JPH09280029A - Composite article of oil pan integrated with gasket - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve adhesive property of a gasket material by irradiating active rays of specific wavelength on the surface to be sealed of an oil pan, and forming the gasket into a two mountain shape, in an oil pan in which after closing dies for forming the oil pan the gasket is integrated with the oil pan through silicon, resin. SOLUTION: The flange surface 2 to be sealed of an oil pan 1 is irradiated by active rays containing both the wavelength 253.7nm and 184.9nm by means of a low pressure mercury lamp and the like. Next when the flange surface 2 of the oil pan 1 is contacted with the contact face 5 of a male forming die 4, a recessed groove 6 is formed on the contact face 5, so that a cavity 8 can be formed on the contact face 5 by the recessed groove 6 on the contact part 7. Silicone resin as a gasket material is injected into the cavity 8 from a jet nozzle 9 through a sprue 10 and a runner 11, and by hardening it, a composite article in which the oil pan 1 is integrated with the gasket 12 having two lines of projecting stripe parts 13 branched continuously in two mountain shape is formed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a composite article in which an oil pan and a gasket are integrated. More specifically, the oil pan and the gasket can be molded by a simple method, the process of fastening the oil pan to the mutual parts can be simplified, the detachability at the time of disassembly is excellent, and the sealing property between the members can be improved. Of composite articles.

[0002]

2. Description of the Related Art An oil pan for storing engine oil in the engine body and gear oil in the transmission section must have some kind of leakage prevention at the connection section in order to prevent oil leakage when connecting to the engine block or transmission case. I have to. Conventionally, the above-mentioned part is cork,
A gasket in which asbestos paper, semi-metallic, cork rubber and the like are punched and formed into a substantially oil pan flange shape, that is, a so-called solid gasket is sandwiched between the flange surface of the oil pan and the connecting member and fastened with a bolt. The gasket secures the sealing property by the elasticity of the gasket material by tightening the flange surface of the oil pan and the connecting member. Therefore, in order to secure the sealing property, it is necessary to maintain a strong tightening force, and it is necessary to maintain a uniform surface pressure. When the area of the flange surface is large, the area near the bolt is tightened strongly, but the tightening force decreases as the distance from the bolt increases. Therefore, it is necessary to reduce the interval between the bolts, that is, increase the number of bolts to be tightened or increase the tightening force. This is not preferable because the number of parts increases and the metal may be deformed due to strong tightening. In addition, the solid gasket has problems such as an increased number of assembly steps such as alignment and handling during assembly, easy damage, poor adhesion, and material loss when punching the solid gasket.

In addition, a method of applying a liquid sealant such as a liquid gasket by a robot to the seal surface and adhering and hardening the same in order to obtain the sealing property of the flange surface of the oil pan and its connecting member has been put into practical use. In this method, since a liquid sealing agent is applied and adhesively hardened, the sealing agent is hardened so as to fill the fine irregularities even if the accuracy of the metal surface of the flange surface is poor, so that the tightening force is not so required. Therefore, it is not necessary to polish the surface of the flange surface, and the number of bolts to be fastened can be reduced.

However, since the liquid gasket has a thin sealing layer, it cannot follow the movement between the oil pan and its connecting portion due to engine vibration or the like. Since the movement is minute, the seal layer does not immediately burst, but when a crack occurs due to vibration or the like, the engine oil may ooze in a slight amount due to a capillary phenomenon. Furthermore, this method requires a little time to cure because it is applied by assembling a liquid material and then assembled, and due to problems such as dripping when uncured, it is applied to the three-dimensional three-dimensional sealing surface as shown in FIG. There was a drawback that it was difficult to put out the sex. Wrinkles and twists were also generated in the solid gaskets and O-rings, and the sealing of the three-dimensionally shaped sealing surface was not suitable.

Further, the liquid gasket strongly adheres to the flange in order to secure the sealing property, and a force is required when the engine is disassembled. Further, for the reassembly, the cured product of the liquid gasket attached to the flange is removed by a gasket remover or the like. Must be used, peeled off and cleaned.
Of course, reuse is impossible. Since the solid gasket is also tightened with a strong tightening force, it is deformed to correspond to the shape of the sealing surface. Since the solid gasket has no restoring property, when it is reused, leakage occurs due to the deformation. Therefore, the conventional solid gasket cannot be reused.

[0006] Therefore, as a method for improving the drawbacks existing in these known techniques, a molding machine provided with an integral mold which can be replaced with each other is used to mold a molded member made of plastic by one of the molds. Then, there is known a method of molding an elastic sealing material on the sealing surface of the plastic molding target member using the other mold. (JP-A-60-52
However, in this method, the member to be molded is also molded at the same time, which is suitable for an article to be newly designed, but it is impossible to integrally mold only the sealing material to the existing member to be molded later. In addition to the above, there is a limitation that the member to be molded is a plastic molded product.

