JPH10184327A - Valve inactivating system for four stroke internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To securely position a plunger having a by-pass port through which a valve stem is penetrated when a valve is inactivated and to perform valve inactivation safely and securely and also to facilitate to form a valve inactivating device as one united part assembly. SOLUTION: This valve inactivating system 9 for a four stock internal combustion engine has a plunger 23 that oscillates a lifter 11a and a cylinder hole 21a formed in the lifter 11a and a lifter spring 24 energizing the lifter 11a and a valve stem 5a of an intake discharge valve to a direction normally apart from each other and a plunger spring 25 energizing the plunger 23 to normally valve inactivating direction and a pressure oil supplying device for acting oil pressure to the plunger 23 against energizing force of the plunger spring 25. The lifter 11a oscillates back and forth in a lifter guide hole 13a according to rotation of a cam 7 and a slide hole 21a into which the valve stem 5a can penetrate is formed and a by-pass port 23b through which the valve stem 5a can penetrate and a pressure receiving surface receiving the oil pressure are formed in the plunger 23.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve deactivation system for a four-stroke internal combustion engine.
The present invention relates to a valve deactivation system which is provided between a cam for driving an intake / exhaust valve of a stroke internal combustion engine to open and close and a valve shaft of the intake / exhaust valve and holds a part of the intake / exhaust valve at a closed position in accordance with an operation state of the internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, in a four-stroke internal combustion engine, a part of a plurality of intake valves or exhaust valves can be maintained in a closed position regardless of a valve open position of a camshaft in accordance with an operation state of the internal combustion engine. Japanese Patent Application Laid-Open Nos. 8-74543 and 7-2 disclose a valve deactivation system having
There is one described in JP-A-53007. Of these, in the former (see FIGS. 12 to 15), the rod portion of the transmission member that abuts on the valve shaft head of the intake / exhaust valve has an escape hole formed in a plunger in the valve rest system. Are relatively slid so that when the camshaft is in the valve open position, the valve opening operation is not transmitted to the valve shaft. That is, in FIG. 12, the valve rest system 09 includes a lifter 011, a transmission member 028, a plunger 023, a lifter spring 024 for constantly biasing the lifter 011 and the transmission member 028 in a direction in which the lifter 011, and a plunger 023 are always attached to the valve rest direction. And an energizing plunger spring 025.

[0003] The lifter 011 is a cam carrier.
A cylindrical body 020 that slides in a lifter guide hole 013 formed in the cylindrical body 020 has a partition wall 020c at a substantially central portion in the axial direction, and a cam nose of a cam shaft is provided at an upper end opening of the cylindrical body 020.
A pad 020a with which a sliding contact is made (not shown) is fixed, and a boss 020d is formed on the upper surface of the partition wall 020c so as to protrude. The boss 020d has a cylinder perpendicular to the axis of the cylindrical body 020. A hole 020e is formed through the cylinder hole 020e.
An opening is formed in an annular groove 020f formed on the outer peripheral surface of the cylindrical body 020, and at one end thereof,
A stopper 020g for regulating the sliding of the plunger 023 is formed, and a locking ring 030 for regulating the sliding of the plunger 023 and positioning the same at the other end.
Is disposed, and the one end is closed by a lid member 031. Further, the lifter 011 has the boss 02
0d, the cylinder hole 020e, the partition wall 020c, and the cylindrical body 02
A slide hole 020h is formed coaxially with 0, and the rod portion 028a of the transmission member 028 can be slidably inserted into the slide hole 020h. Further, the transmission member
The head of the valve shaft of the intake / exhaust valve is in contact with the center of the lower surface of the flange portion 028b (not shown).

Further, the plunger 023 is slidably inserted into the cylinder hole 020e, and an escape hole 023b having a size exactly matching the slide hole 020h is formed near one end of the round rod. Near the other end from the approximate center thereof, a chamber 023i for receiving pressure oil is formed, and on the lower surface thereof,
When the plunger 023 moves within the cylinder hole 020e in the valve rest releasing direction, a rod protruding by a predetermined length 1 in the cylinder hole 020e in a valve closed state (a state in which the base circle of the cam shaft is in sliding contact with the pad 020a). A concave portion 023f capable of receiving the end of the portion 028a is formed, and a ceiling surface of the concave portion 023f is separated from the top surface of the rod portion 028a by a predetermined clearance, but the cam nose of the cam shaft slides on the pad 020a. In the case of contact, a flat force transmission surface 023g is formed so that a force can be transmitted by surface contact with the surface. The plunger spring 025 is accommodated between one end of the plunger 023 and the lid member 031 so as to always bias the plunger 023 rightward (valve resting direction) in FIG. .

