JPS633126B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an engine valve timing control device, and more particularly to a variable mechanism for variably controlling valve timing in accordance with engine operating conditions in a valve train that controls the opening and closing of intake and exhaust valves. It is.

In general, it is preferable from the viewpoint of engine operating characteristics that the valve timing of intake and exhaust valves in an engine be variably controlled depending on the operating state of the engine. For example, when the engine is under low load, shortening the overlap period of the intake and exhaust valves can suppress the residual exhaust gas amount and ensure combustion stability. Furthermore, when the engine is under high load and at low rotation speeds, by shortening the overlap period of the intake and exhaust valves, blowback of intake air can be prevented and charging efficiency can be improved. On the other hand, when the engine is under high load and is rotating at high speeds, extending the opening period of the intake valve can improve the filling efficiency and improve the engine output.

For this reason, various variable mechanisms for variably controlling valve timing in the valve train of an engine have been proposed. For example, Special Public Interest Publication No. 52-35819
As disclosed in the above publication, a planetary gear having a centrifugal cover is interposed between the output shaft of the engine and the camshaft to change the relative position between the output shaft of the engine and the camshaft, or a camshaft. There is a three-dimensional camshaft in which the three-dimensional camshaft is slidable.

However, all of the above-mentioned conventional devices have complicated and large-scale structures, have poor variable control response and reliability, and tend to generate large noises, and thus lack practicality.

The present invention has been made in view of the above, and effectively utilizes the existing valve mechanism to adjust the contact position between the cam surface and the pressure-receiving portion of the tappet that contacts the valve stem for a specific angular position of the camshaft. The main purpose is to provide a highly practical variable mechanism that has a simple structure, can be controlled with good responsiveness and reliability, and generates little noise. It is something to do.

Furthermore, another object of the present invention is to further simplify the above structure by integrally and simultaneously variable controlling the valve timings of adjacent cylinders.

In order to achieve these objects, the configuration of the present invention is such that the valves of the adjacent cylinders are interposed in the power transmission path between the valves of the adjacent cylinders and the cam surfaces of the corresponding camshafts, and the pressure receivers receive the force from the cam surfaces. and a plurality of tappets each having a pressing portion that transmits the force received from the cam surface and the cam surface to the valve stem side, and a plurality of insertion holes into which each of the tappets is slidably inserted; A rotatable rotating member and an operation for rotating the rotating member so that the contact position between each cam surface and the pressure receiving portion of each tappet changes with respect to a specific angular position of the camshaft according to the operating state of the engine. The rotating member is rotated by an operating device to adjust the contact position between each cam surface and one end of each tappet member with respect to a specific angular position of the camshaft in an adjacent cylinder according to the operating state of the engine. The valve timing of adjacent cylinders is controlled by a single mechanism.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

Figures 1 and 2 show an embodiment in which the present invention is applied to a dual induction four-cylinder engine, which has a pair of intake ports and a pair of exhaust ports for low load and high load for one cylinder. Give an example. In the figure, 1 is the engine body, 2a to
2d is the first to fourth cylinders formed in series along the center line l of the engine body 1, and each cylinder 2
A to 2d are each provided with a pair of intake ports 3a, 3b for low load and high load, and a pair of first and second exhaust ports 4a, 4b.
The low-load and high-load intake ports 3a and 3b in each cylinder 2a to 2d are connected from one side (intake side) of the engine body 1 to approximately parallel to the engine body center line l direction (cylinder row direction) of the cylinders 2a to 2d. The low-load intake ports 3a are opened in parallel in the direction, and the passage area of the low-load intake ports 3a is narrowed to a relatively small size in order to increase the intake flow velocity.
On the other hand, the high-load intake port 3b is formed to have a relatively large passage area in order to improve the filling efficiency of intake air. Further, the first and second exhaust ports 4a and 4b in each cylinder 2a to 2d are connected to the other side (exhaust side) of the engine body 1 from the same side to the cylinders 2a to 2d.
They are opened in parallel and parallel to the direction of the centerline l of the engine body in d, and the intake ports 3a, 3b and the exhaust ports 4a, 4b are arranged to face each other across the centerline l of the engine body. ing. Furthermore, the high-load intake ports 3b, 3b and the second exhaust ports 4b, 4b of the same nature in the adjacent first cylinder 2a and second cylinder 2b, and the adjacent third cylinder 2c and fourth cylinder 2d. The high-load intake ports 3b, 3b and the second exhaust ports 4b, 4b, which have the same properties, are arranged adjacent to each other in a back-to-back manner.

