JPH037526Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] This invention relates to a piston valve for a variable cylinder internal combustion engine, and is applicable to OHC such as pivot type, direct type, built-in rotary arm type, etc.
It can be used in most engine valve mechanisms such as OHV.

[Prior Art] In recent years, various types of variable cylinder devices for internal combustion engines have been provided for the purpose of saving energy and improving fuel efficiency of vehicles.

For example, as disclosed in Japanese Patent Application Laid-Open No. 58-180709, a solenoid is driven by a signal from a computer and presses a check ball of a lash adjuster, thereby removing the rigidity of the lash adjuster. There is a variable cylinder device that stops valve lift operation.

[Problems to be Solved by the Invention] The conventional variable cylinder device described above employs a valve operating mechanism using a lash adjuster, and therefore cannot be used in a direct type valve operating mechanism.

The present invention solves this problem by providing a piston valve for a variable cylinder internal combustion engine that can be used in most valve train mechanisms and can smoothly operate and stop valve lift operation.

[Means for Solving the Problems] The piston valve for a variable cylinder internal combustion engine of the present invention includes a valve portion that opens and closes an intake or exhaust hole of an engine combustion chamber, and a valve portion that is integrally formed with the valve portion and is attached to a cylinder head. The stem part is slidably held, and the stem part is pressed in the axial direction by a pressing member such as a cam or a rocker arm, and the movement of the pressing member in the axial direction is transmitted to the stem part, and the valve part is and a connecting part that opens and closes, the connecting part is movable relative to the axial direction of the stem part at the upper end of the stem part, is biased in a direction away from each other, and has a plunger chamber extending in a direction intersecting the axial direction. a housing that is slidably held within the plunger chamber, is biased in one direction by fluid pressure introduced into the plunger chamber, and has an idle hole in which the upper end portion of the stem portion can be inserted and removed; a plunger having a contact surface with which the upper end abuts; and a plunger provided between the housing and the plunger, the plunger being urged by the fluid pressure at a position where the upper end of the stem part can enter and exit the idle hole. a stopper that engages with the housing, and a biasing member provided between the housing and the plunger that biases the plunger in a direction opposite to the biasing direction of the fluid pressure and with a force weaker than the biasing force of the fluid pressure. By applying the fluid pressure, the plunger is locked by the stopper, the upper end of the stem portion is freely inserted into and removed from the idle hole, and the movement of the pressing member in the axial direction is controlled. absorbing relative movement of the connecting portion with respect to the stem portion to immobilize the stem portion and the valve portion and removing the fluid pressure to move the plunger in the opposite direction with the biasing member;
The upper end of the stem portion is brought into contact with the corresponding contact surface of the plunger, the movement of the pressing member is transmitted to the stem portion and the valve portion via the connecting portion, and the intake or exhaust hole is opened and closed by the valve portion. It is characterized by being made to do.

The piston valve referred to in the present invention refers to a device that opens and closes the intake or exhaust port of a cylinder by the pressing movement of a pressing member such as a cam or rocker arm driven by a camshaft, thereby enabling the engine to be driven. This piston valve has a valve part,
It is composed of a stem part integrally formed with the valve part, and a connecting part that transmits the pressing movement of the pressing member to the stem part. The valve part is for opening and closing the intake or exhaust hole provided in the combustion chamber of the cylinder, and the same engine valve as in the conventional engine valve can be used. The stem part is a rod-shaped member whose one end is integrally fixed to the valve part, and is normally biased in a direction approaching the connecting part, and the other end is pressed by a pressing member applied via the connecting part to the cylinder head. It slides inside to open and close the valve section.

The most distinctive feature of the present invention lies in the configuration of the connecting portion.

