JP3252022B2 - Manufacturing method of metal gasket - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a metal gasket, and more particularly to a method for manufacturing a cylinder head gasket for an internal combustion engine, in which a fluid hole is formed in a metal substrate and a bead is formed on an outer peripheral edge of the substrate. The present invention relates to a manufacturing method for manufacturing a metal gasket suitable as the above.

[0002]

2. Description of the Related Art It is well known that a gasket is interposed between joining members to prevent leakage of a pressure fluid from a joining surface. For example, a gasket is provided between a cylinder head and a cylinder block of an internal combustion engine. A cylinder head gasket is interposed. With regard to this type of gasket, a metal gasket made of a metal plate has recently attracted attention.

For example, a fluid hole through which a pressure fluid such as a combustion gas passes is formed in a substantially rectangular metal substrate, and a bead is formed around the fluid hole to secure a high surface pressure on a joining member. What you get is known. Further, there is also known a substrate in which an outer peripheral bead is formed on the outer peripheral edge portion. An outer peripheral bead is generally formed by forming a bent portion along an outer periphery of a substrate to form an inclined portion, and is called a half bead because it has a half shape with respect to a convex bead. In such a metal gasket, a soft sealing material is adhered to the surface of the substrate to improve the sealing property, and a coating layer, that is, a coating layer is formed.

[0004]

However, in the case of a metal gasket in which a coating layer is formed on a substantially rectangular substrate having an outer peripheral bead as described above, the substrate generally curves slightly in the longitudinal direction after the pressing step. In the coating process, the side edge of the substrate in the transport direction rubs against the upper surface of the conveyor, and the coating layer at the edge of the substrate is easily damaged or peeled. If the coating layer comes off to the outer bead portion, the sealing function is impaired, so that it is difficult to ensure a certain level of sealing performance.

Accordingly, the present invention relates to a metal gasket for forming a plurality of fluid holes in a substantially rectangular metal substrate, forming an outer peripheral bead on the outer peripheral edge of the substrate, and forming a coating layer on the surface of the substrate. In a manufacturing method, an object is to be able to manufacture a metal gasket without impairing a sealing function of an outer peripheral bead.

[0006]

In order to achieve the above object, a method of manufacturing a metal gasket according to the present invention comprises the steps of: forming a plurality of fluid holes through which a pressure fluid passes through a substantially rectangular substrate; At the outer peripheral edge, an outer peripheral bead is formed at a position where the distance from the longitudinal side end of the substrate is larger than the distance from the lateral end of the substrate, and the substrate is transported in the longitudinal direction. Meanwhile, a sealing material is applied to the surface of the substrate to form a coating layer. It is preferable that the width of the outer peripheral bead located at the longitudinal end of the substrate is wider than the width of the outer peripheral bead located at the lateral end of the substrate.

[0007]

According to the method of manufacturing a metal gasket of the present invention, a plurality of fluid holes through which a pressure fluid passes are formed in a substantially rectangular metal substrate, and an outer peripheral bead is formed at an outer peripheral edge of the substrate. Is done. Then, a coating layer is formed on the surface of the substrate. In this case, when the metal gasket is conveyed to form the coating layer, the longitudinal side end of the substrate comes into contact with an assembling line or the like. Since the flat portion is located wider than the outer peripheral bead of the portion and the flat portion is formed widely, it is possible to prevent the peeling of the coating from reaching the outer bead, and the coating layer of the outer bead is formed at the time of formation. Maintained in state.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a method for manufacturing a metal gasket according to the present invention. Incidentally, the metal gasket to be the object of the present invention is suitable for a cylinder head gasket interposed between a cylinder head and a cylinder block of a multi-cylinder internal combustion engine, and a metal gasket used as a cylinder head gasket in the following. The manufacturing method will be described.

