JPH0227124Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The invention relates to an engine valve train.
The present invention relates to a valve train equipped with a valve deactivation mechanism that holds an exhaust valve in a closed position, that is, in an inoperative state, and stops operation of its cylinder.

(Prior Art) Conventionally, as disclosed in British Patent No. 1275328 and the drawings, for example, as disclosed in the specification and drawings of British Patent No. 1275328, as a valve train for an engine, a rocker arm of a specific cylinder is used as a cam-side arm that receives force from a camshaft. ,
It is divided into a valve-side arm that drives the intake and exhaust valves, and both arms are supported so as to be movable relative to each other around the rocker shaft, and also supported movably on the cam-side arm so as to come into contact with the valve-side arm using a hydraulic device. A pressed plunger is provided to limit the relative movement of the two arms toward each other, transmitting the force from the camshaft to the valve-side arm, and opening and closing the intake and exhaust valves by the valve-side arm. There is something.

(Problem to be solved by the invention) By the way, in such a configuration, when the engine is in a low load range where not much engine output is required, by relieving the hydraulic pressure of the hydraulic system and eliminating the hydraulic action on the plunger, By moving both arms relative to each other to prevent the force from the camshaft from being transmitted to the valve side arm, cylinder reduction operation is performed in which the intake and exhaust valves are held in a closed position, that is, in an inoperative state, and the operation of the characteristic cylinder is stopped. It is conceivable that this will reduce the displacement in the low load range, reduce pumping loss, and reduce fuel consumption.

In this case, during cylinder reduction operation, the only movable part of the valve train is the cam side arm, which has a small inertial mass, so surging does not occur even when the engine speed becomes high, and the valve side arm and intake and exhaust Since the valve does not jump, it is possible to reliably stop the operation of a specific cylinder, which is advantageous.

However, in the above-mentioned conventional device, it is necessary to provide a hydraulic device on the cam-side arm for pushing the plunger, and to form a hydraulic passage communicating with the hydraulic chamber of the hydraulic device on the cam-side arm or the rocker shaft. There are problems in that the structure of the valve train is complicated, difficult to process, and expensive. Furthermore, since the pressing force of the plunger is adjusted by hydraulic pressure, there is also the problem of poor responsiveness when switching between full-cylinder operation and reduced-cylinder operation. Additionally, since the plunger is pressed so as to come into contact with the valve-side arm, during cylinder reduction operation in which both arms move relative to each other, the contact surfaces of the plunger and the valve-side arm may slide against each other and seize, reducing reliability. It was something missing.

The purpose of the present invention is to control the relative movement of the cam-side arm and the valve-side arm supported on the rocker shaft with a simple configuration as described above, and to control the contact surface between the plunger and the cam-side or valve-side arm. By using a simple configuration and lubrication, there is no seizure during reduced-cylinder operation, and the reliability of each operation between full-cylinder operation and reduced-cylinder operation is high, and the responsiveness when switching is excellent, making it cost-effective. An object of the present invention is to provide a valve train having an advantageous valve deactivation mechanism.

(Means for solving the problem) In order to achieve the above object, the solution of the present invention replaces the Rocker arm that presses and opens the intake and exhaust valves of the engine with the cam-side arm that receives the force from the camshaft. , and a valve-side arm that drives the intake and exhaust valves, and both arms are supported for relative movement around the rocker shaft. Further, a plunger is provided on one of the cam-side arm and the valve-side arm, the plunger being movably supported in a direction perpendicular to the rocker shaft and biased by a spring so as to come into contact with the other arm. Further, a first position is supported on the one arm so as to be movable in the axial direction of the rocker shaft and prevents movement of the plunger and limits the relative movement of the two arms; A lever member is provided which moves to a second position allowing movement. Further, the rocker shaft and the rocker shaft support portion of the rocker arm are configured to form an oil jetting hole through which lubricating oil flowing through the rocker shaft is jetted onto the abutment surface of the plunger and the arm.

(Function) With the above configuration, in the present invention, during all-cylinder operation, the lever member is positioned in the first position to limit the relative movement of both arms approaching each other, and the force from the camshaft is transferred to the valve. The transmission is transmitted to the side arm, and the valve side arm opens and closes the intake and exhaust valves.In the case of cylinder reduction operation, the lever member is positioned in the second position to enable relative movement of both arms, and the valve side arm opens and closes the intake and exhaust valves. The force is absorbed by the spring and not transmitted to the valve-side arm, and the intake and exhaust valves are held in a closed state, that is, inactive, and the lubricating oil in the rocker shaft is transferred to the contact between the plunger and the arm using the oil injection hole. It is designed to lubricate the contact surface by ejecting it to the contact surface.