Since the former valve deactivation system 09 for a four-stroke internal combustion engine is constructed as described above, it operates in a medium / large intake air amount such as when the internal combustion engine is running at medium / high speed or during medium / high load operation. In the region, a part of the lubricating oil pumped up by an oil pump from an oil pan (not shown) in the lower part of the crankcase of the internal combustion engine is supplied from an oil passage 032 formed in a cam carrier 029 fixed to a cylinder head to an annular groove of a cylindrical body 020. 020f, chamber 020i in cylinder bore 020e
Then, the plunger 023 is introduced into the chamber 023i of the plunger 023 to move the plunger 023 leftward in FIG. 12 against the urging force of the plunger spring 025. Then, as shown in FIG. 15, the force transmitting surface 023g of the plunger 023 covers the top surface 028c of the rod portion 028a and comes into contact with the top surface 028c, and the lifter 011 and the valve shaft are connected via the transmitting member 028 to the valve. The cam is lifter 011 because it can transmit the force in the axial direction.
The valve shaft moves up and down following the rotation of the intake and exhaust valves in sliding contact with the pad 020a to open and close the intake and exhaust valves.

Further, in a small intake air amount operation range such as when the internal combustion engine is rotating at a low speed or at a low load, the supply of the lubricating oil to some of the chambers 020i and 023i is cut off, and the plunger is stopped.
15 is moved rightward in FIG. 15 by being urged by a plunger spring 025, and the force transmitting surface 02 of the plunger 023 is moved.
3g comes off the top surface 028c of the rod portion 028a and returns to the original state (see FIG. 12), and the cam is lifted by the lifter 011.
Even if the rod portion 028a slides on the pad 020a and slides in the slide hole 020h and the escape hole 023b of the plunger 023, the transmission member 028 moves in a direction relatively closer to the lifter 011. After all, see FIG. 14).
8 shows that the valve shaft cannot be moved downward and the force transmission relationship between the lifter 011 and the valve shaft via the transmission member 028 is released, so that the intake and exhaust valves do not open and close ( (Valve stop), and keep the closed state.

[0007]

In the valve deactivation system 09 as described above, the end of the rod portion 028a protruding by a predetermined length 1 in the cylinder hole 020e when the valve is in a closed state is formed by the lower portion of the escape hole 023b of the plunger 023. The rotation of the plunger 023 in the cylinder hole 020e is prevented by contact with the inner wall surface and the force transmission surface 023g. However, during operation of the internal combustion engine, this contact may be released due to jumping of the valve or wear of the cam, etc., and if this contact is released,
When the plunger 023 rotates in the cylinder hole 020e and the valve is deactivated, the rod portion 028a moves to the escape hole 02 of the plunger 023.
It becomes difficult to slide inside 3b, the desired valve stop operation can not be performed, or the intersection line between the escape hole 023b of the plunger 023 and the force transmission surface 023g intersects with the peripheral surface at the end of the rod portion 028a, The leftward sliding of the plunger 023 from the valve rest position to the valve rest release position is impeded, and the valve rest cannot be released at all.
The contact between the top surface 028c and the force transmitting surface 023g is not performed correctly, and the opening and closing operation of the intake and exhaust valves may not be performed as expected. The positioning of the plunger 023 is performed by the locking ring 030. To this end, in addition to preparing the locking ring 030, the locking ring 030 is provided on the inner peripheral surface of the cylinder hole 020e. Must be formed, and the structure and manufacture of the positioning means are complicated.

