JPH0634103U - Valve drive for internal combustion engine - Google Patents

Abstract

(57) [Abstract] [Purpose] A valve drive piston that is interlocked and connected to an engine valve that is spring-biased in the valve closing direction and that has a rear surface facing the hydraulic chamber, and hydraulic pressure generation means that is connected to the hydraulic chamber. In the valve operating system of the internal combustion engine, which includes a hydraulic pressure generating means and a hydraulic pressure release valve connected to an oil passage connecting the hydraulic pressure chambers, stable seat cushioning is realized regardless of temperature conditions. [Structure] In a fixed housing (15), a first plunger (56) capable of axial movement within a restricted range, and a movement direction of the first plunger (56) intersecting with the movement direction of the first plunger (56) are possible. Second inwardly urged
The plunger 57 is slidably fitted, and the inner ends of the plungers 56, 57 are brought into sliding contact with each other via cam surfaces 56a, 57a forming an angle with respect to the moving direction of the plungers 56, 57. A restricting member 19 that is brought into contact with the outer end of the first plunger 56 immediately before the engine valve is seated is interlocked and connected to the engine valve.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention includes a valve drive piston that is interlocked with and connected to an engine valve that is spring-biased in the valve closing direction, and that is slidably fitted to a cylinder body with its rear surface facing the hydraulic chamber and an opening of the engine valve. A dynamics of an internal combustion engine including a hydraulic pressure generating unit that generates hydraulic pressure corresponding to a valve timing and is connected to the hydraulic chamber, and a hydraulic release valve connected to an oil passage connecting the hydraulic pressure generating unit and the hydraulic chamber. Regarding the valve device.

[0002]

[Prior art]

 Conventionally, such a device is already known, for example, from Japanese Patent Laid-Open No. 3-9009.

[0003]

[Problems to be solved by the device]

 In the above-mentioned conventional type, a hydraulic pressure is generated in the hydraulic pressure generation chamber in response to the opening timing of the engine, and the hydraulic pressure generation chamber is located in the hydraulic chamber facing the back of the valve drive piston that is linked and connected to the intake valve as the engine valve. The intake valve is opened and closed by guiding the oil pressure of the engine, and the oil pressure release valve is opened during the operation of opening the engine valve to release the oil pressure in the oil pressure chamber to accelerate the closing timing of the engine valve and The valve lift is reduced. By the way, if the engine valve is closed early, the engine valve will bounce unless the closing speed is slowed down when the engine valve is seated. Therefore, in the above-mentioned conventional one, the discharge of the hydraulic oil from the hydraulic chamber is throttled to cushion the seating of the engine valve. However, the viscosity of the hydraulic oil changes depending on the temperature, and when the hydraulic oil viscosity increases at low temperatures, if the hydraulic oil discharge is throttled as described above, there will be a delay in closing the engine valve. There is a risk.

The present invention has been made in view of such circumstances, and an internal combustion engine capable of preventing a delay in closing and cushioning the seating of an engine valve regardless of a change in viscosity of hydraulic oil. It is an object to provide a valve operating system for an engine.

[0005]

[Means for Solving the Problems]

 In order to achieve the above object, according to the invention as set forth in claim 1, a fixed housing is provided with a first plunger capable of axial movement within a restricted range, and a movement direction of the first plunger. The second plunger, which is capable of moving in the intersecting direction and is elastically biased inward in the moving direction, is slidably fitted, and the inner ends of these plungers are in the moving direction of both plungers. A control member that is slidably contacted with each other via a cam surface that makes an angle with the engine valve and that is in contact with the outer end of the first plunger immediately before seating of the engine valve is interlocked and coupled.

According to the second aspect of the invention, in addition to the configuration of the first aspect of the invention, an air pressure chamber that faces the outer end of the second plunger is formed in the housing.

According to a third aspect of the invention, in addition to the configuration of the second aspect of the invention, a spring member for biasing the second plunger axially inward is housed in the pneumatic chamber. To be done.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings.