Further, the low-load and high-load intake ports 3a and 3b in each of the cylinders 2a to 2d are provided with a pair of low-load and high-load intake valves that open and close the intake ports 3a and 3b at predetermined timings, respectively. 5a and 5b are arranged side by side on the intake side of the engine main body 1, and each of the cylinders 2a to 2
First and second exhaust ports 4a, 4b at d
A pair of first and second exhaust valves 6a and 6b that open and close the respective exhaust ports 4a and 4b at predetermined timings are arranged side by side on the exhaust side of the engine body 1. Therefore, on the intake side of the engine body 1, the first cylinder 2a and the second cylinder 2 are adjacent to each other.
The high load intake valves 5b, 5b of the engine body 1 are adjacent to each other, and the high load intake valves 5b, 5b of the adjacent third cylinder 2c and fourth cylinder 2d are adjacent to each other, and on the exhaust side of the engine body 1, 1st cylinder 2
The second exhaust valves 6b, 6b of the cylinder a and the second cylinder 2b are adjacent to each other, and the second exhaust valves 6b, 6b of the third cylinder 2c and the fourth cylinder 2d are adjacent to each other.

In addition, an on-off valve 7 that opens when the engine is under high load is disposed in the high-load intake passage 7a of the intake manifold connected to the high-load intake port 3b of each cylinder 2a to 2d. ~
2d, when the engine is under low load, intake air is supplied only from the low-load intake port 3a, while when the engine is under high load, intake air is supplied from both the low-load and high-load intake ports 3a and 3b.

On the other hand, 8a is a first valve operating mechanism disposed on the intake side of the engine body 1, which controls the opening and closing of the low-load and high-load intake valves 5a and 5b in each cylinder 2a to 2d. The valve mechanism 8a includes a first camshaft 9 which is disposed on the intake side of the engine body 1 in parallel with the engine body center line l and is rotationally driven by the engine crankshaft (not shown) via a timing belt 110. and the first
The camshaft 9 has cam surfaces 9a and 9b formed in the same shape corresponding to the low-load and high-load intake valves 5a and 5b of the respective cylinders 2a to 2d.
The rotation of the camshaft 9 causes the low-load and high-load intake valves 5a, 5b in each cylinder 2a to 2d.
The valves are configured to open and close at the same time with the same valve opening period. Also, 8b is the engine body 1
A second valve mechanism 8b is disposed on the exhaust side of the cylinders 2a to 2d and controls opening and closing of the first and second exhaust valves 6a and 6b in each cylinder 2a to 2d.
Engine body center line l on the exhaust side of engine body 1
The timing belt 110 is also arranged parallel to the timing belt 110.
The second camshaft 10 has a second camshaft 10 that is rotationally driven by the cylinders 2a to 2.
Cam surfaces 10a and 10b corresponding to the first and second exhaust valves 6a and 6b of d are formed in the same shape, and the rotation of the second camshaft 10 causes each cylinder 2a to
2d, the first and second exhaust valves 6a and 6b are controlled to open and close simultaneously with the same valve opening period.

The first valve operating mechanism 8a includes both adjacent high-load intake valves 5b, 5b of the first cylinder 2a and second cylinder 2b, and the third cylinder 2c and fourth cylinder 2d.
Two first variable mechanisms 11, 11 according to the present invention are provided which respectively variably control the valve timing of both high-load intake valves 5b, 5b adjacent to the second valve operating mechanism 8b. are both adjacent second exhaust valves 6 of the first cylinder 2a and the second cylinder 2b.
Two second variable mechanisms 12, 12 according to the present invention are provided to variably control the valve timings of the second exhaust valves 6b, 6b and the adjacent second exhaust valves 6b, 6b of the third cylinder 2c and fourth cylinder 2d, respectively. There is.

