JPH04295113A - Variable cylinder device - Google Patents

Abstract

PURPOSE:To provide a simple structure in a variable cylinder device which includes a hydraulic lifter with a ball check valve built in, by installing a solenoid valve in a pressurized oil passage for a press rod moved by hydraulic pressure, and mounting a rotating plate for opening and closing a passage in its open passage to the atmosphere. CONSTITUTION:At the time of cylinder cut off operation, a solenoid valve 34 is energized to tract a plunger, open a pipe 36 and lead oil from an oil passage 40 into an oil feed hole 27, so that a press rod 23 is pushed up and a ball check valve 22 is opened. This kills the rigidity of an hydraulic lifter 31 and stops pressing down a valve 5 by a locker arm 3 regardless of rotation of a cam 1. At this time, a rotating plate 37 is rotated with the rotation of a gear 41 on a camshaft 1, and when the cam 1 comes into contact with the locker arm 3 and a cam base circle, oil is ejected to an open port 42 through an arc-shaped hole 38 from an atmosphere open port 39 to lower the press rod 23 with a spring 25 and close the ball check valve 25.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable cylinder device for an internal combustion engine.

0002

2. Description of the Related Art FIG. 4 is a partial sectional view showing a conventional hydraulic lifter mechanism for an internal combustion engine, in which a piston (not shown) reciprocates up and down inside a cylinder 51 formed in a cylinder block 50. A combustion section 53 is formed above the piston by a cylinder head 52 forming the upper end of the cylinder 51 . Communication between the combustion section 53 and the cylinder head port 54 is controlled to open and close by a valve 55, and a valve stem 57 is slidably inserted into a valve guide 56 formed in the cylinder head 52. A valve spring 60 is stretched between a spring seat 58 formed at the upper end of the cylinder head 52 and a spring retainer 59 fixed to the upper end surface of the valve stem. As a result, the valve 55 is always urged upward in the figure so as to be seated on the valve seat 61.

[0003] Also, the rocker arm 62 has one end 62
a is connected to the top of the valve stem 57, and the other end 62b is connected to the top of the valve stem 57.
is in contact with the cam surface 63a of the camshaft 63. The rocker arm 62 is fixed to a rocker supporter 64 and is swingable about a fulcrum A of the supporter 64. Further, due to the rotational movement of the camshaft 63, the rocker arm 62 performs a rocking movement, and as a result, the valve 55
The opening and closing operations are repeated.

A lower portion of a known pressure-feed type lash adjuster 70 is inserted and fixed into the hollow portion of the rocker supporter 64. Further, the upper part of the adjuster 70 is slidably inserted into the hollow part of the adjuster supporter 71, and the adjuster body 72 that constitutes the upper part of the adjuster 70 has a cylinder 73 with an open upper end formed therein. A plunger 74 is configured to reciprocate in the vertical direction within the cylinder 73. Further, a reservoir 75 is formed inside the plunger 74, and oil is supplied into the reservoir 75 from an oil pump. 76 is a plunger support having an oil supply port 76a.

On the other hand, the cylinder 73 of the adjuster body 72
A pressure chamber 85 is formed inside by the lower end surface of the plunger 74, and an oil passage 77 is formed at the center of the bottom 74a of the plunger 74.
A known ball check valve 78 is provided on the side. This check valve 78 allows oil to flow from the reservoir 75 to the pressure chamber 85, but prevents oil from flowing from the pressure chamber 85 to the reservoir 75. Further, the check valve 78 is constantly biased in the closing direction by a spring 80 whose one end is supported by the retainer 79. 81 is a plunger return spring, and 82 is a snap ring.

A solenoid valve 83 mounted above the adjuster supporter 71 is operated by a microcomputer (not shown), and the microcomputer senses engine input signals such as vehicle speed, throttle opening, and engine temperature. Thus, the solenoid valve 83 is controlled and operated. The valve stem 84 of the solenoid valve 83 is disposed in the reservoir 75 passing through the center of the upper end surface 71a of the adjuster supporter 71, and is slidable in the vertical direction. Then, the valve stem 84 moves downward in response to the operation of the solenoid valve 83, and the check valve 7
8 is pressed downward, and as a result, the oil passage 77 opens and some of the oil in the pressure chamber 85 moves into the reservoir 75. Further, a ring-shaped stopper 85 is attached to the upper part of the valve stem 84.

In the conventional hydraulic lifter mechanism shown in FIG. 4 constructed as described above, the valve stem 84 moves downward due to the operation of the solenoid valve 83 and pushes the check valve 78, thereby eliminating the rigidity of the hydraulic lifter. The reciprocating movement of the valve 78 is stopped to create a variable cylinder.

