JP2002303206A - Cylinder head cover fixing structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cylinder head cover fixing structure capable of reducing assembly manhours and the number of part items to reduce work labor and cost. SOLUTION: In this fixing structure for a cylinder head cover 2 having a soundproofing cover 3 on an upper surface, the cylinder head cover 2 is tightened with the soundproofing cover 3 to a cylinder head 1. In tightening the cylinder head cover 2 to the cylinder head 1, the soundproofing cover 3 is thus tightened with the cylinder head cover 2, so that tightening positions between the cylinder head 1 and the cylinder head cover 2 are largely reduced compared with conventional devices, thereby assembly manhours and the number of part items are largely reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure for fixing a cylinder head cover to a cylinder head.

[0002]

2. Description of the Related Art In recent years, diesel engines and the like have adopted a structure in which a soundproof cover is provided on the upper surface of a cylinder head cover, and the soundproof cover reflects noise transmitted from the engine to reduce noise. Is coming.

FIG. 3 shows an example of a conventional structure for fixing a cylinder head cover. In FIG. 3, reference numeral 1 denotes a cylinder head, 2 denotes a cylinder head cover, and 3 denotes a soundproof cover. The lower end of the cylinder head cover 2 is fastened to the upper end of the hakama part 4 by bolts 5, and the soundproof cover 3 is fastened to the upper end of the cylinder head cover 2 by bolts 6. Various members such as a valve spring, a rocker arm, a rocker shaft, and a fuel injector are accommodated in a space surrounded by the hakama portion 4 and the cylinder head cover 2.

Here, when the upper end of the skirt portion 4 of the cylinder head 1 and the lower end of the cylinder head cover 2 are fastened with bolts 5, the outer periphery of the bolt 5 is used to maintain a predetermined fastening interval. A collar 7 is externally fitted, and a floating rubber 8 for preventing direct transmission of sound (vibration) from the cylinder head 1 side to the cylinder head cover 2 side is further externally fitted around the collar 7. I have.

[0005] A gasket 9 is attached to the lower end of the cylinder head cover 2 over the entire circumference thereof, and the gasket 9 is pressed between the upper end of the skirt portion 4 to ensure sealing. In addition, by directly supporting the entire cylinder head cover 2 in a floating manner, direct transmission of sound (vibration) from the cylinder head 1 side to the cylinder head cover 2 side is also prevented.

On the other hand, when the upper end of the cylinder head cover 2 and the soundproof cover 3 are fastened with the bolts 6, a collar 10 for keeping a predetermined fastening interval is fitted around the outer periphery of the bolts 6. The color 10 is the soundproof cover 3.
It is attached integrally to.

The soundproof cover 3 is composed of a cover body 3a made of a hard material such as a metal plate, and a buffer sheet 3b made of urethane foam rubber and the like integrally mounted on the lower surface of the cover body 3a. In addition, the former cover body 3a is responsible for substantially reflecting the transmitted sound of the engine, and the latter cushioning sheet 3b avoids wear due to direct contact between the cover body 3a and the cylinder head cover 2.

[0008]

However, in such a conventional structure, the soundproof cover 3 is fastened to the upper surface of the cylinder head cover 2 after the cylinder head cover 2 is fastened to the cylinder head 1. , 6 requires a large number of fastening points, resulting in an increase in the number of assembly steps and the number of parts.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and has a cylinder head cover fixing structure capable of reducing the number of assembling steps and the number of parts, thereby reducing labor and cost. The purpose is to provide.

[0010]

SUMMARY OF THE INVENTION The present invention is a fixed structure of a cylinder head cover provided with a soundproof cover on the upper surface, wherein the cylinder head cover is fastened to the cylinder head together with the soundproof cover. It is.

Thus, when the cylinder head cover is fastened to the cylinder head, the soundproof cover is fastened together with the cylinder head cover, so that the fastening between the cylinder head and the cylinder head cover is performed. The number of locations is greatly reduced as compared with the conventional case, thereby significantly reducing the number of assembling steps and the number of parts.

Further, when the fixing structure of the present invention is specifically embodied, for example, a co-tightening bolt extending from the upper surface of the soundproof cover to the cylinder head through the cylinder head cover, and a bolt head of the co-tightening bolt are used. A floating rubber interposed between the upper surface of the cylinder head cover and the transmission rubber to prevent sound transmission; and a first pressing surface for pressing the upper surface of the cylinder head cover around the bolt hole toward the cylinder head side with the floating rubber. And a second pressing surface for pressing the upper surface of the soundproof cover around the bolt hole toward the cylinder head cover.

With this arrangement, when the cylinder head cover and the soundproof cover are fastened together, the upper surface of the cylinder head cover around the bolt hole is interposed by the first pressing surface of the floating rubber without the soundproof cover interposed therebetween. As a result, the cylinder head cover can be firmly fastened to the cylinder head by applying a large fastening force.

[0014]

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

FIGS. 1 and 2 show an example of an embodiment of the present invention, in which the same reference numerals as in FIG. 3 denote the same parts.

As shown in FIGS. 1 and 2, in this embodiment, when the cylinder head cover 2 provided with the soundproof cover 3 on the upper surface is fastened to the cylinder head 1, the upper end of the skirt portion 4 of the cylinder head 1 and the cylinder The number of fastening points with the lower end of the head cover 2 is greatly reduced, and the soundproof cover 3
The cylinder head cover 2 is fastened to the cylinder head 1 by co-tightening with the soundproof cover 3 by means of a co-tightening bolt 11 extending from the center position in the width direction on the upper surface to the center position in the width direction of the cylinder head 1 through the cylinder head cover 2. ing.

