JPH06167208A - Lubricating device for engine - Google Patents

Abstract

PURPOSE:To guide an oil, which accumulates in a tappet supporting hole and causes rotation resistance, to the gap between the tappet and the tappet supporting hole, and to reduce mechanical loss by forming an oil guide groove directing to the axial direction in a tappet supporting hole, which supports a tappet in a valve driving mechanism of an engine, of a cylinder head. CONSTITUTION:In an engine 2, a valve 6 is inclined and jounalled to a cylinder head 4. The valve 6 is driven by a valve driving mechanism 16. In other words, in the valve driving mechanism 16, a tappet 18 is installed in a stem end 14 of a valve stem 8 while the tappet 18 is supported slidably in a tappet supporting hole 20. The valve driving mechanism 16 hits the tappet 18 by means of a cam 24 of a cam shaft 22 jounalled to the cylinder head 4 so as to drive the valve 6. In this constitution, an oil guide groove 28 directing to the axial direction is formed in the tappet supporting hole 20. In this way, accumulated oil in the tappet supporting hole 20 is guided to the gap between the tappet 18 and the tappet supporting hole.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an engine lubrication device, and in particular, it is possible to reduce mechanical loss due to resistance of oil accumulated in a tappet supporting hole for supporting a tappet to rotation of a cam, and A lubricating device for an engine, which can prevent unnecessary oil from flowing out from the breather due to the oil being scattered by the cam, and can positively lubricate the outer peripheral surface of the tappet and the inner peripheral surface of the tappet support hole. Regarding

[0002]

2. Description of the Related Art In a 4-cycle engine mounted on a vehicle or the like, intake and exhaust are performed by an intake valve and an exhaust valve. These valves are driven by a valve drive mechanism. The valve drive mechanism is a direct drive type valve drive mechanism that drives the valve by directly hitting the valve by a cam of a cam shaft, or a swing arm type valve drive mechanism that drives the valve by a cam of the cam shaft via a swing arm. There is a rocker arm type valve drive mechanism in which a valve is driven by a cam of a cam shaft via a rocker arm.

As an engine equipped with the direct drive type valve drive mechanism, there is one disclosed in Japanese Utility Model Laid-Open No. 1-141313. What is disclosed in this publication is an engine that lubricates a valve lifter, which is a tappet, and a cam nose of a cam shaft by oil stored in an oil storage portion of a cylinder head, and a cam journal of a cam shaft is provided above the oil storage portion. A fence-shaped oil returning means for returning a part of the lubricated oil to the oil pan is provided.

[0004]

By the way, there is a conventional engine having a direct drive type valve drive mechanism as shown in FIG. In FIG. 3, 102 is an engine,
Reference numeral 104 is a cylinder head, 106 is a valve, 108 is a valve stem, 110 is a spring, and 112 is a retainer.

This engine 102 has a cylinder head 1
04, the valve 106 is tilted and axially supported. Valve 1
06 is given an elastic force in the valve closing direction by the spring 110. The spring 110 is the valve stem 10.
6 is supported by a retainer 112 attached to the stem end 114.

The valve 104 is driven by a direct drive type valve drive mechanism 116. Valve drive mechanism 116
Is provided with a tappet 118 attached to the stem end 114 of the valve stem 108. The tappet 118 is axially slidably supported in a tappet support hole 120 of the cylinder head 102. Tappet support hole 120
Are provided so as to be inclined coaxially with the valve stem 108.

The valve drive mechanism 116 drives the valve 106 by directly striking the tappet 118 with the cam 124 of the cam shaft 122 pivotally supported by the cylinder head 102. Incidentally, reference numeral 126 is a notch groove for escape of the cam 124.

However, in such an engine 102, as shown in FIG. 3, there is a problem that oil is accumulated in the tappet support hole 120 for supporting the tappet 118. The oil will be accumulated on the lower side of the inclined tappet support hole 120.

Therefore, the oil accumulated on the tappet 118 of the tappet support hole 120 becomes a resistance to the rotation of the cam 124, which causes a mechanical loss, and the oil is scattered by the cam 124. , There was an inconvenience of being leaked from the breather (not shown).

Further, since the oil accumulated on the tappet 118 is difficult to flow between the tappet 118 and the tappet support hole 120, the oil is collected between the outer peripheral surface 128 of the tappet 118 and the inner peripheral surface 130 of the tappet support hole 120. However, there was a problem that it could not be actively lubricated.

[0011]

Therefore, in order to eliminate the above-mentioned inconvenience, the present invention provides a tappet attached to the stem end of a valve stem of a valve that is axially supported by an engine cylinder head. In an engine in which a tappet support hole of the cylinder head is slidably supported in the axial direction and the tappet is directly driven by a cam of a camshaft, an oil guide groove axially oriented in the tappet support hole is provided. It is characterized by being formed and provided.

[0012]

According to the structure of the present invention, the tappet support hole for supporting the tappet is provided with the oil guide groove oriented in the axial direction, so that the oil can be prevented from being accumulated in the tappet support hole and the tappet can be prevented. The oil can be guided between the tappet support hole and the tappet support hole.

[0013]

Embodiments of the present invention will be described below with reference to the drawings.

1 and 2 show an embodiment of the present invention. In the figure, 2 is an engine mounted on a vehicle or the like, 4 is a cylinder head, 6 is a valve, 8 is a valve stem, 10 is a spring, and 12 is a retainer.