[0008]

[Problems to be Solved by the Invention] The conventional hydraulic lifter mechanism shown in FIG. 4 has no restrictions when the solenoid valve 83 returns and the cylinder is restored. If the solenoid valve 83 returns to its original state when the cam nose is in contact with the rocker arm 62, an incomplete valve lift will occur from that point on, resulting in incomplete combustion and valve seating noise. There were problems such as the occurrence of Furthermore, in the conventional mechanism shown in FIG. 4, the number of solenoid valves 83 required is equal to the number of valves 55 that cut cylinders. For example, when applied to a four-valve, eight-cylinder engine, four out of eight cylinders are cut, and four /2=16 valves are required. This not only increases costs and power consumption, but also increases the size of the mechanism, which is very disadvantageous in terms of installation.

The present invention provides a variable cylinder device that requires only one solenoid valve to solve the above-mentioned conventional problems.

0010

[Means for Solving the Problems] Therefore, the present invention provides a system in which a valve for opening and closing a cylinder and an end of a hydraulic lifter are engaged with a rocker arm that is pushed by rotation of a cam, and a ball of the hydraulic lifter is engaged with a rocker arm that is pushed by rotation of a cam. In a variable cylinder device in which a check valve is made into a variable cylinder by pushing a check valve with a push rod moved by hydraulic pressure to eliminate the rigidity of a hydraulic lifter, a solenoid valve is provided in a pressurizing oil path of the push rod, and the solenoid valve is A rotary plate is provided in the atmosphere opening passage, and the plate is provided with an arcuate hole for turning on and off the atmosphere opening passage, and the rotating plate is arranged so that the atmosphere opening passage is turned on only at the cam base circle of the cam. The cams are synchronized, and this is a means to solve the problem.

[0011]

[Operation] When the ball check valve of the hydraulic lifter is closed, the valve is pushed against force by the rotation of the cam, opening and closing the cylinder. Next, during cylinder reduction operation, the solenoid valve is activated, and hydraulic pressure is applied to the push rod to open the ball check valve, which eliminates the rigidity of the hydraulic lifter, and even when the cam rotates, the plunger of the hydraulic lifter is pushed and sinks. Therefore, the valve remains closed and cylinder reduction operation is performed. Further, in the cam base circle, the atmosphere release passage is turned on, the ball check valve is closed, and the hydraulic lifter has rigidity, so only one solenoid valve is required, and the valve is reciprocated to open and close by the rotating cam.

0012

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. FIGS. 1 to 3 show embodiments of the present invention. In the figure 1
, 2 are cams, and when the cams 1 and 2 rotate, valves 5 and 6 are opened and closed via rocker arms 3 and 4. Also, the upper ends of the valves 5 and 6 are the rocker arm 3,
4, the lower end valve body also engages with the valve seat 15.
, 16, and is urged upward by springs 7 and 8. Moreover, in the upper part of the valves 5 and 6,
Spring retainers 9, 1 via cotters 11, 12
0 is fixed, the upper and lower ends of the springs 7 and 8 are interposed between the grooves of the retainers 9 and 10 and the cylinder head 32, and the convex parts of the cams 1 and 2 press the rocker arms 3 and 4. At this time, if the hydraulic lifters 31, 31 maintain their rigidity, the springs 7, 8 are compressed, and the valves 5, 6 are separated from the valve seats 15, 16. That is, the rocker arms 3 and 4 are supported by the plunger 17 of the hydraulic lifter 31, and the hydraulic lifter 31 is supported by the body 18 fitted to the cylinder head 32, the ball check valve 22, the check valve spring 21, and the plate 33.
, a return spring 20, and a plunger 17, and oil is supplied from an oil supply hole 26, filling a reservoir chamber 30 and a pressure chamber 29.

Reference numeral 19 denotes a plate that comes into contact with the lower surface of the body 18 fitted into the cylinder head 32, and the plate 19 constitutes the bottom surface of the reservoir chamber 30. Reference numeral 23 denotes a push rod urged downward by a spring 25 whose upper end is in contact with the plate 19. The push rod 23 is disposed in the cylinder head 32 so as to be movable up and down. It is designed to hang on the bottom surface of the Further, the oil supply hole 27 communicates with a hole in the block 35 through a pipe 36, and oil is supplied to the hole 27 from an oil passage 40 through the block 35 through the solenoid valve 34 and the pipe 36. The solenoid valve 34 has a solenoid coil 43 and a plunger 44.
4 controls the opening and closing of the pipe 36. A gear 41 is provided on the shaft of the cam 1, and the gear 41 meshes with the gear of a rotary plate 37 having a gear rotatably attached to the block 35. An arcuate hole 38 is provided, and the hole 38 can communicate with and be cut off from an opening 39 provided in the block 35. That is, the hole 38 is only open in the cam base circle of the cam 1.
The rotating plate 37 and the cam 1 are synchronized so as to communicate with the cam 9.

