JPH0225967Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a seal structure for a cylinder head of an internal combustion engine, and in particular, a simple structure that prevents the seal member from shifting and improves sealing performance, workability, and mass productivity. This invention relates to a seal structure for a cylinder head of an internal combustion engine.

[Technical background of the invention and its problems] Overhead camshaft internal combustion engines have been widely used in recent years because they are suitable for high-speed rotation. In this model, as shown in Fig. 1, the cylinder head a is provided with a journal support b for pivotally supporting the camshaft.
For machining, a half-moon or arc-shaped groove (machining relief) d is required at the upper edge of the side wall c of the cylinder head a.

However, since various lubricating oils are supplied to the cylinder head, the groove d must be sealed liquid-tight. For this reason, conventionally, a seal member e having the same radius of curvature was fitted into the groove d. However, not only is the seal member e displaced from the groove d in the axial direction or the thickness direction of the side wall c, but also the groove d and the center of curvature f of the seal member e coincide, as shown in FIG. The member e rotates in its circumferential direction, and the upper surface h of the seal member e is displaced from the upper surface g of the side wall c, which is the sealing surface with the head cover. Misalignment due to this rotation could not be completely prevented even if the seal member e was inserted carefully, and a liquid sealant was used to deal with it, but oil leakage from the seal member e often occurred. It was becoming a problem.

Therefore, a seal member i with a positioning function as shown in Fig. 3 was proposed (Utility Model No. 57-2238
issue). Flanges j are provided on both end surfaces of this seal member i.
However, a protrusion l is formed on the upper surface k, and the flange j restricts the movement of the seal member i in the axial direction, and the protrusion l is formed on the upper surface g of the side wall c.
Rotation of the seal member i in the circumferential direction is restricted by bringing it into contact with the seal member i. Although the protruding part l can prevent the seal member i from shifting due to rotation, the shape of the seal member i becomes complicated and manufacturing becomes difficult, and the protruding part l gets in the way when covering the cylinder head c with a head cover. Become.

[Purpose of the invention] The present invention was devised to effectively solve the above-mentioned conventional problems, and the purpose of the present invention is to prevent the positional shift of the sealing member with a simple structure and improve sealing performance and workability.・An object of the present invention is to provide a cylinder head roll structure for an internal combustion engine that is highly mass-producible.

[Summary of the invention] In order to achieve the above object, the present invention is configured as follows. That is, an arc-shaped groove is formed at the upper edge of the side wall of a cylinder head of an internal combustion engine, and the arc-shaped groove has a center of curvature different from the center of curvature of the groove in the thickness direction of the side wall of the groove. forming a step,
On the other hand, a sealing member is formed to match the curvature of the groove and the stepped portion, and the sealing member is fitted into the groove and the stepped portion of the side wall. This results in
The seal member can be positioned and prevented from shifting, and the seal is improved.

[Embodiments of the invention] Examples of the invention will be described below in detail with reference to the accompanying drawings.

In Fig. 4, 1 is an overhead camshaft type cylinder head.
In the upper part of the cylinder head 1, journal supports 2 for supporting the journal of the camshaft are provided at appropriate intervals in the longitudinal direction of the cylinder head 1. An arc-shaped groove 4 is provided at the upper edge of the side wall 3 of the cylinder head 1, which is located on an extension of the journal receiver 2 or on the axis of the camshaft, as a machining relief when the journal receiver 2 is machined. As shown in FIGS. 5 and 6, the groove 4 has a radius of curvature R ₂ and a center of curvature O ₂ on the upper surface 3 a of the side wall 3 . Further, a stepped portion 5 is formed on the inner side of the cylinder head 1 of the groove 4. The stepped portion 5 also has an arc shape, and its radius of curvature is R ₁
, and the center of curvature O ₁ is located at a distance l ₁ above the center of curvature O ₂ of the groove 4. A head cover is placed over the upper surface 3a of the side wall of the cylinder head 1, and at this time a sealing member 6 is inserted to close the hole formed by the groove 4 and the step 5. Seal member 6
As shown in FIG. 7, it consists of a main part 6a that fits into the groove 4 and a sub part 6a that fits into the step part 5. The seal member 6 is molded from rubber, aluminum, resin containing calcium carbonate, or the like.

