JPH0536605B2 - - Google Patents

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention is directed to a valve train disposed in a valve train having a cam operated by an internal combustion engine and an intake/exhaust valve interlocked with the cam. This relates to a variable cylinder system for internal combustion engines, and is applied to internal combustion engines such as automobiles that stop the operation of some of the intake and exhaust valves linked to multiple cylinders to perform cylinder reduction operation to improve fuel efficiency.

(Prior art) As the above type of prior art, for example,
The one described in Publication No. 87941 is already known. This includes a plunger that is slidably disposed inside the rocker arm and is biased in one direction by a spring and biased in the other direction by hydraulic pressure, and a plunger that is interlocked with the plunger and is pushed to the outside of the rocker arm. It has an extending rod and a stopper actuated by the rod, and the stopper limits the position of a connecting member that engages and disengages the cam and the supply/exhaust valve via the rocker arm.

(Problems to be Solved by the Invention) In the above-mentioned conventional technology, either the connecting member that transmits the operation of the cam to the supply/exhaust valve is held in an interlocking position, or
In order to permit idle operation of the rocker arm relative to the connecting member, the aforementioned plunger, a rod actuated by the plunger, and a stopper actuated by the rod are required to limit the position of the connecting member. However, there were problems in that the structure was complicated and the number of parts increased, resulting in high costs.

Therefore, the technical object of the present invention is to reduce the number of parts and simplify the configuration by allowing or preventing the plunger itself from idling with the stem portion in the valve train.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a cam operated by an internal combustion engine,
A body disposed in a valve train having an intake and exhaust valve interlocked with the cam and sliding in a cylinder formed in a block of the internal combustion engine in constant interlock with the cam;
a stem portion of the valve train that slides within the body in the same direction as the sliding direction of the body; a plunger that is urged to a first position for interlocking the body and the stem portion, and a hydraulic chamber formed in the body by the plunger, and an oil formed between the sliding surfaces of the cylinder and the body. a solenoid valve for supplying and discharging hydraulic pressure through a passage, and for operating the plunger to a second position against the spring by the hydraulic pressure; and a computer for operating the solenoid valve; When the plunger is in the second position, the stem portion, which is always interlocked with the supply/exhaust valve, fits into a recess formed in the plunger, thereby allowing idle operation between the stem portion and the body, thereby allowing the supply/exhaust valve to operate at idle. The system is configured so that the operation of the system stops.

(Function) In the present invention described above, when the plunger is operated to the second position by the hydraulic pressure controlled by the solenoid valve, the stem portion in the valve train moves into the recess formed in the plunger. Since the plunger and the stem are inserted into the recess and are linked to the operation of the cam, they operate at idle, so the operation of the cam is not transmitted to the supply/exhaust valve, and the operation of the supply/exhaust valve can be stopped, and the plunger itself Since the recess formed in the valve system allows idling operation between the valve system and the stem part constituting the valve train, there is no need for a large number of components as in the conventional system. The plunger and spring are placed in a body that slides in a cylinder formed in the block of the internal combustion engine in constant interlocking with a cam, and the slide between the cylinder and the body is placed in a hydraulic chamber formed in the body by the plunger. Since the hydraulic pressure is supplied and discharged through the oil passage formed between the dynamic surfaces, the entire device is compact.

(Example) Hereinafter, an example of the present invention will be described with reference to the accompanying drawings.

