JPH064006Y2 - Valve lifter backside lubricator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a lubricating device for an internal combustion engine having a direct valve operating system, and in particular, forcibly lubricates a contact surface between a valve lifter and a valve stem of an intake / exhaust valve. The lubrication device.

[Conventional technology]

As prior arts related to the present invention, Japanese Utility Model Publication No. 60-170010 and Japanese Utility Model Publication No. 62-21411 are known.

The device disclosed in Japanese Utility Model Laid-Open No. 60-170010 described above forms a groove extending in the circumferential direction on the sliding surface of the valve lifter, and penetrates an oil hole from the groove to the inner peripheral surface. Oil is supplied to the upper end surface of the stem of the valve via the valve.

In the lubrication device disclosed in Japanese Utility Model Laid-Open No. 62-21411, a taper portion is formed inside the valve lifter, with the apex at which the tip of the valve stem abuts.

By constructing the intake / exhaust valve from ceramic, it is possible to reduce the weight and heat resistance of the intake / exhaust valve, and it is possible to significantly improve engine performance.

However, if the intake / exhaust valve is made of ceramic, the contact portion of the inner surface of the valve lifter with the valve stem end is significantly worn, and the timing is deviated. That is, although the valve lifter is hardened by the heat treatment, the hardness of the ceramic is significantly higher than the hardness of the valve lifter, and therefore the wear of the valve lifter becomes significantly large if the lubrication is insufficient. Therefore, when a ceramic intake / exhaust valve is used, the adjusting shim must be frequently adjusted.

For example, in the lubrication structure as disclosed in Japanese Utility Model Laid-Open No. 60-170010, there is no problem when the valve is made of metal, but lubrication becomes insufficient when the valve is made of ceramic. That is, in the lubrication structure as disclosed in Japanese Utility Model Laid-Open No. 60-170010, there is no means for guiding the oil from the oil hole penetrating the sliding surface of the valve lifter to the upper end surface of the valve stem.
Similar to the above, the contact surface between the valve lifter and the upper end surface of the stem of the valve cannot be sufficiently lubricated.

Further, in the device of Japanese Utility Model Laid-Open No. 62-21411, since a plurality of oil holes penetrating the inner surface of the valve lifter are formed in the recess of the valve lifter in which the shim is fitted, similarly, the strength against a compressive load is reduced, There is a problem of reduced reliability.

Therefore, the applicant of the present invention has previously proposed a valve train lubrication device capable of forcibly lubricating the contact surface between the valve lifter and the upper end surface of the valve stem without lowering the strength of the valve lifter ( Actual application 62-127482).

In this lubrication device, an oil passage is formed in a cylinder head, the oil passage opening to a sliding surface with a valve lifter, and a recess is provided at a position on the outer peripheral surface of the valve lifter that can face the opening of the oil passage. An oil reservoir is formed to store the oil supplied from the passage, and the oil in the oil reservoir is guided to the contact surface between the oil reservoir of the valve lifter and the contact surface with which the upper end surface of the valve stem abuts. It is formed by forming an oil passage means.

In the valve train lubrication device configured as described above, the oil stored in the oil reservoir is supplied to the contact surface between the valve lifter and the upper end surface of the valve stem of the intake / exhaust valve via the oil passage means. The contact surface is forcibly lubricated with oil. Therefore, even if the intake / exhaust valve is made of ceramic, the wear of the valve lifter is significantly suppressed as compared with the conventional structure.

[Problems to be solved by the invention] However, this application No. 62-127482 (Actual development 64-3240)
There is also a problem left in the device of Japanese Patent No. 8). That is, in this device, oil is supplied to the contact surface between the valve lifter and the valve stem of the intake / exhaust valve, but since there is no mechanism for positively supplying oil, wear of the valve lifter is prevented. The lubrication effect was still inadequate in order to suppress it to a level where there was practically no problem.

Further, in this device, when the oil supplied to the contact surface between the valve lifter and the valve stem of the intake / exhaust valve is increased, a large amount of oil flows down along the outer peripheral surface of the valve stem and reaches the umbrella portion of the exhaust valve. As a result, the problem of increasing the emission of harmful substances arises.

