etc. while being introduced into the protruding portion of the cam 512 whose base circle portion has a diameter smaller than that of the tappet portion 516, and therefore, the distance between the cam 512 and the tappet portion 516 The contact parts between are fully lubricated.

Therefore, since the contact surfaces can avoid high friction and high wear levels, the output efficiency and fuel consumption of the engine are improved while further improving the durability and reliability of the engine.

A sixth embodiment of the present invention will be described with reference to FIGS. 15 to 17. FIGS. 15 and 16 are front views showing a diagrammatic arrangement of a valve driving device according to the sixth embodiment, wherein FIG. 15 shows a state where the valve lifter is not pushed down. And Fig. 16 shows the situation of pushing down the valve lifter, and Fig. 17 is a diagram showing that a part of the valve driving device is cut away along line XIV-XIV in Fig. 15 .

As shown in Figures 15 and 16, the cam 631 is arranged on the top of the cylinder head 611 of the engine, and the diameter r' of the tappet part 616 is made smaller than the diameter R' of the base circle part of the cam 631, and the tappet part 616 is formed from it. The circumferential portion protrudes toward the outer diameter direction of the guide portion 615 to form a protruding portion ( 630 ), and an oil pool 632 serving as an oil pool portion in which lubricating oil 619 is stored is formed on the periphery of the upper portion of the guide hole 613 . As shown in FIG. 17, the oil pool 632 is provided with an enlarged-diameter portion 633 formed by partially removing two opposite parts of the inner peripheral wall of the oil pool in an oval shape in such a state that its main axis portion is directed perpendicular to the cam. In the direction of the axis of the rotation center of 631 (left and right directions in the figure), each part of the oil pool 632 portion except the enlarged diameter portion 633 faces the tappet portion 616 with a small gap therebetween.

According to the valve driving device arranged in this state, when the valve lifter 614 is lifted, the lubricating oil 619 is pushed out from the diameter-enlarged portion 633 to the upper surface of the tappet portion 616, and at the same time, the lubricating oil 619 is introduced into the cam 631 and the tappet portion. 616 on the contact surface. Further, in particular, when the engine rotates in a high-speed range, the lubricating oil 619 in the enlarged-diameter portion 633 is squeezed and splashed by the tappet portion 616. In this case, since the diameter r′ of the tappet portion 616 is made is smaller than the diameter R′ of the base circle portion of the cam 631 , so the splashed lubricating oil 619 is directly introduced onto the protruding portion of the cam 631 . Therefore, the contact portion between the cam 631 and the tappet portion 616 is sufficiently lubricated.

Therefore, since high friction and a high degree of wear on the contact surfaces can be avoided, the output efficiency and fuel consumption of the engine are improved and the durability and reliability of the engine are further improved.

A valve driving device according to a seventh embodiment of the present invention will be described with reference to FIGS. 18 and 19 .

As shown in these figures, the valve 717 is set so as to be inclined with respect to the axis of the cylinder (that is, toward the direction perpendicular to the axis of the rotation center of the cam relative to the vertical direction), and the tappet portion 716 is directed from its circumferential portion toward the direction of the guide portion 715. The outer diameter direction protrudes to form a protruding portion (730), and an oil pool 736 serving as an oil pool portion in which lubricating oil 719 is stored is formed at the periphery of the upper portion of the guide hole 713, the oil pool 736 is provided with a diameter-enlarged portion 737, This portion is formed by partially removing a portion of the inner peripheral wall of the oil pool in a semi-elliptical shape in such a state that its main axis portion is placed on the inclined inner side toward the axis direction perpendicular to the rotation center of the cam 731 (in the figure). The left side of the oil pool), the portion 736 of the oil pool faces the tappet portion 716 except the enlarged diameter portion 737 through a small gap therebetween.