In order to improve this, Japanese Patent Laid-Open No. 60-2372.
In the method described in Japanese Patent Publication No. 67, a liquid rubber is put on the sealing surface of a molding member, and then a cover mold is covered and cured to obtain a composite molded product. However, in this method, in the molding cavity However, it was difficult to completely release the air, and voids were liable to be formed, and if the coating amount was too large, burrs were liable to be formed.

It is also known to manufacture a composite article of a member to be sealed and a gasket. This is a cavity formed between the mold surface and the sealed surface of the molded member after inserting the molded member such as an oil pan into the molding mold consisting of the male mold and the female mold. An insert molding method is used in which a resin material is injected into a resin to obtain a composite article in which a sealing member is integrated.

However, in these methods, a groove is formed in the sealed surface to fix the sealed surface and the gasket, and the gasket material is seated therein, or a through hole is provided in the sealed surface. It is necessary to adopt a mechanical structural fixing method of fixing by penetrating into the front and back. This is because the gasket material has weak adhesiveness, and particularly the two-liquid mixing type addition type silicone resin has poor adhesiveness.

[0010]

However, it is easy to provide a groove or a through hole in a resin molded member obtained by molding a polycarbonate material or the like, but an oil pan obtained by press-forming a steel plate is used. It is difficult to provide a groove, and an oil pan having a narrow flange width and a small thickness cannot form a groove or fix with a through hole, so that a mechanical structure fixing method cannot be adopted.

Therefore, the method of fixing the gasket to the work, which cannot adopt the mechanical structure fixing method, has used chemical bonding. However, the two-liquid mixing type addition type silicone does not have adhesiveness due to the releasability from the molding die, and in order to obtain the adhesiveness, the portion to be bonded must be treated with a primer in advance. The primer treatment is performed by diluting and dissolving a silane coupling agent in an organic solvent. It is applied to the adhered part, dried, and injection-molded on the part so that the work and the gasket are adhered and integrated. You can

However, the primer treatment requires a step of coating the substrate to be adhered and a step of drying the solvent,
Continuous productivity is poor. In particular, the drying time limits the number of units produced per hour. Also, because it uses an organic solvent,
Local exhaust equipment is also required during the coating process and drying process.

Further, even the gasket integrated by the above-mentioned insert molding method has the above-mentioned disadvantages. That is, when the member to be sealed and the member to be sealed are fastened with bolts, a large fastening force is generated near the bolt fastening position, so that the surface pressure of the sealing material in the fastening region is extremely high. On the other hand, the fastening force physically decreases toward the intermediate portion between the bolts, and the surface pressure of the gasket tends to decrease accordingly. Therefore, there is a large variation in the overall surface pressure distribution of the sealing material, and there is a disadvantage that a sealing failure occurs due to a partial decrease in sealing performance.

In particular, when the sealing surface has a three-dimensional three-dimensional shape, for example, when the sealing surface has a curved surface that is depressed in an arc shape as shown in FIG. 5, it is relatively difficult to secure the same sealing surface pressure. Has been done.

[0015]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to integrate an oil pan and a gasket into various existing oil pans by a simple molding process and to solve the above problems. Sometimes to provide a composite article.

[0016]

In order to achieve the above-mentioned object, according to the present invention, an oil pan is inserted into a molding die made up of a male die and a female die, and after the die is clamped, the oil pan is closed. In a composite article in which an oil pan and a gasket are obtained by injecting a silicone resin into a cavity formed between the surface to be sealed and the mold, the oil pan is inserted into the molding die. Previously, the wavelength of 253.7 nm was previously applied to the sealed surface of the oil pan.
And actinic radiation containing both 184.9 nm and
There is provided a composite article in which an oil pan and a gasket are integrated, wherein the gasket includes two projecting ridges which are branched so as to be continuous in a double mountain shape.

[0017]

The feature of the present invention is that the wavelengths of 253.7 nm and 184.9 nm are previously formed on the flange surface of the oil pan before the gasket is integrally formed on the flange surface.
It is to irradiate an actinic ray containing both. As a result, the molecules of the coating or deposits on the surface of the flange surface are cut to lower the molecular weight, and further polar groups or reactive groups such as carboxylic acid groups, carboxyl groups, and hydroxyl groups are generated. It is presumed that it exhibits an action of enhancing adhesiveness. As a result, in the present invention, the flange surface is modified by the irradiation of the above-mentioned actinic rays, and the gasket can be integrally molded without applying a primer.