[0008]

SUMMARY OF THE INVENTION The present invention relates to a valve deactivation system for a four-stroke internal combustion engine which solves the above-mentioned problems. The first aspect of the present invention relates to a four-stroke cycle internal combustion engine. A valve stop system for the engine, a lifter, a plunger that slides in a cylinder hole formed in the lifter in a direction perpendicular to a valve axis of the intake / exhaust valve, and a direction in which the lifter and the valve shaft are always separated from each other. A lifter spring that urges the plunger in the valve rest direction, and a pressure oil supply mechanism that applies a hydraulic pressure to the plunger against the urging force of the plunger spring. Slides reciprocally within a lifter guide hole formed on the cylinder head side in accordance with the rotation of the cam, and has a slide hole through which the valve shaft can enter. The lancer is formed with a relief hole through which the valve shaft can be inserted, and a pressure receiving surface receiving the hydraulic pressure, and when the pressure receiving surface does not receive the hydraulic pressure, the lancer is urged by the plunger spring to form the relief hole and the relief hole. When the lifter moves down in accordance with the rotation of the cam when the pressure receiving surface is not subjected to hydraulic pressure, the valve shaft is positioned inside the slide hole and the escape hole. To hold the intake and exhaust valves closed, and, when the pressure receiving surface receives hydraulic pressure, when the lifter moves down in accordance with the rotation of the cam, the plunger moves the head of the valve shaft. In a valve deactivation system of a four-stroke cycle internal combustion engine that operates to open the intake / exhaust valve by contacting a part, the positioning means of the plunger includes:
A valve deactivation system for a four-stroke internal combustion engine, comprising a positioning pin that passes through the lifter and the plunger.

According to the first aspect of the present invention, since the plunger is reliably prevented from rotating in the cylinder hole by the positioning pin passing through the lifter and the plunger. When the plunger is rotated in the cylinder bore, the valve axle does not slide easily in the plunger escape hole during the valve pause operation, which does not cause a problem that the intended valve pause operation cannot be performed. . Further, the manufacturing of the positioning pin is easy, and the work of forming a hole through which the positioning pin passes through the lifter and the plunger can be easily performed, so that the structure and manufacturing of the positioning means of the plunger are simplified. Furthermore, due to the positioning using such pins, even if the plunger is urged by the plunger spring, the plunger does not jump out of the cylinder hole at all, and as a result, the operation of the valve deactivation system is further ensured. In addition, it becomes easy to configure the valve rest system as one integrated component assembly.

According to the second aspect of the present invention, when the valve is deactivated, the plunger at the head of the valve shaft can smoothly enter the escape hole. At the same time, the valve rest releasing operation is reliably performed, the force is smoothly transmitted between the lifter and the valve shaft, and the opening and closing operation of the intake and exhaust valves is performed accurately.

According to the third aspect of the present invention, the shim for adjusting the slight opening operation of the intake / exhaust valve during the valve stop operation can be replaced. It will be easier.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment (Embodiment 1) of the invention described in claims 1 to 3 shown in FIGS. 1 to 9 will be described below. The four-stroke internal combustion engine in the present embodiment is a four-cylinder four-valve internal combustion engine, and each cylinder has two intake valves and two exhaust valves. FIG. 1 is a schematic plan view showing a state in which a cylinder head cover and a camshaft of the internal combustion engine are removed. In FIG. 1, reference numerals 10a and 10b denote crown covers of valve shaft heads of two intake valves of each cylinder. The intake lifters 12a and 12b are intake lifter guide holes into which the intake lifters 10a and 10b are slidably fitted, and 11a and 11b are covered by valve shaft heads of two exhaust valves of each cylinder. Exhaust lifter, 13a, 13b
Is an exhaust lifter guide hole into which the exhaust lifters 11a and 11b are slidably fitted, and 14 is an ignition plug. Reference numeral 16 denotes an oil passage for supplying oil pressure to an intake-side valve deactivation system 8 described later, reference numeral 17 denotes an oil passage for supplying oil pressure to an exhaust-side valve deactivation system 9 described later, and reference numeral 15 denotes supply of pressure oil to these oil passages. , A switching valve for controlling shutoff.

In this embodiment, a valve rest system is incorporated in the intake lifter 10b and the exhaust lifter 11a, and an intake valve and an exhaust valve connected to a valve shaft cooperating with the valve rest system are provided by an internal combustion engine. The opening / closing operation of the engine is stopped according to the operating state of the engine, and the valve closing position can be maintained regardless of the valve opening position of the camshaft. As described above, when the lifter in which the valve rest system is incorporated is selected as the intake lifter 10b and the exhaust lifter 11a which are covered by the intake valve and exhaust valve shaft heads symmetrically positioned with respect to the ignition plug 14, At the time of the valve stop operation, the intake air that has flowed in through the valve openings of the remaining normally operated intake valves is discharged from the valve openings of the normally operated remaining exhaust valves that are located symmetrically with respect to the ignition plug 14 after combustion. Will be
As a result, blow-through of intake air at the time of valve overlap is reduced, which is advantageous for emission and the like.