According to the valve driving device arranged in such a state, when the valve lifter 714 is lifted, the lubricating oil 719 is pushed out from the diameter-enlarged portion 737 to the upper surface of the tappet portion 716, while the lubricating oil 719 is introduced into the cam 731 and the tappet portion 716. On the contact surface between, further, especially, when the engine rotates in the high-speed range, the lubricating oil 719 in the portion 737 of enlarged diameter is squeezed and splashed by the tappet portion 716, in this case, due to the tappet The diameter r' of the portion 716 is made smaller than the diameter R' of the base circle portion of the cam 731, so that the splashed lubricating oil 719 is directly introduced into the protruding portion of the cam 731, therefore, the distance between the cam 731 and the tappet 716 Contact parts are adequately lubricated.

Therefore, since high friction and a high degree of wear can be avoided at the contact surfaces, the output efficiency and fuel consumption of the engine are improved and the durability and reliability of the engine are further improved.

A valve driving device according to an eighth embodiment of the present invention will be described with reference to FIGS. 20 to 24 .

As shown in these figures, the cylindrical guide portion 812 of the valve lifter 811 is placed in the guide hole 806 of the cylinder head 802 so as to freely slide therealong. A disc-shaped lifter portion 813 is integrally provided on the upper portion of the guide portion 812, the diameter R of the lifter portion 813 is larger than the diameter r of the guide portion 812, and the lifter portion 813 is shaped so as to continue to the upper portion of the guide portion 812 to form an umbrella.

The tappet portion 813 constitutes a substantially flat circular shape at a portion which is in contact with the protruding portion of the cam 803, and the protruding portion of the cam 803 is in line contact with the tappet portion 813, and the valve driving means is set in such a state , that is, when the valve 807 is pushed down to the maximum position, that is, when the lifting amount of the valve lifter 811 reaches the maximum value, only the guide part 812 is placed in the guide hole 806 (the tappet part 816 is not placed in the guide hole hole 806).

At the root of the tappet portion 813, a circumferential groove 814 is formed on the outer periphery of the guide portion 812 as an elastic deformation promoting portion, so that when the guide portion 812 is placed in the guide hole 806, the circumferential groove 814 promotes the guide portion 812. elastic deformation.

According to the valve lifter 811 thus constructed, as shown in FIGS. 21 and 22, the load is applied from the cam to the right side surface of the tappet portion 813 in FIG. Therefore, the torque acting on the valve lifter 811 is generated in the same direction as the rotation direction of the cam 803, so the valve lifter 811 is tilted to the right in the figure (that is, toward the direction perpendicular to the cam). The direction of the axis of the rotation center with respect to the vertical direction) while therefore the gap between the guide portion 812 and the guide hole 806 becomes smaller on the right side at the upper portion thereof.

When the valve lifter 811 is changed in its posture by a torque acting thereon in the same direction as the rotation direction of the cam 803, the guide portion 812 is elastically deformed due to the circumferential groove 814 provided on the outer periphery of the guide portion 812, so the guide portion 812 The outer periphery of the guide hole 806 is fitted to the inner periphery of the guide hole 806, therefore, since the lubricating oil between the guide portion 812 and the guide hole 806 is prevented from being pushed to one side while the oil film is maintained between them, when the valve lifter changes its posture, by The noise caused by striking action can be suppressed. At the same time, wear caused by striking action can also be suppressed, thereby reducing friction.

As shown in FIGS. 23 and 24, since the load is applied from the cam to the left side surface of the tappet portion 813 in FIG. Cam 803 is rotated in the opposite direction so that valve lifter 811 is tilted to the left in the figure. The gap between the guide portion 812 and the guide hole 806 thus becomes smaller on the left at its upper part.

When the valve lifter 811 changes its posture due to the torque acting thereon in the direction opposite to the direction of rotation of the cam 803, the guide portion 812 faces the same direction as that of FIG. The opposite direction elastically deforms in the case, so the outer circumference of the guide portion 812 fits into the inner circumference of the guide hole 806 . Therefore, since the lubricating oil between the guide portion 812 and the guide hole 806 is prevented from being pushed sideways while maintaining an oil film therebetween, the noise caused by the striking action when the valve lifter changes its posture can be suppressed while also suppressing the noise caused by the striking action. friction caused by movement, thus reducing friction.