The first and second variable mechanisms 11 and 12 have the same structure as shown in enlarged detail in FIG. 3, respectively. That is, the first variable mechanism 11 has a pressure receiving portion (pressure receiving surface) 13a that comes into contact with each corresponding cam surface 9b of the first camshaft 9 at one end (upper end).
and adjacent cylinders (2a and 2b, 2c and 2
d) Two tappet members 13, 13 each consisting of a pressing part (pressing surface) 13b and a cylindrical guide part 13c that come into contact with the valve stem of each high-load intake valve 5b, 5b, and each of the tappet members 13 , 13 have two fitting holes 14a, 14a in which the fitting holes 14a, 13 are slidably inserted and held in the vertical direction, and an arc-shaped bottom surface is slidably guided by the arc-shaped guide surface 1a formed on the engine body 1. a bucket-shaped rotating member having a sliding surface 14b, rotatably supported on the first camshaft 9, and capable of rotating around the first camshaft 9 with guidance assistance of the guide surface 1a; 14, and the rotating member 14 is moved to each cam surface 9b, 9b and each tappet member 1 to a specific angular position of the first camshaft 9 according to the operating state of the engine.
and an operating device 15 that rotates the first camshaft 9 about the rotation axis so that the contact position with the pressure receiving part 13a and the pressing part 13b of the first camshaft 9 changes. The portion supported by the camshaft 9 is divided into upper and lower portions, and is joined together with bolts 16, 16. Further, the operating device 15 is configured to control the engine body center line l.
The two first variable mechanisms 11, 1 are arranged parallel to each other.
A swing shaft 1 that connects the upper ends of both rotating members 14, 14 and rotates the rotating members 14, 14.
7, and a reciprocating shaft 18 that is disposed in the center of the engine body 1 in the direction of the center line l and perpendicular to the center line l, and engages with the swing shaft 17 to swing the swing shaft 17. , a drive motor 19 that converts rotational motion into reciprocating motion and reciprocates the reciprocating shaft 18. Each output of a load sensor 21 that detects the engine is inputted, and when the engine is under high load and at high rotation speeds during a specific engine operation, the reciprocating shaft 18 is moved to the right in FIG. 2 by the operation of the drive motor 19. By rotating the swing shaft 17 in the same direction as the rotation direction X of the first camshaft 9 (clockwise in FIG. 2), the rotation members 14, 14 are rotated in the rotation direction X around the first camshaft 9. It rotates in the same direction. As described above, when the engine is under high load and rotates at high speed, the operating device 15 causes the rotating members 14, 14 to rotate in the same direction as the rotation direction X of the first camshaft 9. The contact position between the surfaces 9b, 9b and the pressure receiving portions 13a, 13a of each tappet member 13, 13 changes to the delayed side with respect to the rotational direction The valve timing is configured to be controlled to shift the valve timing to the delay side.

Further, the second variable mechanism 12 is made of the same constituent members as the first variable mechanism 11 (the constituent members of the first variable mechanism 11 are represented by adding a '' (dart) to the reference numerals), One end contacts the corresponding cam surfaces 10b, 10b of the second camshaft 10, and the other end contacts the adjacent cylinders (2a and 2b, 2c and 2d).
The two tappet members 13', 13' that come into contact with the valve stems of the respective second exhaust valves 6b, 6b, and the respective tappet members 13', 13' inserted into the holes 14'a, 1
A rotating member 14' that is slidably inserted into and held by 4'a and rotates around the second camshaft 10, and an operating device 15' that rotates the rotating member 14' in accordance with the operating state of the engine. It will be equipped with. The operating device 15' includes a swing shaft 17' that connects both rotating members 14', 14' of the two second variable mechanisms 12, 12 at their upper ends, and a swing shaft 17' that swings the swing shaft 17'. 1st
It is equipped with a reciprocating shaft 18 that is shared with the variable mechanism 11, and a drive motor 19 that is also shared with the first variable mechanism 11 that reciprocates the reciprocating shaft 18. The operation of the motor 19 causes the swing shaft 16' to move to the second position via the reciprocating shaft 18.
By rotating the camshaft 10 in the same direction as the rotational direction
The pressure receiving portion (pressure receiving surface) 1 of each cam surface 10b, 10b and each tappet member 13', 13' is rotated in the same direction as the rotation direction
3'a, 13'a to the lag side with respect to the rotational direction X of the second camshaft 10, and controls the valve timing of each second exhaust valve 6b, 6b to the lag side. be.