FIG. 2 is a partial schematic sectional view of the internal combustion engine taken along the line II-II of FIG.
1 is an internal combustion engine in which only a portion above the cylinder head is shown, 2 is a cylinder head, 3 is a cylinder head cover, 4 is an intake valve, 4a is the same valve shaft, 5 is an exhaust valve, 5a is the same valve shaft, and 6 is An intake valve drive cam shaft, 7 is an exhaust valve drive cam shaft,
Reference numeral 8 denotes an intake-side valve deactivation system incorporated in the intake lifter 10b inserted into the intake lifter guide hole 12b.
Is an exhaust lifter fitted in the exhaust lifter guide hole 13a.
This is an exhaust valve stop system built into the 11a side. Hereinafter, the structure and operation of the valve deactivation system will be described. In the present embodiment, the intake-side valve deactivation system 8 and the exhaust-side valve deactivation system 9 both have the same structure. In operation, the exhaust-side valve deactivation system 9 will be described below.
Its structure and operation will be described in detail, and detailed description of the intake-side valve deactivation system 8 will be omitted.

FIG. 3 is an enlarged view of a portion centered on the exhaust side valve deactivation system 9 in FIG. 2. In these figures, the valve deactivation system 9 includes an exhaust lifter 11a.
And a plunger 23 which is housed in a cylinder hole 21a formed orthogonal to the valve shaft 5a of the exhaust valve 5 and which slides in the hole in a plunger holder 21 which will be described later, which is a component of the exhaust lifter 11a. A lifter spring 24 for constantly urging the exhaust lifter 11a and the valve shaft 5a away from each other, a plunger spring 25 for constantly urging the plunger 23 in a valve resting direction (rightward in the figure), and a plunger. A pressure oil supply mechanism for applying a hydraulic pressure to the urging force of the plunger spring 25 is provided on the pressure sensor 23.

The exhaust lifter 11a has a sliding contact surface 20a with a cam, is fitted into the exhaust lifter guide hole 13a, and slides in the hole. The plunger holder 21 accommodated in the bottom cylinder 20 and a shim 22 interposed between the inverted bottomed cylinder 20 and the plunger holder 21 are provided. As shown in detail in FIG. 5, a cylinder hole 21a, a slide hole 21b orthogonal to the cylinder hole 21a, through which the head of the valve shaft 5a can enter and penetrate, and a spring receiving surface 21c for receiving a lifter spring 24 (FIG. 3), an annular groove 21d formed on the outer peripheral surface for guiding oil, and a shim receiving surface 21e formed on the inner peripheral wall of the top of the slide hole 21b to receive the shim 22.
An insertion hole 21f for the pin 26 described later is formed. In addition, the plunger holder 21 is formed as a round block-shaped part whose thickness is reduced except for a cross-shaped part in plan view for weight reduction. The shim 22 is a disk having a size large enough to cover the head of the valve shaft 5a. Here, the lifter spring 24 constantly urges the plunger holder 21 and the valve shaft 5a in a direction in which the plunger holder 21 and the shim 22 and the inverted bottomed cylindrical body 20 are separated from each other. While being pressed by the cam of the camshaft 7 from above, they come into contact with each other and are integrated, and follow the rotation of the camshaft 7 so as to reciprocate integrally in the exhaust lifter guide hole 13a.

As described above, the plunger 23 is accommodated in the cylinder hole 21a formed in the plunger holder 21 and slides through the hole. In FIG. 3, the hole 23a formed at the left end in FIG. The plunger spring 25 is compressed and interposed between the inner step 23h and the bottom surface 21g of the cylinder hole 21a, and as shown in detail in FIG. An escape hole 23b through which the valve shaft 5a can be inserted is formed near the left end, a U-shaped groove 23c is formed at the right end thereof, and a groove bottom 23d of the U-shaped groove 23c is formed by the plunger 23d. When is urged by the plunger spring 25 and slides rightward, it comes into contact with a pin 26 provided through the plunger holder 21 in the valve axis direction. In this contact state, the relief hole 23b and the slide hole 21b formed in the plunger holder 21 are aligned with each other so that the head of the valve shaft 5a can enter and slide in these holes. Have been.

