JPH09317409A - Cam plate for overhead camshaft engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the maintainability of a cam plate by arranging an elastic seal member on the outer periphery of the cam plate as to cover the whole width thereof to facilitate its checking after their assembly. SOLUTION: A camshaft 5 is at its end rotatably supported through a bushing 3 by a hole 4 formed in a cylinder head 2 of an engine, and an annular cam plate 9 is fitted in a hole 12a formed in a gear case 12 with a plurality of bolts 16 through seal washers 22. An elastic oil resistant rubber seal 20 is stuck on the outer periphery of the cam plate 9 as to cover the whole width (t) thereof, and an O ring 11 is fitted into the O ring groove formed in the cam plate 9 at its surface adjoining the cylinder head 2. The fitting of the rubber seal 20 on the cam plate 9 over its whole width facilitates the checking thereof whether normally assembled or not from the outside after their assembly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cam plate used in an overhead camshaft engine (hereinafter referred to as OHC engine) in which a camshaft penetrates a cylinder head.

[0002]

2. Description of the Related Art For example, as shown in FIG. 2, a cam shaft 5 penetrating a cylinder head 2 is rotatably supported by the cylinder head 2 via a bush 3, and a cam plate provided at the end of the cylinder head. A technique for axially positioning the camshaft 5 and the gear 7 by means of 9 is known.

There is also a technique for preventing oil leakage between the cam plate 9 and the gear case 12 by mounting an O-ring 10 in an O-ring groove provided on the outer periphery of the cam plate 9 having a circular outer periphery. It is known. Reference numeral 1 is a cylinder block, 4 is a bush mounting hole, 11 is an O-ring, 14 is a cam cover, 15 is a seal, and 8 and 16 are mounting bolts.

[0004]

However, in the above technique, when the cam plate 9 is assembled, the O ring 10 of the O ring groove provided on the outer circumference of the cam plate 9 is inserted into the hole of the gear case 12. This is a difficult and troublesome task. Further, it is impossible to confirm whether or not the O-ring is securely inserted so as not to be twisted without damaging the O-ring after mounting. Also, if there is an oil leak due to after-service etc., the cam plate can be removed if the cam gear and the cam shaft are integrated, but it is not possible to remove the cam plate alone, and removing the cam shaft is very troublesome and requires man-hours. I have a problem to say.

Therefore, an object of the present invention is to provide a cam plate for an OHC engine which can be assembled reliably and easily and has good maintainability.

[0006]

According to the present invention, in a cam plate used in an overhead camshaft engine in which a camshaft penetrates a cylinder head, elastic seals are arranged around the entire periphery of the camplate. A cam plate for an overhead camshaft engine, wherein the member covers the entire edge of the cam plate in the thickness direction.

Further, according to the present invention, in a cam plate used in an overhead camshaft engine in which a cam shaft penetrates the cylinder head, the cam plate is attached to the cylinder head by a plurality of mounting bolts, and the cam plate is attached. Has a plurality of bolt mounting holes formed with female threads, the inner diameter of the bolt mounting hole is larger than the outer diameter of the male screw portion of the mounting bolt,
The mounting bolt is screwed only with the female screw portion formed on the cylinder head, and is not screwed with the female screw portion of the bolt mounting hole.

Further, according to the present invention, in the cam plate used in the overhead camshaft engine in which the camshaft penetrates the cylinder head, elastic seals are arranged around the entire periphery of the edge, and the elastic seal member is the camplate. The cam plate is attached to the cylinder head with a plurality of mounting bolts and covers the entire area in the thickness direction of the edge portion. The cam plate has a plurality of bolt mounting holes with female threads formed therein. The inner diameter of the hole is larger than the outer diameter of the male screw part of the mounting bolt, the mounting bolt is screwed only with the female screw part formed on the cylinder head, and is not screwed with the female screw part of the bolt mounting hole. An O-ring groove accommodating an O-ring is provided on the side surface that contacts the cylinder head.

Further, according to the present invention, when the overhead camshaft engine cam plate according to any one of claims 2 to 4 is detached from the cylinder head, the engagement with the cylinder head is released and the mounting bolt is attached. A step of removing, a step of screwing a removal bolt having an outer diameter that is screwed into the female thread portion of the bolt mounting hole into the bolt mounting hole, and a step of gripping the removal bolt and removing the cam plate from the cylinder head. There is provided a method for removing a cam plate of an engine for an overhead cam shaft having the above.

Since the elastic seal is adhered to the outer periphery of the cam plate from the surface of the cam plate to the entire area in the thickness direction so that it can be confirmed after assembly, the work is easy and the post-work confirmation is possible. In addition, since a discard screw larger than the outer diameter of the mounting bolt is provided in the mounting hole of the cam plate, after removing the mounting bolt, you can insert the bolt into the discard screw, pull the cam plate, and remove the cam plate alone. It becomes possible and maintainability is improved.

[0011]

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

In the drawings, members having the same functions as those in the prior art are designated by the same reference numerals, and the duplicated description will be omitted.