The connecting portion is mainly composed of a housing and a plunger that slides within a plunger chamber provided within the housing, and can be generally arranged above the stem portion so as to be slidable within a block such as a cylinder head. The housing is located at the upper end of the stem and is movable relative to the stem in the axial direction of the stem. Then, it is urged by a spring or the like in a direction away from the stem part, and the upper surface is always in contact with the pressing member. Further, a hole is provided on the bottom surface of the housing into which one end of the stem portion is fitted so as to protrude into the plunger chamber. A plunger chamber is formed within the housing in a direction intersecting the axial direction of the stem portion. The plunger chamber has a fluid passageway that conducts fluid pressure to the plunger. This fluid passage is usually provided in the side wall of the housing and applies fluid pressure to one end surface of the plunger to bias the plunger in a direction perpendicular to the axial direction of the stem portion. Although pneumatic pressure or oil pressure can be used for this fluid pressure, it is convenient to use engine oil pressure. In order to guide the fluid pressure to the fluid passage, an introduction hole communicating with the oil pump may be provided in a block such as the cylinder head to guide the engine oil pressure directly to the plunger, or a hole between the outer wall of the housing and the block may be provided. A groove is provided on the boundary surface that goes around the outer wall of the housing.
It is also possible to introduce fluid pressure from the introduction hole through the groove. In this case, by using engine oil, the lubricating action of the oil works, and the effect that the housing slides smoothly is produced. In addition, when the fluid pressure is variable cylinder, it is necessary to energize the plunger only when stopping the opening/closing operation of the valve section. To perform such control, for example, between the introduction hole and the oil pump,
This can be done by providing a valve that turns on and off the flow of engine oil and opening and closing this valve. Although this valve may be opened and closed manually, it is preferable to use an electromagnetic valve and to control the opening and closing by a computer that detects signals such as engine negative pressure and throttle opening. In this way, accurate and detailed control becomes possible, which can greatly contribute to energy savings and improved fuel efficiency.

The plunger is disposed within the plunger chamber so as to slide on the inner surface of the plunger chamber in a direction intersecting the axial direction of the stem portion. This plunger has an idle hole into which the upper end of the stem portion can be inserted and removed. This idle hole is a hole into which the upper end of the stem portion is inserted and removed when the valve lift operation is to be stopped. The housing is pushed by the pressing member, and even when the housing is closest to the stem, the upper end of the stem remains within the idle hole.
Constructed so that pressure is not transmitted. The plunger also has a contact surface against which the upper end of the stem comes into contact. And when the engine is running normally,
By abutting the upper end of the stem portion on this contact surface, it becomes possible to transmit the axial movement of the stem portion of the pressing member to the valve portion. Note that it is desirable that the upper end of the stem portion and the corresponding contact surface have a gap that provides a clearance when the pressing force of the pressing member becomes the smallest. This makes it possible to flexibly deal with deformation of each component due to thermal expansion, fatigue, etc.

In the connecting part, when the valve lift operation is to be stopped, fluid is introduced into the fluid passage, and the plunger is biased in one direction by the pressure of the fluid, so that the upper end of the stem part enters and exits the idle hole. It becomes possible. The connecting portion also includes a biasing member that biases the plunger in a direction opposite to the biasing direction of the fluid pressure. Although pressure such as air can be used as the biasing member, it is convenient to use a spring. When the engine is normally driven, the plunger is urged in the other direction by the urging force of the urging member, and the contact surface maintains a state in which it can come into contact with the stem portion.

The urging force of this urging member needs to be smaller than the pressure of the fluid introduced into the fluid passage. For example, when oil pressure from engine oil is used, the pressure may pulsate depending on engine driving conditions and the like.
Therefore, even when the oil pressure becomes a small value, the biasing force of the biasing member is set to be smaller. In this way, during valve lift operation, the pressure of the fluid always overcomes the biasing force of the biasing member, and the plunger is always biased to move the stem into and out of the idle hole.

Further, the connecting portion is provided with a stopper that locks the plunger at a position where the idle hole can be inserted into and removed from the stem portion when the plunger is urged by fluid pressure as described above. For example, one end of the plunger is a central hole with a bottom, and one end of the spring is in contact with the bottom of the hole, and when the spring is compressed by the pressure of the fluid, the peripheral edge of the one end of the plunger touches one end surface of the plunger chamber of the housing. It can be made to abut and be locked. It is also possible to provide a central projection on one end of the plunger or one end surface of the plunger chamber, and insert the central projection into the spring to serve as a stopper. When the plunger is locked by a stopper such as a peripheral portion of the plunger or a central protrusion, the idle hole becomes a position in which the upper end of the stem portion can be inserted and removed.

[Function] In the piston valve for a variable cylinder internal combustion engine of the present invention configured as described above, during normal engine operation, the plunger is biased by the biasing member at one end in a direction opposite to the direction in which fluid pressure is applied. Ru. Then, the contact surface of the plunger can come into contact with the end of the stem portion, and the movement of the pressing member is transmitted to the valve portion via the connecting portion, thereby opening and closing the intake and exhaust holes of the engine combustion chamber.

On the other hand, for example, when the load on the engine becomes small and the drive of that cylinder is stopped, fluid pressure is applied to the other end of the plunger, urging the plunger in a direction intersecting the axial direction of the stem portion. In this case, since the biasing force of the biasing member is always smaller than the biasing force due to the pressure of the fluid, the plunger slides within the plunger chamber due to the pressure of the fluid. The stopper locks the stem in a fixed position, and the upper end of the stem can be inserted into and removed from the idle hole. Therefore, when the pressing member presses the connecting portion, the upper end of the stem portion enters the idle hole, and the pressing force is not transmitted to the stem portion and the valve portion. As a result, the intake and exhaust holes are always closed, and the drive of that cylinder is stopped.