Further, as a feature of the present invention, the gasket shape is provided with two projecting ridges which are branched so as to be continuous with each other in a double mountain shape. As a result, when the oil pan that is the composite article of the present invention is assembled and a fastening force is applied between the members, the ridge portion is deformed by this fastening force. At this time, since the ridge portion has a shape in which it is branched so as to be continuous with two peaks, the top side is greatly deformed with the skirt portion as a base portion. Therefore, in the region where the fastening force directly acts, this can be absorbed by the large deformation of the ridge portion, while in the region where the fastening force is relatively low, the ridge portion has a small deformation to reduce the surface pressure accordingly. By avoiding this, it becomes possible to make the variations in the surface pressure distribution of the entire gasket uniform.

In particular, in the shape in which the ridges are connected to each other via the V-shaped or U-shaped recesses, the ridges are greatly expanded in the direction in which they are spaced apart from each other to support smooth deformation. Further, in the structure in which the outer hem portion of the protruding portion is expanded outward to have a skirt shape, so-called strong deformation can be generated and durability can be imparted.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is a cross-sectional view of one embodiment of a method for obtaining the composite article of the present invention, and FIG. 2 is a perspective view of the composite article having an integrated oil pan and gasket obtained by the method of FIG. is there. Reference numeral 1 denotes an oil pan, which is formed by press-forming a steel plate by cationic electrodeposition, and has a flange surface 2 which is a sealed surface. The flange surface 2 is irradiated with an actinic ray having both wavelengths of 253.7 nm and 184.9 nm. (Not shown) Actinic rays containing such wavelengths are efficiently generated from a low pressure mercury lamp. The irradiation time is 5 seconds to 10 minutes, preferably 5 seconds to 5 minutes. The above-mentioned oil pan 1 is then placed on the female molding die 3 with the flange surface 2 facing upward, and the male molding die 4 is covered over this, and the contact surface 5 of the male molding die 4 and the flange of the oil pan 1 are covered. The surfaces 2 are brought into contact. At this time, if the concave groove 6 is formed in the contact surface 5, the cavity 8 is formed in the contact portion 7 by the concave groove 6.

Then, a silicone resin as a gasket material is injected into the cavity 8 from the injection nozzle 9 through the sprue 10.
Further, by injecting it through the runner 11 and curing it, a composite article in which the oil pan and the gasket are integrated as shown in FIG. 2 is molded. In FIG. 2, 12 is a cured gasket.

The cavity 8 is formed so that the shape of the gasket 12 obtained by injection molding is provided with two projecting ridges which are branched so as to be continuous in a double mountain shape. FIG. 3 shows a sectional view of the gasket of the present invention. Further, FIG. 4 is a cross-sectional view of a gasket shape when assembled with a mutual member to which a composite article in which the oil pan and the gasket of the present invention are integrated is fastened. The mutual member to which the composite article is fastened is, for example, an engine block or a mission case.

In FIG. 3, the gasket 12 comprises a ridge portion 13 located above the flange surface 2. As shown in FIG. 4, the protrusion 13 is formed as a region in contact with the mutual member 15 to which the oil pan is fastened. The ridges 13 have a two-row arrangement in which the top has an arcuate shape and the cross-sectional shape thereof is continuous and bifurcated in a bimodal shape. They are formed in series with each other. The V-shaped or U-shaped opening angle α1 is preferably 30 ° to 90 °. 3
When the tightening force is applied below 0 degree, each ridge 1
This is because it becomes difficult for the elastic members 3 to elastically deform smoothly in the direction in which they are separated from each other, and an excessive tensile stress acts on the recesses 14 between the protrusions 13 to reduce the strength of the protrusions 13. On the other hand, when the angle is 90 degrees or more, the amount of flexural deformation becomes small and the rigidity is lowered, so that the correction of the surface thickness cannot be expected.

The outer hem portion 13A of the ridge portion 13 has an angle α
It is formed in such a manner that it is inclined in a direction of gradually expanding through 2 and its cross-sectional shape is a substantially skirt shape. here,
The angle α2 is preferably 30 degrees to 90 degrees. When the tightening force is less than 30 degrees, it is difficult for the protrusions 13 to be elastically deformed smoothly in the direction in which they are separated from each other, and an excessive tensile stress acts on the recesses 14 between the protrusions 13. 90
This is because the ridges 13 are less likely to bend if the degree of bending is higher than the limit.

The relative ratio of the distance H1 from the bottom point of the recess 14 to the flange surface 2 to the distance H2 from the flange surface 2 to the apex of the protrusion 13 is set to 2: 1 or a little around this. As a result, the ridges 13 are easily bent in the directions away from each other.