(Effect of the invention) Therefore, according to the invention, on either the cam side arm or the valve side arm,
A plunger is provided that comes into contact with the other arm, and by changing the position of the lever member, movement of the plunger is prevented or allowed, thereby controlling the relative movement of both arms. The engine can be switched between full-cylinder operation and reduced-cylinder operation, improving responsiveness during switching, and ensuring that plunger movement is prevented or allowed, thereby improving the reliability of each of the above operations. You can improve your performance. Furthermore, since a simple configuration of providing a lever member and a plunger on the arm is sufficient, cost reduction can be advantageously achieved.

In addition, oil spout holes are formed in the rocker shaft and the rocker shaft support part of the rocker arm to supply the lubricating oil in the rocker shaft to the contact surface between the plunger and the arm, making it possible to lubricate the contact surface and prevent seizure. It is possible to further improve the reliability of operation.

(Example) Hereinafter, an example as a specific example of the technical means of the present invention will be described based on the drawings.

FIG. 1 shows an embodiment in which the present invention is applied to an in-line four-cylinder engine. H is a cylinder head disposed on a cylinder block (not shown). In the cylinder block, first to fourth cylinders C, . . . are formed at equal pitches in order from the front side (left side in FIG. 1). Above cylinder head H
A camshaft 1 extending in the front-rear direction is located in the center of the left-right direction.
is supported by rocker brackets R..., and suction and exhaust cam portions 2 and 3 are formed at portions of the camshaft 1 corresponding to the respective cylinders C. Rocker shafts 4, 4 extending parallel to the camshaft 1 are disposed on both left and right sides of the camshaft 1 and are supported by the rocker brackets R. An oil passage 4a extending in the axial direction is formed in the rocker shaft 4, and although not shown, the oil passage 4a communicates with an oil pump, and is supplied with lubricating oil discharged from the oil pump. It is done like this.

On the other hand, in the cylinder head H, an intake port and an exhaust port are formed corresponding to each cylinder C, although not shown, and an intake valve 5 and an exhaust valve 6 are provided to open and close the intake and exhaust ports. It is being The intake and exhaust valves 5 and 6
is biased in the valve closing direction by a valve spring, and the upper ends of its stem portions protrude to the outside of the rocker shafts 4, 4 on both the left and right sides.

The rocker shafts 4, 4 on both the left and right sides are as follows:
Intake rocker arms 7, 8 and exhaust rocker arms 9, 10, which press and open the intake and exhaust valves 5, 6, are rotatably supported.
Each of the rocker arms 7 to 10 is provided such that its inner end abuts the corresponding cam portion 2, 3 of the camshaft 1, and its outer end abuts the upper end of the stem portion of the intake and exhaust valves 5, 6. As the camshaft 1 rotates, the cam portions 2 and 3 press the intake and exhaust valves 5 and 6 against the biasing force of the valve spring to open the valves at a predetermined timing. There is.

Of the Rocker arms 7 to 10, the intake and exhaust Rocker arms 7 and 9 of the first cylinder C and the fourth cylinder C are provided with a valve deactivation mechanism, which is a main component of the valve train according to the present invention. . This valve deactivation mechanism will be explained with reference to the exhaust rocker arm 9 of the first cylinder C.As shown in detail in FIGS. 11 and a valve-side arm 12 that presses the exhaust valve 6.
1 and 12 are supported for relative movement around the rocker shaft 4. A guide hole 13 that opens toward the valve side arm 12 is formed in the upper part of the cam side arm 11.
A cylindrical plunger 14 is movably supported on the valve side arm 1 by a spring 15 installed in the guide hole 13.
It is biased so as to contact 2. That is,
The plunger 14 is supported so as to be movable in a direction perpendicular to the rocker shaft 4.

Further, a lock-off plate 16 as a lever member having a surface perpendicular to the guide hole 13 is supported on the upper part of the cam-side arm 11 so as to be movable in the axial direction of the rocker shaft 4. As shown in FIG. 4, a guide sleeve 17 movable in the axial direction is attached to the rocker shaft 4 between the support portion of the valve side arm 12 and the rocker bracket R by a return spring 18. A ring-shaped drive sleeve 19 is supported between the guide sleeve 17 and the rocker bracket R.
An end portion of the lock-off plate 16 is attached to the upper surface of the guide sleeve 17.

On the other hand, as shown in FIG. 1, a solenoid 20 is disposed at the rear of the cylinder head H, and an excitation shaft 21 that is pressed forward when the solenoid 20 is activated is connected to the solenoid 20. The excitation shaft 21 is a rocker bracket R.
The drive sleeve 1 is supported by the drive sleeve 1 and extends forward.
9, and the return spring 1
When the solenoid 20 is actuated, the lock-off plate 16, which is in the first locked position, is moved forward through the drive sleeve 19 and the guide sleeve 17 to the second unlocked position.

