JPH0586070U - Head gasket - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention is a head that can secure a good sealing property even in a low surface pressure contact portion between bolt pitches, does not have substantial leakage in the low surface pressure portion, and can reduce the manufacturing cost. Provide gasket. [Constitution] A foamed rubber layer 2 having closed cells is provided on both sides of a metal plate 1.
To form. [Effect] Since the gasket having the above structure is formed of the foamed rubber layer having a large compression amount on both sides, it firmly adheres to the surface of the mating member even in the low surface pressure portion where the bolt pitch is long. Therefore, the sealing surface follows the deformation due to heat and vibration and prevents leakage of gas, oil and cooling water. Further, since the foamed rubber layer is formed of closed cells, the airtightness is high even in the low surface pressure portion, and there is no substance leakage. Furthermore, since good sealability can be secured even in a portion where the tightening surface pressure is hard to be applied, the weight of the cylinder head and the number of bolts can be reduced.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention mainly relates to an improvement of a head gasket used by being mounted between a cylinder block and a cylinder head of an automobile engine.

[0002]

[Prior Art]

 Conventionally, this type of head gasket is known as a punched product of a mild steel plate or a sheet gasket formed by laminating an asbestos joint sheet or an expanded graphite sheet on both sides of a steel plate or an embossed aluminum base material.

[0003]

[Problems to be solved by the device]

 A metal gasket made by punching a mild steel plate has a high elastic modulus and is difficult to deform. Therefore, the low surface pressure between the cylinder block and the cylinder head (the part that is separated from the tightening bolts) has poor adhesion to the mating member surface. Therefore, it is not possible to follow the deformation due to thermal strain or thermal vibration, and there is a problem that fluid leakage (gas, oil, cooling water) occurs.

The asbestos joint sheet has good adhesion to the mating member even in a low surface pressure portion, but when the contact surface pressure is low, a large number of minute spaces are held inside the material, so that sufficient contact is achieved. There is a drawback that denseness cannot be obtained. Moreover, the use of asbestos joint sheets is restricted due to the environmental pollution of asbestos.

A gasket using an expanded graphite sheet is expensive, and in a gasket having a large area such as a cylinder gasket, if the entire surface is made of graphite, the gasket manufacturing cost will increase significantly. Further, graphite has a drawback in that workability is poor because it is easily damaged.

[0006]

[The purpose of the device]

 An object of the present invention is to provide a head gasket which can secure good sealing property even in a low surface pressure contact portion, has no substantial leakage in the low surface pressure portion inside the material, and can reduce the manufacturing cost. To do.

[0007]

[Means for Solving the Problems]

 In order to achieve the above object, the present invention has a gist of a structure in which a foamed rubber layer having closed cells is formed on one side or both sides of a metal plate.

[0008]

[Action]

 In the head gasket having the above structure, since the foamed rubber layer having closed cells is formed on the metal plate surface, a large amount of compression can be obtained with a small tightening pressure. Therefore, the adhesion with the mating member is good, and sufficient sealing property is secured especially in the low contact area where the bolt pitch around the cooling water and oil is long. Moreover, since the foamed rubber layer is composed of independent air bubbles, there is no leakage of fluid at the low surface pressure area inside the gasket.

[0009]

【Example】

 The drawings show an embodiment of the present invention. FIG. 1 is a sectional view of a gasket material, FIG. 2 is a plan view, and FIG. 3 is a plan view of a completed head gasket.

In the figure, A is a sheet gasket material, 1 is a metal plate, and 2 is a foamed rubber layer of closed cells formed on both sides of the metal plate. In the illustrated example, the foamed rubber layer 2 having closed cells is formed on both sides of the metal plate, but it may be formed on only one side of the metal plate.

A stainless steel plate (SUS), a cold rolled steel plate (SPCC), an aluminum plate or the like is used as the metal plate constituting the head gasket material A, but the metal plate is not limited thereto.

Examples of the rubber material forming the closed-cell foam rubber layer include nitrile rubber, acrylic rubber, and fluororubber, but other rubber materials can be arbitrarily selected and used. It is preferable that the metal plate has a thickness of 0.10 to 3.0 mm and the foam rubber layer has a thickness of about 200 to 1000 μm.

Specific Example A cold rolled steel sheet having a thickness of 0.25 mm is treated on both sides with an alkali degreasing agent, then surface-roughening treatment is performed, and then phosphate chemical conversion treatment is performed to remove a phenol resin. Primer modified with NBR rubber compound as a main component is applied to both sides, dried, and then a rubber compound solution containing a foaming agent and others is applied to the surface to a predetermined thickness, dried and then further applied. The non-adhesive layer was applied, vulcanized for 10 to 20 minutes, and foamed at the same time as the vulcanization to obtain a sheet gasket material having a closed-cell foam rubber layer having a thickness of 350 μm or more on one side.

The sheet gasket material A prepared above is punched into a predetermined cylinder head gasket shape as shown in FIG. 3, and a U-shaped grommet 3 made of stainless steel is attached to the periphery of the cylinder bore. , Made head gasket.

4 to 8 show various examples of grommet processing and bead processing in the cylinder bore of the head gasket.

In FIG. 4, the foam rubber layer 2 in the bore portion is removed, and the grommet 4 is attached to the metal plate 1. In FIG. 5, the metal plate 1 is made of spring steel, and the bead 5 is formed over the entire bore portion. In FIG. 6, the foam rubber layer 2 in the bore portion is removed and the beads 6 are formed on the metal plate 1. FIG. 7 is a combination of FIG. 4 and FIG. FIG. 8 shows an assembly of the metal ring 7 shown in FIG.

