JPS63268907A - Valve system for engine - Google Patents

Abstract

PURPOSE:To aim at reducing time required for assembling work by providing an elastic body between two rocker arms with different oscillating quantities and setting the elastic force of the elastic body to be smaller than the friction force by a compressive spring. CONSTITUTION:An elastic body 18 is provided between a rocker arm 10 and a rocker arm 14 with different oscillating quantities. A compressive spring 24 is installed, compressed, between a spring bearing part 10a of the rocker arm 10 and a spring bearing part 14a of the rocker arm 14. The elastic force of the elastic body 18 is set to be smaller then the friction force produced at the stopper surface between the rocker arms 10, 14 by the compressive spring 24. This enables both rocker arms to be integrated with each other at the time of assembling, thereby time required for assembling work can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a valve train for an engine, and in particular to a swing arm type valve train in which two types of rocker arms with different suspensions are provided with engagement mechanisms. Related to improving things.

(Prior Art) Conventionally, this type of swing arm type valve operating device 4 has been arranged adjacent to each other and used for high-speed operation of a camshaft. It is equipped with a first rocker arm and a second rocker arm that contact the cam and the low-speed cam, respectively, and an engagement mechanism that freely engages the two rocker arms. The first rocker arm is swung to perform the third opening operation of the intake valve (or exhaust valve), while the tenth rocker arm is engaged with the second rocker arm by the engagement mechanism during the first rotation of the engine at high speed. Accordingly, it is known that an intake valve (or exhaust valve) is opened and closed by swinging a first rocker arm via a second rocker arm in accordance with a high-speed cam.

In this case, the first rocker arm and the second rocker arm are connected by the above-mentioned engagement mechanism.
For engagement with the rocker arms, each rocker arm is formed into a hollow shape, and during normal operation of the engine (during medium/low speed rotation), an engagement pin is inserted into the hollow part of the first rocker arm from the second rocker arm side using a spring (elastic spring). During a specific operation of the engine (during high speed rotation), the engagement bottle is moved from the hollow part of the first rocker arm against the elastic force of the spring using hydraulic pressure or the like. The structure is such that it is moved to the second rocker arm side and straddled between the hollow part of the first rocker arm and the hollow part of the second rocker arm.

(Problems to be Solved by the Invention) Conventionally, the first rocker arm and the second rocker arm have been assembled individually for each rocker arm, although the work is time-consuming. is the current situation. This is because when both rocker arms are installed as one unit, a spring (elastic body) disposed in the hollow part of the second rocker arm is used to create a space between the two rocker arms.
), an elastic force is acting on the second rocker arm that causes the two rocker arms to repel each other in the camshaft direction, while the second rocker arm is operated by a return spring that brings the second rocker arm into contact with the first speed cam. Relationship-1- In which the elastic force J acts in the direction of rotation and rocking around the fulcrum of the rocker arm, the two rocker arms are integrated while regulating the elastic force acting in the two directions as described above. This is because it is extremely difficult to assemble.

The present invention has been made in view of these points, and its purpose is to
By utilizing the elastic force acting in one direction by making appropriate improvements to both rocker arms,
The purpose is to make it possible to integrate both arms at the time of assembly, to shorten the time required for assembly work, to simplify the work, and to improve the efficiency of assembly work.

(Means for Solving the Problems) In order to achieve the above object, the solving means of the present invention provides two types of rocker arms that are arranged adjacent to each other and have different rocking fl as a valve train for an engine. an engagement mechanism that engages both the rocker arms during a specific operation of the engine; an elastic body that is provided between the two rocker arms and causes the rocker arms to repel each other in the camshaft direction; A compression spring is provided between the rocker arms and repels both rocker arms in the direction of rocking each other with elastic force, and the relative maximum rocking position of both rocker arms due to the elastic force of the compression spring exceeds the maximum rocking angle between the two arms. and a stopper for regulating the displacement of. The elastic force of the elastic body is set to be smaller than the friction force generated by the stopper at the relative maximum rocking position (α) of both rocker arms due to the elastic force of the compression spring.

