JPS60252112A - Valve operating device with valve stop function - Google Patents

Abstract

PURPOSE:To regulate the operation time of a shift pin and to prevent a bad engagement by disposing a timing plate urged by a spring between a stopping locker arm and a driving locker arm. CONSTITUTION:A hollow locker shaft 2 is provided with a driving locker arm 3 and a stopping locker arm 4, and the connection and disconnection between two locker arms is controlled by an actuator 6 disposed between both locker arms. A timing plate 11 urged to a valve by a spring 8 is provided between both locker arms, whereby the moving timing of a shift pin 6a of the actuator 6 driven by oil pressure is set at the initial stage of the base circle period of the driving locker arm 3. Accordingly, even if oil pressure works at any time, the engagement of the shift pin 6a with an engaging hole 6e can be reliably accomplished.

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to an internal combustion engine in which a plurality of intake or exhaust valves are arranged in one cylinder, and to an internal combustion engine in which a plurality of intake or exhaust valves are provided. The present invention relates to a valve device, and more specifically, it relates to a valve device having a function of stopping some of a plurality of valves when an engine is operated at low speed or high speed.

(Prior Art and its Problems) Conventionally, as the above-mentioned valve operating device, those shown in FIGS. 16 and 17 are known.

This valve train has a hollow rocker arm shaft 2 supported by a cylinder head of an internal combustion engine, and a pair of rocker arms 3.4 adjacent to each other.
is caused to swing by a cam 5a on a camshaft 5 that rotates in synchronization with the movement of the piston in the cylinder, and the other rocker arm 4 is engaged with and disengaged from the rocker arm 3 by an actuator 6 to interlock with the rocker arm 3 at appropriate times. The valve 7b (located behind the valve 7a shown in FIG. 17) driven by the other rocker arm 4 is placed in the active or rest state.

The actuator 6 is of a reciprocating type that uses hydraulic pressure to project a shift pin 6a slidably provided in one rocker arm 3 toward the other rocker arm 4, and has a hydraulic chamber that slidably holds the shift pin 6a. 6b is communicated with an oil passage 6d utilizing a hollow portion of the rocker arm shaft 2 via an oil passage 6C bored in this one rocker arm 3. Also, the other rocker arm 4
The shift bin 6 is located at a position corresponding to the hydraulic chamber 6b.
An engagement hole 6e into which the shift bin 6a is fitted is formed, and in the engagement hole 6e there is a return bin 6f for pushing the shift bin 6a back into the hydraulic chamber 6b, and this return bin 6f is inserted into one of the rocker arms 3.
It has a configuration in which an elastic member 6g is provided to urge it to the side. Then, only when the engine rotates at high speed, hydraulic oil at a predetermined pressure is supplied from an oil supply device (not shown) to the oil passage 6d.
One of the other rocker arms 4 is interlocked with the rocker arm 3.

By the way, as shown in FIG. 18, the rocker arm 3 is in a state where the top part (A) of the cam 5a is in contact with the slipper surface 3a, and the rocker arm 3 swings during the lift period A in which the valve 7a is opened and closed, and the cam The base circle (b) of 5a is a slipper, and 3a
The base circle moves periodically, alternating with the base circle period B in which the base circle is in contact with the base circle and remains stationary at the fully ascended position. On the other hand, the rocker arm 4 is supported so as to be lightly pressed against the valve copper by a rocker arm spring 8 (see FIG. 16) to prevent it from swinging, and is stationary at the fully raised position.

Therefore, switching from the rest state to the interlocking state is limited to when the movement of the rocker arm 3 reaches the base circle period B. In order to reliably complete the switching within such a base period B, since the base circle period B is very short, the timing at which the shift bin 6a enters the engagement hole 6e must be adjusted based on the base period B. It is required to align with the beginning of the yen period.

This is because, in the conventional device described above, the oil passage 6d connected to the oil supply device and the hydraulic chamber 6b are always in communication, and as long as the oil supply device operates, hydraulic oil is supplied to the hydraulic chamber 6b. The shift bin 6a is about to enter the engagement hole 6e. Therefore, depending on the operating timing of the refueling system, the thrusting operation of the shift bin 6a may start at the end of the base circle period B as shown by (c) in FIG. 18. However, if the thrusting motion of the shift bin 6a is started at the end of the base circle period B, the shift bin 6a will immediately shift to the lift period A and the rocker arm 3 will begin to move. I don't have enough time to get into it. Therefore, even if the shift bin 6a enters the engagement hole 6e, the amount of the shift bin 6a is small, and it may come off in the middle of the lift period A, which is a so-called engagement failure, which may cause problems such as a delay in switching and generation of shock. There was that.

