JPH0440529B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a bushing member for supporting a camshaft of an internal combustion engine.

Generally, in internal combustion engines, a bushing member is used to support a camshaft. This bushing member has a cylindrical sleeve-shaped bushing body, and the bushing body is formed with an oil inlet hole and an oil outlet hole.

However, in conventional bushing members, when a large load is applied to the camshaft, as will be explained in detail later, the oil film breaks partially and abnormal wear occurs on the inner peripheral surface of that part, and this abnormal wear becomes serious. There was a problem that burn-in occurred if the image quality was too high.

The present invention has been made in view of the above-mentioned circumstances, and its object is to provide an improved bushing member for a camshaft that can prevent abnormal wear and seizure from occurring.

According to the present invention, in a bushing member for a camshaft in an internal combustion engine, which includes a cylindrical sleeve-shaped bushing body in which an oil inlet hole and an oil outlet hole are formed, the bushing member communicates with the oil inlet hole and does not communicate with the oil outlet hole. There is provided a bushing member for a camshaft of an internal combustion engine, characterized in that an oil groove is formed over substantially the entire circumference of the inner peripheral surface of the bushing body.

A more detailed explanation will be given below with reference to the accompanying drawings. In FIG. 1 showing a part of an internal combustion engine equipped with a conventional bushing member for a camshaft, a camshaft 2 equipped with a cam for opening and closing a valve is supported by a cylinder block 6 via a bushing member 4. There is. A camshaft gear 8 is attached to one end of the camshaft 2 via a key member 10 and further fixed with a mounting screw 12. Although not shown, the camshaft gear 8 is drivingly connected to a crank gear fixed to one end of the crankshaft via an idle gear.
Therefore, when the crankshaft is rotated by the vertical movement of the piston, the camshaft 2 is rotated via the crank gear, the idle gear, and the camshaft gear 8.

Next, referring to FIGS. 2 and 3 as well as FIG. 1, the bushing member 4 includes a bushing body 14 in the shape of a cylindrical sleeve. The bush main body 14 has an oil inlet hole 16 and an oil outlet hole 18 formed therein. The oil inlet hole 16 is further formed with a groove 19 for smoothing the inflow of oil. The bushing member 4 has an oil inlet hole 16 connected to an oil passage 20 (FIG. 1) formed in the cylinder block 6, and an oil outlet hole 18 connected to a cylinder head (not shown) formed in the cylinder block 6. )
The cylinder block 6 is connected to an oil passage (not shown) for supplying oil to the cylinder block 6. On the other hand, the camshaft 2 is further formed with a T-shaped oil feed passage 22 in association with the oil inlet hole 16 and the oil outlet hole 18 . The oil feed passage 22 includes a supply passage portion 24a that penetrates the camshaft 2 and a supply passage portion 24b that is connected to the supply passage portion 24a from the outside of the camshaft 2. Therefore, when the camshaft 2 is rotated clockwise in FIG. 3 as described above and positioned at the position shown in FIG.
b and the oil outlet hole 18 and the supply passage portion 24a are in communication with each other, so that lubricating oil from an oil pump (not shown) is supplied to the oil passage 20,
The oil is delivered to the cylinder head through the oil inlet hole 16, the oil feed passage 22 and the oil passage. Further, when the camshaft 2 is further rotated approximately 270 degrees from the position shown in FIG. 3, the oil inlet hole 16 and the supply passage portion 24a and the oil outlet hole 18 and the supply passage portion 24b are brought into communication, respectively. Lubricating oil from the oil pump is delivered to the cylinder head in the manner described above. Thus, in an internal combustion engine equipped with the bushing member 4, when the camshaft 2 rotates once, oil is intermittently supplied from the oil pump to the cylinder head twice.

However, in the conventional camshaft bushing member 4 described above, a large load acts on the camshaft 2 (for example, when the output gear is drivingly connected to the camshaft gear 8 via the idle gear when output is extracted from the internal combustion engine). etc.), a large load is applied to the inner circumferential surface of the bushing body 14, and this causes the oil film to break partially, causing abnormal wear on the inner circumferential surface of that area, and causing severe seizure in the interior. I was awake.

The present invention has been made in order to solve the above problem, and includes a camshaft outer circumferential surface and an inner circumferential surface of the bushing body, which communicate with the inlet hole but do not communicate with the outlet hole. It is characterized by the provision of oil grooves whose main purpose is lubrication between the surfaces.

Hereinafter, a camshaft bushing body constructed according to the present invention will be described with reference to FIGS. 4 to 7.

In FIG. 4 showing a cross-section of a bushing member for a camshaft according to a first embodiment of the present invention and FIG. It has a bush main body 32. This bush main body 32 has an oil inlet hole 34 and an oil outlet hole 36 formed therein. Furthermore, an oil groove 38 is formed in the inner circumferential surface of the bush main body 32, which communicates with the oil inlet hole 34 and does not communicate with the oil outlet hole 36. The oil groove 38 includes a first portion 40a extending from one side of the oil inlet hole 34 toward one side of the oil outlet hole 36, and a first portion 40a extending from the opposite side of the oil inlet hole 34 toward one side of the oil outlet hole 36.
(therefore, extending in a direction opposite to the direction of the first portion 40a).
The bushing body 32 has a portion 40b formed over substantially the entire circumference of the inner circumferential surface of the bush main body 32. As described above, in this bushing member 30, the oil inlet hole 34 is connected to the oil passage 20 (see FIG. 1), and the oil outlet hole 36 is connected to the oil passage (not shown) for supplying oil to the cylinder head. It is mounted on the cylinder block 6 so as to be connected to the cylinder block 6. In addition, when the bushing member 30 is unfolded as shown in FIG. 5, each of the projections 42 formed at one end of the bushing main body 32 is fitted into each of the recesses 44 formed at the other end. It is formed into a cylindrical sleeve shape as shown in FIG.