As described above, in the present invention, the groove 4 is formed with a stepped portion 5 having a different center of curvature and the sealing member 6 is fitted into the stepped portion 5, so that the rotation center O ₂ of the main portion 6a of the sealing member 6 and the secondary The rotation center _O1 of the portion 6b is different,
As a result of the integral main part 6a and sub-part 6b of the seal member 6 regulating mutual rotation, displacement of the seal member 6 due to rotation in the circumferential direction is prevented. Furthermore, in the present invention, by inserting the sealing member 6, the positioning is automatically performed without any adjustment, and the upper surface 3 of the side wall 3 is automatically positioned.
a and the upper surface 6c of the sealing member 6 match to form a sealing surface. Therefore, by covering the head cover, the upper opening of the side wall 3 can be easily sealed liquid-tightly. Furthermore, in the present invention, the seal member 6
Since the stepped portion 5 for regulating the rotation of the seal member 6 is arc-shaped, the stepped portion 5 and the seal member 6 can be easily molded or processed.

In the above embodiment, the stepped portion 5 is provided on the inner side of the cylinder head 3 of the groove 4, but it may be provided in the center of the groove 4 as shown in FIG. 9, or in the groove 4 as shown in FIG. They may be provided on the inside and outside of the cylinder head 3. A sealing member 6 shown in FIG. 8 that fits into the groove 4 and the stepped portion 5 in FIG. 9 is used, and a groove 4 in the embodiment shown in FIG. 11 is used.
And for the shape of the stepped portion 5, the sealing member 6 shown in FIG. 10 is used. In these embodiments, the stepped portion 5
This makes it possible not only to position the seal member 6 in the axial direction but also to prevent it from shifting. Furthermore, in the above embodiment, the lowermost end of the stepped portion 5 was located _l2 above the lowermost end of the groove 4 as shown in FIG. 6, but as shown in FIG. 5 may be made to coincide with each other. An example of this case is shown in Figure 14.
This is Figure 6. In FIG. 14, the steps 5 are on both sides of the groove 4, and in FIG. 16, the steps 5 are on one side of the groove 4. The sealing member 6 shown in FIG. 15 is used respectively. Further, as shown in FIG. 17, the stepped portion 5 may be formed such that its lowermost end is l ₂ below the lowermost end of the groove 4. An example of this case is the 19th
18, a step 5 is formed on one side of the groove 4, and a sealing member 6 shown in FIG. 18 is used correspondingly. Furthermore, in this case, the step portions may be formed on both sides or in the center of the groove. After all, it is sufficient that the center of curvature O ₁ of the step portion 5 and the center of curvature O ₂ of the groove 4 are different.
The size of the radius of curvature R ₁ and R ₂ does not matter.

[Effects of the invention] In summary, according to the invention, the structure is simple, and the positioning and positioning of the sealing member is easy.
It has excellent effects such as preventing misalignment, improving sealing performance, workability, and mass productivity, and reducing oil leakage and improving quality.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing the seal structure of a conventional cylinder head, Fig. 2 is an enlarged front view of the seal part,
Fig. 3 is a perspective view showing another embodiment of the conventional seal member, Fig. 4 is a perspective view showing the seal structure of the cylinder head according to the present invention, and Fig. 5 is an enlarged view of the groove and stepped portion of the cylinder head. A perspective view, FIG. 6 is a diagram also explaining the positional relationship between the groove and the step, and FIG.
Enlarged perspective views of the sealing members shown in Figures 8 and 10.
13, 15, and 18 are perspective views showing other embodiments of the sealing member of the present invention, and FIGS. 9, 11, 14, 16, and 19 are FIGS. 12 and 17 are perspective views showing other embodiments of the grooves and steps in the side wall of the cylinder head according to the invention; FIGS. be. In the figure, 1 is the cylinder head, 2 is the journal receiver of the camshaft, 3 is the side wall, 3a is the top surface, 4 is the groove, 5 is the step, 6 is the seal member, O ₁ is the center of curvature of the step, O ₂ is the groove is the center of curvature of

Claims (1)

[Scope of utility model registration request] An arc-shaped stepped portion that penetrates the side wall of a cylinder head of an internal combustion engine and forms an arc-shaped groove on its upper edge, and has a center of curvature different from the center of curvature of the groove in the thickness direction of the side wall of the groove. A sealing structure for a cylinder head of an internal combustion engine, characterized in that a sealing member is formed having a curvature that matches the curvature of the groove and the stepped portion, and the sealing member is fitted into the groove and the stepped portion of the side wall. .