[Purpose of the invention]

This invention has been made in view of the above circumstances, and when switching the resting side rocker arm from the resting state to the interlocking state, the oil supply device for supplying hydraulic oil to the shift pin side is connected to the driving side rocker arm. No matter what time the shift bin is activated during periodic motion, there will be no problems with the shift bin, and the valve can be reliably switched with a single rush movement of the shift bin. The purpose is to provide.

C) Configuration of the Invention) The valve operating device with a valve stop function according to the present invention is provided between the stop-side rocker arm and the drive-side rocker arm, and is biased from the cam side toward the valve copper by the elastic force of a spring. The structure includes a timing plate 1 which closes a part of the engagement hole into which the shift bin enters from the cam side, and the timing of entry of the shift bin is controlled by the timing plate.

[Embodiments of the invention]

Figures 1 and 2 show one embodiment of the present invention, and common parts in these figures, such as parts in Figures 16 and 17, are denoted by the same numbers to simplify the explanation. become

This valve operating device with a valve deactivation function is provided with a hydraulic chamber 6b in the drive side rocker arm 3 so as to be released toward the deactivation side rocker arm 4, and a shift bin 6a housed in the hydraulic chamber 6b.
By causing the inactive rocker arm 4 to enter and retract from the engagement hole 6e provided in the inactive rocker arm 4, the inactive rocker arm 4 can be put into a resting state or brought into an interlocking state with the driving rocker arm 3.This point is the same as the conventional one. It is.

However, in this valve train, various improvements have been made to the actuator 6 that engages and disengages the double-ended hook arms 3 and 4 using the shift bin 6a, the oil passage 10 that guides hydraulic oil to the hydraulic chamber 6b of the actuator 6, etc. In addition, a timing plate 11 is provided between the rocker arms 3 and 4 to control when the shift bin 6a enters the engagement hole 6e.

Hereinafter, parts that are different from the above-mentioned conventional one will be sequentially explained.

In the actuator 6, a shift bin 6a and a return bin 6f are each formed into a substantially cylindrical shape. Further, the end portion of the return bin 6f that comes into contact with the shift bin 6a is a small diameter portion 6h with a reduced outer diameter. The length of this small diameter portion 6h is set to substantially match or slightly smaller than the dimension of the gap C between the two-end hook arms 3.4, and the small diameter portion 6h allows the recess 61 into which the timing plate 11 is fitted to be formed. It is formed. On the other hand, a hydraulic piston 6j is provided in the hydraulic chamber 6b together with the shift bin 6a. This hydraulic piston 6j receives the pressure of the hydraulic oil supplied to the hydraulic chamber 6b, and uses the pressure as thrust to move the shift bin 6a.
A recess 6k is formed on the shift bin 6a side of the hydraulic piston 6j, and the recess 6k
1, the spring 12 is inserted into the compressed state, and the spring 1
2 in a direction away from the shift bin 6a. Further, a bushing rod 6J for opening a check valve 13, which will be described later, is protruded from the end face of the hydraulic piston 6j facing the hydraulic chamber 6b.

The oil passage 10, as shown in FIGS. 1 and 3,
A first oil passage 15 leading from the oil supply device 14 to the oil passage 6d which is the hollow part of the rocker arm shaft 2, an oil passage 6C bored in the rocker arm 3, and an oil passage passing through the peripheral wall of the rocker arm shaft 2. Passage 6C and oil passage 6d
The oil passage 6C has a check valve 13 from the hydraulic chamber 6b side to the oil passage 6C, and a communication passage 16 that communicates with each other.
As shown in FIGS. 4 and 5, a first hole (timing port) 17 is provided in the peripheral wall of the rocker arm shaft, and a second hole (timing port) is provided in the rocker arm 3. ) 18 are perforated.

The oil supply device 14 shown in FIG. 3 is provided with a spool valve 19 on the outlet side of an oil pump (not shown).

