JPH04101858U - Sealing structure between hole and blind plug - Google Patents

Abstract

(57) [Summary] [Purpose] The object of the present invention is to provide a sealing structure that ensures a secure seal between the outer circumferential surface of a blind plug and the inner circumferential surface of a hole. [Structure] A blind plug 4 is press-fitted into the opening 2a of a hole 2 formed in the cylinder head 1 from the outside to the inside. A tapered surface 5 is formed, and an annular stepped portion 7 is formed on the inner circumferential surface of the hole 2, making line contact over the entire circumference of the tapered surface 5 of the blind plug 4.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention is a seal structure between a hole formed in an article and a blind plug press-fitted into the hole. Regarding.

0002

[Conventional technology]

For parts with holes for liquid flow, the hole openings should be closed with blind plugs, if necessary. Adopts a structure that press-fits and closes the hole to prevent liquid flowing through the hole from flowing out from the opening. There are things to do.

0003 For example, a passageway for flowing liquids such as cooling water and lubricating oil into an engine's cylinder head. When forming the cylinder by bending it at right angles, for processing reasons, the cylinder should be bent as shown in Figure 3. One hole 2 is formed from the outer surface of the pad 1 toward the inside, and then a hole 2 is formed directly against this hole 2. The other hole 3 is formed from the outer surface of the cylinder head 1 inward along the angular direction. , this hole 3 is communicated with the middle part of the hole 2, and further opened on the outer surface of the cylinder head 1. A configuration is adopted in which a blind plug 4 is press-fitted into the opening of the hole 2 to close the opening. There is.

0004 This forms a passage curved at right angles that connects the holes 2 and 3 and allows the liquid to flow through the holes 2 and 3. The opening of the hole is closed by a blind plug 4, and the liquid flows through the holes 2 and 3 as shown by the arrows in the figure. The body does not flow out from the opening of the hole 2.

[0005] Here, parts such as gaskets can also be mentioned as parts that close the opening of hole 2. However, since the liquid flowing through the holes 2 and 3 of the cylinder head 1 has a high pressure, this pressure I can't stand it. On the other hand, when the blind plug 4 is press-fitted into the opening of the hole 2, the liquid It can withstand high pressure and prevent liquid from flowing out.

[0006]

[Problem that the idea aims to solve] In order to press fit the blind plug 4 into the opening of the hole 2, insert the blind plug 4 into the cylinder head. Insert the blind plug 4 into the opening of hole 2 from the outside of hole 2 using a machine. nothing. When the blind plug 4 enters the opening of the hole 2, the outer circumferential surface of the blind plug 4 touches the opening of the hole 2. The outer circumferential surface of the blind plug 4 and the inner circumferential surface of the opening of the hole 2 are in sliding contact with the inner circumferential surface of the opening. Galling, or scratching, may occur on one or both.

[0007] This scratch occurs between the outer peripheral surface of the blind plug 4 and the inner peripheral surface of the opening of the hole 2. This may adversely affect the condition of the seal, making this seal unreliable and allowing water to flow through holes 2 and 3. This prevents liquid from leaking out of the cylinder head 1 from between the blind plug 4 and the hole 2. be.

[0008] The present invention was made based on the above circumstances, and the outer circumferential surface of the blind plug and the inner circumferential surface of the hole The purpose is to provide a seal structure that ensures a secure seal between the

[0009]

[Means to solve the problem]

In order to solve the above-mentioned purpose, the sealing structure of the blind plug of the present invention is designed so that the outer surface of the product is A blind plug is press-fitted into the opening of the hole formed from A tapered surface that becomes larger in diameter from the front side toward the rear side in the press-fitting direction is formed on the outer circumferential surface. The inner peripheral surface of the hole is provided with an annular step that is in line contact with the tapered surface of the blind plug over the entire circumference. It is characterized by the formation of

0010

[Effect]

When press-fitting the blind plug into the opening of the hole, the tapered surface of the blind plug touches the annular step of the hole. Line contact. The force for press-fitting the blind plug into the hole is concentrated on this line contact part. Therefore, a great sealing effect can be obtained. For this reason, the outer peripheral surface of the blind plug and the hole opening Even if there is a scratch on the inner circumferential surface of the part, the line contact part will cut off the inside and outside of the part. The liquid flowing inside the hole leaks between the outer circumferential surface of the blind plug and the inner circumferential surface of the hole opening. It can prevent leakage.

[0011]

【Example】

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2.

0012 This embodiment is directed to the example shown in FIG. i.e. engine cylinder Inside the da head 1, holes 2 and 3 through which liquid flows are formed to intersect at right angles, and one hole 2 A blind plug 4 is press-fitted into the opening to close the opening.

[0013] The sealing structure between the opening of the hole 2 and the blind plug 4 will be explained.

[0014] The blind plug 4 has a circular cross section with a diameter larger than the diameter of the hole 2. The front end of the blind plug 4 (the front end in the press-fitting direction when press-fitting into the hole) has a A tapered surface 5 is formed whose diameter increases from the front side to the rear side. Ma In addition, an annular groove 6 is formed in the longitudinally intermediate portion of the blind plug 4 over the entire circumferential direction. It is. This annular groove 6 is provided with a sealing material as described later.