1 to 6 show an embodiment of the present invention. FIG. 1 is a vertical sectional side view of a valve operating device, FIG. 2 is an enlarged view taken along line 2-2 of FIG. 1, and FIG. 2 is a sectional view taken along line 3-3 of FIG. 2, FIG. 4 is an enlarged sectional view of an essential part of FIG. 1, FIG. 5 is an enlarged sectional view of a seat cushioning mechanism, and FIG. 6 is a sectional view corresponding to FIG. 5 during seat cushioning.

First, in FIG. 1 to FIG. 3, an intake valve port 6 is provided in a cylinder head 5 of this internal combustion engine so as to face a ceiling surface of a combustion chamber 8, and the cylinder head 5 of the cylinder head 5 is communicated with the intake valve port 6. An intake port 9 that opens to one side is provided. An intake valve 11 as an engine valve capable of opening and closing the intake valve port 6 is supported by the cylinder head 5 so as to be able to open and close, and the intake valve 11 is a valve spring 1 compressed between the intake valve 11 and the cylinder head 5. 3 are urged upward, that is, toward the valve closing direction.

A support block 15 is coupled to the upper part of the cylinder head 5, and a camshaft that is interlocked and coupled between the support block 15 and the cylinder head 5 with a crankshaft (not shown) at a reduction ratio of 1/2. 16 is rotatably supported. An intake side rocker shaft 17 having an axis parallel to the cam shaft 16 is fixedly supported by the cylinder head 5. A base of a rocker arm 19 as a restricting member is swingably supported on the intake side rocker shaft 17, and a tappet screw 20 screwed to the tip of the rocker arm 19 so that the forward / backward position can be adjusted is sucked. It abuts on the upper end of the valve 11. Thus, the intake valve 11 is opened and closed according to the rocking motion of the rocker arm 19.

An exhaust side rocker shaft 18, which is a constituent element of a valve train for driving an exhaust valve (not shown), is fixed to the support block 15 in parallel with the intake side rocker shaft 17.

The valve operating device for driving the intake valve 11 to open and close operates the operating force acting means 25 that is interlocked with and connected to the intake valve 11 via the rocker arm 19 and the hydraulic pressure according to the opening timing of the intake valve 11. A hydraulic pressure generating means 26 for generating and supplying to the operating force acting means 25, a seat cushioning mechanism 27 for buffering the seating speed of the suction valve 11, a hydraulic pressure connected to the operating force acting means 25 and the hydraulic pressure generating means 26. And a circuit 28.

In FIG. 4, the actuating force acting means 25 includes a hydraulic pressure between the first cylinder body 30 fixed to the support block 15 at a portion corresponding to the tip of the rocker arm 19 and the first cylinder body 30. A valve drive piston 32, which defines a chamber 31 and is slidably fitted to the first cylinder body 30 and is interlocked and connected to the upper portion of the rocker arm 19 near the tip, is provided with a valve drive piston 32. That is, at the lower end, an adjusting screw 39 that abuts a protruding portion 19a that is provided on the upper portion near the tip of the rocker arm 19 is screwed so as to adjust the forward / backward position. The first cylinder body 30 is provided with a communication hole 34 for communicating the oil passage 33 provided in the support block 15 with the hydraulic chamber 31.

According to the configuration of the operating force acting means 25, when the hydraulic pressure is generated by the hydraulic pressure generating means 27, the hydraulic pressure is guided from the oil passage 33 to the hydraulic chamber 31, and the hydraulic pressure in the hydraulic chamber 31 causes the valve to move. When the drive piston 32 is pushed down and the rocker arm 19 is pushed down, the intake valve 11 is opened against the spring force of the valve spring 13.

When the hydraulic pressure generated by the hydraulic pressure generating means 27 decreases after the intake valve 11 is fully opened, the intake valve 11 is driven upward by the spring force of the valve spring 13, that is, in the valve closing direction. The valve drive piston 32 is also pushed upward by the closing operation of the intake valve 11, and the oil in the hydraulic chamber 31 is discharged to the oil passage 33.