An end surface 23 at the right end of the plunger 23
e and the groove bottom 23d, the chamber in the cylinder hole 21a partitioned by these and the inner peripheral surface of the inverted bottomed cylindrical body 20 is a hydraulic chamber 21.
Therefore, when hydraulic pressure is introduced into the hydraulic chamber 21h, the pressure receiving surface becomes a pressure receiving surface for receiving the hydraulic pressure. Then, when the pressure receiving surface receives the hydraulic pressure, the plunger 23 is slid leftward in the figure (valve rest release direction) against the urging force of the plunger spring 25. As a result, the coincidence between the escape hole 23b and the slide hole 21b is broken and a staggered state occurs (see FIG. 8), so that the head of the valve shaft 5a can no longer enter these holes and slide. Have been.

Further, at the substantially central portion of the lower surface of the plunger 23, when the valve is closed, the head of the valve shaft 5a can protrude into the cylinder hole 21a by a predetermined length l, and a predetermined clearance is still formed. A recess 23f is formed in the recess. The concave portion 23f is formed by cutting a substantially central portion of the lower surface of the plunger 23 by a plane, and has a length at least in which the plunger 23 moves in the cylinder hole 21a against the urging force of the plunger spring 25 in the drawing. When moved to the left, the ceiling surface 23g has a length covering the majority of the top surface 5b of the valve shaft 5a, and the exhaust lifter 11a and the valve shaft 5a are connected to each other through contact between the ceiling surface 23g and the top surface 5b. The length is such that it does not hinder the transmission of force between them. This length is desirably slightly longer than the escape hole 23b of the plunger 23 to the left. By forming the concave portion 23f in this manner, the head of the valve shaft 5a is moved away from the escape hole 23 of the plunger.
When approaching into b, the approach will be guided and you will be able to enter smoothly. In addition, the valve rest release operation is performed reliably, the force transmission between the exhaust lifter 11a and the valve shaft 5a is accurately and smoothly performed in the valve axis direction, and the opening and closing operation of the exhaust valve 5 is performed accurately. become.

Next, the pressure oil supply mechanism will be described. In FIG. 1, part of the lubricating oil pumped up by an oil pump from an oil pan (not shown) in the lower part of the crankcase of the internal combustion engine flows through the switching valve 15 to the oil passage 16 and the oil passage 17 in a divided manner. Then, as described above, the pressure oil is supplied therefrom to the intake-side valve deactivation system 8 and the exhaust-side valve deactivation system 9, respectively. here,
The pressure oil supplied to the exhaust-side valve deactivation system 9 is shown in FIG.
As shown in detail in FIG. 1, the communication passage 17a from the oil passage 17, an annular groove 13c formed in the inner peripheral surface of the exhaust lifter guide hole 13a, a communication hole 20b formed in the inverted bottomed cylindrical body 20,
Through the annular groove 21d formed on the outer peripheral surface of the plunger holder 21, it is introduced into the hydraulic chamber 21h in the cylinder hole 21a of the plunger holder 21.

The switching valve 15 is controlled to be opened and closed by the ECU 18 in accordance with the operating state of the internal combustion engine 1, so that the medium / large intake air amount such as when the internal combustion engine 1 is running at medium / high speed or during medium / high load operation. It is opened in the operating range, and closed in the small intake air amount operating range such as during low-speed rotation or low-load operation.

Exhaust-side valve deactivation system 9 of the present embodiment
Is configured as described above, when the switching valve 15 is opened in a medium / large intake air amount operation range such as at the time of medium / high speed rotation of the internal combustion engine 1 or at the time of medium / high load operation, The pressurized oil flows through the cylinder hole 21 of the plunger holder 21 as described above.
a, the pressure receiving surfaces 23e and 23d receive the hydraulic pressure of the pressure oil, and move the plunger 23 leftward in the figure against the urging force of the plunger spring 25 (valve rest release direction).
To slide. As a result, the escape hole 23b and the slide hole 21
It is in a state of disagreement with b, the ceiling surface of plunger 23 23 g
And the top surface 5b of the valve shaft 5a can come into contact with each other, and the head of the valve shaft 5a can come into contact with the plunger 23 (see FIG. 8). 11
When a moves downward in the exhaust lifter guide hole 13a, a force is transmitted between the exhaust lifter 11a and the valve shaft 5a, and the valve shaft 5a
Also moves down (see FIG. 9), and the exhaust valve 5 is opened. Camshaft 7
When the rotation of the valve further advances, the valve shaft 5a rises due to the action of the valve spring 27, and the plunger abutting on the head thereof
Since the exhaust lifter 11a moves upward through 23, it returns to the original state shown in FIG. 8, and the exhaust valve 5 is closed. In this way, in the above-described operating range, the internal combustion engine 1
, All the intake and exhaust valves open and close.