[Effects of the Invention] The piston valve for a variable cylinder internal combustion engine of the present invention can be used in most valve mechanisms such as direct type and pivot type. In addition, even when the fluid pressure fluctuates, the stem moves smoothly into and out of the idle hole, and there is no problem such as damage to the stem end or plunger contact surface, and variable cylinder control is performed smoothly and accurately. etc., the effects of this invention are significant.

[Embodiment] The drawing shows a piston valve according to an embodiment of the present invention.

Cylinder 11 formed in cylinder block 10
A piston (not shown) reciprocates up and down inside. Combustion chamber 12 and intake/exhaust hole 13 above the piston
The opening and closing of communication with the valve 30 is controlled by a valve 30. The valve 30 is integrally formed with a cylindrical valve stem 31, and the valve stem 31 is slidably inserted into a valve guide 32 formed in the cylinder block 10. cylinder block 1
0, a cylindrical hole 14 having a larger diameter than the valve guide 32 is provided coaxially above the valve guide 32. Between a spring seat 33 formed at the bottom of the hole 14 and a spring retainer 34 fixed near one end of the valve stem 31,
A valve spring 35 is tensioned. The valve spring 35 always urges the valve 30 upward so that it is seated on the valve seat 15.

A cylindrical housing 40 is slidably inserted into the hole 14 above the valve stem 31 . A housing spring 36 is stretched between the housing 40 and the spring seat 33, and the housing 40 is urged upward.

A rectangular parallelepiped plunger chamber 41 is formed in the housing 40 and extends in a direction perpendicular to the axial direction of the valve stem 31, with one end having a bottom and the other end opening at a side surface of the housing 40. housing 40
A stem hole 42 communicating with the plunger chamber 41 and an air hole 43 are provided on the lower end surface facing the valve stem 31 , and one end of the valve stem 31 projects into the plunger chamber 41 from the stem hole 42 . Further, the plate 46 fixed to the upper end surface of the housing 40 is connected to the housing spring 36.
Due to the urging force of , the cam surface 61 of the camshaft 60
is in contact with.

Furthermore, a housing groove 44 is provided on the side circumferential surface of the housing 40 and extends around the circumferential direction thereof. The cylinder block 10 is formed with an oil passage 16 for supplying hydraulic pressure of engine oil, and the inner surface of the hole 14 at least partially overlaps with the housing groove 44 even when the housing 40 slides up and down. An oil groove 17 communicating with the oil passage 16 is provided. Therefore, the oil passage 16 and the plunger chamber 41
Communication is always maintained.

Inside the plunger chamber 41 is a plunger chamber 41.
A plunger 50 is inserted which is slidable in the direction of extension.

The plunger 50 has a bottomed spring hole 51 on the end face facing the bottom of the plunger chamber 41. The other end of a spring 52, one end of which is fixed to the bottom of the plunger chamber 41, comes into contact with the bottom of the spring hole 51, and the plunger 50 is urged toward the opening side of the plunger chamber 41. A snap ring 53 is fixed to the opening side of the plunger chamber 41 to restrict movement of the plunger 50.

Further, the plunger 50 is provided with a cylindrical idle hole 54 that has substantially the same diameter as the valve stem 31 and passes through the plunger 50 in the axial direction of the valve stem 31 . and plunger 5
0 includes the opening of the idle hole 54,
An oval recess 55 larger than the opening is provided. The depth of this recess 55 is slightly larger than the height of one end of the valve stem 31 that is biased by the valve spring 35 and protrudes from the stem hole 42 .

In the plunger 50 described above, the spring 52
When the plunger 50 is pressed so as to contract the air, air escapes from the air hole 43 and the spring hole 5
The peripheral edge of the plunger chamber 41 contacts the bottom of the plunger chamber 41,
Movement of the plunger is restricted at that position. In this case, the valve stem 31 and the idle hole 5
4 are coaxially located, and the valve stem 31 can be inserted into and removed from the idle hole 54. Note that the spring 52
The biasing force is smaller than the biasing force due to the hydraulic pressure of the engine oil applied to one end surface of the plunger 50 through the oil passage 16, the oil groove 17, and the housing groove 44. Further, when the hydraulic pressure is cut off, the plunger 50 is locked with one end in contact with the snap spring 53 due to the biasing force of the spring 52. At this time, the bottom surface of the recess 55 faces the end surface of the valve stem 31.