With particular attention to FIG. 3, the hydraulic pressure generating means 26 defines a hydraulic pressure generating chamber 38 between the second cylinder body 37 fixed to the support block 15 and the second cylinder body 37. The cam driven piston 39 slidably fitted to the second cylinder body 37, the hydraulic pressure generating cam 40 provided on the cam shaft 16, and the operation of the hydraulic pressure generating cam 40 are transmitted to the cam driven piston 39. Therefore, a rocker arm 41 swingably supported on the intake-side rocker shaft 17 is provided, and a roller 42, which is in sliding contact with the hydraulic pressure generating cam 40, is axially supported on the rocker arm 41 and the cam driven piston 3 is provided. A pressing portion 41 a that abuts on 9 is provided.

The second cylinder body 37 and the support block 15 are provided with an oil passage 43 which is in constant communication with the oil pressure generating chamber 38. The oil passage 43 is connected to the oil pressure chamber 31 of the actuating force acting means 25. It communicates with the existing oil passage 33.

The hydraulic circuit 28 controls the release time of the hydraulic pressure from the hydraulic pressure chamber 31 and the hydraulic pressure generation chamber 38, that is, the lift amount and the closing timing of the intake valve 11, and the hydraulic pressure release valve 44 and The accumulator 45, the one-way valve 46, and the replenishment check valve 47 are provided on the support block 15.

The hydraulic pressure release valve 44 is a solenoid valve provided between an oil passage 33 communicating with the hydraulic chamber 31 and an oil passage 48 formed in the support block 15 while communicating with the accumulator 45. The one-way valve 46 is arranged in the support block 15 between the oil passages 33 and 48, bypassing the oil pressure release valve 44, and the oil pressure of the oil passage 48 is set to be higher than that of the oil passage 33. When the pressure exceeds the pressure, the valve is opened to allow only oil to flow from the accumulator 45 to the oil passage 33, that is, to the hydraulic chamber 31.

The replenishment check valve 47 is arranged in the support block 15 so as to allow only the flow of the hydraulic oil from the hydraulic oil replenishing means 49 to the oil passage 48, and the hydraulic oil replenishment is performed. The means 49 is an oil pump 51 for pumping hydraulic oil from the oil pan 50, a filter 52 connected to the discharge port of the oil pump 51, and a relief provided between the discharge port of the oil pump 51 and the oil pan 50. Valve 53.

In FIG. 5, the seat cushioning mechanism 27 has a support block 15 that functions as a housing, a first plunger 56 that is movable within a restricted range, and a moving direction of the first plunger 56. Are movable in the directions orthogonal to each other and slidably fitted to a second plunger 57 that is elastically urged inward in the axial direction, and the inner ends of the plungers 56 and 57 are cammed. The surfaces 56a and 57a are in sliding contact with each other.

At the lower portion of the support block 15 at a position substantially corresponding to the rocker arm 19, there is a bottomed first cylinder hole 58 whose outer end faces the upper portion of the rocker arm 19 and is orthogonal to the first cylinder hole 58. A bottomed second cylinder hole 59 is formed, and a plug member 60 is screwed to the opening end of the second cylinder hole 59.

A first plunger 56 is slidably fitted in the first cylinder hole 58 with its outer end projecting from the first cylinder hole 58. The second plunger 57 is slidably fitted in the second cylinder hole 59. Thus, the inner surface of the first plunger 56 is provided with a cam surface 56a that makes an angle of 45 degrees with the axis of the first plunger 56, and the inner surface of the second plunger 57 is provided with the cam surface 56a of the second plunger 57. A cam surface 57a forming an angle of 45 degrees with the axis is provided, and both cam surfaces 56a and 57a are in sliding contact with each other.