Here, between the bolt head 11a of the bolts 11 and the upper surface of the cylinder head cover 2, a floating rubber 12 for preventing transmission of sound from the engine is interposed. Reference numeral 12 denotes a step having a large-diameter portion and a small-diameter portion having a downwardly convex shape, and the bottom surface of the lower-diameter small-diameter portion is formed on the cylinder head cover 2 around the bolt hole 13 by the cylinder head. The first pressing surface 14 presses the upper surface of the soundproof cover 3 around the bolt hole 13 toward the cylinder head cover 2. It has become.

A collar 16 for keeping a predetermined fastening interval is fitted around the outer periphery of the co-tightening bolt 11, and an upper end of the collar 16 is provided at an axial center of the floating rubber 12. The floating rubber 12, the collar 16, and the washer 17 are also integrally attached to the floating rubber 12, and are also joined to the washer 17 mounted on the upper surface of the floating rubber 12.
Are treated as one assembly (see FIG. 2).

In the illustration in FIG. 2, a structure is shown in which the fastening portion between the upper end of the skirt portion 4 of the cylinder head 1 and the lower end of the cylinder head cover 2 is left.
If a sufficient fastening force can be obtained by the above-mentioned co-tightening bolt 11, the fastening portion between the upper end of the skirt portion 4 of the cylinder head 1 and the lower end of the cylinder head cover 2 can be completely eliminated.

In FIG. 2, reference numeral 18 denotes an oil cap, 19 denotes an oil supply port, and 20 denotes a fuel injector that penetrates through the cylinder head cover 2 and protrudes upward.

When such a fixing structure of the cylinder head cover 2 is employed, when the cylinder head cover 2 is fastened to the cylinder head 1 by the bolts 11, the bolt head 11 a of the bolts 11 a is used. The floating rubber 12 is pressed toward the cylinder head 1, and the upper surface of the cylinder head cover 2 around the bolt hole 13 is pressed toward the cylinder head 1 by the first pressing surface 14 of the floating rubber 12.
As a result of the upper surface of the soundproof cover 3 around the bolt holes 13 being pressed toward the cylinder head cover 2 by the second pressing surface 15, the soundproof cover 3 is fastened together with the cylinder head cover 2, so that the cylinder head 1 The number of fastening points between the cylinder head cover 2 and the cylinder head cover 2 is greatly reduced as compared with the related art, thereby significantly reducing the number of assembly steps and the number of parts.

In particular, in the present embodiment, when the cylinder head cover 2 is fastened together with the soundproof cover 3, the upper surface of the cylinder head cover 2 around the bolt holes 13 is covered by the first pressing surface 14 of the floating rubber 12. 3 can be pressed directly into the cylinder head 1 without the intervention of the cylinder head 1, so that the cylinder head cover 2 can be firmly fastened to the cylinder head 1 by applying a large fastening force. It is possible to significantly reduce or eliminate the fastening portion between the upper end of the hakama portion 4 and the lower end of the cylinder head 1.

Therefore, according to the above embodiment, when the cylinder head cover 2 is fastened to the cylinder head 1,
Since the soundproof cover 3 can be fastened together with the cylinder head cover 2, the number of fastening points between the cylinder head 1 and the cylinder head cover 2 can be greatly reduced as compared with the conventional case, and the number of assembling steps and the number of parts can be greatly reduced. It is possible to reduce the labor and labor of the work, and the cost can be significantly reduced.

Incidentally, the fixing structure of the cylinder head cover of the present invention is not limited to the above-described embodiment.
The shape of the floating rubber interposed between the bolt head of the co-tightening bolt and the upper surface of the cylinder head cover is not limited to the illustrated example, and other various modifications can be made without departing from the scope of the present invention. Of course.

[0025]

According to the cylinder head cover fixing structure of the present invention described above, when the cylinder head cover is fastened to the cylinder head, the soundproof cover can be fastened together with the cylinder head cover. The number of fastening points with the cylinder head cover can be greatly reduced compared to the conventional case, the number of assembly steps and the number of parts can be significantly reduced, the work labor can be significantly reduced, and the cost can be significantly reduced. An excellent effect that it can be achieved.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an example of an embodiment of the present invention.

FIG. 2 is a perspective view showing an exploded state of a fixing structure of the cylinder head cover of FIG. 1;

FIG. 3 is a cross-sectional view showing an example of a conventional cylinder head cover fixing structure.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder head 2 Cylinder head cover 3 Soundproof cover 11 Co-tightening bolt 11a Bolt head 12 Floating rubber 14 First pressing surface 15 Second pressing surface

Continued on the front page F-term (reference) 3G024 AA05 AA13 AA72 BA03 BA10 BA11 BA13 GA29

Claims (2)

[Claims] 1. A fixing structure of a cylinder head cover provided with a soundproof cover on an upper surface, wherein the cylinder head cover is fastened to the cylinder head together with the soundproof cover. 2. A joint bolt extending from the upper surface of the soundproof cover to the cylinder head through the cylinder head cover, and is interposed between the bolt head of the joint bolt and the upper surface of the cylinder head cover to transmit sound. A first pressing surface that presses the upper surface of the cylinder head cover around the bolt hole toward the cylinder head, and a top surface of the soundproof cover around the bolt hole toward the cylinder head cover. The cylinder head cover fixing structure according to claim 1, wherein the second pressing surface and the second pressing surface are separately formed.