The present invention focuses on the above problem, and can positively lubricate the contact surface between the valve lifter and the valve stem, and can significantly suppress the amount of oil flowing down along the valve stem. The purpose is to provide a device.

[Means for Solving the Problems]

A valve lifter rear surface lubrication device according to the present invention for this purpose is used in a valve operating system of an internal combustion engine in which an upper end surface of a valve stem of an intake / exhaust valve is in contact with a top portion of an inner surface of a valve lifter slidably fitted to a cylinder head. A flow path for guiding oil supplied from the oil supply passage to the contact surface between the valve stem and the valve lifter, the oil supply passage being formed in the cylinder head so as to open on a sliding surface with the valve lifter. A retainer for holding one end of a valve spring located on the outer periphery of the upper end of the valve stem for axially urging the intake / exhaust valve, and an oil hole opening on the inner surface side of the valve lifter. On the lower surface side, the oil compressed when the valve lifter descends again flows down along the valve stem from the oil hole to the inside of the valve lifter. It consists of providing the oil reservoir portion for jetting towards.

[Action]

In the valve lifter back surface lubrication device configured as described above, the oil from the oil supply passage of the cylinder head is guided to the contact surface between the valve stem and the valve lifter via the flow passage means provided in the valve lifter. The oil that lubricates the contact surface flows down along the outer peripheral surface of the valve stem and is stored in the oil storage portion provided on the lower surface side of the retainer. Therefore, the amount of oil reaching the umbrella portion of the intake / exhaust valve is suppressed to an extremely small amount, and the amount of harmful substances discharged is reduced.

Also, since the oil sump is compressed when the valve lifter is at the lowest position, the compression force causes the oil accumulated in the oil sump to be ejected from the oil hole provided in the retainer toward the inner surface of the valve lifter. To be done. Therefore, the oil from the oil supply passage and the oil sprayed by the oil reservoir and adhered to the inner surface of the valve lifter are supplied to the contact surfaces of the both, and are guided to the contact surface between the valve stem and the valve lifter. The amount of oil is larger than in the conventional structure, and the contact surface is extremely lubricated. As a result, wear of the valve lifter is significantly suppressed, and valve timing adjustment is almost unnecessary.

〔Example〕

Hereinafter, a preferred embodiment of a valve lifter rear surface lubrication device according to the present invention will be described with reference to the drawings.

First Embodiment FIGS. 1 to 3 show a first embodiment of the present invention. In the figure, 1 indicates a cylinder head, and 2 indicates a valve lifter formed in a cylindrical cup shape. The valve lifter 2 is slidably fitted in the valve lifter hole 3 of the cylinder head 1. A recess 2 is provided on the top surface of the valve lifter 2.
a is formed, and the adjusting shim 4 is fitted in the recess 2a. The cam surface 5 a of the cam shaft 5 is in contact with the adjusting shim 4. Inside the valve lifter 2, for example, the valve stem 6a of the exhaust valve 6 is located, and the upper end surface 6b of the valve stem 6a is the inner top surface of the valve lifter 2, that is, the ceiling surface 2
It is in contact with b.

The valve stem 6a is supported by a valve stem guide 7 fixed to the cylinder head 1 side so as to be vertically slidable. A retainer 13 is attached near the upper end of the valve stem 6a via a cotter 8. A valve spring 9 is interposed between the retainer 13 and the portion of the cylinder head 1 where the valve stem guide 7 is located.

An oil supply passage 1 formed in the cylinder head 1 is provided on a sliding surface 1 a of the cylinder head 1 with respect to the valve lifter 2.
One of 0 is open. The other side of the oil supply passage 10 is connected to an oil pump (not shown) so that oil pumped up from the oil van by the oil pump is supplied to the outer peripheral surface 2c of the valve lifter 2 via the oil supply passage 10.