This spool valve 19 has a flange portion 19 for opening and closing the flow path.
A small-diameter auxiliary passage 19c is formed in the spool 19b having a diameter of 10 mm, opening on both sides of the flange 19a to communicate the flow path, even when the flange 19a closes the flow path as shown in the figure. , the first to such an extent that the actuator 6 is not actuated.
The construction is such that hydraulic oil is supplied to the oil passage 15 and the communication passage 16 to prevent air from entering these passages 15 and 16. In addition, in FIG. 3, the tube 20 fixed to the end of the rocker arm shaft 2 is connected to the passage 15.
．． This is for venting air when air gets mixed into 16.

The check valve 13 described above is connected to the oil passage 6C from the hydraulic chamber 6b side.
A structure comprising a headed cylindrical valve body 13a that closes the oil passage 6G by seating on the open end of the valve body, and a resilient member 13b that biases the cough valve body 13a toward the open end of the oil passage 6C. When working oil at a predetermined pressure is supplied to the oil passage 6C, or when the valve body 13a is activated by the hydraulic piston 6 as shown in FIG.
When the bushing rod 6j of the bushing rod 6j is pushed down from the side, the oil passage 6C is opened to allow operating fluid to flow into the hydraulic chamber 6b 1 or to allow hydraulic fluid to flow out from the hydraulic chamber 6b.

The above-mentioned first hole 17 and second hole 18 are used to control the discharge timing of the hydraulic fluid in the hydraulic chamber cb when switching the rest-side rocker arm 4 from the interlocking state to the rest state. This is to smooth out the exit operation, and during the base circle period B, the positions are shifted from each other as shown in FIG. 4, and the isolated state of the hydraulic chamber 6b is maintained.
The mutual positions are set so that at the time of the maximum lift in the lift period A, the mutual positions are completely aligned and communicated as shown in FIG. 5, and the hydraulic chamber 6b is released to the oil passage 6d. There is.

As shown in FIGS. 1 and 2, the timing plate 11 is rotatably supported by the rocker arm shaft 2, and is urged by the rocker arm spring 8 from the cam 5a side toward the valve 7b side. Then, the curved inner edge 11a on the tip side is connected to the small diameter portion 6h of the return bottle 6f.
By intervening in the recess 61 so as to come into contact with it, a part of the engagement hole 6e is closed, thereby preventing the shift bin 6a from entering the engagement hole 6e. The timing plate 11 also includes a stopper 2 protruding from the base end of the rocker arm 4 (the part that fits with the rocker arm shaft 2).
1, and the stopper 21 restricts rotation toward the valve 7b.

The operation of the above embodiment will be explained below.

First, a case where the engine is operated at a predetermined number of revolutions or less will be explained. In this case, as shown in Figure 3,
A spool valve 19 of the oil supply device 14 closes the first oil passage 15. Therefore, no hydraulic oil is supplied to the first oil passage 15 side except for the amount leaked from the spool valve 19. Therefore, as shown in FIG. 1 and FIG. 6 (ω, (b)), the hydraulic piston 6j and the shift bin 6a are activated by the elastic member 6g that urges the return bin 6f.
(the spring 12 in the hydraulic piston 6j is formed to be weaker than the elastic member 6g), and the timing plate 11 maintains a state in which a part of the engagement hole 6e is closed, The locking arm 4 remains at rest. In addition, in such a state, the check valve 13 is released by the bushing rod 6J and the hydraulic chamber 6 is opened.
b is in communication with the oil passage 6d in the rocker arm shaft 2, that is, when the oil supply device 14 is activated, the pressure of the hydraulic oil is immediately applied to the hydraulic piston 6j.

