JP2003193818A - Oil supply structure to camshaft bearing part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an oil supply structure to a camshaft bearing part easy to work and manufacturable with at reduced cost. <P>SOLUTION: An oil supply groove 6 in parallel with a cylinder row is formed on the outer peripheral side and a journal oil supply groove 7 branched from this oil supply groove 6 and reaching a bearing part 2 is formed in a groove shape on a connecting surface 1a of a cylinder head 1 and a cam bracket 3 in the structure constituted as the cam bracket 3 in a ladder structure integrally formed in a shape along an outer periphery of the cylinder head is connected onto the cylinder head 1 through a bolt 5 and a camshaft 4 is supported free to rotate between this cam bracket 3 and the bearing part 2 of the cylinder head 1. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil supply structure for supplying oil to a camshaft bearing portion.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
As shown in the plan view of FIG. 6 and the side view of FIG. 7, the bearing portion 5 of the camshaft is provided on the upper surface side of the cylinder head 51.
4, 54 are formed, and in order to supply oil for lubrication to the bearings 54, 54, in the cylinder head 51, in parallel with the arrangement of the cylinders, in the cylinder head oil supply passages 52, 52 is formed,
Journal oil supply passages 53, 53 are formed so as to communicate with the bearing portions 54, 54 from the oil supply passages 52, 52 in the cylinder head, respectively, and oil is transferred from the oil supply passage 53 in the cylinder head to the journal oil supply passage 53. It is configured to be supplied to the bearing portion 54 through.

In such a cylinder head 51, the oil supply passages 52, 52 in the cylinder head are integrally formed by using a core during casting, but in order to prevent the core from breaking during casting. , The oil supply passage 52,
Since the diameter of 52 is required to be 12 mm or more, the cylinder head 51 is heavy, the material cost is high, and the number of cores is increased to complicate the work during casting, resulting in high cost. is there. When the oil supply passages 52, 52 in the cylinder head are formed by gun drilling, there are problems that the processing depth is longer than the diameter, special equipment is required, and the processing time becomes long. there were. In addition, the oil supply passages 52, 5 in the cylinder head
There is a problem in that blind plugs 55, 55 are required at the end of No. 2 and the cost is increased accordingly.

Conventionally, as shown in the plan view of FIG. 8 and the side view of FIG. 9, a bearing portion 54 of a cylinder head 51 is used.
When the cam shafts 57, 57 that are rotatably provided between the cam brackets 56 are hollow, the oil supply passage 57a is formed in the cam shaft 57, and as shown in the enlarged view of FIG. There is a structure in which a journal oil supply hole 57b is formed in 57 and oil is supplied from the journal oil supply hole 57b to the bearing portion 54 and the bearing portion of the cam bracket 56. To make the inside of 57 hollow, it is necessary to increase the diameter of the cam shaft 57 in order to ensure the rigidity of the cam shaft 57. Also, when the cam shaft 57 is made of cast iron, a core is used. It is necessary to deal with whether it is hollow or drilled after casting, which complicates the work during casting and requires special equipment such as a gun drill. Next, the processing time is prolonged, there is a problem that the increase in cost.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems of the prior art, and is an oil for a camshaft bearing which is easy to process, can shorten the processing time, and can reduce the cost. With the aim of not providing a supply structure,
A first gist of the invention is that a cam bracket having a ladder structure, which is integrally formed in a shape along the outer circumference of the cylinder head, is joined on a cylinder head through a bolt, and rotates between the cam bracket and a bearing portion of the cylinder head. In a structure in which the cam shaft is supported as much as possible, an oil supply groove parallel to the cylinder arrangement is formed on the outer peripheral side on the joint surface between the cylinder head and the cam bracket,
A journal oil supply groove that branches from the oil supply groove and reaches the bearing portion is formed. A second gist is that the oil supply groove and the journal oil supply groove are formed on one side or both sides of the cylinder head and the cam bracket. Also,
A third gist is that a counterbore that serves as an oil passage is formed in the journal oil supply groove on the outer periphery of a bolt screw hole into which the bolt is screwed.

