JPS6323559Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an apparatus for attaching a cylinder head cover of an internal combustion engine to an engine body when the cylinder head cover is made of resin.

[Prior Art] Conventional engine cylinder head covers are usually made from aluminum die-casting or press working. (Utility Model Publication No. 55-100044). For this reason, conventional cylinder head covers have sufficient rigidity to withstand deformation over time and strong tightening.
To install it on the engine body, insert a gasket such as rubber between the head cover and the engine body.
It has a structure that is fixed with bolts. moreover,
In order to simplify the assembly of the fixing bolts, insert around three fixing bolts into the center of the head cover, press and tighten the head cover from the top to the bottom with nuts, and tighten the head cover from the top to the bottom with these nuts. The presser force applied directly to the gasket seals the gasket and securely fixes the cover to the engine body.

[Problems to be solved by the invention] However, if the cylinder head cover is made of metal such as aluminum die-casting, it will be heavy, which is not desirable in terms of reducing the weight of the vehicle, and the noise from the engine body will be transmitted, with almost no attenuation. The problem was that this was not desirable in terms of noise countermeasures, as the noise would be dissipated to the surrounding area without being dissipated.

In order to solve these problems, it is believed that constructing the cylinder head cover from a synthetic resin material is effective because of its light weight and noise suppressing properties due to the vibration transmission damping properties of the material itself.
However, when a load is applied to synthetic resin, the material slips and deforms, causing a greater creep phenomenon than metal materials. Therefore, in the structure of conventional metal cylinder head covers, metal materials such as aluminum are simply replaced with resin. If the cylinder head cover were simply changed to the one above, the shape of the cylinder head cover would deform significantly over time due to the load of the fixing bolts, resulting in incomplete sealing of the bolt insertion area, and the gasket interposed between the cover and the engine body would be damaged. There was a serious problem in that the initial pressure that had built up in the engine part was relaxed and oil began to leak. For this reason, prior to the adoption of resin cylinder head covers, it has been desired to develop a practical fixing structure that includes means such as replacing the rubber gasket with a liquid gasket. Another problem is that when engine vibrations are transmitted to the bolts that secure the cylinder head cover, the bolts become loose and the oil leak described above becomes worse. Furthermore, when a liquid gasket is used, the liquid gasket firmly adheres to the sealing surface after hardening, making it difficult to remove the resin cylinder head cover if it becomes necessary. When space is restricted by surrounding parts, it is difficult to insert a screwdriver or the like and pry up, and there is also the problem that removal becomes extremely difficult.

This invention completely prevents oil leakage from the sealing part between the head cover and the engine body as well as oil leakage from the bolt insertion part even during long-term use when the cylinder head cover is made of resin. It is an object of the present invention to provide a cylinder head cover mounting device which can suppress the amount of damage caused by the cylinder head and which can also easily remove a resin cylinder head cover.

[Means for Solving the Problems] In order to achieve this object, the cylinder head cover mounting device of the present invention consists of the following.

(1) In a device that attaches a resin cylinder head cover to an engine body consisting of a cylinder head or cam housing, the gasket interposed between the resin cylinder head cover and the engine body is made into a liquid gasket and the adhesive properties of the liquid gasket are utilized. to seal between the resin cylinder head cover and the engine body, and a fixing bolt that is planted on the engine body and has a stepped part on the underside of the resin cylinder head cover is formed in the center of the resin cylinder head cover. The resin cylinder head cover is inserted into the hole and held and fixed by being held and fixed from both the upper and lower sides by the stepped part and the nut screwed onto the fixing bolt, and then the fixing bolt and the resin cylinder head cover are A cylinder characterized in that a pair of rubber washers are interposed between the two so as to contact the resin cylinder head cover from above and below, respectively, and a means for engaging with a bolt rotation jig is provided at the upper end of the fixing bolt. Head cover attachment device.

The above device can take the following embodiments.

(2) The cylinder head cover mounting device according to (1), wherein the engaging means is a notch formed in the upper end of the fixing bolt.

(3) The cylinder head cover mounting device according to (1), wherein the engaging means comprises a chamfer formed on the upper end of the fixing bolt.