Further, since the circumferential groove 814 provides a recess required for performing the grinding work of the rear surface of the tappet portion 813 and the outer peripheral surface of the guide hole 812, the valve lifter 811 can be relatively easily processed.

Claims (7)

1, a kind of valve drive that uses direct drive-type valve lifter, this valve lifter is arranged on the cam (102,212 that forms on camshaft, 312,412,512,631,731,803) and poppet valve (105,117,118,217,317,417,517,617,717,807) between, described poppet valve is arranged on the cylinder head (111,211,311 at internal-combustion engine, 411,511,611,711,802) move so that open and close described passage in the passage (121,122) that upward forms and on the axial direction of described valve, described device comprises:

The pilot hole that on described cylinder head, forms (123,213,313,413,513,613,713,806); With

One direct drive-type valve lifter (101,214,314,414,514,614,714,811), it comprises the tappet part (103 that contacts with described cam and oppressed by described cam, 216,316,416,516,616,716,813) and have and be attached to the end on the described tappet part and be arranged at targeting part (104 in the described pilot hole, 215,315,415,515,615,715,812), so that freely slide to the axial direction of described poppet valve therein with a kind of interlock mode, the action that is promoted by described cam as described tappet part;

The diameter of wherein said pilot hole (r) is made forr a short time than the diameter (R) of described tappet part;

It is characterized in that:

Described valve lifter (101,214,314,414,514,614,714,811) in perpendicular to the direction of the rotation axis of described cam, tilt, and valve lifter (101) is with the state setting with respect to the axis tilt of cylinder (113) with respect to the cylinder head screw (109) that is used for fixing described cylinder head; With

Described valve lifter is provided in the plane view adjacent with described cylinder head screw;

The gentle cylinder cover screw of described valve lifter (109) is arranged to make described cylinder head screw the screw supporting surface diameter and extend described tappet part (103 by axis along Aspirating valves, 216,316,416,516,716,813) diameter (R) and the virtual cylindricality that obtains is overlapping in planimetric map; And satisfy the following relationship formula:

P+R＞p-d

P is the pitch of tappet part (103) in the formula, and R is the diameter of tappet part (103), and p is the pitch of cylinder head screw (109), and d is the diameter of the screw supporting surface of cylinder head screw (109);

At suction side and exhaust side, tappet part (103) all is arranged on the outside of the noses of cylinder head screw (109).

2, valve drive as claimed in claim 1 is characterized in that, described passage comprises the air intake passage (121) of described internal-combustion engine at least.

3, valve drive as claimed in claim 2, it is characterized in that, described camshaft be arranged on the upside of described cylinder head and described air intake passage at the one end towards the combustion chamber openings of described internal-combustion engine and in the upper surface open of its other end towards described cylinder head.

4, valve drive as claimed in claim 2, it is characterized in that, at least two described air intake passages (121) are set, and each described air intake passage (121) extends in the direction perpendicular to the rotation axis of described cam and is provided with described poppet valve in each cylinder of described internal-combustion engine.

5, valve drive as claimed in claim 1 is characterized in that, the diameter of described tappet part is less than the diameter of the base circle portion of described cam.

6, valve drive as claimed in claim 1 is characterized in that, comprises that also resiliently deformable promotes part (814), when being used in described targeting part is arranged on described pilot hole, promotes the resiliently deformable of described targeting part,

Described resiliently deformable promotes part to be arranged on the groove of the excircle part of described targeting part.

7, valve drive as claimed in claim 6 is characterized in that, described resiliently deformable promotes part to be arranged on the described guide portion office of the boundary vicinity between described tappet part and the described targeting part.

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