Next, a case where the tIlrlJ rotational speed increases from a predetermined rotational speed or less to a predetermined rotational speed or more and the rocker arm 4 is switched from a resting state to a state in which it is interlocked with the rocker arm 3 will be described. In this case, when the rotation speed reaches a predetermined number or higher, the spool valve 19 of the oil supply device 14 is opened, and hydraulic oil is supplied to the hydraulic chamber 6b through the first oil passage 15, the oil passage 6d1, the communication passage 16, and the oil passage 6c. be done. This supply of hydraulic oil causes the hydraulic piston 6j to shift into the shift bin 6.
The shift bin 6a attempts to enter the engagement hole 6e, but when this period is in the base circle period B, the timing plate 11 becomes an obstacle as shown in FIG. 6(a), and the shift bin 6a does not enter. Then, the lift period begins while the oil pressure remains ON. When this lift period A begins, Fig. 6 (C
), the shift bin 6a pushes the return bin 6f and the tip of the shift bin 6a touches the side 4 of the rocker
a, that is, the tip of the shift bin enters the lower side of the timing plate 11. During this lift period A, the shift bin 6a and the engagement hole 6
Since the shift pin 6a is offset from the rocker arm 4, the shift pin 6a only pushes the side surface of the rocker arm 4, and cannot enter the engagement hole 6e. Then, at the end of the lift period A, as shown in FIG. . As a result, at the beginning of the base circle period B following this lift period A, the timing plate 11 does not interfere with the shift bin thrusting operation, and the shift bin 6a and the engagement hole 6e
A state is obtained in which the positions of the shift bin 6a and the shift bin 6a coincide with each other, and the shifting of the shift bin 6a is started, and an interlocking state as shown in FIG. 7 is formed. In this way, when switching from the rest state to the interlocking state, even if the oil supply device 14 starts supplying hydraulic oil to the hydraulic chamber 6b during the base circle period of the rocker arm 3, the engagement hole of the shift bin 6a The entry operation to 6e is always started at the beginning of the next base circle period B due to the action of the timing plate 11. Therefore, sufficient time is secured for the engagement of the double-ended hook arm 3.4 to be completed, and therefore, irrespective of the operating timing of the oil supply device 14, poor engagement of the shift bin 6a is prevented, and the shift bin 6a is The entry operation of the switch reliably switches from the dormant state to the interlocking state.

Next, the engine speed decreases from a predetermined speed or higher to a predetermined speed or lower, and the rocker arm 4
A case will be described in which the state is switched from the state linked to the state to the hibernation state. In this case, the first oil passage 15 is first closed by the spool valve 19 of the oil supply device 14, and the supply of hydraulic oil to the oil passage 6d in the rocker arm shaft 2 is stopped. Valve 19
The oil outlet 19d (see FIG. 3) is placed in communication with the oil outlet 19d (see FIG. 3). As a result, the pressure inside the oil passage 6d is reduced. Then, the check valve 13, which had been released until then, opens as shown in Fig. 8 (
It is in a closed state as shown in J.

Therefore, the hydraulic fluid in the hydraulic chamber 6b flows through the first hole 17 and the second hole 18 when the rocker arm 3 reaches the lift period A.
The hydraulic piston 6j1, that is, the shift bin 6a, does not move because the hydraulic chamber 6b remains sealed until the two communicate with each other. Then, during the lift period, the first hole 17 and the second hole
When these holes 17 and 18 are in communication with each other, hydraulic oil can be discharged from these holes 17 and 18 to the oil passage 6d side. but,
During the lift period, the jitbin 6a is mounted on the rocker arm 3.
4 They receive frictional force (shearing force) from each other, and are unable to move due to this frictional force. Therefore, Fig. 8 (C
), only the hydraulic piston 6j is returned by the force of the spring 12 depending on the amount of hydraulic oil discharged from the hole 18.

However, this hydraulic piston 6J has a check valve 13.
A bushing rod 6 is provided to release the oil, and when the hydraulic piston 6j starts to return, the check valve 13 is released as shown in FIG. 8(C), and the hydraulic oil is also discharged from the oil passage 6C. That will happen. Therefore, when the lift period A begins, the hydraulic oil in the hydraulic chamber 6b is discharged in a very short time, and the hydraulic piston 6j is completely pushed back by the spring 12, as shown in FIG. state.

Therefore, from the rocker arms 3 and 4 to the shift bin 6,
When the frictional force (shearing force) is not applied to a, that is, when the base circle period is reached, the shift bin 6a starts to return into the hydraulic chamber 6b due to the elastic force of the elastic material 6g, and during the base period B When the return of the shift bin 6a is completed, the system enters the rest state shown in FIG. To summarize the case where the linked state is switched to the idle state, when the supply of hydraulic oil from the oil supply device is stopped, regardless of the timing of the stop, the discharge of hydraulic oil from the hydraulic chamber 6b is stopped. This is efficiently done during the first lift period after the supply stop, and the return of the shift bin 6a is started from the beginning of the base circle period B following this lift period. Therefore, sufficient time is secured for the return of the shift bin, and as a result, switching to the rest state can be smoothly performed without causing engagement failures or the like.