In FIG. 1, an end of a camshaft 5 is rotatably supported in a hole 4 provided in a cylinder head 2 of an engine via a bush 3. A gear case 12 for accommodating a gear train for driving the camshaft 5 is attached to an end portion of the cylinder head 2, and a hole 12a provided in the gear case 12 has a cam plate 9 formed in a circular shape and a plurality of bolts. 16 is attached via a seal washer 22. Further, an oil resistant rubber seal 20 which is an elastic seal made of an elastic material is adhered to the outer periphery of the cam plate 9 over the entire area t in the thickness direction of the cam plate, and the surface contacting the cylinder head 2 is attached. An O-ring 11 is provided in the O-ring groove. Then, at the end of the cam shaft 5, a step portion 7b having the same size as the thickness of the cam plate is provided at the end portion of the cam shaft 5, and a gear 7 in which the step portion 7b is loosely fitted in a hole 9a provided in the cam plate 9. It is centered by a protrusion 7a at the tip of the step 7b and is fixed by a plurality of bolts 8.

A female screw 21, which is a discard screw, is provided in the mounting hole 21 of the cam plate 9, and the root diameter of the female screw 21 is larger than the outer diameter of the mounting bolt. It is configured to be screwed into a screw hole provided in the.

The operation will be described below.

When assembling, the cam shaft 5 is attached to the cylinder head 2, the gear case 12 is attached to the end faces of the cylinder head 2 and a cylinder block (not shown), and then the cam plate 9 is attached to the hole 12 of the gear case 12.
a. At this time, the O-ring 11 is as usual.
For example, it may be pasted in the groove with grease, and the rubber seal 20 is adhered to the cam plate 9 on the outer circumference. Therefore, if a small amount of oil is applied to the outer circumference of the rubber seal 20, it can be easily assembled. Since the rubber seal 20 covers the entire area of the cam plate 9 in the thickness direction, it can be confirmed that the rubber seal 20 is normally assembled from the outside after the assembly. Therefore, the gear 7 may be attached to the end of the camshaft with the bolt 8.

Since the O-ring 11 is on the camshaft side of the mounting bolt 16 and the mounting bolt 16 is provided with a seal washer 22, there is no oil leakage from the contact surface between the cylinder head 2 and the gear case 12. .

When removing the cam plate 9,
The gear 7 is removed, the bolt 16 that attaches the cam plate 9 is removed, another bolt is screwed into the female screw 21 provided in the attachment hole of the attachment bolt 16, and the cam plate 9 can be easily pulled out by pulling the bolt. You can

[0019]

The present invention is configured as described above,
Since the elastic seal is adhered to the outer periphery of the cam plate from the surface of the cam plate to the entire area in the thickness direction so that it can be confirmed after assembly, the work is easy and the confirmation after the work is possible. In addition, since the cam plate mounting hole is provided with a discard screw, the cam plate can be detached and the maintainability is improved.

[Brief description of drawings]

FIG. 1 is a side sectional view of an end portion of a camshaft of an OHC engine showing an embodiment of the present invention.

FIG. 2 is a side sectional view of an end portion of a camshaft of an OHC engine showing an example of the related art.

[Explanation of symbols]

 1 ... Cylinder flock 2 ... Cylinder head 5 ... Cam shaft 7 ... Gear 9 ... Cam plate 10, 11 ... O-ring 12 ... Gear case 20 ... Rubber seal 21. ..Female threads 22 ... Seal washers

Claims (5)

[Claims] 1. A cam plate used in an overhead camshaft engine in which a cam shaft penetrates a cylinder head, wherein an elastic seal member is arranged around the entire circumference of the edge, and the elastic seal member has a thickness of the edge of the cam plate. A cam plate for an overhead camshaft engine, which is characterized by covering the entire direction. 2. A cam plate used in an overhead camshaft engine, wherein the cam shaft penetrates the cylinder head, wherein the cam plate is attached to the cylinder head by a plurality of mounting bolts, and the cam plate is formed with an internal thread. A plurality of bolt mounting holes are bored, the inner diameter of the bolt mounting hole is larger than the outer diameter of the male screw part of the mounting bolt, and the mounting bolt is screwed only on the female screw part formed on the cylinder head to mount the bolt. A cam plate for an overhead camshaft engine, characterized in that it is not screwed into the female screw portion of the hole. 3. A cam plate used in an overhead camshaft engine, in which a camshaft penetrates a cylinder head, wherein elastic seals are arranged around the entire circumference of the edge, and the elastic seal member is in the thickness direction of the edge of the camplate. It covers the whole area, the cam plate is attached to the cylinder head by a plurality of mounting bolts, and a plurality of bolt mounting holes formed with female threads are bored in the cam plate, and the inner diameter of the bolt mounting holes is Overhead camshaft engine, characterized in that it is larger than the outer diameter of the male thread of the bolt, and the mounting bolt is screwed only with the female thread formed on the cylinder head, and not with the female thread of the bolt mounting hole. Cam plate for. 4. An O-ring groove accommodating an O-ring is formed on a side surface of the cylinder head, which is in contact with the cylinder head.
A cam plate for an overhead camshaft engine as described in. 5. When removing the overhead camshaft engine cam plate according to any one of claims 2 to 4 from the cylinder head, the step of removing the mounting bolt by releasing the screw engagement with the cylinder head, and bolt mounting. And a step of screwing a removal bolt having an outer diameter that is screwed into the female thread portion of the hole into the bolt mounting hole, and a step of gripping the removal bolt and removing the cam plate from the cylinder head. Engine cam plate removal method for overhead cam shaft.