Further, in a small intake air amount operation range such as when the internal combustion engine 1 is rotating at a low speed or at a low load, the switching valve 15 is operated.
Is closed, the introduction of pressure oil into the hydraulic chamber 21h is cut off,
Since the pressure receiving surfaces 23e and 23d stop receiving the oil pressure, the plunger 23 is urged by the plunger spring 25 and slides rightward (valve resting direction) in the drawing until it comes into contact with the pin 26. As a result, the escape hole 23b and the slide hole 21b coincide with each other to return to the original state, the contact between the ceiling surface 23g of the plunger 23 and the top surface 5b of the valve shaft 5a is released, and the head of the valve shaft 5a and the plunger 23 Of the camshaft 7 (see FIG. 3).
The exhaust lifter 11a is driven by the exhaust lifter guide hole
When the valve shaft 13a moves down, the head of the valve shaft 5a enters these holes and slides, so that the transmission of force between the exhaust lifter 11a and the valve shaft 5a is interrupted, and the exhaust valve 5 is closed. This state is maintained (see FIG. 7). When the rotation of the camshaft 7 further advances, the lifter spring 24 moves the exhaust lifter 11a upward, separates from the valve shaft 5a, and returns to the original state shown in FIG. In this way, in the operating range as described above,
In the internal combustion engine 1, part of the intake and exhaust valves (one intake valve and one exhaust valve) are stopped from opening and closing.

In this case, the head of the valve shaft 5a has a relief hole.
23b and the degree of entry into the slide hole 21b are determined by the camshaft 7
When the cam nose 7a is in sliding contact with the sliding contact surface 20a of the exhaust lifter 11a (see FIG. 7), if the top surface 5b of the valve shaft 5a is slightly in contact with the lower surface of the shim 22, even if the valve is in the stop operation, Since the exhaust valve 5 is slightly opened, when the internal combustion engine 1 is exhausted, a small amount of the combustion gas is exhausted from the valve port of the exhaust valve 5, and the solid content in the combustion gas is fixed to the valve seat and the exhaust port. Is prevented. When similar measures are applied to the intake-side valve deactivation system 8, the fuel carbide is prevented from sticking to the valve seat of the intake valve 4 or the intake port. The above-described adjustment of the degree of entry is performed by disassembling the exhaust lifter 11a and replacing the shim 22 with one having an appropriate thickness.

In the present embodiment, the switching valve 15 is closed and the supply of the pressure oil to the hydraulic chamber 21h is cut off in the small intake air amount operation range such as when the internal combustion engine 1 is rotating at a low speed or during a low load operation. The pin 26 is used to position the stop position when the plunger 23 is urged by the plunger spring 25 and slides in the valve rest direction. And this pin
26, the pin insertion hole 21f of the plunger holder 21 which is a component of the exhaust lifter 11a and the plunger
Through the U-shaped groove 23c of 23, it is held by the plunger holder 21. For this reason, the plunger 23 is reliably prevented from rotating in the cylinder hole 21a, and when the plunger 23 rotates in the cylinder hole 21a, the head of the valve shaft 5a is moved during the valve stop operation. It is difficult to slide the inside of the escape hole 23b of the plunger 23, and the desired valve stop operation cannot be performed. Also, the intersection line between the escape hole 23b of the plunger 23 and the ceiling surface (force transmission surface) 23g is located at the head of the valve shaft 5a. Intersecting with the peripheral surface, the leftward sliding of the plunger 23 from the valve rest position to the valve rest release position is hindered, so that the valve rest cannot be released at all, or when the valve rest is released, the top surface 5b of the valve shaft 5a is in contact with the top surface 5b. There is no problem that the contact with the ceiling surface 23g is not performed correctly and the opening and closing operation of the exhaust valve 5 is not performed as expected.