The middle part of the plunger 14 is notched to reduce the shaft diameter to form an engaging part 22, while the lock-off plate 16 is formed with a switching hole 23 as shown in FIG. There is. The switching hole 23 consists of a locking hole portion 23a that is slightly larger than the shaft diameter of the plunger engaging portion 22, and an insertion hole portion 23b that is connected to the rear of the locking hole portion 23a and is slightly larger than the shaft diameter of the plunger 14. , when the lock-off plate 16 is positioned at the lock position due to the deactivation of the solenoid 20, as shown by the solid line in FIG. 14 is prevented from moving, and the plunger 14 protruding from the guide hole 13 presses the valve side arm 12 to close the cam side arm 11.
This restricts the relative movement of the cam-side arm 11 and the valve-side arm 12 toward each other, thereby transmitting the force received by the cam-side arm 11 from the camshaft 1 to the valve-side arm 12 via the plunger 14 to close the exhaust valve 6. While driving the lock-off plate 1 to open and close, the lock-off plate 1 is activated by the operation of the solenoid 20 as shown by the phantom line in FIG.
6 is positioned at the release position, the insertion hole 23b is positioned coaxially with the plunger 14, allowing movement of the plunger 14 and allowing relative movement between the cam side arm 11 and the valve side arm 12. As a result, the force received by the cam side arm 11 from the camshaft 1 is transmitted to the spring 15 by the movement of the plunger 14, and is absorbed by the compressive deformation of the spring 15, and is not transmitted to the valve side arm 12, and the force is transmitted to the exhaust valve 6. is configured to maintain the switch in a closed or inoperative position. Incidentally, the intake rocker arm 7 is also configured with a valve deactivation mechanism similar to that of the exhaust rocker arm 9.

Therefore, in the medium load range or high load range of the engine, the first and fourth solenoids are not operated without operating the solenoid 20.
While cylinders C and C are operated to perform full-cylinder operation, in the low load range of the engine, the solenoid 20 is activated to stop the operation of the first and fourth cylinders C and C to perform reduced-cylinder operation. being done.

In addition, the rocker shaft 4 is formed with a first oil ejection hole 25a that extends in the radial direction and has one end communicating with the oil passage 4a of the rocker shaft 4 and the other end opening on the outer peripheral surface. The rocker shaft support part of
When the cam-side arm 11 is at a predetermined rotation angle, the rocker shaft 4 and the cam-side arm 11 communicate with each other at the sliding surface, so that one end is connected to the first jet hole 25.
A second oil passage 25b is formed which communicates with the cam side arm 11 and whose other end opens toward the contact surface 24 between the plunger 14 and the valve side arm 12. When this happens, the lubricating oil in the rocker shaft 4 is intermittently jetted and supplied to the abutment surface 24.

In addition, 26... is a coil spring that restrains the movement of the rocker arms 7 to 10 in the direction of the four axes of the rocker shaft, 27 is a sprocket that drives the camshaft 1, 28 is an adjuster screw for adjusting the valve brush, and 29 is a valve side arm. 12 is a contact portion with which the plunger 14 comes into contact, and is made of a chip material with excellent wear resistance. 30 is a lock nut for adjusting the position of the excitation shaft 21, 31 is a boss for attaching a distributor, and 32 is a cylinder head cover.

Therefore, in the above embodiment, the operation or stop of the first and fourth cylinders C and C can be freely switched, so that all-cylinder operation is sufficient in the medium load range or high load range of the engine. While generating the necessary engine output, in the low load range of the engine, cylinder reduction operation is performed to generate the required output while halving the displacement to reduce fuel consumption and halving pumping loss to reduce horsepower loss. Therefore, fuel consumption rate can be reduced.

At this time, the lock-off plate 16 is placed in the lock position or the release position to prevent or allow the movement of the plunger 14 to switch between full-cylinder operation and reduced-cylinder operation. It is possible to improve the responsiveness during switching compared to the case where the Moreover, during the reduced-cylinder operation, the movement of the plunger 14 can be reliably prevented by the engagement between the locking hole 23a of the lock-off plate 16 and the engaging portion 22 of the plunger 14, and during the reduced-cylinder operation, the insertion hole 23b
Since the movement of the plunger 14 can be reliably allowed, each operation can be performed with high reliability.

Furthermore, during cylinder reduction operation, the only movable part of the valve train is the cam side arm 11, and the inertial mass of the movable part is small, so surging does not occur even when the engine speed becomes high, and the valve side Arm 12
Also, the intake and exhaust valves 5 and 6 do not jump. Therefore, the operation of the first and fourth cylinders C and C can be reliably stopped, cylinder reduction operation can be performed stably over the entire engine speed range, and the fuel consumption rate can be further reduced. Can be done.