(Function) Based on the above configuration, in the present invention, the elastic force t of the compression spring that causes the rocker arms to repel each other in the direction of rocking is regulated by the stopper at the relative maximum rocking position of the rocker arms, The elastic force of the elastic body that causes the rocker arms to repel each other in the camshaft direction is 1. Since the force is set to be 6 smaller than the 9m force generated by the stopper using the elastic force of the shoreline spring, the elastic force generated by the elastic body to repel the two lever arms toward the camshaft is generated by the stopper. IfJ fD is regulated by the force and this j? The frictional force acts on both []l lever arms, making it possible to integrate both [l] lever arms, reducing the time required for assembly work, and reducing the work to 1!1111. Can be done.

In addition, since the compression spring is provided between both rocker arms, compared to the conventional return spring type b which is displaced by the amount of rocker arm rocking, the compression spring is displaced by the amount of rocker arm rocker arm rocker arm movement. It is only necessary to displace the spring by the amount of oscillation f:lI fi, and by reducing the width of the displacement, the durability of the spring itself can be improved.

(First example) Embodiments of the present invention will be described below based on the drawings.

FIG. 3 shows a 5OHC (single A-bar head camshaft) engine 1 to which a swing arm type valve train according to the first embodiment of the present invention is applied. A plurality of manifolds are arranged in the axial direction of a shaft (not shown), and openings to corresponding cylinders of an intake manifold and an exhaust manifold (not shown) formed in the cylinder head 2 are opened and closed by a valve train @3, respectively. Two intake valves 4, 5 and an exhaust valve 6 are provided. Moreover, on the cylinder head 2,
As shown in FIG. 6, a camshaft 7 is provided which extends in the direction of the cylinder row and is rotationally driven by a crankshaft (not shown). Low speed cams 7a and 7b,
A high-speed cam 7C having a high-speed cam profile is provided between the two low-speed cams 7a and 7b. Note that an exhaust cam 7d having an exhaust cam profile is disposed between one of the low-speed cams 7a (on the left side in FIG. 6) of the camshaft 7 and the high-speed cam 7C.
is provided.

As shown in enlarged detail in FIGS. 1 and 2, the valve train 3 (only the intake side will be explained) has one end connected to one low-speed cam 7a of the camshaft t'71-7 via the roller 8. (on the left side in Fig. 6), and the other end is in contact with one intake brake r4 (left side in Fig. 6).
In FIG. 2, a first rocker arm 10 is swingably supported by a rocker arm 1r)h9 whose intermediate portion extends in the direction of the camshaft 7 and which is in contact with the left side in FIG. The other low speed cam 7b
(on the right side in FIG. 6), the other end abuts on the other intake valve 5 (on the right side in FIG. 2), and the intermediate portion is swingably supported by the rocker arm shifter 9.
a rocker arm 12, the first rocker arm 10 and the second rocker arm 12;
The third [3] is disposed adjacent to the rocker arm 12, one end abuts the high-speed cam 7C of the camshaft 7 via the slipper 13, and the intermediate portion is swingably supported by the O-tsuka arm shift 1 shift 9. It consists of a first rocker arm 10J3 and a 20th rocker arm 14.
The second and third CI rack arms 14 differ in their swinging calendars.

As shown in FIG. 4, each of the rocker arms 10
, 12.14, each rocker arm 10.12.14
Hollow portions 15a and 15b communicate with each other.