In FIGS. 1 to 4 showing the first embodiment of the present invention,
A direct type valve train for an internal combustion engine has a cam 10 rotated by the internal combustion engine, and an intake/exhaust valve 11 interlocked with the cam 10. Supply and exhaust valve 11
The engine has an integral stem part 14 that slides inside a cylinder 18 formed in the block 12 through a valve guide 13 that is press-fitted into the engine block 12. A retainer 16 is fixed. The spring 17 disposed between the retainer 16 and the block 12 is
Valve 11 is biased upward in FIG. A body 19 that is above the cylinder 18, engages with the cam 10, and slides within the cylinder 18 in accordance with the rotation of the cam 10 has a plunger 21 inside thereof that is slidable by a spring 20. have The plunger 21 partitions an atmospheric pressure chamber 22 in which a spring 20 is disposed and a hydraulic pressure chamber 23 in the body 19, and is normally placed in a first position (a first position) regulated by a snap spring 24 by the spring 20. 1, 2)
is urged to. The atmospheric pressure chamber 22 is connected to the atmosphere through a hole 25 formed in the body 19, a cylinder 18, and an appropriate hole formed in the block 12. An annular groove 26 on the outer periphery of the body 19 leading to the hydraulic chamber 23
The groove 26 is connected to a hydraulic power source 2 as appropriate via a passage 27 formed in the block 12 and a solenoid valve 28.
It is connected to 9. Reference numeral 30 denotes a computer that generates a signal to control the number of operating cylinders according to the driving situation of the vehicle. The hydraulic pressure is transmitted to the hydraulic chamber 23. At this time, the plunger 21 is moved to the left against the spring 20 to the second position (Figs. 3 and 4).
leading to. The upper end of the stem portion 14 of the supply/exhaust valve 11 is
It extends to the plunger 21 through a hole 34 formed in the body 19 and is fitted into a groove 31 formed in the plunger 21 to have a function of preventing rotation of the plunger 21. The plunger 21 includes a stem portion 1
It has a recess 32 formed as an elongated hole capable of receiving the upper end of the cylindrical member 4. Further, a spring 33 having a smaller urging force than the spring 17 is disposed between the body 19 and the retainer 16.

In the above configuration, the plungers 21 are the first and second plungers.
When in the first position shown, the upper end of the stem portion 14 of the supply/exhaust valve 11 is fitted into the groove 31 of the plunger 21, and therefore, the rotation of the cam 10 causes the body 19 to move inside the cylinder 18. When it slides, the supply and exhaust valve 11 is opened and closed via the plunger 21, and is operated steadily. Note that when the base circle of the cam 10 is engaged with the body 19, a predetermined clearance A is formed between the plunger 21 and the upper end of the stem portion 14, and the valve 11 is closed by the spring 17. , the cam portion 35 of the cam 10
When the plunger 21 comes into contact with the body 19, the body 19 is moved downward, and the plunger 21 comes into contact with the upper end of the stem portion 14, thereby opening the valve 11. The above-mentioned solenoid valve 28 supplies the hydraulic pressure to the hydraulic chamber 23, and the plunger 21 moves to the second position (third, fourth position).
When reaching the position shown in FIG. 3, the upper end of the stem portion 14 is inserted into the elongated hole 32. Therefore, at this time, even if the body 19 having the plunger 21 slides within the cylinder 18 in response to the operation of the cam 10, the operation of the body 19 is not transmitted to the stem portion 14, and the operation of the supply/exhaust valve 11 is not transmitted. will be stopped.

The switching of the supply/exhaust valve 11 from the working position to the non-working position or vice versa is done when the base circle of the cam 10 is engaged with the body 19, and therefore, especially in the former case. The supply and exhaust valve 11 is
Since the valve 11 is in the closed position or close to the closed position, rapid movement of the valve 11 at the time of switching is prevented, the noise of the valve 11 coming into contact with the seat formed in the block 12, etc. is reduced, and the valve part This prevents the durability from deteriorating.

FIG. 5, which shows a modification of the present invention, shows an example applied to an OHV type internal combustion engine, in which substantially the same members as in the previous embodiment are designated by the same numbers.
Detailed explanation will be omitted.