Moreover, the switching between full-cylinder operation and reduced-cylinder operation is as follows:
The lock-off plate 16 is supported movably in the axial direction of the rocker shaft 4 at the upper part of the cam-side arm 11, and its position is changed between a lock position (first position) and a release position (second position) by an excitation shaft 21. Since this is done by changing the lock-off plate 16, the position of the lock-off plate 16 can be changed smoothly and reliably, and the upper structure of the cam-side arm 11 can be made as compact as possible.
For example, lock off plate with lock shaft 4
Compared to the case where the movable parts are movably supported in a direction perpendicular to the engine, the increase in the inertial mass of the movable parts can be greatly suppressed, which is particularly advantageous in preventing surging in the high rotational range of the engine. Therefore, the reliability of each operation between the full-cylinder operation and the reduced-cylinder operation as well as the switching between the operations can be significantly improved.

In addition, since the configuration is simple in that a guide hole 13 is formed in the cam side arm 11 to support the plunger 11 and the spring 15, and a lock-off plate 16 whose position is changed by the solenoid 20 is provided, each member It is easier to process and implement, and costs can be reduced, compared to those in which hydraulic chambers and hydraulic passages are provided.

In addition, first and second oil ejection holes 25a and 25b are formed in the rocker shaft 4 and the rocker shaft support portion of the cam side arm 11, so that the lubricating oil in the rocker shaft 4 reaches the contact surface between the plunger 14 and the valve side arm 12. 24, the corresponding contact surface 24 can be lubricated. In particular, this effectively prevents seizure caused by sliding contact between the contact surfaces 24 of the plunger 14 and the valve-side arm 12 during cylinder reduction operation in which the arms 11 and 12 move relative to each other, and lubricates the corresponding contact surfaces 24. can be carried out effectively, thereby further improving the reliability of the above-mentioned operation.Moreover, the above-mentioned jetting supply of lubricating oil is carried out when the cam-side arm 11 reaches a predetermined rotation angle. Since it is intermittent, it is possible to suppress a drop in the oil pressure in the rocker shaft 4 as much as possible, and it is advantageous that the oil pressure of the lubrication system of the entire engine can be maintained at a predetermined value. Further, the structure for supplying lubricating oil to the contact surface 24 is advantageous in that it is simple in structure and easy to implement, since it is sufficient to provide oil jet holes 25a and 25b in the rocker shaft support portion of the rocker shaft 4 and the rocker arm. be.

In the above embodiment, the plunger 14 is provided on the cam side arm 11, but the plunger 14 may be provided on the valve side arm 12 so that the plunger 14 comes into contact with the cam side arm 11.

Further, in the above embodiment, the second oil jet hole 25b
is formed in the rocker shaft support portion of the cam side arm 11, but it is formed in the rocker shaft support portion of the valve side arm 12, or in the rocker shaft support portions of both arms 11 and 12, so as to be able to communicate with the first oil jet hole 25a of the rocker shaft 4. However, the oil in the rocker shaft 4 may be supplied to the contact surface between the plunger 14 and the cam-side or valve-side arms 11 and 12.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a plan view of the cylinder head, FIG. 2 is an enlarged view of the main part of FIG. 1, FIG. 3 is a sectional view taken along the line - FIG. 2 is a sectional view taken along the - line in FIG. 2; 1...Cam shaft, 4...Rotskar shaft, 5...
...Intake valve, 6...Exhaust valve, 7, 8...Rotsuker arm, 9,10...Rotsuker arm, 1
1...Cam side arm, 12...Valve side arm,
14...Plunger, 15...Spring, 16
... Lock-off plate, 22 ... Engagement part, 23
...Switching hole, 24...Abutment surface, 25a...First oil ejection hole, 25b...Second oil ejection hole.

Claims (1)

[Claim for Utility Model Registration] The Rocker arm that presses and opens the intake and exhaust valves of the engine is divided into a cam-side arm that receives force from the camshaft and a valve-side arm that drives the intake and exhaust valves. , and both arms are supported so as to be movable relative to each other around the rocker shaft, and supported by one of the cam-side arm and the valve-side arm so as to be movable in a direction orthogonal to the rocker shaft, and abut against the other arm. A plunger is provided with a plunger biased by a spring, and a first arm is supported by the one arm so as to be movable in the axial direction of the rocker shaft, and prevents movement of the plunger to limit relative movement of the two arms.
A lever member is provided that moves between the two positions and a second position that allows relative movement of both arms by allowing movement of the plunger. A valve operating device for an engine, characterized in that an oil ejection hole is formed for ejecting oil onto a contact surface between the plunger and the arm.