15C are formed respectively, and each of the above hollow parts 15a
, 15b and 15c have two engaging mechanisms 16.
17 are arranged. One of the engaging mechanisms 16 and 17 (the left side in FIG. 4) is
It is arranged in the hollow part 15a of the rocker arm 10 and is urged toward the third rocker arm 14 side (camshaft 7 direction) by a spring 18 which is an elastic body, and the Iζ return pin 19 and the left side in the hollow part 15c of the third rocker arm 14 The engagement pin 20 is disposed in the hollow portion 15C and is slidable in the direction of the camshaft 7 within the hollow portion 15C. The other engagement mechanism 17 (on the right side in FIG. 4) is disposed in the hollow part 15b of the second rocker arm 12, and is supported by a spring 21 as an elastic body on the third rocker arm 14 side (camshaft I/foot 7 direction). ), the engagement pin 23 is disposed on the right side of the hollow part 15C of the third rocker arm 14, and is movable in the hollow part 15C by 131% in the direction of the camshaft 7. has been done. In this case, as shown in FIG.
Between 4 and 4, each rocker arm 10, 12, 14 is moved by each spring 18, 21 to the forceps 1r and 7.
+ is acting on the elastic force that repels each other in the direction, and + is acting on the elastic force.

In addition, near the other end of the 10th cuff I-m 10 and the second rocker arm 12 (above the intake valves 4 and 5), there is a 3rd cuff arm 14 side (camshaft 7 direction).
Spring receiving portions 1Qa and i2a extending therein are formed, and the vicinity of the other end (bottom surface portion) of the third rocker arm 14 facing each of the spring receiving portions 10a and 12a is formed.
Concave spring receiving portions 14a and 14b are formed in the respective portions. Between the spring receiving part 10a of the first rocker arm 10 and the spring receiving part 14a of the third rocker arm 14 (left side in FIG. 2), and between the spring receiving part 12a of the second rocker arm 12 and the spring of the third rocker arm 14. Compression springs 24.25 are compressed between the receiving portion 14b (on the right side in FIG. 2), and these compression springs 24.25 are connected to the first rocker arm 10 and the second rocker arm. 2. The elastic force causes the third rocker arm 14 to repel each other in the direction of rocking. 2 (see Figure 5) is acting on.

During normal operation of the engine 1 (during medium/low speed rotation), the engagement bins 20 and 23 are connected to the return bins 19 and 2.
2, the first rocker arm 11, the second rocker arm 12, and the third rocker arm 14 are arranged in the hollow part 15c of the third rocker arm 14, and the first rocker arm 11, the second rocker arm 12, and the third rocker arm 14 are connected to the low-speed cams 7a, 7b and the high-speed cam 7C of the camshaft 7 2a.
The oscillations are made in accordance with different lift days.

Further, an oil injection hole 26 is opened in the center of the hollow part 15c of the third rocker arm 15, and during a specific operation of the engine 1 (during high speed rotation), an oil injection hole 26 is opened in the hollow part 15c of the third rocker arm 14 in advance. The stored low fE oil is transferred from the engine 1 to the hydraulic control device 27 (see Figure 7).
Even though each engagement bottle 20.23 is pressurized by high-pressure oil injected from the oil injection hole 26 through the return bottle 19.22 and urged by the spring 18.21 via the return bottle 19.22. Regardless, the respective engagement bins 20 and 23 are placed on the first rocker arm 10 side and the second rocker arm 12 side (
The first rocker arm 10, the second rocker arm 12, and the third rocker arm 14 are engaged with each other by the engaging machine #416.17, and the first rocker arm 10 and the second rocker arm 12 are without contacting the low-speed cams 7a and 7b.
A pulp timing variable mechanism 28 is configured to swing in response to the lift Fil of the rocker arm 14.

Furthermore, a position 1 is provided at the upper intermediate portion of the third rocker arm 14.
Claw-shaped protrusions 14c and 14d extending toward the first rocker arm 10 and second rocker arm 12 (in the direction of the camshaft 7), respectively, are formed on both sides of the rocker arm 6. Then, the elastic force of each of the compression springs 24 and 25 is equal to 2
, at the relative maximum rocking position of the first rocker arm 10, the second rocker arm 12, and the third rocker arm 14 according to 2, each protrusion 14c of the third rocker arm 14
, i4d (left side in FIG. 2) and the middle part of the upper surface of the first rocker arm 10, there are stopper surfaces 14e and 10b that abut against each other in the direction in which each arm 14.10 swings. As each is formed,
The other protrusion 14d (on the right side in FIG. 2) of the third rocker arm 14 and the middle part of the upper surface of the second rocker arm 12 are provided with stopper surfaces 14f and 12b that abut against each other in the direction in which each arm 14.12 swings. are formed respectively,
The first rocker arm 10 and the second rocker arm 1 are
Displacement between the rocker arm 2 and the third rocker arm 14 that exceeds the maximum swing angle is restricted.

