JPH0610637A - Variable intake and exhaust engine - Google Patents

Abstract

PURPOSE:To provide weight reduction, in a variable intake and exhaust engine whose jointing member between a stem and a cam/a rocker arm is formed of a material which can withstand the high load of the stem and is a member which requires switching operation, thus causing unavoidable weight increase. CONSTITUTION:A slider 22 is disposed in the plunger 17 of a jointing member 8, and the slider 22 is engaged and disengaged with/from a stem 4. Moreover, the slider 22 is guided by a pad 12 to make a plunger come into smooth action.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable intake / exhaust engine having a mechanism for suspending at least a pair of intake / exhaust valves of the intake / exhaust valves.

[0002]

2. Description of the Related Art The operation of intake / exhaust valves and fuel supply are stopped to deactivate the cylinder, or the valve timing and stroke are changed to change the intake / exhaust amount according to the load condition of the engine to reduce the fuel consumption amount. Also, it is known to improve the output.

Generally, an intake / exhaust valve for opening and closing an intake hole and an exhaust hole opened in an engine combustion chamber has one end of a rocker arm swinging around a support shaft abutting the tip of a stem integral with the valve and the other end. It is often used to control the opening and closing by a mechanism that connects the push rod to the push rod via the adjuster and connects the push rod to the cam via the tappet, or to connect the cam to the other end of the rocker arm, and also to lift the stem to the lifter. A direct method in which a cam is directly abutted via a valve is also widely used, and many opening and closing mechanisms for intake and exhaust valves have been proposed.

In order to stop the cylinder by keeping the intake and exhaust valves closed, a lifter, that is, a connecting member between the pressing member such as the rocker arm and the cam and the tip of the stem is improved. An example thereof is disclosed in Japanese Utility Model Publication No. 3-7526.

In this known example, a plunger having an axial center orthogonal to the axial direction of the stem is arranged in the connecting member. The plunger has a receiving surface that can come into contact with the tip of the stem, and an idle hole that receives the tip of the stem.
When the hydraulic pressure is applied to one end, it slides in the connecting member against the urging force of the spring on the other end, and guides the stem tip portion, which is in contact with the receiving surface, to the idle hole. When the stem tip enters the idle hole, the reciprocating motion from the pressing member such as the rocker arm or cam only moves the stem tip into and out of the idle hole of the plunger of the connecting member, and is not transmitted to the stem.
The intake and exhaust valves remain closed. When the hydraulic pressure to one end of the plunger is released and the connecting member reaches the upper limit position (the stem tip is protruding from the idle hole at this time), the spring at the other end of the plunger returns the plunger to the initial position, that is, the receiving surface. Return the stem tip to the position where it abuts,
It is possible to open and close the intake and exhaust valves regularly.

[0006]

In the above-mentioned conventional example,
The receiving surface of the plunger in the connecting member receives the spring load of the stem and comes into contact with the tip of the stem. At this time, since the line of action of the spring force of the stem and the axial direction of the plunger are orthogonal to each other, the plunger receives a force to deflect the axial center and this force is applied to the connecting member via the outer peripheral surface of the plunger. Will be transmitted. Such force transmission causes uneven wear on the plunger receiving surface and the outer peripheral surface, and also deflects the axial center of the plunger, resulting in a lack of smooth movement of the plunger and leaving a problem in the reliability of valve switching operation. ing.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to use a valve system or the like of the duct type so as to establish cylinder deactivation or variable valve timing and lift. .

[0008]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention basically comprises means for arranging a slider capable of contacting a stem in a plunger that receives hydraulic pressure and a biasing force of a spring. Used for.

Specifically, the present invention relates to an intake / exhaust valve connected to a stem that opens and closes an intake hole and an exhaust hole that open to an engine combustion chamber and reciprocates, and at least one of the intake and exhaust valves. A connecting member arranged between the stem and a device for reciprocating the stem, wherein the connecting member is a housing housed in a cylinder head; A cylinder having an axis perpendicular to the axis, a plunger that slides in the cylinder by hydraulic pressure acting on one end, and a spring that acts to oppose the other end of the plunger to the hydraulic pressure,
There is provided a variable intake and exhaust engine having a slider arranged in the plunger so as to come into contact with the tip of the stem during valve operation. Preferably, the housing has a pad, which extends into the cylinder and is slidable on the slider.

Preferably, the spring is a leaf spring or a wire spring, one end is locked to the plunger and the other end is locked to the housing, the plunger is made of an aluminum alloy, and the slider is an iron-based alloy. Even when the valve is stopped, a part of the pad is in contact with the slider.

[0011]

Since the slider adopted in the present invention receives the load applied to the stem and the load from the stem is not transmitted to the plunger and the cylinder, the sliding relationship of the plunger with respect to the cylinder is properly maintained. Further, at that time, the slider can serve as a guide surface for the sliding.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A variable intake / exhaust engine as an example of the present invention will be described with reference to FIG. A valve 3 that opens and closes an intake hole or an exhaust hole 2 that opens in a cylinder head 1 made of aluminum alloy.
The stem 4 is extended to the outside integrally with. Stem 4
A valve 7 is provided by a spring 7 arranged between a retainer 5 held on the stem 4 and the bottom wall of the hole 6 of the cylinder head 1.
Is urged in the closing direction.

At the upper opening of the hole 6 of the cylinder head 1, a lifter or connecting member 8 is arranged. The connecting member 8 transmits the movements of the cam 9 and the rocker arm (not shown) to the stem 4, and functions to open and close the valve 3 periodically.