The operation of the piston valve configured as described above will be explained below.

During engine operation, the hydraulic pressure from the oil passage 16 is cut off, and the plunger 50 is urged toward the opening side of the plunger chamber 41 by the spring 52 as shown in FIG. is facing. In this state, camshaft 6
0 rotates and the housing 40 is pushed down, the bottom surface of the recess 55 comes into contact with the end surface of the valve stem 31 and pushes the valve stem 31 down. Therefore, the valve 30 is separated from the valve seat 15, and the cylinder 11 is sucked and exhausted. After that, the valve stem 31 and the housing 40 are moved by the urging force of the valve spring 35 and the housing spring 36.
returns to its original state. Thermal expansion and clearance generated in the valve lift mechanism during engine operation are absorbed by the gap between the bottom surface of the recess 55 and the end surface of the valve stem 31, the valve spring 35, and the housing spring 36, so that the valve lift mechanism always maintains a constant dimension. It is working as follows.

Now, when the engine load is small, the cylinder switching computer 70 detects signals such as engine negative pressure, vehicle speed, throttle opening, etc.
1 to supply engine oil from oil passage 16.
It is guided through the housing groove 44 to the opening side of the plunger chamber 41. Then, the urging force of the hydraulic pressure overcomes the urging force of the spring 52, and the plunger 50 is locked at a position where the peripheral edge of the spring hole 51 contacts the bottom of the plunger chamber 41. Therefore, the valve stem 31 can be inserted into and removed from the idle hole 54, and even if the housing 40 is pushed down by the camshaft 60, the valve stem 31 only enters the idle hole 54, and the pressing force by the camshaft 60 is not transmitted. Therefore, the valve 30 is held seated on the valve seat 15, and the cylinder 11 is not sucked or exhausted. Note that even when the oil pressure fluctuates and reaches the minimum value, the urging force of the spring 52 is configured to be smaller than the urging force of the oil pressure. Therefore, even if the oil pressure fluctuates, the plunger 50 remains in contact with the bottom of the plunger chamber 41, and problems such as damage caused by contact between the idle hole 54 and the recess 55 and the valve stem 31 do not occur.

[Brief explanation of drawings]

1, 2, 3, and 4 relate to the piston valve according to the embodiment of the present invention.
The figure is an explanatory cross-sectional view of the engine during normal engine operation, FIG. 2 is a cross-sectional view taken along the line A-A in FIG. It is a sectional view taken along the line BB in the figure. 30... Valve, 31... Valve stem, 40
...Housing, 44...Housing groove, 50...
...Plunger, 51...Spring hole, 54...
...Idle hole, 55... recess.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) A valve portion that opens and closes the intake or exhaust hole of an engine combustion chamber; a stem portion that is formed integrally with the valve portion and is slidably held in the cylinder head; a connecting portion that is pressed in the axial direction of the stem portion by a pressing member such as a cam or a rocker arm, transmits movement of the pressing member in the axial direction to the stem portion, and opens and closes the valve portion; a housing having a plunger chamber movable relative to one end of the stem portion in the axial direction of the stem portion and biased away from each other and extending in a direction intersecting the axial direction; is slidably held in a fluid-tight manner and is biased in a direction intersecting the axial direction by fluid pressure introduced into the plunger chamber;
a plunger having an idle hole into which the one end of the stem can be inserted and removed; and a contact surface with which the end surface of the one end of the stem comes into contact and transmits movement of the housing to the stem; a stopper provided between the plungers and configured to lock the plunger, which is urged by the fluid pressure, in a position where the one end of the stem portion can be inserted into and removed from the idle hole; and between the housing and the plunger. a biasing member for biasing the plunger in a direction opposite to the biasing direction of the fluid pressure and with a force weaker than the biasing force of the fluid pressure. valve. (2) The piston for a variable cylinder internal combustion engine according to claim 1, wherein the housing of the connecting portion is cylindrical, and the cylindrical circumferential surface has a groove for introducing fluid in the circumferential direction. valve. (3) The plunger chamber is a bottomed hole with one end open and the other end closed, and the biasing member is a spring held in a compressed state between the bottom of the plunger chamber and one end of the plunger.Registration of a utility model. A piston valve for a variable cylinder internal combustion engine according to claim 1. (4) one end of the plunger has a bottomed central hole;
4. The piston valve for a variable cylinder internal combustion engine according to claim 3, wherein one end of the spring abuts the bottom, and the peripheral edge of the one end constitutes a stopper. (5) The piston valve for a variable cylinder internal combustion engine according to claim 3, wherein one end of the plunger has a central projection, and the central projection constitutes a stopper.