[0017]

[Effect of the device]

(A) Since the plate surface of the metal plate is formed of the foamed rubber layer having a large amount of compression, even the low pressure surface portion having a long bolt pitch closely adheres to the surface of the counterpart member. Therefore, the seal surface follows the deformation due to heat and vibration, and prevents leakage of gas, oil and cooling water. (B) Since the foamed rubber layer is in close contact with the surface of the mating member, the lateral movement of the mating member due to thermal deformation or vibration is absorbed in the foamed rubber layer, which causes leakage due to wear on the gasket surface. Prevent. (C) Since the foamed rubber layer is formed of closed cells, the airtightness is high even in the low surface pressure portion, and gas, oil, and cooling water do not leak from the substantial portion. (D) Since the integrated production including the formation of the foamed rubber layer and the adhesion to the metal substrate can be achieved, the cost can be significantly reduced. (E) Since the good sealing property can be secured even in the portion where the tightening surface pressure is hard to be applied, the weight of the cylinder head and the number of bolts can be reduced. (F) For example, in a conventional head gasket in which a mill board and a graphite sheet are attached to both sides of a nailing metal plate, and the cylinder bore is grommet-processed, all of the combustion gas, water, and oil are sealed. 1500 kgf / cm ^2, at the same time it is necessary to ensure a 100 kgf / cm ² or more surface pressure on the sheet. In recent years, however, in order to reduce the weight of the engine, the bolts have become thinner and the surface pressure on the grommet has been secured, and even if the gas can be completely sealed, the surface pressure on the seat is insufficient and water and oil are In many cases, it is not possible to sufficiently seal and vice versa, and advanced technology is required for the design of the head gasket. In other words, how to distribute the limited bolt tightening pressure in a well-balanced manner.

According to the actual results of comparing the sealability between the conventional product having the above structure and the product of the present invention, the former is 100 kgf / cm ² and the latter is 10 kgf / cm ² for sealing 5 kgf / cm ² gas. Although it has been confirmed that the surface pressure required for the cylinder bore and grommet is sufficient, the present invention can seal water and oil with a lower surface pressure than the conventional product with the above structure. The surface pressure can be applied, and the design becomes very easy.

[Submission date] May 11, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction content]

4 to 11 show various examples of grommet processing and bead processing in the cylinder bore of the head gasket.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0016

[Correction method] Change

[Correction content]

In FIG. 4, the foam rubber layer 2 in the bore portion is removed, and the grommet 4 is attached to the metal plate 1. In FIG. 5, the metal plate 1 is made of spring steel, and the bead 5 is formed over the entire bore portion. In FIG. 6, the foam rubber layer 2 in the bore portion is removed and the beads 6 are formed on the metal plate 1. FIG. 7 is a combination of FIG. 4 and FIG. FIG. 8 shows an assembly of the metal ring 7 shown in FIG. In FIG. 9, the grommet 4 is attached in a state of sandwiching the foamed rubber layer 2 in the bore portion . In FIG. 10, a metal ring is assembled inside the bore portion. FIG. 11 is a combination of FIG. 9 and FIG.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a head gasket material showing an embodiment of the present invention.

FIG. 2 is a plan view of a head gasket material.

FIG. 3 is a plan view of a finished head gasket product.

FIG. 4 is an enlarged sectional view of a cylinder bore / grommet portion of a head gasket according to another embodiment.

FIG. 5 is an enlarged sectional view of a cylinder bore portion of a head gasket according to another embodiment.

FIG. 6 is an enlarged sectional view of a cylinder bore portion of a head gasket according to another embodiment.

FIG. 7 is an enlarged sectional view of a cylinder bore / grommet portion of a head gasket according to another embodiment.

FIG. 8 is an enlarged cross-sectional view of a cylinder bore / grommet portion of a head gasket according to another embodiment.

[Explanation of symbols]

 1 Metal plate 2 Foamed rubber layer with closed cells 3 Grommet

─────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] May 11, 1992

[Procedure 3]

[Document name to be amended] Statement

[Name of item to be corrected] Brief explanation of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a cross-sectional view of a head gasket material showing an embodiment of the present invention.

FIG. 2 is a plan view of a head gasket material.

FIG. 3 is a plan view of a finished head gasket product.

FIG. 4 is an enlarged sectional view of a cylinder bore / grommet portion of a head gasket according to another embodiment.

FIG. 5 is an enlarged sectional view of a cylinder bore portion of a head gasket according to another embodiment.

FIG. 6 is an enlarged sectional view of a cylinder bore portion of a head gasket according to another embodiment.

FIG. 7 is an enlarged sectional view of a cylinder bore / grommet portion of a head gasket according to another embodiment.

FIG. 8 is an enlarged cross-sectional view of a cylinder bore / grommet portion of a head gasket according to another embodiment.

FIG. 9 is a cylinder of a head gasket according to another embodiment .
It is an expanded sectional view of a bore grommet portion.

FIG. 10 is a head gasket cylinder according to another embodiment .
It is an expanded sectional view of a Doboa ring portion.

FIG. 11 is a head gasket cylinder according to another embodiment .
It is an expanded sectional view of a doboa grommet portion.

[Explanation of reference numerals] 1 metal plate 2 closed-cell foam rubber layer 3 grommet

[Procedure amendment 4]

[Document name to be corrected] Drawing

[Correction target item name] Figure 9

[Correction method] Added

[Correction content]

[Figure 9]

[Procedure Amendment 5]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 10

[Correction method] Added

[Correction content]

[Figure 10]

[Procedure Amendment 6]

[Document name to be corrected] Drawing

[Name of item to be corrected] Fig. 11

[Correction method] Added

[Correction content]

FIG. 11

Claims (1)

[Scope of utility model registration request] 1. A head gasket, wherein a foamed rubber layer having closed cells is formed on one or both sides of a metal plate.