When the temperature of the molding die is kept at 150 ° C. to 200 ° C., the silicone resin hardens into an elastomer in a short time.

As shown in FIG. 4, when a fastening force is applied to the oil pan by a bolt (not shown), the protrusions 13 are deformed by the fastening force in the arrow direction in FIG. Will be done. At this time, the amount of deformation of the gasket 12 existing in a region where the fastening force is excessively large, that is, in a certain region around the bolt fastening position, becomes relatively large. On the other hand, in the central fastening region between the bolts, the deformation amount of the ridge portion 13 is relatively small in order to follow the decrease in fastening force.

Therefore, according to the present embodiment, the surface pressure difference caused by the difference between the fastening force in the fixed region at the bolt fastening position and the fastening force in the central fastening region between the bolts is determined by the amount of deformation of the ridge 13. Since the fine adjustment can be performed, the sealing property of the gasket 12 as a whole can be secured on average.

As the gasket material that can be used in the above-mentioned molding method, any material can be used as long as it can be injected, cast, or transfer-molded. For example,
Styrene-based, olefin-based, polyvinyl chloride-based, polyurethane-based, polyamide-based, fluorine-based, chlorinated polyethylene-based 1,2-polybutadiene-based thermoplastic resins, silicone-based, polyurethane-based, epoxy-based, polyamide-based, polyester-based A thermosetting resin such as acrylic urethane type is used. However, since the present invention is used as a gasket for an oil pan, a silicone resin is used because of its heat resistance and chemical resistance.

A silicone resin was injection-molded into the oil pan which was cationically coated by the above procedure to obtain a composite article in which the oil pan and the gasket were integrated. The gasket was firmly fixed to the flange surface of the oil pan. In addition, the molding accuracy of the gasket was good.

[0031]

By integrally molding the solid gasket made of silicone rubber on the oil pan, the assembly process of the oil pan is simplified, the oil pan can be automatically assembled and fastened, and the stock and parts management man-hours can be reduced. is there.
In addition, it can be reused at the time of reassembly. Also, since the oil pan and the gasket are integrated, unlike the liquid gasket, there is no possibility that the uncured resin will elute into the oil, and especially in the mission oil pan, the foaming of the mission oil can be prevented. . Further, since the gasket has excellent heat resistance and chemical resistance and a good sealing property, it can seal against polar oil such as engine oil and gear oil.

Further, the oil pan flange can be molded even if it has a three-dimensional shape, and the gasket can be fixed without forming a groove or a through hole in the flange of the oil pan. Therefore, according to the present invention, the sealing material can be integrated without changing the shape of the oil pan made of the existing material.

Further, it is possible to sufficiently give the deformation allowance when the fastening force is applied to the gasket, and the surface of the region where the fastening force is directly applied and the region where the fastening force is applied relatively low. The pressure distribution can be made as uniform as possible to stabilize the sealing property as a whole, and a predetermined sealing effect can be obtained by itself when applied to a sealing surface having a three-dimensional three-dimensional shape. A sealing effect can be obtained.

[0034]

[Brief description of drawings]

FIG. 1 is a sectional view of a specific example for carrying out the present invention.

FIG. 2 is a composite article in which the oil pan and the gasket obtained in FIG. 1 are integrated.

FIG. 3 is a sectional view of a gasket of a composite article according to an embodiment of the present invention.

FIG. 4 is a cross-sectional view of a gasket shape when the composite article of the present invention is fastened to a mutual member.

FIG. 5: Example of an oil pan with a three-dimensional structure

[0035]

[Explanation of symbols]

 1 ... Oil pan 2 ... Flange surface 3 ... Female mold 4 ... Male mold 6 ... Recessed groove 8 ... Cavity 9 ... Injection nozzle 10 ... Sprue 11 ... Runner 12 ... Gasket 13 ...... Protruding ridge 14 ...... Concave 15 ...... Parts to which the oil pan is fastened

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Claims (1)

[Claims] 1. An oil pan 1 is inserted into a molding die composed of a male die 4 and a female die 3, and is formed between a sealed surface 2 of the oil pan 1 and the die after the die is clamped. In a composite article in which an oil pan and a gasket obtained by injection-molding a silicone resin in the cavity 8 are integrated, the oil pan 1 is inserted into the molding dies 3 and 4 in advance. The surface to be sealed 2 is irradiated with an actinic ray containing both wavelengths of 253.7 nm and 184.9 nm, and the gasket 1 is provided with two projecting ridges 13 which are branched so as to be continuous in a double mountain shape. A composite article in which an oil pan and a gasket are integrated.