In this engine 2, a valve 6 is tilted and pivotally supported by a cylinder head 4. The valve 6 is given an elastic force in the valve closing direction by a spring 10. The spring 10 is supported by a retainer 12 attached to the stem end 14 of the valve stem 6.

The valve 4 is driven by a direct drive type valve drive mechanism 16. The valve drive mechanism 16 is provided with a tappet 18 attached to the stem end 14 of the valve stem 8. The tappet 18 is provided so as to be slidable in the axial direction in a tappet support hole 20 of the cylinder head 2. The tappet support hole 20 is provided so as to be inclined coaxially with the valve stem 8.

The valve drive mechanism 16 includes the cylinder head 2
The tappet 18 is directly hit by the cam 24 of the cam shaft 22 which is pivotally supported by the valve 24 to drive the valve 6. Reference numeral 26 is a notch groove for escape of the rotating cam 24.

In such an engine 2, an oil guide groove 28 is formed in the tappet support hole 20 so as to be oriented in the axial direction. The oil guide groove 28 is formed so as to reach from the upper end to the lower end of the tappet support hole 20 that is supported in an inclined manner, on the lower side of the inclination. Further, the oil guide groove 28 is formed so that the upper end thereof is located at the central portion of the cutout groove 26 on the lower side of the inclination of the tappet support hole 20.

Next, the operation will be described.

When the engine 2 is driven, the valve drive mechanism 1
6 taps the tappet 18 directly by the cam 24 of the rotating cam shaft 22 to drive the valve 6. The tappet support hole 20 slidably supporting the tappet 18 of the valve drive mechanism 16 is provided with an oil guide groove 28 extending from the upper end to the lower end on the inclined lower side.

When the engine 2 is driven, the oil that drops on the tappet 118 flows to the lower side of the tappet support hole 20 inclining. The oil flowing to the lower side of the tilt of the tappet support hole 20 is guided by the oil guide groove 28.
It is guided below 0 and returned to the oil pan by a return passage (not shown).

As described above, by providing the oil guide groove 28 in the tappet support hole 20 for supporting the tappet 18, it is possible to prevent the oil from being accumulated in the tappet support hole 20, and at the same time, the tappet 18 and the tappet 18 can be prevented. Oil can be guided between the support holes 20.

Therefore, it is possible to prevent the oil accumulated on the tappet 18 of the tappet supporting hole 20 from becoming a resistance against the rotation of the cam 24, and the mechanical loss due to the resistance of the oil can be reduced. Further, the accumulated oil can be prevented from being scattered by the cam 24, and the oil can be prevented from flowing out from the breather (not shown).

The oil guide groove 28 is provided in the tappet 18
By guiding oil between the tappet support hole 20 and the tappet support hole 20, the outer peripheral surface 30 of the tappet 18 and the inner peripheral surface 32 of the tappet support hole 20, which rotate while the engine 2 is driven, can be positively lubricated. . Therefore, the space between the tappet 18 and the tappet support hole 20 can be satisfactorily lubricated, which can contribute to the reduction of mechanical loss.

Further, the oil guide groove 28 is formed so that its upper end is located in the central portion of the cutout groove 26 on the lower side of the inclination of the tappet support hole 20, so that it is scattered by the rotation of the cam 24. Collect the oil you need and tappet 1
8 can guide the oil between the tappet support hole 20 and the outer peripheral surface 30 of the tappet 18 and the tappet support hole 2
The inner peripheral surface 32 of 0 can be more positively lubricated.

[0026]

As described above, according to the present invention, the oil guide groove provided in the tappet support hole can prevent oil from accumulating in the tappet support hole, and the gap between the tappet and the tappet support hole can be prevented. You can guide the oil to.

Therefore, it is possible to prevent the oil accumulated in the tappet supporting hole from becoming a resistance against the rotation of the cam, and it is possible to reduce the mechanical loss due to the resistance of the oil, and the accumulated oil is prevented by the cam. The oil can be prevented from being scattered, and the oil can be prevented from leaking out from the breather. In addition, the oil guide groove can guide the oil between the tappet and the tappet support hole to positively lubricate the outer peripheral surface of the tappet and the inner peripheral surface of the tappet support hole, thereby reducing mechanical loss. Can contribute to.

[Brief description of drawings]

FIG. 1 is a sectional view of a cylinder head showing an embodiment of an engine lubricating device according to the present invention.

FIG. 2 is a plan view of the cylinder head taken along the arrow 〓 of FIG.

FIG. 3 is a sectional view of a cylinder head showing a conventional example of a lubricating device for an engine.

[Explanation of symbols]

 2 engine 4 cylinder head 6 valve 8 valve stem 10 spring 12 retainer 14 stem end 16 valve drive mechanism 18 tappet 20 tappet support hole 22 camshaft 24 cam 26 notch groove 28 oil guide groove 30 outer peripheral surface 32 inner peripheral surface

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[Procedure amendment]

[Submission date] February 10, 1993

[Procedure Amendment 1]

[Document name to be corrected] Drawing

[Correction target item name] All drawings

[Correction method] Change

[Correction content]

[Figure 1]

[Fig. 2]

[Figure 3]

Claims (1)

[Claims] 1. A tappet is attached to a stem end of a valve stem of a valve axially supported by an engine cylinder head, and the tappet is axially slidably supported in a tappet support hole of the cylinder head. Further, in an engine in which the tappet is directly driven by a cam of a camshaft, an oil guide groove that is axially oriented is formed in the tappet support hole, and the engine lubrication device is provided.