Here, the contact positions between the cam surfaces 9b, 10b of the camshafts 9, 10 and the pressure receiving parts 13a, 13'a of the tappet members 13, 13' are determined by the rotation of the camshafts 9, 10 during normal operation without variable control. It is set on the advance side of the contact point P on the shortest straight line connecting the centers of the camshafts 9 and 10 and the valve stem in direction It is preferable to set the contact point to be located near P due to side displacement. That is, in this case, the cam surfaces 9b, 10
The so-called PV value, which is the product of the surface pressure caused by the contact between B and the tappet members 13 and 13' and the sliding speed, can be kept low even at high engine speeds, and the advantage is that the effective variable control range of valve timing can be expanded. have

In addition, in the above embodiment, the tappet member 1 includes the pressure receiving portions 13a, 13'a, the pressing portions 13b, 13'b, and the guide portions 13c, 13'c.
3 or 13', a hydraulic tappet device A may also be used as shown in FIG. That is, the hydraulic tappet device A is connected to the camshaft 9 (or 1
0) and a first circular closing portion (pressure receiving portion) 23a that is in sliding contact with the cam surfaces 9b, 10b and extending at right angles from the outer periphery of the closing portion and communicating with the oil passage 22 provided in the rotating members 14, 14'. It has a communicating hole 23b and fitting holes 14a, 1 for the rotating members 14, 14'.
A cylindrical tappet member 23 having a side part (guide part) 23c that slides inside the tappet member 4'a, a side wall 24a fitted into the inner periphery of the tappet member 23, and valve stems of the intake and exhaust valves 5b and 6b. The tappet member 23 is provided with a bottom wall (pressing portion) 24b that comes into contact with the
A cylindrical first member 2 arranged in a direction opposite to the direction of
4, and is arranged between the tappet member 23 and the first member 24 so that the outer periphery is in sliding contact with the inner periphery of the first member 24, and the tip is pressed against the closed portion 23a of the tappet member 23 by a spring 25. ,
One end side (upper side) is the closed part 2 of the tapepet member 23.
3a and the notch groove 23 formed in the closing portion 23a.
An oil reservoir chamber 26 is formed which communicates with the first communication hole 23b through the hole b, while the other end (lower side) forms a hydraulic pressure chamber 27 with the bottom wall 24b of the first member 24, and the center The oil reservoir chamber 26 and the hydraulic pressure chamber 27
A second member 28 having a substantially H-shaped cross section and having a second communication hole 28a that communicates with the camshaft 9,
When the pressure suddenly increases due to the pressing force of the cam surfaces 9b and 10b, the valve is closed and the second communication hole 2 is closed.
The check valve 29 is configured to close the second communication hole 28a and to open the second communication hole 28a at other times, depending on the reaction force difference between the oil reservoir chamber 26 and the hydraulic pressure chamber 27. By opening and closing the second communication hole 28a to change the amount of oil in the hydraulic pressure chamber 27, the closed portion 23a of the tappet member 23 is always kept in sliding contact with the cam surfaces 9b and 10b, thereby increasing the engine speed. The cam force is transmitted to the valve stem without creating valve clearance even during rotation. Incidentally, when the hydraulic tappet device A is not used as the tappet as shown in FIG. 4, the valve clearance may be adjusted by interposing a shim between the tappet and the cam surface.

In FIG. 1, reference numeral 30 denotes a bearing portion that rotatably supports the first and second camshafts 9, 10, and the bearing portion 30 is a bearing portion that rotatably supports the first and second camshafts 9, 10.
Each rotating member 14, 14, 14', 1 of 1, 12
4' and to suppress the deflection of the first and second camshafts 9, 10 as much as possible at both ends and in the center of the engine body 1 in the direction of the center line l. Further, in FIG. 2, 31 is a valve spring that urges each intake and exhaust valve 5a, 5b, 6a, 6b in the valve closing direction, and 32 is a valve guide.

Next, to describe the operation of the above embodiment, when the engine is under low load, the first and second variable mechanisms 11 and 12 are in a non-operating state, and each cylinder 2a to 2
Intake valves 5a and 5b for low load and high load in d
The opening and closing of the first and second exhaust valves 6a and 6b are controlled at predetermined valve timings by first and second valve operating mechanisms 8a and 8b, respectively. That is, as shown by the solid line in FIG. 5, the valve timings of the first and second exhaust valves 6a and 6b are such that they open near the bottom dead center of the piston and then close near the top dead center to perform the exhaust stroke. In addition, the valve timing of both the low-load and high-load intake valves 5a and 5b is such that the overlap period with the exhaust valves 6a and 6b is reduced, and the valve timings are opened near the top dead center of the piston and then closed near the bottom dead center. It is controlled to perform an intake stroke. Further, the low-load intake ports 3b in each of the cylinders 2a to 2d are closed by the closing operation of the on-off valve 7, and intake air is supplied only from the low-load intake ports 3a.