In addition, in the above-mentioned embodiment, the first hole 17, the second hole
Although the return timing of the shift bin 6a is controlled by a combination of the hole 18, the bushing rod 611, the check valve 13, etc., the means for controlling the return timing of the shift bin 6a is not limited to the above embodiment.

For example, a valve train as shown in FIGS. 9 to 11 may also be considered. This valve train includes an engagement groove 22 provided around the outer periphery of a shift pin 6a, and a timing bin that engages with the engagement groove 22 when the shift pin 6a enters the engagement hole 6c by a predetermined amount. 23 is provided inside the rocker arm 3. The timing gun 23 is slidably supported in a guide hole 24 formed on the outer periphery of the shift bin 6a, and is urged toward the rocker arm shaft 2 by a resilient member 25. A pressure receiving part 23'a that receives the pressure of hydraulic oil is formed on the rocker arm shaft 2 side.The guide hole 24 is connected to the oil passage 6d in the rocker arm shaft 2 on the peripheral wall of the rocker arm shaft 2. Hole (timing port) 26 communicating with
is formed. Similar to the relationship between the first hole 17 and the second hole 18 described above, the hole 26 and the guide hole 24 are completely aligned and in communication when the rocker arm 3 is lifted to the maximum. The positions are set so that there is no communication during circular period B (see FIG. 10).

As described above, the engagement groove 22, the timing pin 23,
In place of the resilient member 25, hole 26, etc., the check valve 13, timing boats 17, 18, etc. in the first embodiment are omitted.

Hereinafter, the operation of the valve train shown in FIGS. 9 to 11 will be briefly explained.

When the engine rotation speed is lower than a predetermined rotation speed, hydraulic pressure is applied to the hydraulic chamber 6b and the pressure receiving portion 23a of the timing bin 23, and the rocker arm 4 is brought to a rest state as shown in FIG. 9 1c. It has become.

When the engine speed increases from a predetermined speed or lower to a predetermined speed or higher, hydraulic oil is supplied to the hydraulic chamber 611'' through the oil passage 6d and the oil passage 6c in order.The shift bin 6a is supplied with this hydraulic oil. The shift bin 6a tries to enter the engagement hole 6e, but the start of entry of the shift bin 6a is set at the beginning of the base circle period B by the timing board 11, and the entry is completed within the same period B of the base where entry started and the state is in a rest state. Then, when the interlocking state is reached, that is, the state in which the shift bin 6a enters the engagement hole 6C by a predetermined amount, the oil pressure supplied from the hole 26 to the pressure receiving part 23a of the timing bin 23 during the subsequent lift period. As a result, the timing pin 23 protrudes into the engagement groove 22 of the shifter 1 to pin 6a, resulting in the state shown in FIG. 12.

When the engine speed drops from a predetermined speed or higher to a predetermined speed or lower, the supply of hydraulic oil to the hydraulic chamber 6b is cut off, so the shift bin 6a is closed to the resilient material that urges the return pin 6. 69 tries to return into the hydraulic chamber 6b.

However, as shown in FIG. 13, the hydraulic oil supplied from the hole 26 to the pressure receiving part 23a of the timing bin 23 during hydraulic pressure continues during the lift period even if the supply of hydraulic oil to the oil passage 6d is cut off. The guide hole 24 and the hole 26 remain sealed until they are brought into communication. Therefore, until the lift period begins, the timing bin 23 remains engaged with the engagement groove 22, and the timing bin 23 prevents the shift bin 6a from returning. Then, during the lift period, the hydraulic oil that was sealed in the pressure receiving part 23a is removed from the oil passage 6d.
When the timing bin 23 is returned to the rocker arm shaft 2 side by the force of the resilient member 25 as shown in FIG.
is pushed back into the hydraulic chamber 6b by the force of the elastic material 6g,
Switch to hibernation state.

In the embodiment shown in FIG. 9, the tip 23b of the timing bin 23 that enters the engagement groove 22 is formed into a spherical shape, and the engagement pin 23b is engaged with the tip 23b when the shift bin 6a returns. Although the side surface 22a of the groove 22 is made into an inclined surface, with such a structure, when the tip portion 23b comes into contact with the side surface 22a of the engagement groove 22, the frictional force that acts between them becomes small. And as shown in FIG. 15(a),
A force F that pushes out the timing bin 23 is generated. Therefore, the return movement of the timing bin 23 becomes smoother, and compared to the case where the engagement groove 22 has a shape like No. It becomes possible to create a small device with small constants.