FIG. 2 shows a part of an apparatus provided for an embodiment of the method for manufacturing a metal gasket according to the present invention. The apparatus includes a long rolled metal plate, for example, a stainless steel plate (SUS) material 2.
Is wound in a roll shape, and is supported by the support device 3 so as to be rotatable around the axis of the coil. The material 2 is guided by a guide 4, and is fed by a feeder 5 to a first pressing device 6.
Are supplied at predetermined intervals. In the first press device 6, a blanking process is performed on the material 2 to form a substrate 10 having a plurality of combustion chamber holes 11 and the like as shown in FIG. That is, a substantially rectangular substrate 10 is punched from the raw material 2 so that, for example, the direction perpendicular to the rolling direction is the longitudinal direction, and at the same time, the number corresponding to the number of cylinders (for example, four for an in-line four-cylinder internal combustion engine). Individual) combustion chamber holes 11
Are formed in a row on the longitudinal axis of the substrate 10. At the same time, a plurality of cooling water holes, lubricating oil holes and the like (not shown) are formed in the substrate 10, and a plurality of bolt holes 12 are formed around each combustion chamber hole 11. It should be noted that the processing by the first press device 6 may be replaced by cutting by a laser cutting device or the like.

Subsequently, the substrate is supplied to a second pressing device 7 shown in FIG. 2 to form an annular bead 13 shown in FIG. 1 around each combustion chamber hole 11 of the substrate 10 and to bend all around the substrate 10. A curved portion is provided, and an outer peripheral bead 14 is formed. The outer peripheral bead 14 is a half bead composed of only one inclined surface as shown in FIG. The outer peripheral bead 14 is
The width Wat of the portion located at the longitudinal end of the substrate 10 is
0 (Wat> Was), and the distance from the longitudinal side end of the substrate 10, that is, the width Wb of the flat portion 10a.
is formed at a position where t is greater than the distance from the side end in the width direction of the substrate 10, that is, the width Wbs of the flat portion 10b (W
bt> Wbs).

Although the equipment is not shown in FIG. 2, the entire substrate 10 is cleaned and heated, and then left for a predetermined time to perform a so-called aging process (aging process). That is, in order to improve the spring characteristics of the substrate 10 which is formed with a plurality of perfect circular combustion chamber holes 11 in a direction orthogonal to the rolling direction with respect to the raw material 2 of the rolled metal plate and which is cut into a substantially rectangular shape, After heating, it is left for a predetermined time to perform aging treatment. As a result, the combustion chamber hole 11 having a perfect circle shrinks in the rolling direction, and as shown in FIG. 3, is deformed into an elliptical hole having a long axis in a longitudinal direction. Although FIG. 3 shows an elliptical shape having a large difference between the major axis and the minor axis for ease of explanation, the difference between the major axis and the minor axis is actually a small difference of 1 mm or less, and can be said to be substantially circular.

In view of the above, it is possible to form a predetermined elliptical hole by forming a perfect circular hole in the substrate 10 and actively performing aging treatment. Then, when an intermediate plate is interposed between a pair of substrates to form a three-layer structure, for example, the intermediate plate is not subjected to aging treatment and is left as a perfect circular hole, and the pair of substrates is subjected to aging treatment to form an elliptical hole. Is formed, the holes surrounding the combustion chamber holes can be easily secured when these are stacked and caulked and fixed. Alternatively, when the cross section of the combustion chamber of the internal combustion engine is elliptical, it is not easy to form an elliptical combustion chamber hole in the substrate to conform to this, but it is easy to use the above-mentioned aging treatment. An elliptical combustion chamber hole can be formed.

After the above-described molding, the substrate 10 is transferred to a coating apparatus 8, where the substrate 10 is coated with a sealing material, and a coating layer 30 is formed on the substrate 10 as shown in FIG. In the coating device 8, first, the substrate 10 is placed on the conveyor 8b such that the lower side of the substrate 10 in FIG. 4 is upward, and the substrate 10 transported in the longitudinal direction by the conveyor 8b is supplied from the supply device 8a. Liquid sealing material such as unvulcanized fluorine rubber is sprayed,
The coating layer 30 is formed on one surface of the substrate 10.