Therefore, in the intake stroke of each cylinder 2a to 2d, the intake air takes advantage of the characteristics of the low-load intake port 3a, and even at a high intake flow rate.
This is done by generating a swirl within the combustion engine, increasing the combustion speed and improving combustion performance when the engine is under low load. Furthermore, since the overlapping period between the low-load intake valve 5a and the exhaust valves 6a and 6b is short, the amount of residual exhaust gas can be kept low and the above-mentioned good combustibility can be ensured.

On the other hand, when the engine is running at low speed and under high load, the on-off valve 7 of the high-load intake port 3b is opened, and air is taken in from the high-load intake port 3b in addition to the low-load intake port 3a. Since the first and second variable mechanisms 11 and 12 are both inactive, the overlapping period between the intake and exhaust valves 5a and 5b and 6a and 6b is short, preventing intake air from blowing back and improving filling efficiency. can. Moreover,
In this case, in the exhaust stroke of each cylinder 2a to 2d, the first and second pair of exhaust ports 4a, 4b are opened and closed by the pair of exhaust valves 6a, 6b, respectively, so that the effective opening area for exhaust is a single one. Compared to the case of an exhaust port, the scavenging efficiency is increased and the filling efficiency can be further improved.

Furthermore, when the engine is under high load and at high speed, the first
and the second variable mechanisms 11 and 12 operate together,
As shown by the imaginary line in FIG. 5, the valve timing of the second exhaust valve 6b of the pair of exhaust valves 6a, 6b in each cylinder 2a to 2d is delayed by the second variable mechanism 12, and the valve timing of the second exhaust valve 6b is delayed by the second variable mechanism 12, and Among the valves 5a and 5b, the valve timing of the high-load intake valve 5b is the first.
The variable mechanism 11 performs variable control to shift to the delay side. In addition, the high-load intake ports 3b in each cylinder 2a to 2d are opened by the opening operation of the on-off valve 7, and intake air is supplied from the high-load intake ports 3b in the same way as during high load and low rotation. .

Therefore, in the intake stroke of each cylinder 2a to 2d, in addition to supplying intake air from both the low-load and high-load intake ports 3a and 3b, the valve timing of the high-load intake valve 5b is delayed. The total opening period of both intake valves 5a and 5b as a whole becomes longer by the amount of the deviation, without changing the opening area.
Moreover, in combination with the shift on the lag side where the inertial effect of the intake air is large, the filling efficiency of the intake air can be significantly improved, and the output performance at high load and high rotation times of the engine that requires output can be greatly improved. Can be done. Moreover, in this case, the valve timing of the low-load intake valve 5a is fixed, and the high-load intake valve 5 at the high-load intake port 3b with excellent filling efficiency
Since the valve timing of b is made variable and shifted to the delayed side, it is effective in improving the filling efficiency.

Furthermore, in this case, in the exhaust stroke of each cylinder 2a to 2d, both exhaust valves 6a, 6b are adjusted by the amount of the delay side deviation of the valve timing of the second exhaust valve 6b.
Since the total valve opening period as a whole becomes longer, together with the increase in the effective opening area for exhaust, the scavenging efficiency can be significantly improved, and the filling efficiency of the intake air can be further improved, and the output It is possible to achieve even greater improvements in performance.

In this case, when the engine is under high load and at high speed, the amount of intake air is large and the inertia speed of the intake air is high. Even if the opening period of the valve 5b lags into the compression stroke, the amount of residual exhaust gas brought in can be minimized and blowback of intake air is less likely to occur, so combustibility is not affected.

In addition, the valve timing of the high-load intake valve 5b and the second exhaust valve 6b is gradually delayed as the engine speed shifts from low engine speed to high engine speed by the first and second variable mechanisms 11 and 12. It is effective to perform variable control so as to shift the position, since it allows smooth variable control without causing torque shock during transition.