In this case, each rocker arm 10°12.1
The elastic force acting on each rocker arm 10, 12.14 by each spring 18.21 arranged between 4.
, 2 is the elastic force of the compression spring 2/1.25, and the relative maximum position of the first rocker arm 10, the second rocker arm 12, and the 30th arm 14 is due to the elastic force of the compression spring 2/1.25. 1-2 Each stroke surface 10b, 12b, 14
The frictional forces generated at e and 14f are set to be smaller than the frictional forces "," (see Figs. 1 and 2).

Next, the configuration of the hydraulic controller 1 to the roll device 27 will be explained with reference to FIG. 7.

The pressurized oil from the engine 1 is supplied to the oil supply passage 30
This oil supply passage 30 has an expansion chamber 3 on the way.
1, and a first branch passage 32 communicating with the oil injection hole 26 at a branch part 30a on the downstream side of the expansion chamber 31;
A second branch passage 33 communicating with an oil pan (not shown)
(relief passage) and the expansion chamber 31.
is a piston 31b with a spring 31a compressed on its back.
, and constitutes an accumulator that stores pressurized oil in the oil supply passage 30.

Branch portion 3 between the first branch passage 32 and the second branch passage 33
A control valve 34 that controls opening w1 of both branch passages 32 and 33 is disposed at 0a. The control valve 34 is connected to the first branch passage 32 and the oil supply passage 30 or the second branch passage 3 by movement of the valve body 34b by the operation of the actuator 34a.
When the valve body 34b opens (advances) due to the OFF operation of the actuator 34a, the first branch passage 32 and the second branch passage 33 are communicated with each other, while the ON operation of the actuator 34a When the valve is opened (retracted), the oil supply passage 30 and the first branch passage 32 are arranged to communicate with each other.

Further, the oil supply passage 30 at the bottom of the expansion chamber 31 and the first branch passage 32 are communicated by a bypass passage 35 that bypasses the control valve 34 .

This bypass passage 35 is provided with a passage diameter smaller than that of the oil supply passage 30. Furthermore, the above 11jj
A relief valve 36 is interposed in the second branch passage 33 on the downstream side of the till valve 34, and the relief valve 36 has a valve opening setting pressure of a ball 36b caused by a spring 36a that corresponds to each cylinder fO.
The pressure value is set to be lower than the driving pressure when moving the engagement pins 20.23 of each of the engagement mechanisms 16.17, which are arranged in pairs in the camshaft 7 direction.

The operation of the control valve 34 is controlled by a control signal from a control means 37 to its actuator 34a. The control valve 34 is closed (<0): F: activated) during normal operation of the engine 1 (during middle/low speed rotation), and is open (ON) during specific operation of the engine 1 (during 6th speed rotation). It operates for a predetermined period of time (ON operation) when the engine is started. Further, the control means 3
7 has a built-in safety system 37a,
This self-safe system 37a is configured such that, due to a malfunction in the hydraulic system, any one of the engagement bins of the engagement mechanism 16. If the control valve 34 cannot be moved by a predetermined amount, the control valve 34 is forcibly closed and locked (OFF operation).
This is to switch to . The control means 37 receives a signal from a rotation sensor 38 that detects the engine rotational speed, and based on this engine rotational speed signal, determines the operating range during startup, ^ speed rotation, or medium/low speed rotation, and controls the control valve 34.
A self-safe system 37 outputs a drive signal to the actuator 34a and receives information from a hydraulic sensor 39 that detects oil pressure in an oil pan (not shown).
Due to a, the actuator 3 of the control valve 34 is activated only when the oil pressure sensor value is abnormal, regardless of the engine operating range a.
4a outputs a closing signal 0 (closing valve ↑ of valve body 34b).