The connecting member 8 has a housing 10 made of an aluminum alloy having an axis perpendicular to the axis of the stem 4. A spring 1 arranged between the housing 10 and the bottom wall of the hole 6.
1, the pad 12 provided on the upper surface of the housing 10 is always brought into contact with the cam 9. A cylinder 13 made of aluminum alloy is fitted into the central hole of the housing 10. The cylinder 13 has its opposite ends supported by the housing 10. Cylinder 13
One end 14 is closed and the other end 15 is open. The opening 15 communicates with an oil pump (not shown) via an oil passage 16 between the housing 10 and the inner peripheral surface of the hole 6.

An aluminum alloy plunger 17 is slidably arranged in the cylinder 13. One end 18 of the plunger 17 is closed and one end of the leaf spring 19 is fixed. Leaf spring 19
The other end extends from the opening of the cylinder 13 to the inner wall of the housing 10 and abuts against this inner wall. Plunger 17
The other end 20 is exposed to the opening 15 of the cylinder 13. Thus, the urging force of the spring 19 acts on one end 18 of the plunger 17 and the hydraulic pressure acts on the other end 20, so that the plunger 17 can slide left and right in response to these forces.

The outer peripheral surface of the plunger 17 is in the shape of a cylinder that is in sliding contact with the inner peripheral surface of the cylinder 13, and the stepped wall surfaces 21 face each other between them, as shown in FIG.

A slider 22 is mounted between the stepped wall surfaces 21 of the plunger 17. The slider 22 is made of a wear-resistant iron-based alloy, and has a surface 23 that is engageable with the tip of the stem 4,
The step portion 2 seated on the step portion of the facing wall surface 21 of the plunger 17.
4, housing 10, cylinder 13 and plunger 17
It has a guide surface 25 that is in constant contact with the portion of the pad 12 that extends through. The slider 22 is supported by the plunger 17 by the elastic force of a seat spring or an O-ring provided on the stepped portion 24 of the slider 22 to bring the slider 22 and the pad 12 into sliding contact with each other and prevent relative movement with respect to the plunger 17.

The state shown in FIG. 1 is when the valve is operated, and the stem 4 is connected to the cam 9 and the like via the slider 22 and the pad 12. The rotational movement of the cam 9 is caused by the springs 7 and 1.
The connecting member 8 and the stem 4 are pushed down against the urging force of 1, and the valve 3 is opened. The movement of the cam 9 eventually allows the connecting member 8 and the stem 4 to return to their original positions by the urging forces of the springs 7 and 11 to close the valve 3.

Next, when the valve 3 is stopped, an oil pressure is supplied to the inside of the opening 15 of the cylinder 13 through a passage 16 by a device (not shown) to apply a pressure to the wall 20 of the plunger 17 to cause the leaf spring 19 to move. Plunger 1 against urging force
7, is moved to the left as shown in FIG. This movement is performed while the guide surface 25 is guided by the pad 12, and the engagement of the stem 4 with the surface 23 of the slider 22 is released. Therefore, the tip of the stem 4 can be retracted between the facing surfaces 21 of the plunger 17.

Even if the rotational movement of the cam 9 is transmitted to the pad 12 and the connecting member 8 is pushed down, the stem 4 remains as it is, and the tip of the stem 4 simply appears and disappears between the facing surfaces 21. The valve 3 remains closed.

[0021]

According to the present invention, since the slider that abuts the stem is a member separate from the plunger, only the slider needs to be made of a wear-resistant material, compared to the case where the entire plunger is made of a wear-resistant material. Not only is it economical,
Cylinder wear can be reduced. Since a leaf spring is attached to one end of the plunger, and this leaf or wire spring is in contact with the inner wall surface of the housing to secure its length, compared to attaching a coil spring to the plunger,
The length of the cylinder can be shortened, which contributes to weight reduction. Stopping the valve and switching the operation are smooth because the slider is always in contact with the pad and the movement of the plunger is guided by the pad.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an example of the present invention.

FIG. 2 is a sectional view showing a position of a slider when a valve is stopped.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a sectional view taken along the line IV-IV in FIG.

[Explanation of Codes] 1 Cylinder head 3 Valve 4 Stem 7, 11 Spring 12 Pad 13 Cylinder 17 Plunger 19 Leaf spring 22 Slider

Claims (5)

[Claims] 1. An intake / exhaust valve connected to a stem that opens and closes an intake hole and an exhaust hole opened to an engine combustion chamber and reciprocates, and reciprocates at least one stem for the intake / exhaust valve and the stem. A connecting member disposed between the moving member and a device for moving the moving member, the connecting member being a housing housed in a cylinder head, and an axis supported in the housing and orthogonal to an axis of the stem. A cylinder having a core, a plunger that slides in the cylinder by hydraulic pressure acting on one end, a spring that acts to oppose the hydraulic pressure at the other end of the plunger, and a tip that abuts on the tip of the stem during valve operation. A variable intake and exhaust engine having a slider disposed in a plunger. 2. The variable intake / exhaust engine according to claim 1, wherein the housing has a pad, and the pad extends into the cylinder and is slidably contactable with the slider. 3. The variable intake / exhaust engine according to claim 2, wherein the spring is a leaf spring or a wire spring, and one end is locked to the slider and the other end is locked to the housing. 4. The plunger is made of an aluminum alloy,
The variable intake / exhaust engine according to claim 3, wherein the slider is an iron-based alloy. 5. The variable intake / exhaust engine according to claim 2, wherein a part of the pad is in contact with the slider even when the valve is stopped.