In variably controlling the valve timing of the intake and exhaust valves 5b and 6b as described above, each of the variable mechanisms 11 and 12 is equipped with tappet members 13 and 13 in an existing valve operating mechanism (direct drive type overhead cam mechanism). , 13', 13', and the operating devices 15, 15' for rotating the rotating members 14, 14' around the camshafts 9, 10. The structure is simple and can be implemented easily and inexpensively.

Moreover, the variable mechanisms 11 and 12 have two tappet members 13 and 13 on one rotating member 14 and 14'.
13, 13', 13' are fitted into the holes and the adjacent cylinders (2a
and 2b, 2c, and 2d), the valve timings of the high-load intake valves 5b, 5b (each of the second exhaust valves 6b, 6b) are integrally and simultaneously variable controlled, thereby further simplifying the structure. Can be done.

Further, the variable control of the variable mechanisms 11 and 12 is performed by adjusting the cam surfaces 9b and 10b and the tappet members 13 and 13, respectively, for specific angular positions of the camshafts 9 and 10.
This is done by changing the contact position of the pressure receiving parts 13a, 13'a of the camshafts 9, 10 around the camshafts 9, 10, so there is less lift loss and sliding speed of the intake and exhaust valves 5b, 6b, and therefore variable control is possible. It can be performed stably with good responsiveness and reliability.

Furthermore, each of the above-mentioned tappet members 13, 13'
are the fitting holes 14a, 14'a of the rotating members 14, 14'.
Since it is fitted and held inside and slides up and down, when transmitting cam force, only a slight thrust load acts on the rotating members 14, 14', and no force or moment acts on other parts. Therefore, there is no rattling, and together with the features of the direct drive type overhead cam mechanism, we aim to further improve the reliability and stability mentioned above, have excellent durability, and minimize noise generation. can be controlled.

In addition, in the above embodiment, a pair of intake ports 3a, 3b and a pair of intake valves 5a, 5b in each cylinder 2a to 2d, and a pair of exhaust ports 4a, 4
b and a pair of exhaust valves 6a, 6b are respectively arranged on the intake side and exhaust side of the engine main body 1 and arranged parallel to the center line l direction, and the adjacent cylinders (2a
and 2b, 2c and 2d), high load intake valve 5b,
5b and the second exhaust valves 6b and 6b are arranged adjacent to each other, and the adjacent cylinders (2a and 2
b, 2c and 2d) with the same properties, and the second exhaust valves 6b, 6.
Since the variable mechanisms 11 and 12 can be used for variable control, the bearing parts 30, 30, 30 of each camshaft 9, 10 can be controlled between the central part and both ends in the direction of the center line l of the engine body 1. It is advantageous because it can be placed at any point without any problem.

It should be noted that the present invention is not limited to the above-mentioned embodiments, but also includes various other modifications. For example, in the above embodiment, an example was shown in which the application was applied to a dual induction type 4-valve engine that has intake ports for low load and high load.
The present invention can be similarly applied to a simple four-valve type engine. In this case, by variable control of the valve timing by the variable mechanism, when the engine is under high load and at low speed, the effective opening area of the pair of intake ports is increased, thereby improving the filling efficiency without causing intake air blowback.
When the engine is under high load and at high speed, the filling efficiency can be further improved by increasing the total open period of both intake valves in addition to increasing the effective opening area. Moreover, as shown in FIG. 6, one cylinder 2a to 2d
It can also be applied to a normal four-cylinder engine, for example, which has a single intake port 3 and a single exhaust port 4. In this case, the intake port between adjacent cylinders (2a and 2b, 2c and 2d) 3,3
(or exhaust ports 4, 4) are arranged adjacent to each other, and variable mechanisms 11, 12 as described above are arranged at the center S of the camshaft of the valve train, spanning between the intake valves (or between the exhaust valves). Bye. In addition, it is also applicable to various types of single-cylinder or multi-cylinder engines.

Further, in the above embodiment, the intake and exhaust valves 5b, 6b
Although the specific engine operation during which the valve timing of the engine is variably controlled is when the engine is under high load and at high rotation speed, variable control may also be performed by the variable mechanisms 11 and 12 during other operations as necessary. In short, the present invention provides suction and
This can be applied to variably control the valve timing of an exhaust valve.