The positioning pin 26 can be easily manufactured, and the pin insertion hole 21f of the plunger holder 21 through which the pin 26 is inserted and the U-shaped groove 23c of the plunger 23 can be easily formed. The structure and manufacturing of the positioning means are simplified. Furthermore, because of the positioning using the pins 26, even if the plunger 23 is urged by the plunger spring 25, the plunger 23 does not jump out of the cylinder hole 21a at all. Operation is further ensured, and it is easier to configure the valve deactivation system 9 as a unitary component assembly.

Furthermore, since the shim 22 is a relatively small member, it is easy to prepare a plurality of types of the shim 22, and the exchange can be easily performed in combination with the fact that the exhaust lifter 11a can be disassembled. .

Next, another embodiment (Embodiment 2) of the first or second aspect of the present invention shown in FIGS. 10 and 11 will be described. In this embodiment, there is no particular difference from the first embodiment except that the structure of the exhaust lifter 11a is different from the first embodiment. The operation is basically the same as that of the first embodiment. FIG. 10 and FIG.
FIGS. 2 and 3 are similar to FIGS.
The exhaust lifter 11a is the same as the inverted bottomed cylindrical body 20 in the first embodiment.
And the plunger holder 21 are integrated and integrally formed. Then, instead of the shim 22 in the first embodiment, the sliding contact surface 20a with the cam (the bottom wall of the inverted bottomed cylindrical body 20 in the first embodiment) is separate from other parts,
This is also used as a shim. When the sliding contact surface 20a ′ thus separated and also used as a shim is incorporated into the main body 11c of the exhaust lifter 11a, a receiving surface formed on the top inner wall surface of the main body 11c of the exhaust lifter 11a is used.
Fit tightly with 21d or secure with bolts.

In this embodiment, as described above, the inverted bottomed cylindrical body 20 and the plunger holder 21 in the first embodiment are used.
As a result, the cylinder hole 21a, the slide hole 21 and the cylinder hole 21a of the first embodiment are formed.
b, spring receiving surface 21c, shim receiving surface 21e, positioning pin 26
The insertion hole 21f, the bottom surface 21g of the cylinder hole 21a, etc.
21b ', spring receiving surface 21c', shim receiving surface 21e ', positioning pin
The 26 insertion holes 21f 'and the bottom surface 21g' of the cylinder hole 21a 'are formed. Further, the annular groove 21d in the first embodiment has been removed, and the hydraulic chamber 21h is formed as a hydraulic chamber 21h '. The hydraulic chamber 21h' has a bottom surface 23i of a circular hole formed in the plunger 23; It is formed as a chamber partitioned by a groove bottom 23d 'of the upper and lower U-shaped grooves through which the pin 26 passes, an end face 23e' of the plunger 23, and an inner peripheral surface of the exhaust lifter guide hole 13a. By forming the hydraulic chamber 21h 'in this manner, the surface of the plunger 23 facing the hydraulic chamber 21h' (the groove bottom 23d ', the end surface 23e', and the bottom surface 23i acting as a pressure receiving surface) can easily receive the hydraulic pressure. The weight of the plunger 23 can be reduced.

Exhaust-side valve deactivation system 9 of the present embodiment
Is configured as described above, the separately formed sliding contact surface 20a 'also serving as a shim is a relatively large part, and although there is some difficulty in replacing it, the number of parts is reduced and the structure is reduced. Because it is simple, costs are reduced.

As described above, the effects of the exhaust-side valve deactivation system 9 in the first and second embodiments are similarly exerted in the intake-side valve deactivation system 8.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of a valve deactivation system of a four-stroke internal combustion engine according to a first embodiment of the present invention, with a cylinder head cover and a cam shaft removed.

FIG. 2 is a partial schematic cross-sectional view taken along line II-II of FIG. 1 and includes a cylinder head cover and a cam shaft.

FIG. 3 is an enlarged view of a portion centering on an exhaust side valve deactivation system in FIG. 2;

FIG. 4 is a partial sectional view taken along line IV-IV of FIG.

FIG. 5 is a perspective view of the plunger holder in the embodiment of FIG. 1;

FIG. 6 is a perspective view of the plunger in the embodiment of FIG. 1;

FIG. 7 is a view showing an operation state of the valve deactivation system in the embodiment of FIG. 1;

FIG. 8 is a view showing another operation state of the valve deactivation system in the embodiment of FIG. 1;

FIG. 9 is a view showing still another operation state of the valve deactivation system in the embodiment of FIG. 1;

FIG. 10 is a view showing a valve deactivation system of a four-stroke internal combustion engine according to a second embodiment of the present invention, similar to FIG. 2;

FIG. 11 is an enlarged view of a portion centering on the exhaust-side valve deactivation system of FIG. 10, and is a view similar to FIG. 3;

FIG. 12 is a diagram showing a conventional valve deactivation system of a four-stroke internal combustion engine.