I and II control means 37 of the above hydraulic controller 1 to roll device 27
The operation of the self-safety system 37a built in the eighth
The explanation will be based on the flowchart shown in the figure.

First, in step S+, a signal is input from the oil pressure sensor, and then in step S2, it is determined whether the oil pressure sensor value is a normal value. And YES if the oil pressure sensor value is normal.
In this case, the variable valve timing mechanism is unlocked to the low speed side in step S3, and the process returns to step S1.

On the other hand, if the oil pressure sensor value is an abnormal value (NO in step S2), the switching status of the engagement mechanism for each cylinder to the low speed side and high speed side by the variable valve timing mechanism and the engine rotation sensor are determined in step S4. After understanding the current state of the engine from data such as the rotational speed and the injection amount of the fuel injection valve, the engine rotational speed is slightly lowered by correcting the injection amount of the fuel injection valve by a small amount in step S5.

Next, in step S6, the engine speed is maintained until the engine speed reaches a speed (medium/low speed) suitable for switching to the low speed side by the variable valve timing mechanism, and when the engine speed reaches the medium/low speed, in step S7, the control valve actuator is activated. A close signal is output and the valve timing is enabled' [After the side is locked to the low speed side, the process returns to step S1.

Next, to explain the operation and effect of the above embodiment, when each rocker arm 10, 12. The elastic force of the compression springs 24 and 25 that repel each other in the direction of the stopper surface 10b of the first rocker arm 10 and the second rocker arm 12
The stopper surface 12b of the rocker arm 1o, 12.
Rocker arm 10.12 each at 14 relative maximum swing positions
．． 14 in the direction of the camshaft 7, the elastic force of each spring 18.
, 14e and the elastic forces of the compression springs 24 and 25 generated at the stopper surfaces 12b and 14f of the second rocker arm 12 and the third rocker arm 14, respectively.
Since it is set smaller than the frictional forces F and F using K2, the elastic force generated by each spring 18.21 that causes each rocker arm 10.12.14 to repel each other in the direction of the camshaft 7 is , each of the above frictional forces F,
υj is defined by F, and this frictional force [, 1:] is applied to each horn arm 10. 12.14, it is possible to integrate each rocker arm 10, 12.14, and the time required for assembly work can be shortened and the work can be simplified. This will result in an improvement of 1!1.

Further, each of the compression springs 24, 25 is connected between the spring receiver 10a of the first rocker arm 10 and the spring receiver N514a of the third rocker arm 14, and between the spring receiver 12a of the second rocker arm 12 and the spring of the third rocker arm 14. Since each compression spring 24 is compressed between the receiving part 14b and the rocker arm that contacts the high-speed cam, the compression spring 24 is .25 is
By simply displacing the distance between the first rocker arm 10 and the second rocker arm 1112 and the third rocker arm 14, which have relative swings, J:<, the width of the displacement is reduced to create a spring. It can improve its durability.

Further, in the valve train 3 (intake side), the operating states of the engagement mechanisms 16 and 17, two of which are provided for each cylinder, are detected by oil pressure sensors to 39, and in the event of an abnormality, the pulp timing variable Since a self-safety system 37a is provided that switches the M428 to the low-speed lock state, it is possible to secure a certain degree of running performance without impairing the durability of the engine due to torque shock or the like.

(Second Large Drop Example) FIGS. 8 and 9 show a second embodiment of the present invention, and this second embodiment is similar to the first embodiment described above for each rocker arm 10.
12. Instead of forming a stopper surface on each of 14, the first rocker arm 10 and the second rocker arm 12
A stopper is provided only at the bottom. Incidentally, the same parts as in the first embodiment are given the same reference numerals and the explanation thereof will be omitted.