Furthermore, as a variable mechanism that variably controls the valve timing of the intake and exhaust valves, the above-mentioned variable mechanism 1
Various modifications other than No. 1 and No. 12 can be adopted.
For example, the variable mechanism 33 shown in FIGS. 7 and 8
Here, the rotating member 34 has a through hole 34b through which the camshaft 35 passes through the central cylindrical portion 34a, and arcuate portions 34 on both sides of the cylindrical portion 34a.
camshaft 35 at one end of each of c and 34c.
and a fitting hole 3 into which a tapepet member 37 which contacts the valve stem 36 at the other end is slidably inserted and held.
4d and 34d, and the lower arcuate sliding contact surface 3
4e, it is rotatably supported on an arcuate guide surface 1'a centered on the central axis of the camshaft 35 formed in the engine body 1', and is rotatably provided around the camshaft 35; Further, a fan-shaped gear portion 34f is formed on the outer peripheral surface of the upper portion of the cylindrical portion 34a of the rotating member 34. On the other hand, the operating device 38 is connected to the gear 3 that meshes with the fan-shaped gear portion 34f.
9 and a motor (not shown) that rotates the gear 39 via a rotating shaft 40. Therefore, by rotating the gear 39 with the motor (not shown), the rotating member 34 is moved to the guide surface 1'. The camshaft 35 is rotated around the camshaft 35 while being in sliding contact with the camshaft 35, whereby one end of each tapepet member 37, 37 held by the rotation member 34 and each cam surface 35a, 35a relative to a specific angular position of the camshaft 35 are rotated. By changing the contact position, the valve timing of adjacent cylinders can be integrally and variably controlled.

Furthermore, in the above embodiment, two
Although one intake valve or two exhaust valves are variably controlled at the same time, three or more intake valves or exhaust valves may be variably controlled at the same time.

As explained above, according to the present invention, variable valve timing control of multiple cylinders can be reliably performed with a single mechanism with a simple structure, responsiveness, and reliability. This has the effect of generating less noise, and is therefore extremely effective in facilitating the implementation of valve timing control for multi-cylinder engines.

[Brief explanation of the drawing]

The drawings illustrate an embodiment of the present invention, in which Fig. 1 is a cutaway plan view when applied to a dual induction four-cylinder engine, Fig. 2 is a vertical cross-sectional side view of Fig. 1, and Fig. 3 is a variable mechanism. Enlarged perspective view of part, 4th
The figure is a vertical sectional side view of the main part showing a modification of the tappet member portion of the variable mechanism, Figure 5 is an explanatory diagram showing the valve timing of the intake and exhaust valves, and Figure 6 is a schematic diagram when applied to a normal 4-cylinder engine. A schematic diagram, FIG. 7 is a vertical cross-sectional side view showing a modification of the variable mechanism, and FIG.
FIG. 3 is a perspective view of the rotating member shown in the figure. 2a to 2d...1st to 4th cylinders, 3a to 3b...
...Intake port, 4a, 4b...Exhaust port, 5
a, 5b...Intake valve, 6a, 6b...Exhaust valve, 8
a, 8b... Valve mechanism, 9, 10... Camshaft, 9a, 9b, 10a, 10b... Cam surface, 1
1...First variable mechanism, 12...Second variable mechanism, 1
3, 13'... Tappet member, 13a, 13'a...
...Pressure receiving part, 13b, 13'b...Pressing part, 14,
14'... Rotating member, 14a, 14'a... Fitting hole, 15, 15'... Operating device, A... Hydraulic tappet device, 33... Variable device, 34... Rotating member, 34b... ...Insertion hole, 35...Camshaft,
35a...Cam surface, 36...Valve stem, 37
... Tappet member, 38 ... Operating device.

Claims (1)

[Claims] 1 A pressure receiving part is installed in the power transmission path between the valve of an adjacent cylinder and the cam surface of the corresponding camshaft, and receives the force from the cam surface, and the pressure receiving part receives the force from the cam surface and transfers it to the valve stem side. A plurality of tappets each having a pressure transmitting portion, a plurality of fitting holes into which each of the tappets is slidably fitted, and a rotating member rotatably movable around the camshaft; and the rotating member. an operating device for rotating the camshaft so that the contact position between each cam surface and the pressure receiving part of each tappet changes with respect to a specific angular position of the camshaft according to the operating state of the engine. Valve timing control device.