Further, in the embodiment shown in FIG. 9, the locking portion 11b of the timing plate 11 is brought into contact with a stopper bin 27 fixedly installed on the cylinder head 1 side, and the stopper bin 27
However, with this configuration, even if the rocker arms 3 and 4 are lowered, the plate 11 will not be lowered together. Therefore, the weight of the timing plate 11 is not added to the inertial mass of the valve drive system, and an increase in the inertial mass is prevented.

〔Effect of the invention〕

As explained above, in the valve operating device with a valve deactivation function of the present invention, the valve is biased from the cam side to open by a spring between the deactivation side rocker arm and the drive side rocker arm, and the shift bin is pushed in from the cam side. The structure includes a timing plate that closes a part of the engagement hole for shift 1.
- No matter when the oil pressure for operating the bin is activated, the timing at which the shift bin enters the engagement hole is always set at the beginning of the base circle period B of the drive-side rocker arm by the timing plate. Therefore, sufficient time is secured for the shift bin to plunge into the engagement hole, preventing poor engagement of the shift bin regardless of the timing of the hydraulic pressure activation, and ensuring a single plunge movement of the shift bin. It is now possible to switch from hibernation state to linked state.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of an embodiment of the valve train of the present invention, FIG. 2 is a cross-sectional view taken along the line ■-■ in FIG. 1, and FIG.
-[[Cross-sectional view along the line, Figures 4, 5, 6 (aJ
~(d), Figures 7 and 8 (al ~ (e) Lt are explanatory diagrams of the operation of one embodiment, respectively. Figure 9 is a sectional view of another embodiment of the valve train according to the present invention. Figure 10 is The figure is X- in Figure 9.
11 is a cross-sectional view taken along the XI-XI line in FIG. 9, FIGS. 12, 13, 14, and 1.
Figure 5 (al, (b+) is an explanatory diagram of the operation of the other embodiments, Figure 16 is a cross-sectional view of the conventional valve operating system with valve stop function A, and Figure 17 is
FIG. 18, which is a sectional view taken along the VU line, is an explanatory diagram of the operation of the rocker arm. 3.4...Rocker arm, 5a...
Cam, 6... Acticoator, 6a...
・Shift bin, 6b...Hydraulic pressure to, 5c, 5d・
...Oil passage, 6e...Engagement hole, 6f...
... Return bottle, 6g ... Bullet material, 6h...
...small diameter part, 61 ... recess, 7b ...
... Valve, 8 ... Rocker arm spring, 1
1... Timing plate, 14...
Lubricating device, A...Ref l-period, B...
・Base yen period. Applicant Honda Motor Co., Ltd. Figure 1 Figure 6 Figure 7 Figure 8 Figure 5CR11, < Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 d Figure 14 Figure 15 Figure 16 Figure 18 valve

Claims (1)

[Claims] In an internal combustion engine in which a plurality of intake or exhaust valves are arranged in one cylinder, a pair of rockers adjacent to each other and pivotally supported on a hollow rocker arm shaft for opening and closing the plurality of valves. It is equipped with an arm, a hydraulic actuator that engages the pair of rocker arms with each other, and a cam that rotates in synchronization with the movement of the piston in the cylinder and swings one of the pair of rocker arms. The hydraulic actuator disengages the φ rocker arms from each other depending on the situation, and the valve operated by the rocker arm on the side not driven by the cam is placed in a rest state. The actuator includes a hydraulic chamber formed in one of the pair of rocker arms so as to be released to the other, a shift pin for engaging both O-tsuka arms that is slidably housed in the hydraulic chamber, and a shift pin that corresponds to the hydraulic chamber. an engagement hole formed in the other rocker arm into which the shift pin can be inserted; a return pin slidably housed in the engagement hole; and the return pin is pressed against the shift pin to engage the shift pin. It includes an elastic member that is biased so as to be pushed out of the hole, and an oil passage that guides hydraulic fluid to the hydraulic chamber in order to cause the shift scissin to protrude toward the other rocker arm side against the urging force of the elastic member. A small diameter portion is formed at the end of the return pin that abuts the shift pin, and a spring urges the valve copper from the cam side by a spring, and the outer periphery of the small diameter portion is formed between the pair of rocker arms. 1. A valve operating device with a valve stop function, characterized in that a timing plate is provided which abuts a part of the engagement hole and prevents the shift pin from entering.