That is, in this embodiment, on the side of the upper surface of the first rocker arm 10 and the second rocker arm 12 (on the side of the third rocker arm 14), there are protrusions iQb' and 12b extending upward.
' are formed respectively, and each protrusion 10b'
12b' from the upper end to the third rocker arm 14 side (camshi p
) Cylindrical stopper portions 10C extending in the 1-7 directions)
', 12C' are provided respectively. Then, due to the elastic force of each compression spring 24, 25, the first rocker arm 10, the second rocker arm 12, and the third rocker arm 14 are at the relative maximum swing position C1.
C1 Each of the above steps 0C' and 120' are the third
The first rocker arm 10 , the second rocker arm 12 , and the third rocker arm 1 are in contact with the upper surface of the rocker arm 14 .
4 and the maximum oscillation angle is regulated.

Note that even if J3 is used in this example, the same functions and effects as in the first embodiment can be obtained.

<Effects of the Invention> As described below, according to the engine valve system of the present invention, the elastic force of the elastic body that causes both rocker arms to repel each other in the direction of the camshaft 7 causes the two rocker arms to swing relative to each other. Fi! which is generated in S1hetsupa which regulates the elastic force of fE compression spring which repel each other in the direction of Since the lh is also set small, the elastic force of the elastic body is regulated by the frictional force, making it possible to integrate both rocker arms, reducing the time required for assembly work and the efficiency of the work itself. As a result, assembly work efficiency can be improved. Moreover, the compression spring only needs to be displaced by the amount m of relative rocking between both rocker arms, and the durability of the spring itself can be improved.

[Brief explanation of the drawing]

1 to 8 show a first embodiment of the present invention.
The figure is a cross-sectional view taken along line I-I in Figure 2, Figure 2 is a plan view of the valve train on the intake side, Figure 3 is a plan view of the engine with the cam cap removed, and Figure 4 is the engaged state. A diagram equivalent to Figure 2 showing the structure of the mechanism, Figure 5 is a schematic diagram showing the arrangement of springs, Figure 6 is a side view of the camshaft 1 shift, and Figure 7 is a diagram schematically showing the configuration of the hydraulic control device. Figure, 8th
The figure shows flowchart 1 showing the operation of the self-safety system.
-Illustration. 9 and 10 show a second embodiment of the present invention, FIG. 9 is a sectional view of rx-tx cotton in FIG. 10, and FIG. 10 is a view corresponding to FIG. 2. DESCRIPTION OF SYMBOLS 1... Engine, 3... Valve train, 7... Cam shift, 10... First rocker arm, 10b, 12b
...Stopper surface, 10C', 12C'...Stopper part, 12...Second rocker arm, 14...Third rocker arm, 14e, 14f...Stopper surface, 16.1
7... Engagement mechanism, 18.21... Spring, 24
．． 25...Compression spring, K+, 2...Elastic force, F...Frictional force. ””-”:”1 Patent applicant Mazda Motor Corporation
Makoto Rihito 1) Hiroshi
2! -・Figure 1 Figure 2 I Figure 5 Figure 6 Figure 7 ゞ1 (ENG) Figure 9 Figure 10 Ix

Claims (1)

[Claims] (1) Two types of rocker arms that are arranged adjacent to each other and have different rocking amounts, an engagement mechanism that engages both rocker arms during a specific operation of the engine, and an engagement mechanism that is provided between the two rocker arms, and that An elastic body that causes the rocker arms to repel each other with elastic force in the direction of the camshaft, a compression spring provided between the two rocker arms that causes the rocker arms to repel each other with elastic force in the direction of rocking each other, and an elastic force of the compression spring. The elastic force of the elastic body is controlled by the relative displacement of both rocker arms due to the elastic force of the compression spring. A valve train for an engine, characterized in that the friction force is set to be smaller than the friction force generated by the stopper at the maximum swing position.