Cylinder head 1 on outer peripheral surface 2c of valve lifter 2
At a position where it can face the opening of the oil supply passage 10 on the side,
An inlet 11 into which the oil supplied from the oil supply passage 10 flows is formed. The inflow ports 11 are arranged at predetermined intervals in the circumferential direction. An oil groove 12 is formed between the inflow port 11 and the ceiling surface 2b as a flow path means for guiding the oil flowing from the oil supply passage 10 to the inflow port 11 to the ceiling surface 2b. The position of the inflow port 11 is higher than the ceiling surface 2b, and the oil groove 12 described above is inclined so as to descend toward the ceiling surface 2b.

A control valve 14 that controls the flow of oil is provided in the oil supply passage 10 on the cylinder head 1 side. The opening of the oil supply passage 10 and the inflow port 11 of the valve lifter 2 communicate with each other at a position where the exhaust valve 6 is most lowered. Then, the control valve 14 is opened by the open signal A only when the inlet 11 of the valve lifter 2 and the opening of the oil supply passage 10 communicate with each other, and the oil from the oil supply passage 10 becomes an oil jet to the inlet 11 side. It is supposed to be ejected to.

A retainer 13 that holds one end of a valve spring 9 that axially urges the exhaust valve 6 is located on the outer periphery of the upper end of the valve stem 6a. The retainer 13 is provided with an oil hole 19 penetrating the upper and lower surfaces, and the opening on the upper surface side of the oil hole 19 is directed to the oil groove 12 as the above-mentioned flow passage means.
On the lower surface side of the retainer 13, an oil sump portion 15 for accumulating oil flowing down along the outer peripheral surface of the valve stem 6a is provided.

The oil sump 15 is made of a cylindrical elastic body (for example, oil resistant rubber or neoprene rubber), and its upper end is liquid-tightly joined to the lower surface of the retainer 13. A bellows portion 16 is formed in the central portion of the oil sump portion 15, and the oil sump portion 15 is capable of expanding and contracting in the axial center C direction of the valve stem 6a. The lower end of the oil sump portion 15 projects inward in the radial direction, and a seal ring 17 capable of sliding contact with the valve stem 6a is provided on the inner peripheral portion thereof. That is, the oil sump 15 has a liquid-tight structure, and most of the oil that has flowed into the oil sump 15 is injected from the oil holes 19 provided in the retainer 13 to the inner surface side of the valve lifter 2. ing.

Directly below the oil sump 15 is a push rod 18 extending vertically.
Is provided. The height of the push rod 18 is equal to that of the valve lifter 2.
Is set so as to come into contact with the oil sump portion 15 when is most lowered. That is, when the valve lifter 2 is at the lowest position, the oil sump 15 is compressed by the push rod 18, and the oil flowing into the oil sump 15 is injected toward the oil groove 12 side through the oil hole 19. .

Next, the operation of the first embodiment will be described.

FIGS. 3A to 3D show a process in which oil is supplied from the oil supply passage 10 on the cylinder head 1 side to the valve lifter 2 side. FIG. 3A shows a state in which the valve lifter 2 is most raised. In this state, the control valve 14 is closed, and the opening of the oil supply passage 10 and the inflow port 11 of the valve lifter 2 do not coincide with each other. FIG. 3 (B) shows a state in which the valve lifter 2 is slightly lowered from the state of (A). Also in this case, the control valve 14 is closed as in (a), and oil is not supplied to the valve lifter 2 side.

FIG. 3C shows the state in which the valve lifter 2 is most lowered. In this state, the oil supply passage 10 communicates with the inflow port 11 of the valve lifter 2, and the control valve 14 is automatically opened by the open signal. Therefore, the oil pumped by the pump becomes an oil jet B as shown in the figure, and flows into the inflow port 11 of the valve lifter 2. FIG. 3D shows a state in which the valve lifter 2 moves up again. In this case, the oil that has flowed into the inflow port 11 is guided to the ceiling surface 2b along the oil groove 12 that serves as the flow path means. That is, the oil is guided to the contact surface between the valve stem 6a and the valve lifter 2, and the contact surface is lubricated by the oil.