An air pressure chamber 63 is formed between the outer end of the second plunger 57 and the plug member 60, and a spring member 64 for urging the second plunger 57 inward in the axial direction is contracted. It Moreover, inside the plug member 60, a check valve 65 for introducing air from the outside into the air pressure chamber 63 according to the increase in the volume of the air pressure chamber 63 is provided.

A regulation groove 61, which extends in the axial direction and is closed at both ends, is provided on the side surface of the first plunger 56, and a pin 62 fitted into the regulation groove 61 is fixed to the support block 15. Therefore, the first plunger 56 is slidably fitted into the first cylinder hole 58 while enabling the movement within the range in which the pin 62 abuts on both ends of the restriction groove 61. Thus, the maximum amount of protrusion of the first plunger 56 from the support block 15 is that the rocker arm 19 interlocking with the intake valve 11 contacts the outer end of the first plunger 56 immediately before seating when the intake valve 11 is closed. Is set as follows.

Next, the operation of this embodiment will be described. By the rotational operation of the hydraulic pressure generating cam 40 according to the operation of the engine, the hydraulic pressure generating means 26 generates the hydraulic pressure corresponding to the opening timing of the intake valve 11. Then, this hydraulic pressure acts on the hydraulic chamber 31 via the oil passages 43 and 33, so that the actuating force acting means 25 generates an oil pressure that pushes down the valve drive piston 32, and the oil pressure causes the rocker arm 19 to move. The intake valve 11 is driven to open in response to the swing drive.

When the hydraulic pressure release valve 44 is opened to release the hydraulic pressure in the oil passage 33 during the opening operation of the intake valve 11, the hydraulic force for continuing to push the valve drive piston 32 against the spring force of the valve spring 13. Cannot be ensured in the hydraulic chamber 31, the intake valve 11 is actuated upward by the spring force of the valve spring 13, that is, in the closing direction, and the intake valve 11 is closed by the hydraulic pressure generating cam 40. Will be closed sooner, and the lift amount of the intake valve 11 will be reduced accordingly.

During the early closing control of the intake valve 11, a bounce will occur unless the seating of the intake valve 11 is buffered. However, the rocker arm 19 contacts the outer end of the first plunger 56 of the seat cushioning mechanism 27 immediately before the seat is closed when the intake valve 11 is closed. Therefore, the intake valve 11 closes while the first plunger 56 is pushed up via the rocker arm 19 in the subsequent valve closing operation immediately before the intake valve 11 is seated.

The first plunger 56 is in contact with the inner end of the second plunger 57 via the cam surfaces 56a and 57a, and the second plunger 57 is biased inward in the axial direction by the spring member 64. Therefore, the rocker arm 19 or the intake valve 11 must push up the first plunger 56 by overcoming the frictional force on the cam surfaces 56a and 57a and the spring force of the spring member 64. Further, after the first plunger 56 has moved upward, the pneumatic chamber 53 contracts, and the first and second plungers 56, 57 are pressed in the direction in which the cam surfaces 56a, 57a are pressed against each other. A minute gap 58a (see FIG. 6) formed between the inner surface of the hole 58 and the outer surface of the first plunger 56 and a minute gap 59a (formed between the inner surface of the second cylinder hole 59 and the outer surface of the second plunger 57 ( Part of the air is extruded from the air pressure chamber 58 by using (see FIG. 6) as an orifice. Therefore, in addition to the spring force of the spring member 64, the air spring associated with the contraction of the air pressure chamber 53 also acts on the second plunger 57.

Therefore, the intake valve 11 consumes a part of its seating energy in order to overcome the spring force acting on the first plunger 56 and the frictional force on the cam surfaces 56a and 57a. The shock is alleviated and the intake valve 11 does not bounce.

Moreover, in the seat cushioning mechanism 27, the frictional force and the spring force act as cushioning force and do not depend on the temperature, so that stable seat cushioning can be always realized regardless of the temperature condition.