FIG. 13 is a sectional view taken along line XIII-XIII of FIG.

FIG. 14 is a diagram showing an operation state of the valve deactivation system of FIG.

FIG. 15 is a view showing another operation state of the valve deactivation system of FIG. 12;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Internal combustion engine, 2 ... Cylinder head, 3 ... Cylinder head cover, 4 ... Intake valve, 4a ... Valve shaft, 5 ... Exhaust valve, 5a
... Valve shaft, 5b ... Top surface, 6 ... Cam shaft, 7 ... Cam shaft, 8 ... Intake side valve rest system, 9 ... Exhaust side valve rest system, 10a, 10b ... Intake lifter, 11a, 11b ... Exhaust lifter, 11c ... Exhaust lifter body, 12a, 12b ... Intake lifter guide holes, 13a, 13b ... Exhaust lifter guide holes, 14 ... Ignition plug, 15 ... Switching valve, 16 ... Oil passage, 17 ... Oil passage, 18
... ECU, 20 ... Inverted bottomed cylinder, 20a '... Sliding contact surface (separate body),
21: Plunger holder, 21a: Cylinder hole, 21b: Slide hole, 21c: Spring receiving surface, 22: Shim, 23: Plunger, 23b: Relief hole, 23f: Recess, 23g: Ceiling surface (force transmission surface), 24 … Lifter spring, 25… plunger spring, 26… pin, 27… valve spring.

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] December 24, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] FIG.

[Correction method] Change

[Correction contents]

[Figure 10] A diagram showing a valve deactivation system of the four-stroke internal combustion engine in a second embodiment of the invention of claim 1 or claim 2 wherein, is a view similar to FIG.

Claims (3)

[Claims] 1. A lifter, a plunger which slides in a cylinder hole formed in the lifter in a direction perpendicular to a valve axis of an intake / exhaust valve, and a plunger which is provided in a direction in which the lifter and the valve shaft are always separated from each other. A lifter spring for biasing, a plunger spring for constantly biasing the plunger in a valve rest direction, and a pressure oil supply mechanism for applying a hydraulic pressure to the plunger against the biasing force of the plunger spring. A slide hole is formed in the lifter guide hole formed on the cylinder head side so as to reciprocate in accordance with the rotation of the cam to allow the valve shaft to enter, and the plunger is a relief through which the valve shaft can be inserted. A hole and a pressure receiving surface for receiving the hydraulic pressure are formed, and when the pressure receiving surface does not receive the hydraulic pressure, the plunger spring is urged to position the relief hole and the slide hole so that they match. When the lifter moves down according to the rotation of the cam when the pressure receiving surface does not receive the hydraulic pressure, the valve shaft slides inside the slide hole and the relief hole, and the intake and exhaust valve When the lifter moves down in response to the rotation of the cam when the pressure receiving surface receives hydraulic pressure, the plunger abuts on the head of the valve shaft, and A valve deactivation system for a four-stroke internal combustion engine that operates to open a valve, wherein the positioning means of the plunger is constituted by a positioning pin that passes through the lifter and the plunger. Valve deactivation system. 2. The plunger has a predetermined length on a lower surface thereof in the cylinder hole when the plunger moves in the cylinder hole in the valve rest releasing direction against the urging force of the plunger spring. A concave portion capable of receiving the head of the valve stem protruding by 1 is formed, and the ceiling surface of the concave portion is configured as a force transmitting surface separated by a predetermined clearance from the top surface of the valve shaft. The valve deactivation system for a four-stroke internal combustion engine according to claim 1, wherein 3. The inverted bottomed cylindrical body having a sliding contact surface with the cam and sliding in the lifter guide hole, a plunger holder housed in the inverted bottomed cylindrical body, The plunger holder is formed with a cylinder hole, the slide hole, and a spring receiving surface for receiving the lifter spring. The valve deactivation system of a four-stroke internal combustion engine according to claim 1 or 2, wherein the system is operated.