The oil that lubricates the contact surface between the valve stem 6a and the valve lifter 2 flows down through the gap between the cotter 8 and the valve stem 6a, as shown in FIG.
Flowed into 15. Since the oil sump 15 has a liquid-tight structure, the oil that has flowed into the oil sump 15 almost never flows down along the outer peripheral surface of the valve stem 6a, and the amount of oil drop as in the conventional case is reduced. It can be kept extremely small. Therefore, the amount of oil reaching the umbrella portion of the exhaust valve 6 is also small, and the amount of harmful substances discharged is reduced.

Further, the oil that has flowed into the oil sump portion 15 is ejected toward the oil groove 12 through the oil hole 19 when the oil sump portion 15 is compressed. Therefore, the jetted oil flows down again along the oil groove 12 and is guided to the contact surface between the valve stem 6a and the valve lifter 2. In this way, the contact surface (ceiling surface 2b)
Since the oil from the oil supply passage 10 and the oil from the oil sump 15 are supplied to the valve, the contact surface is extremely lubricated, and even if the exhaust valve 6 is made of ceramic, the valve lifter The wear of No. 2 is remarkably suppressed.

Since the oil supplied to the inflow port 11 also lubricates the outer peripheral surface of the valve lifter 2, the progress of wear of the outer peripheral surface is suppressed particularly in the case of the valve lifter made of an aluminum alloy. Further, by injecting the oil in the oil reservoir 15 onto the inner peripheral surface of the valve lifter 2, it is possible to reduce the wear between the valve stem 6a made of ceramic and the cotter 8.

Second Embodiment FIG. 4 shows a second embodiment of the present invention. The second embodiment is different from the first embodiment only in the structure of the oil reservoir, and the other parts are the same as the first embodiment. Therefore, the same parts as those in the first embodiment are designated by the same reference numerals. Description of parts will be omitted, and only different parts will be described. The same applies to other embodiments described later.

In FIG. 4, reference numeral 21 in the drawing denotes an oil sump. Similar to the first embodiment, the oil sump 21 has an upper end joined to the retainer 13 and a lower end provided with a seal ring 17 capable of sliding contact with the valve stem 6a. A spiral protrusion 22 is formed at the center of the oil sump 21. The protrusion 22 is arranged so as to be housed in the gap of the valve spring 9, and the protrusion 22 is compressed by the valve spring 9 when the valve lifter 2 is most lowered.

In the second embodiment constructed in this way, when the valve lifter 2 is most lowered, the protrusion 22 of the oil sump 21 is
Is pinched and compressed by the valve spring 9,
The oil accumulated in the oil reservoir 21 is the oil hole of the retainer 13.
It is jetted from 19 toward the inner surface of the valve lifter 2. As described above, in this embodiment, the push rod 18 as in the first embodiment is unnecessary, and the structure is simplified. Other actions are first
According to the example.

Third Embodiment FIG. 5 shows a third embodiment of the present invention. The third embodiment differs from the first embodiment only in the structure of the flow path means provided in the valve lifter. In the first embodiment, the inlet 11 formed on the outer peripheral surface of the valve lifter 2 and the ceiling surface 2
An inclined oil groove 12 is provided as a flow path means for guiding the oil to the contact surface between the valve stem 6b and the valve lifter 2 between b and b, but in the present embodiment, instead of the oil groove 12, an oil passage 31 is provided. Is provided.

In the third embodiment configured as described above, the thickness of the valve lifter 2 in the compression load direction can be made thicker than in the first embodiment, so that the strength of the valve lifter 2 can be further increased.

Although the present embodiment shows an example applied to a structure in which the oil sump portion is compressed by the push rod, it is of course applicable to a structure in which the oil sump portion is compressed by the valve spring as in the second embodiment. .

Fourth Embodiment FIG. 6 shows a fourth embodiment of the present invention. In the first embodiment, the control valve 14 for controlling the oil flow is provided in the oil supply passage on the cylinder head side, but in the present embodiment, the pressurizing pump 40 is provided. Pressure pump
40 is a cylinder portion 41 formed in the cylinder head 1,
It is composed of a plunger 42, a flange 43, and a spring 44. The plunger 42 is slidably fitted in the cylinder portion 41, and a flange portion 43 is attached to the outer peripheral surface of the upper portion of the plunger 42. A spring 44 that urges the plunger 42 toward the camshaft 5 is located between the collar portion 43 and the upper surface of the cylinder head 1. The top of the plunger 42 is in contact with the cam surface 5b provided on the cam shaft 5, and the plunger 42 moves up and down by the rotation of the cam shaft 5. Upstream of the pressure pump 40,
A check valve 45 is arranged. Check valve 45
Is for preventing oil from flowing back when the pressure pump 40 is pressurized.