In this modification, the operation of the cam 10 is controlled by the supply/exhaust valve 11 via a body 19 interlocked with the cam 10, a plunger 21 disposed within the body 19, a piston 50, a push rod 51, and a well-known rocker arm 52. transmitted to. Body 19 is
It has a cylinder 54 extending from a wall portion 53 housing the plunger 21 toward the push rod 51, and a piston 50 is slidably disposed within the cylinder 54. The piston 50 is biased by a spring 55 disposed between it and the wall 53 of the body 19, and has a large diameter portion 56 that slides within the cylinder 54 and a stem portion 57. A stem portion 57 extends toward the plunger 21 through a hole in the wall portion 53 as in the previous embodiment. The atmospheric pressure chamber 22 is connected to the atmosphere through the hole 25, the chamber in which the spring 55 is housed, and the hole 58. The illustrated upper end of piston 50 receives the lower end of push rod 51.

Also in this modification, when the plunger 21 is in the first position shown, the stem portion 5 of the piston 50
7 is located in the groove 31 of the plunger 21, and the operation of the cam 10 is similar to the previous embodiment.
transmitted to. Hydraulic pressure is supplied to the chamber 23,
When the plunger 21 reaches the second position, the piston 5
The stem portion 57 of the piston 50 is fitted into the recess 32 formed as a long hole of the plunger 21.
In order to allow idle operation between the pump and the plunger 21, the operation of the cam 10 is not transmitted to the supply/exhaust valve 11, similar to the above-described implementation difference.

〔Effect of the invention〕

As described above, in the present invention, the hydraulically operated plunger itself is formed with a recess into which the stem portion of the valve train or the like is fitted, allowing idling operation between the plunger and the stem portion, thereby achieving variable cylinder control. Because of this, the structure is simple and the number of parts does not increase as in the conventional case. The plunger and spring are placed in a body that slides in a cylinder formed in the block of the internal combustion engine in constant interlocking with a cam, and the slide between the cylinder and the body is placed in a hydraulic chamber formed in the body by the plunger. Since the hydraulic pressure is supplied and discharged through the oil passage formed between the dynamic surfaces, the entire device is compact. Further, the variable cylinder device according to the present invention has the advantage that it can be applied to various types of internal combustion engines, including the OHV type and the direct type.

[Brief explanation of the drawing]

Fig. 1 shows an embodiment of the present invention, and shows the interlocking state of the cam and the supply/exhaust valve, and Fig. 2 shows the -
3 is a sectional view showing a non-interlocking state of the cam and the supply/exhaust valve, FIG. 4 is a sectional view taken along the line -- of FIG. 3, and FIG. 5 is a view showing a modification of the present invention. 10...cam, 11...supply/exhaust valve, 14,57
... Stem section, 19 ... Body, 20 ... Spring, 21 ... Plunger, 23 ... Hydraulic chamber, 2
8... Solenoid valve, 29... Hydraulic power source, 30... Computer, 32... Long hole (recess).

Claims (1)

[Claims] 1 disposed in a valve train having a cam operated by an internal combustion engine and an intake/exhaust valve interlocked with the cam;
A body that slides inside a cylinder formed in a block of an internal combustion engine in constant interlocking with the cam, a stem portion of the valve train that slides inside the body in the same direction as the sliding direction of the body, and the body. a plunger that is slidably disposed within the body in a direction perpendicular to the sliding direction of the body and is biased by a spring to a first position that interlocks the body and the stem portion; A hydraulic pressure is supplied and discharged to a hydraulic chamber formed within the cylinder through an oil passage formed between a sliding surface of the cylinder and the body, and the hydraulic pressure moves the plunger to a second position against the spring. The stem portion is provided with a solenoid valve for actuating the solenoid valve and a computer for actuating the solenoid valve, and is in constant communication with the supply/exhaust valve within a recess formed in the plunger when the plunger is in a second position. A variable cylinder device for an internal combustion engine, wherein the variable cylinder device for an internal combustion engine is characterized in that idling operation between the stem portion and the body is permitted and operation of the intake and exhaust valves is stopped by fitting the stem portion into the variable cylinder device.