[0015] The opening 2a of the hole 2 of the cylinder head 1 is a plug press-fitting hole into which the blind plug 4 is press-fitted. , has a diameter larger than the diameter of the hole 2 that matches the diameter of the blind plug 4, and , and is formed to have a length that matches the length of the blind plug 4. Inside the opening 2a of the hole 2 An annular stepped portion 7 is provided on the inner circumferential surface of the end, and is in line contact with the tapered surface 5 of the blind plug 4 over the entire circumference. is formed. This annular step portion 7 has a triangular cross section, and this triangular step portion 7 has a triangular cross section. The apex of the blind plug 1 is in line contact with the tapered surface 5 of the blind plug 1. of the annular step 7 The apex of the triangle is smaller than the diameter of plug press-fit hole 7 and larger than the diameter of hole 2. It has a large diameter.

[0016] When press-fitting the blind plug 4 into the opening 2a of the hole 2, it should be inserted with the tapered surface 5 facing forward. Insert the blind plug 4 into the opening 2a from the outside of the cylinder head 1, and The blind plug 4 is then press-fitted into the opening 2a.

[0017] When the blind plug 4 is press-fitted into the opening 2a of the hole 2, the tapered surface 5 of the blind plug 4 is inserted into the hole. 2 and the apex of the annular step 7. This allows the blind plug 4 to The pad surface 5 is in line contact with the apex of the annular step 7 of the opening 2a of the hole 2. This line contact part A large sealing effect is achieved because the force for press-fitting the blind plug 4 into the opening 2a of the hole 2 is concentrated. have.

[0018] Therefore, there are scratches on the outer peripheral surface of the blind plug 4 and the inner peripheral surface of the opening 2a of the hole 2. However, the line contact portion between the tapered surface 5 of the blind plug 4 and the annular step 7 of the opening 2a of the hole 2 The inside and the outside are cut off through the line contact part, and the liquid flowing inside the hole 2 leakage between the outer peripheral surface of the blind plug 4 and the inner peripheral surface of the opening 2a of the hole 2. However, the liquid flowing inside the hole 2 can be prevented from leaking to the outside of the hole 2.

[0019] Further, the annular groove 7 formed in the blind plug 4 is filled with a sealing material, for example, a microcapsule. If a shaped sealing material 8 is provided, this sealing material 8 will fit between the outer peripheral surface of the blind plug 4 and the hole 2. A seal is formed between the opening 2a and the inner circumferential surface of the opening 2a. The microcapsule-shaped sealing material 8 is The material is packed inside a large number of microcapsules, for example, outside the blind plug 4. It is applied to the surrounding surface, and when the blind plug 4 is inserted into the opening 2a of the hole 2, the blind plug The microcapsules are crushed by the outer circumferential surface of 4 and the inner circumferential surface of the opening 2a of the hole 2, and the microcapsules are crushed. The sealing material packed inside the microcapsule comes out and connects the outer circumferential surface of the blind plug 4 and the hole 2. A seal is formed between the opening 2a and the inner circumferential surface of the opening 2a. In this way, the sealing material is provided in the annular groove 7. By this, a more reliable seal can be achieved in combination with the seal structure using the abutment described above. effect can be obtained.

[0020] Note that the sealing material is not limited to microcapsule-shaped sealing materials, but also O-phosphorus. It may also be

[0021] The structure of the annular step portion 7 is also not limited to the embodiment.

[0022] Additionally, this invention is limited to the case where a blind plug is press-fitted into a hole in a cylinder head. A blind plug is inserted into the opening of the fluid passage hole formed in the engine crankcase. It can be applied to a wide range of applications, such as press-fitting plugs.

[0023]

[Effect of the idea]

As explained above, according to the sealing structure between the hole and the blind plug of the present invention, the blind plug The tapered surface of the hole makes a line contact with the annular stepped part of the hole, and this line contact part presses the plug into the hole. It receives the concentrated force of the blind plug and has a large sealing effect, so the outer circumferential surface of the blind plug and the hole Even if there are scratches on the inner circumferential surface, the liquid flowing inside the hole will leak out to the outside of the hole. can be reliably prevented.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the sealing structure between a hole and a blind plug according to the present invention.

FIG. 2 is an enlarged view of the Z section in FIG. 1;

FIG. 3 is a sectional view showing an example of a conventional sealing structure between a hole and a blind plug.

[Explanation of symbols]

1... Cylinder head, 2, 3... Hole, 4... Blind plug, 5...
Tapered surface, 7... annular stepped portion.

Claims (1)

[Scope of utility model registration request] Claim 1: A blind plug is press-fitted into the opening of a hole formed in the article from the outer surface to the inside, and the outer peripheral surface of the blind plug has a tapered surface that becomes larger in diameter from the front side toward the rear side in the press-fitting direction. A sealing structure between a hole and a blind plug, characterized in that an annular stepped portion is formed on the inner peripheral surface of the hole and is in line contact with the tapered surface of the blind plug over the entire circumference.