[0006]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a plan configuration diagram in which a pair of cam shafts are provided on the upper surface of a cylinder head via a cam ladder bracket, and FIG. 2 is a side configuration diagram thereof.

In the figure, the upper surface of the cylinder head 1 is a flat joint surface 1a, and bearing portions 2 and 2 are integrally formed in a concave shape on the joint surface 1a. The cam shafts 4 and 4 are rotatably provided, and the cam ladder bracket 3 is joined to the joint surface 1a via the bolt 5 from the upper surface side. This cam ladder bracket 3 is a cylinder head 1.
The cam rudder bracket 3 is put on the joint surface 1a of the cylinder head 1 and tightened with bolts 5 so that the pair of cam shafts 4 and 4 can be rotatably supported. It is a thing.

In the present embodiment, the joint surface 1a on the upper surface of the cylinder head 1 is provided with a recessed oil supply groove 6 and a journal oil supply groove 7 branched from the oil supply groove 6. The supply groove 6 and the journal oil supply groove 7 can be integrally formed when the cylinder head 1 is cast, and can be easily formed in a groove shape without using a core or the like. The oil supply groove 6 is
The camshafts 4 and 4 are formed on the outer peripheral side of the pair of camshafts 4 in parallel to the cylinder arrangement so as to surround the outer peripheral side from the left side to the right side.

The tip of the oil supply groove 6 on the left side is communicated with the oil supply passage 8 from the cylinder block, and the oil from the oil pump passes through the oil supply passage 8 from the cylinder block. The oil flows into the oil supply groove 6 through the plurality of journal oil supply grooves 7 branched from the oil supply groove 6, and is supplied to the bearing portions 2 and the bearing portions of the cam ladder bracket 3. .

As shown in the enlarged plan view of the main part in FIG. 3, a counterbore 7a is provided in each journal oil supply groove 7, and a bolt 5 is screwed into the center of the counterbore 7a. The bolt screw hole 1b is formed, and as shown in the sectional view of FIG. 4, the bolt 5 is tightened in the bolt screw hole 1b to join the cam ladder bracket 3 to the joint surface 1a of the cylinder head 1 in an oil-tight manner. ,
Oil is satisfactorily supplied into the bearing portion 2 through the passage of the counterbore 7a. That is, the oil flows along the outer circumference of the bolt 5 and is supplied to the bearing portion 2.

The bearing portion 2 of the camshaft 4 is the cam 4
Since it is arranged between a and 4a, the width of the bearing portion 2 cannot be increased, and a screw hole 1b for screwing the bolt 5 and oil are passed through the narrow width of the bearing portion 2. Although it is difficult to form the grooves 7 separately, as in this example, the counter bore 7a is formed in the journal oil supply groove 7.
By providing the counter bore 7a on the outer circumference of the bolt screw hole 1b, the bolt screw hole 1b and the journal oil supply groove 7 can be favorably provided within the width of the narrow bearing portion 2.

The oil supply groove 6 and the journal oil supply groove 7 can be formed on the joint surface on the cam ladder bracket 3 side, and oil can be supplied to the cylinder head 1 side and both sides of the cam ladder bracket 3 respectively. The groove 6 or the journal oil supply groove 7 may be formed.

The plan view of FIG. 5 shows a modified example. In FIG. 5, the left oil supply groove 6a and the right oil supply groove 6b are formed independently of each other. A plurality of journal oil supply grooves 7 are branched and formed in the grooves 6a and 6b.