Next, the substrate 10 is turned over so that the protruding surface of the annular bead 13 faces upward, and is conveyed in the direction of the supply device 8a by the conveyor 8b. Then, when the substrate 10 is conveyed from left to right in FIG. 4 and passes through the lower part of the supply device 8a, a sealing material is sprayed on the substrate 10, and a coating layer 30 is formed on the surface on the opposite side of the substrate 10. You. In this case, the width Wbt of the flat portion 10a is
Is wider than the width Wbs.
Even if peeling occurs at 0, it does not reach the outer peripheral bead 14.

After that, it is dried, solidified, and vulcanized to form a vulcanized coating layer. Instead of the spray-type supply device 8a, a coating device (not shown) having a supply device on the upper side and a storage device on the lower side may be used. According to the device, the sealing material continuously flows down from the supply device to form a film-like flow lower surface in a vertical direction, and the sealing material flowing down to the storage device arranged on the lower side is returned to the supply device, and the film is constantly filmed. A bottom surface is formed.

As shown in FIG. 4, a coating layer 30 is formed on both the upper and lower surfaces of the substrate 10. The thickness of the coating layer 30 can be appropriately set by adjusting the amount of the sealing material sprayed from the supply device 8a, the transport speed of the conveyor 8b, and the like. Further, if necessary, after forming the coating layer 30 on the substrate 10, the substrate 10 is transported again in the reverse direction,
An unvulcanized coating layer may be formed.

The metal gasket constructed as described above has a fastening bolt (not shown) inserted therein, and is arranged, for example, so that the projecting side of the annular bead 13 is on the cylinder block (not shown) side. It is clamped between a head (not shown) and a cylinder block. As a result, the annular bead 13 and the outer peripheral bead 14 are deformed, and a predetermined surface pressure is secured around each combustion chamber hole 11 of the substrate 10 by the elastic restoring force of the annular bead 13 and the outer peripheral bead 14.
In this case, since the width Wat of the peripheral bead 14 at the portion located at the longitudinal end of the substrate 10 is formed to be wider than the width Was of the portion located at the lateral end, the outer bead 14 is excessively large with respect to the peripheral bead 14. The desired elastic restoring force can be maintained without applying a load.

[0018]

Since the present invention is configured as described above, the following effects can be obtained. That is, according to the method for manufacturing a metal gasket of the present invention, since the outer peripheral bead formed at the longitudinal end of the substrate is formed inside the outer peripheral bead formed at the width end, It is possible to prevent the outer bead portion from being damaged or peeled off from the coating layer, and to manufacture a metal gasket having good sealing properties without impairing the sealing function of the outer bead.

[Brief description of the drawings]

FIG. 1 is a plan view of a metal gasket manufactured by a manufacturing method according to an embodiment of the present invention.

FIG. 2 is an explanatory view showing a main part of a manufacturing process in one embodiment of the method for manufacturing a metal gasket of the present invention.

FIG. 3 is an enlarged plan view of a combustion chamber hole portion of a substrate manufactured by a manufacturing method according to one embodiment of the present invention.

FIG. 4 is an explanatory view showing a state in which a coating layer is formed by the coating device in FIG. 2;

[Explanation of symbols]

 Reference Signs List 2 material 3 support device 4 guide 5 feeder 6 first press device 7 second press device 8 coating device 10 substrate 11 combustion chamber hole (fluid hole) 13 annular bead 14 outer peripheral bead 30 coating layer

Claims (1)

(57) [Claims] A plurality of fluid holes through which a pressure fluid passes are formed in a substantially rectangular substrate, and a distance from a longitudinal side end of the substrate at an outer peripheral edge of the substrate is equal to a width of the substrate. Forming a peripheral bead at a position larger than the distance from the side end in the direction, and applying a sealing material to the surface of the substrate while transporting the substrate in the longitudinal direction to form a coating layer, thereby producing a metal gasket. .