[Function] In the device of the present invention, a liquid gasket is used instead of the conventional rubber gasket to seal between the cylinder head cover and the main body, and the sealing property is ensured by adhesive force, thereby creating a seal on the cylinder head cover. There is no need to apply force. In addition, in order to prevent the seal and adhesive state of the liquid gasket from being destroyed due to the transmission of vibrations from the engine body, and to firmly hold the cylinder head cover until the liquid gasket hardens, the cylinder head cover is held by fixing bolts. However, to hold and fix the cylinder head cover with the fixing bolts, insert the fixing bolts into the fixing bolt insertion holes built into the engine, and then tighten the head cover insertion holes in pairs with the fixing bolts and nuts. This is achieved by clamping the cylinder head cover through a rubber washer, and due to this fixed structure, there is essentially no force acting on the cylinder head cover that presses the cover downward as in the conventional case, and the resin is not subject to creep deformation. Care has been taken to ensure that this does not occur. Further, to prevent engine vibrations from being transmitted through the fixing bolts and causing the head cover to vibrate, an elastic body such as rubber interposed between the fixing bolts and nuts and the head cover blocks vibrations. Furthermore, since we have provided an engagement means with the rotation jig at the upper end of the bolt, simply by engaging the rotation jig with it and rotating the fixation bolt, the stepped part of the fixation bolt can be connected to the resin cylinder. The head cover can be lifted and removed easily. There is usually a maintenance space above the fixing bolt, so it is easy to insert the rotation jig.

[Embodiments] Hereinafter, preferred embodiments of the cylinder head cover mounting device of the present invention will be described with reference to the drawings.

The figure shows the device according to the present invention.
Reference numeral 2 denotes the engine body, specifically the cylinder head or a cam housing attached to the upper part of the cylinder head. The upper part of the engine body 2 is covered with a cylinder head cover 1, and the cylinder head cover 1 is made of synthetic resin.

A stepped portion 8 is formed around the cylinder head cover 2, and a liquid gasket 3 is interposed between the cover 1 and the engine body 2. The liquid gasket 3 has a moderately hard viscosity when installed, and as time passes, it becomes hard as it reacts with the moisture in the air, and has sufficient adhesive properties in the hardened state. Ordinary commercially available products can be used.

A fixing bolt 5 extending upward is fixed to the engine body 2 in an upright manner, and a portion of the bolt 5 is inserted through a hole 6 drilled approximately in the center of the cylinder head cover 1 and protrudes to the outside. . A stepped portion 8 is located below the cylinder head cover insertion portion of the fixing bolt 5, and a screw 7 into which a nut 9 is screwed is provided at the upper end of the bolt.

The fixing bolt 5 insertion portion of the cylinder head cover 1 is held between upper and lower sides by a pair of rubber washers 10 and 11 as elastic bodies. As a result, the fixing bolts 5 do not directly contact the cylinder head cover 1, and the rubber washers 10, 11
Vibration transmitted through the fixing bolt 5 is blocked by this. The rubber washers 10, 11 are clamped and tightened between the stepped portion 8 and a nut 9 which is threadedly attached to the screw 7 at the tip of the bolt.

In addition, as shown in FIGS. 2 and 3, the tip of the fixing bolt 5, which is a stepped bolt, has a
A notch 12 is formed that can be engaged with a jig, such as a driver, for rotating the fixing bolt 5. This notch 12 extends in the diametrical direction at the upper end of the fixing bolt 5 and has a width into which a driver or the like can be inserted.

4 and 5 show the tip structure of a stepped bolt of a cylinder head cover mounting device according to another embodiment. In this example, the means for engaging with the screw rotation jig formed at the tip of the fixing bolt 5, which is a stepped bolt, has a chamfered structure having widths across flats 13, 13.

In the fixing device having the above configuration, when initially fixing the cylinder head cover, first apply the liquid gasket 3 onto the engine body 2, then attach the resin cylinder head cover 1 on top of it, and then fix the cylinder head cover in this state. The cylinder head cover 1 is held and fixed in that state by a fixing bolt 5 and a pair of rubber washers 10, 11 without pressing the head cover 1 downward.
The liquid gasket 3 takes quite a long time to harden, and during that time the adhesive strength is low, but the fixing bolt 5
By holding the cylinder head cover 1 by the cylinder head cover 1, the cylinder head cover 1 is sufficiently held. Also,
After curing, the liquid gasket seals between the cylinder head cover 1 and the engine body 2 with sufficient adhesive force, and at this time, even if vibrations are transmitted from the engine body 2 during operation, the cylinder head cover 1 remains fixed. Since it is held and fixed by the bolts 5, the adhesion and sealing properties of the liquid gasket 3 are not destroyed and are maintained with high reliability.