When the intake valve 11 is actuated again in the opening direction after being seated, air is introduced into the air pressure chamber 53 from the outside through the check valve 65, and the seat cushioning mechanism 27 causes the seat cushioning mechanism 27 to seat the next seat valve 11. Return to the initial state in preparation for.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above embodiments, and various modifications can be made without departing from the present invention described in the scope of claims for utility model registration. It is possible to make design changes.

For example, the invention can be implemented in connection with an exhaust valve.

[0036]

[Effect of device]

 As described above, according to the first aspect of the invention, in the fixed housing, the first plunger capable of moving in the axial direction within the restricted range and the moving direction of the first plunger are arranged in a direction intersecting with each other. A second plunger that is movable and elastically biased inward in the moving direction is slidably fitted, and the inner ends of these plungers form an angle with respect to the moving directions of both plungers. When the engine valve is seated, the engine valve is slidably contacted with each other, and a regulating member that is in contact with the outer end of the first plunger immediately before the engine valve is seated is interlocked with the engine valve. A portion of the seating energy can be expended to overcome the friction and spring forces on the cam surface to provide seat cushioning, and since these friction and spring forces do not depend on temperature, they close at low temperatures. Degauss the delay Seating buffer which stably at all times regardless of the temperature conditions without the can and Hatasuko.

According to the second aspect of the invention, in addition to the configuration of the first aspect of the invention, an air pressure chamber that faces the outer end of the second plunger is formed in the housing. An air spring associated with the contraction of the chamber can be used as the spring force.

According to a third aspect of the invention, in addition to the configuration of the second aspect of the invention, a spring member for biasing the second plunger axially inward is housed in the pneumatic chamber. Therefore, the spring force of the spring member and the spring force of the air spring can be used together.

[Brief description of drawings]

FIG. 1 is a vertical side view of a valve train.

FIG. 2 is an enlarged view taken along line 2-2 of FIG.

FIG. 3 is a sectional view taken along line 3-3 of FIG.

FIG. 4 is an enlarged cross-sectional view of a main part of FIG.

FIG. 5 is an enlarged cross-sectional view of a seat cushioning mechanism.

FIG. 6 is a cross-sectional view corresponding to FIG. 5 when seating cushioning is performed.

[Explanation of symbols]

 11 intake valve as an engine valve 15 support block as a housing 19 rocker arm as a restricting member 26 hydraulic pressure generating means 30 cylinder body 31 hydraulic chamber 32 valve drive piston 33 oil passage 44 hydraulic release valve 56 first plunger 56a, 57a cam surface 57 2nd plunger 63 Air pressure chamber 64 Spring member

Claims (3)

[Scope of utility model registration request] 1. An engine valve (1) which is spring-biased in a valve closing direction.
It is interlocked with and connected to 1) and the rear side is a hydraulic chamber (31).
And a valve drive piston (32) slidably fitted to the cylinder body (30) facing the valve, and generating hydraulic pressure corresponding to the opening timing of the engine valve (11) and the hydraulic chamber (31).
And a hydraulic passage (3) connecting the hydraulic pressure generating means (26) and the hydraulic pressure chamber (31).
In a valve operating system for an internal combustion engine, which comprises a hydraulic release valve (44) connected to 3),
The first plunger (56) capable of axial movement within a restricted range and the movement direction of the first plunger (56) intersect the movement direction, and the inward movement direction The second plunger (57) which is biased is slidably fitted to the plungers (56, 57).
The inner ends of the two are slidably in contact with each other via cam surfaces (56a, 57a) forming an angle with respect to the moving directions of the plungers (56, 57). ) A valve operating device for an internal combustion engine, characterized in that a regulating member (19) abutting on the outer end of the first plunger (56) is interlocked and coupled immediately before the seat is seated. 2. The valve operating system for an internal combustion engine according to claim 1, wherein an air pressure chamber (63) facing the outer end of the second plunger (57) is formed in the housing (15). . 3. A spring member (6) for urging the second plunger (57) axially inward in the air pressure chamber (63).
4. The valve operating system for an internal combustion engine according to claim 2, wherein 4) is housed.