In the bushing member 30 as described above,
The oil flowing in from the oil inlet hole 34 fills the oil groove 38 (specifically, the first portion 40a and the second portion 40b).
No oil flows out through the oil outlet hole 36. (Thus, intermittent supply of oil to the cylinder head is achieved as in the conventional case.) Therefore, in an internal combustion engine equipped with such a bushing member 30, the oil groove 38 is filled with oil. , lubrication between the inner circumferential surface of the bush main body 32 and the outer circumferential surface of the camshaft 2 (see FIG. 1) is performed over substantially the entire circumference of the inner circumferential surface of the bush main body 32,
In this way, abnormal wear and seizure of the inner circumferential surface of the bush main body 32 can be prevented.

Next, other specific examples of the camshaft bushing member will be described with reference to FIGS. 6-A, 6-B, and 7. Note that the same members as those described above are given the same numbers.

In FIG. 6-A showing a developed state of a bushing member for a camshaft according to a second embodiment of the present invention, a bushing member 30' includes a bushing body 32, and an inner circumferential surface of the bushing body 32 is shown in FIG. An oil groove 38 that communicates with the oil inlet hole 34 and does not communicate with the oil outlet hole 36 is formed over the entire circumference of the inner peripheral surface. The oil groove 38 has a first portion 40a extending from one side of the oil inlet hole 34 to one side of the oil outlet hole 36.
a second portion extending from the opposite side of the oil inlet hole 34 toward the opposite side of the oil outlet hole 36 (therefore extending in the opposite direction to the direction of the first portion 40a); It has a third portion 40c that communicates the first portion 40a and the second portion 40b through one side (the upper side in FIG. 6-A) of the hole 36.

In an internal combustion engine equipped with such a bushing member 30', lubrication between the inner circumferential surface of the bushing body 32 and the outer circumferential surface of the camshaft 2 (see FIG. 1) is applied to the entire circumference of the inner circumferential surface of the bushing body 32. Since this is carried out across the entire body, abnormal wear and seizure of the inner peripheral surface of the bush main body 32 can be further prevented.

In the second specific example above, the oil groove 38
A third portion 40c is formed on one side of the oil outlet hole 36, if desired, as shown in FIG. 6-B.
6 (upper and lower sides in FIG. 6-B).

In FIG. 7, which shows the unfolded state of the bushing member for a camshaft according to a third embodiment of the present invention, the bushing member 30'' includes a bushing body 32, and the inner circumferential surface of the bushing body 32 is An oil groove 38 that communicates with the oil inlet hole 34 and does not communicate with the oil outlet hole 36 is formed over the entire inner peripheral surface of the oil groove 38.
are a full circumferential portion 42a formed over the entire circumference of the inner circumferential surface of the bush main body 32, and a full circumferential portion 42a.
and a connecting portion 42b that communicates with the oil inlet hole 34.
It has

Even in an internal combustion engine equipped with such a bushing member 30', since oil lubrication is carried out all around the inner peripheral surface of the bushing body 32, the inside of the bushing main body 32 is Abnormal wear and seizure of the peripheral surface can be further prevented.

Although specific examples of the camshaft bushing member constructed according to the present invention have been described above, the present invention is not limited to such specific examples.
Various modifications and variations can be made without departing from the scope of the invention.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a part of an internal combustion engine equipped with a conventional camshaft bushing member. FIG. 2 is a perspective view showing a conventional camshaft bushing member. 3 is a cross-sectional view showing a state in which a camshaft is attached to the camshaft bushing member of FIG. 2; FIG. FIG. 4 is a sectional view showing a first specific example of a camshaft bushing member constructed according to the present invention. FIG. 5 is an exploded view showing the camshaft bushing member shown in FIG. 4 in an expanded state. FIG. 6-A is an exploded view showing a second embodiment of a camshaft bushing member constructed according to the present invention in an expanded state. FIG. 6-B is a developed view showing a modified example of the second specific example shown in FIG. 6-A.
FIG. 7 is an exploded view showing a third embodiment of a camshaft bushing member constructed according to the present invention in an expanded state. 4, 30, 30' and 30''...button members,
14 and 32...button body, 16 and 34...
...Oil inlet hole, 18 and 36...Oil outlet hole, 38...Oil groove.

Claims (1)

[Scope of Claims] 1. A bushing member for a camshaft in an internal combustion engine comprising a cylindrical sleeve-shaped bushing body in which an oil inlet hole and an oil outlet hole are formed, the bushing member being in communication with the oil inlet hole and not connected to the oil outlet hole. A bushing member for a camshaft in an internal combustion engine, characterized in that a communicating oil groove is formed over substantially the entire circumference of the inner peripheral surface of the bushing body. 2. The oil groove has a first portion extending from one side of the oil inlet hole toward one side of the oil outlet hole, and a second portion extending from the opposite side of the oil inlet hole toward the opposite side of the oil outlet hole. A bushing member for a camshaft in an internal combustion engine according to claim 1, comprising: a bushing member for a camshaft in an internal combustion engine; 3. A camshaft in an internal combustion engine according to claim 2, wherein the oil groove includes a third portion that communicates with the first portion and the second portion through one side of the oil outlet hole. Bushing parts. 4. A camshaft in an internal combustion engine according to claim 2, wherein the oil groove includes a third portion that communicates with the first portion and the second portion through both sides of the oil outlet hole. Bushing parts. 5. Claims in which the oil groove includes a circumferential portion formed over the entire circumference of the inner circumferential surface of the bushing body, and a connecting portion that communicates the circumferential portion with the oil inlet hole. A bushing member for a camshaft in an internal combustion engine according to item 1.