In the above tightening, the cylinder head cover 1 is not subjected to any pressure from above, so
That is, since the cylinder head cover 1 is fixed only by the force of clamping, the entire cylinder head cover 1 will not be deformed due to creep. In this case, the cylinder head cover 1 is held between the top surface of the stepped part 8 and the bottom surface of the nut 9 at the exact center so as not to apply any pressing force, but the distance between the top surface of the stepped part 8 and the cylinder head cover 1 is adjusted. This can be done by changing the amount of embedding of the fixing bolts 5 into the engine body 1, and because the stepped portion 8 is provided in this way, it is possible to fix the cylinder head cover 1 with zero pushing force. be. Further, the pressure in the liquid gasket part 3 does not change, and the liquid gasket part 3 and the fixing bolt insertion part are deformed and the sealing performance is destroyed and the internal oil does not leak out.

In addition, in the embodiments shown in FIGS. 2 and 3, when removing the cylinder head cover 1, first remove the nut 9, and then insert the tip of a screwdriver as a rotation jig into the notch 12 of the stepped bolt 5. When engaged and rotated, the fixing bolt 5 will gradually come out. At this time, the stepped portion 8 provided on the fixing bolt 5 serves to lift the cylinder head cover 1 upward, causing the liquid gasket layer to peel off, and as a result, the cylinder head cover 1 and the engine body 2 are separated. The upper part of the stepped bolt 5 usually has a space for maintenance, so it can be easily accessed. Rotate the fixing bolt 5 and remove the cylinder head cover 1.
can be removed.

Furthermore, in the embodiments shown in FIGS. 4 and 5, when removing the cylinder head cover 1, a jig that engages the chamfer 13 across flats with male and female parts is fitted onto the tip of the fixing bolt 5, and then The stepped bolt 5 can be removed by rotating it. In this case as well, the stepped portion 8 serves to lift the cylinder head cover 1 upward, making it easy to remove the cylinder head cover 1.
can be separated from the engine body 2.

[Effects of the invention] Therefore, when using the cylinder head cover mounting device of the present invention, even if a resin cylinder head cover is used, creep deformation of the cylinder head cover does not occur essentially, so that the cylinder head cover can be easily replaced with the cylinder head cover. Oil leakage from the seal with the engine body as well as oil leakage from the bolt insertion part can be completely prevented. In addition, the interposition of the rubber washer suppresses the transmission of engine vibration from the fixing bolt to the cylinder head cover, thereby reducing noise and suppressing loosening of the fixing bolt and an increase in oil leakage due to loosening of the fixing bolt. This makes it possible to put resin cylinder head covers into practical use, which not only helps reduce the weight of internal combustion engines, but also contributes to noise reduction due to the noise transmission and attenuation properties of the resin itself. Furthermore, since we have provided an engagement means with the rotating jig at the upper end of the fixing bolt, which is a stepped bolt, it is possible to use this to rotate the fixing bolt in a narrow space, making it suitable for use with liquid gaskets. Regardless, the cylinder head cover can be easily removed by pushing it up on the stepped portion.

[Brief explanation of the drawing]

Figure 1 is a longitudinal sectional view of the cylinder head cover mounting device of the present invention, Figure 2 is a plan view of the fixing bolt of the device in Figure 1, Figure 3 is a front view of Figure 2, and Figure 4 is a front view of the device shown in Figure 1.
This figure is a plan view of another fixing bolt used in the device of FIG. 1, and FIG. 5 is a front view of FIG. 4. 1... Cylinder head cover, 2... Engine body, 3... Liquid gasket, 5... Fixing bolt consisting of a stepped bolt, 7... Screw, 8... Stepped part, 9... Nut, 10. 11... Rubber washer, 12... Notch, 13... Chamfer across the width of both sides.

Claims (1)

[Scope of Claim for Utility Model Registration] (1) In a device for attaching a resin cylinder head cover to an engine body consisting of a cylinder head or cam housing, the gasket interposed between the resin cylinder head cover and the engine body is a liquid gasket. The adhesive properties of the liquid gasket are used to seal between the resin cylinder head cover and the engine body, and the fixing bolts, which are planted in the engine body and have a stepped portion on the underside of the resin cylinder head cover, are attached to the resin cylinder. The resin cylinder head cover is inserted into the hole formed in the center of the head cover and held and fixed by being inserted from both the upper and lower sides between the stepped part and the nut screwed onto the fixing bolt, and then the fixing bolt A pair of rubber washers are interposed between the resin cylinder head cover and the resin cylinder head cover so as to contact the resin cylinder head cover from above and below, respectively, and a means for engaging with a bolt rotation jig is provided at the upper end of the fixing bolt. A cylinder head cover mounting device characterized by the following. (2) The cylinder head cover mounting device according to claim 1, wherein the engaging means is a notch formed in the upper end of the fixing bolt. (3) The cylinder head cover mounting device according to claim 1, wherein the engaging means comprises a chamfer formed on the upper end of the fixing bolt.