The movement of the plunger 42 of the pressurizing pump 40 depends on the valve lifter 2.
In synchronism with the movement of the valve lifter 2, the oil is pressurized at the position where the valve lifter 2 is most lowered, and the oil is ejected to the inflow port 11 of the valve lifter 2.

In the fourth embodiment thus configured, the oil is ejected to the inflow port 11 by mechanical means, so that the movement of the valve lifter 2 and the oil injection timing can be reliably synchronized.

Although a plurality of inlets 11 are formed on the outer peripheral surface of the valve lifter 2 in each of the above-described embodiments, the inlets 11 may have a groove shape continuously extending in the circumferential direction.

[Effects of the Invention] As described above, in the case of the valve lifter rear surface lubrication device according to the present invention, the oil in the oil supply passage is supplied to the contact surface between the valve lifter and the valve stem through the flow passage means, and The oil that lubricates the contact surface is made to flow into the oil reservoir, and the oil reservoir is compressed to inject this oil to the inner surface of the valve lifter, so the contact surface between the valve lifter and the valve stem is
Very well lubricated with oil from both. Therefore, even if the intake / exhaust valve is made of a ceramic having a high hardness, the wear of the valve lifter can be significantly suppressed, and the valve timing adjustment by the adjusting shim becomes almost unnecessary.

Also, most of the oil that flows down along the valve stem is stored in the oil sump, so that the oil almost never flows to the umbrella of the exhaust valve, reducing the amount of harmful substances contained in the exhaust gas. You can

[Brief description of drawings]

1 is a sectional view of a valve lifter rear surface lubrication apparatus according to a first embodiment of the present invention, FIG. 2 is a partially enlarged sectional view of FIG. 1, and FIGS. 3 (a) to 3 (d) are the apparatus of FIG. 4 is a sectional view showing an oil supply process to the valve lifter in FIG. 4, FIG. 4 is a partially enlarged sectional view of a backside lubricator for a valve lifter according to a second embodiment of the present invention, and FIG. 5 is a valve lifter according to a third embodiment of the present invention. FIG. 6 is a sectional view of a backside lubricating device, and FIG. 6 is an enlarged sectional view of the vicinity of an oil supply passage in a valve lifter backside lubricating device according to a fourth embodiment of the present invention. 1 ... Cylinder head 2 ... Valve lifter 2b ... Ceiling surface (contact surface with valve stem) 6 ... Exhaust valve 6a ... Valve stem 10 ... Oil supply passage 11 ... Inlet 12 ... Oil groove ( Flow passage means 13 …… Retainer 14 …… Control valves 15, 21 …… Oil reservoir 19 …… Oil hole provided in retainer 31 …… Oil passage (flow passage means) 40 …… Pressurizing pump

Claims (1)

[Scope of utility model registration request] 1. In a valve train of an internal combustion engine in which an upper end surface of a valve stem of an intake / exhaust valve is in contact with a top portion of an inner surface of a valve lifter slidably fitted in a cylinder head, the cylinder head is provided with a valve lifter. An oil supply passage opening to the sliding surface is formed, and the valve lifter is provided with a flow passage means for guiding the oil supplied from the oil supply passage to the contact surface between the valve stem and the valve lifter, and the upper end of the valve stem. The retainer, which is located on the outer periphery and holds one end of the valve spring that biases the intake / exhaust valve in the axial direction, is provided with an oil hole that opens to the inner surface side of the valve lifter, and the lower surface side of the retainer is compressed when the valve lifter descends. An oil reservoir is provided to inject the oil that has flowed down along the valve stem from the oil hole toward the inner surface of the valve lifter. Valve lifter back surface lubricating apparatus characterized.