In the case of FIG. 5, the oil supply passages 8a and 8b from the cylinder block are connected to the respective ends of the left oil supply groove 6a and the right oil supply groove 6b, and the oil supply passages 8a and 8b from the cylinder block are connected to each other. Oil passes through the oil supply passages 8a and 8b of this cylinder block,
The oil is supplied into the left and right oil supply grooves 6a and 6b, passes through the journal oil supply groove 7, and is supplied to the respective bearing portions 2. In addition, this FIG.
In the case of, it is not necessary to use a blind plug as in the conventional case, and the oil supply grooves 6a and 6b and the journal oil supply groove 7 can be easily formed in a groove shape on the cylinder head 1 side or the cam ladder bracket 3 side or both. Can be formed,
Processing is easy and processing time can be shortened.

[0015]

According to the present invention, a cam bracket having a ladder structure integrally formed on the cylinder head along the outer circumference of the cylinder head is joined via bolts so that it can rotate between the cam bracket and the bearing portion of the cylinder head. In the structure in which the cam shaft is supported on the outer peripheral side of the cylinder head and the cam bracket, an oil supply groove parallel to the cylinder arrangement is formed, and the oil supply groove is branched to the bearing part. By forming the journal oil supply groove to reach, since the oil supply groove and the journal oil supply groove are groove-shaped, it is easy to process with few hole drilling, and it is possible to manufacture in a short processing time, which is good. The oil can be supplied to the bearing.

Further, since the oil supply groove and the journal oil supply groove are formed on one side or both sides of the cylinder head and the cam bracket, the oil supply groove is formed when the cylinder head or the cam bracket is formed by casting or the like. Further, the journal oil supply groove can be easily formed, and the cost can be reduced.

Further, in the journal oil supply groove, a counterbore serving as an oil passage is formed on the outer periphery of the bolt screw hole into which the bolt is screwed, so that the bolt screw to screw the bolt to the narrow bearing portion. A hole and a journal oil supply groove can be provided, and the oil can be satisfactorily passed around the bolt to supply the oil to the bearing portion.

[Brief description of drawings]

FIG. 1 is a plan configuration diagram of a cylinder head with a cam shaft and a cam ladder bracket of a first embodiment attached.

FIG. 2 is a side configuration diagram of FIG.

FIG. 3 is an enlarged plan configuration diagram of a main part of a cylinder head.

FIG. 4 is an enlarged vertical cross-sectional configuration diagram of a portion of FIG.

FIG. 5 is a plan configuration diagram corresponding to FIG. 1 showing a second embodiment.

FIG. 6 is a plan configuration diagram of a conventional cylinder head.

7 is a side view of the configuration of FIG.

FIG. 8 is a plan configuration diagram of a cylinder head with a camshaft attached showing another conventional example.

9 is a side configuration diagram of FIG. 8. FIG.

10 is a partially enlarged view of the cam shaft shown in FIGS. 8 and 9. FIG.

[Explanation of Codes] 1 Cylinder head 1a Joint surface 1b Bolt screw hole 2 Bearing part 3 Camrader bracket 4 Cam shaft 4a Cam 5 Bolt 6,6a, 6b Oil supply groove 7 Journal oil supply groove 7a Counterbore 8,8a, 8b Cylinder Oil supply passage from block

Claims (3)

[Claims] 1. A cam bracket having a ladder structure integrally formed on the cylinder head along the outer periphery of the cylinder head is joined via bolts so that the cam bracket is rotatable between the cam bracket and the bearing portion of the cylinder head. In a structure in which a cam shaft is supported, an oil supply groove parallel to the cylinder arrangement is formed on the outer peripheral side on the joint surface between the cylinder head and the cam bracket, and the bearing is branched from the oil supply groove. A structure for supplying oil to a camshaft bearing portion, which is characterized in that a journal oil supply groove extending to the portion is formed. 2. The camshaft bearing portion according to claim 1, wherein the oil supply groove and the journal oil supply groove are formed on one side or both sides of the cylinder head and the cam bracket. Oil supply structure. 3. The journal oil supply groove according to claim 1, wherein a counterbore serving as an oil passage is formed at an outer periphery of a bolt screw hole into which the bolt is screwed. Oil supply structure to the camshaft bearing part of.