Next, the operation will be explained. First, during cylinder reduction operation,
When current flows through the solenoid coil 43 of the solenoid valve 34, the plunger 44 is pulled and the pipe 3
6 is opened, oil from the oil passage 40 flows through the pipe 36 and enters the oil supply hole 27, and since oil pressure is applied to the push rod 23, the push rod 23 is pushed up and pushes the ball check valve 22. Therefore, as the oil in the pressure chamber 29 flows into the reservoir chamber 30, the rigidity of the hydraulic lifter 31 is lost, and the cam 1 rotates and the rocker arm 3
Even if , the plunger 17 moves within the body 18, so the rocker arm 3 does not push down the valve 5. Valve 5 therefore remains closed. In this case, since the O-ring 28 is fitted into the plate 19, oil from the reservoir chamber 30 will not flow into the chamber on the upper surface of the push rod 23. Therefore, when the push rod 23 is pushed up, the oil in the chamber on the upper surface escapes from the oil drain hole, and the push rod 23 moves smoothly.

The oil supply hole 27 communicates with the block 35 through a pipe 36, and oil is supplied from the oil passage 40 to the solenoid valve 34 via the block 35.
When the solenoid valve 34 is on, that is, current flows through the solenoid coil 43, the plunger 44 moves to open the pipe 36, and oil is supplied from the pipe 36 to the oil supply hole 27. Further, when the gear 41 rotates, the rotating plate 37 having a gear that meshes with the gear 41 rotates, and when the cam 1 is in contact with the rocker arm 3 at the cam base circle, the arc-shaped hole is opened from the atmosphere opening 39 of the solenoid valve 34. Oil is released through 38 into the opening 42. Therefore, the push rod 23 is the return spring 25
The ball check valve 22 comes into contact with the seat surface of the body 18 due to the urging force of the spring 21, and communication between the pressure chamber 29 and the reservoir chamber 30 is cut off.

[0016]

Effects of the Invention As explained in detail above, the present invention synchronizes the rotating plate and the cam so that the atmosphere release passage is turned on only at the cam base circle, which eliminates the need for solenoids, which were conventionally required for the number of valves. Only one is needed. In other words, when the cam base circle of one cam is in contact with the rocker arm, the hydraulic lifter maintains its rigidity, so
When the other cams push each rocker arm in turn, the valves open in sequence. Therefore, since only one solenoid valve is required, the number of parts is small, the structure is simple, and costs can be reduced. Moreover, it has excellent effects such as reliable on/off switching. be.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of a variable cylinder device showing an embodiment of the present invention.

FIG. 2 is a side sectional view of the solenoid valve section in FIG. 1;

FIG. 3 is a view taken along arrow A in FIG. 1;

FIG. 4 is a longitudinal sectional view of a conventional variable cylinder device.

[Explanation of symbols]

1, 2 Cam 3, 4 Rocker arm 5, 6 Valve 7, 8 Spring 9, 10 Retainer 11, 12 Cotter 15, 16 Valve seat 17 Plunger 18 Body 19 Plate 20, 21 Spring 22 Ball check valve 23 Push rod 25 Spring 26, 27 Oil supply hole 29 Pressure chamber 30 Reservoir room 31 Hydraulic lifter 32 Cylinder head 34 Solenoid valve 35 blocks 36 pipe 37 Rotating plate 38 Arc-shaped hole 39 Atmospheric release port 40 Oil road 41 Gear 42 Open mouth

Claims (1)

[Claims] Claim 1: A valve that opens and closes a cylinder and an end of a hydraulic lifter are engaged with a rocker arm that is pushed by the rotation of a cam, and a pusher that moves a ball check valve of the hydraulic lifter using hydraulic pressure. In a variable cylinder device that makes a variable cylinder by pushing with a rod to eliminate the rigidity of a hydraulic lifter, a solenoid valve is provided in the pressurizing oil path of the push rod, and a rotary plate is provided in the atmosphere opening path of the solenoid valve, The plate is provided with an arcuate hole for turning on and off the atmosphere opening passage, and the rotary plate and the cam are synchronized so that the atmosphere opening passage is turned on only at the cam base circle of the cam. Variable cylinder device.