JP2021131118A - Sealed structure and method for manufacturing the same - Google Patents

Abstract

To provide a sealed structure that reduces time and effort for production, is readily molded by reducing the difficulty in manufacturing the compression member thereof and is improved in eccentric followability and difficult-to-come out property.SOLUTION: A sealed structure 100 includes: a seal lip 11 with an annular lip part 10; and an annular compression member 13 disposed in the lip part 10 of the seal lip 11. The compression member 13 is made of a rubber elastic material and fixed to the lip part 10 with crosslinking adhesion.SELECTED DRAWING: Figure 2

Description

The present invention relates to a sealed structure and a method for producing the same. More specifically, the present invention relates to a sealing structure used as a plug tube seal or the like in automobiles and the like, and a method for manufacturing the same.

Conventionally, the cylinder head cover of an internal combustion engine in a vehicle such as an automobile is provided with an insertion hole for inserting an insertion member such as a plug tube or an injection pipe (hereinafter, also referred to as a "shaft member"). With the insertion member inserted, a sealing structure (sealing device) such as a plug tube seal (PTS) or injection pipe seal (IPS) is attached so as to seal between the insertion member and the housing such as the cylinder head cover. There is.

A spring, which is a pressurizing member, is arranged on the lip portion of these PTSs and IPSs, and this spring contributes to maintaining a tightening allowance (tension force) with the insertion member.

This spring is made of metal (indicated by reference numeral "113" in FIG. 5), and is manufactured so that the spring is included in the lip portion in the sealed structure (see, for example, Patent Document 1). .. A spring embedded in the lip portion and contained therein may be referred to as a mold spring. FIG. 5 shows a conventional sealing structure 200, in which the metal spring 113 is embedded in the lip portion 10 of the sealing lip 11 as shown in FIG.

Jikkenhei 7-714 Gazette

The sealing device described in Patent Document 1 is a molded spring in which a metal spring is included in the lip portion, and it is preferable that the spring does not easily come off. Therefore, an adhesive for strengthening the adhesive force with the spring may be used. However, since it takes time and effort to apply the adhesive to the spring, there is room for reducing the time and effort for manufacturing the sealing device by reducing the number of steps for performing this process. Further, since the spring is made of metal, there is still room for improvement in terms of difficulty in manufacturing, and there is room for improvement in terms of manufacturing the pressure member more easily. Further, since the spring is made of metal, there is still room for improvement in moldability. Further, the sealing device described in Patent Document 1 has room for further improvement in that the eccentric followability to the insertion member and the like is further improved and the spring is prevented from coming off (falling off) when the spring is inserted into the insertion member. there were.

As a result, the labor of manufacturing is reduced, the difficulty of manufacturing is low, the molding is easy (the moldability is good), and the eccentricity followability and the detachment difficulty are improved (that is, the pressure member). , A member corresponding to a spring) has been desired to be developed.

The present invention has been made in view of such a prior art, and the problems thereof are that the labor for manufacturing is reduced, the difficulty of manufacturing is low, the molding is easy, and the eccentricity followability and detachment are achieved. The purpose is to develop a sealed structure including a pressure member with improved difficulty.

According to the present invention, the following sealed structure and a method for producing the same are provided.

[1] A seal lip having an annular lip portion in contact with the outer peripheral surface of the shaft member, and
An annular pressure member, which is arranged on the lip portion of the seal lip and applies a force toward the shaft member to the lip portion, is provided.
The pressure member has a sealed structure made of a rubber elastic material and fixed to the lip portion by cross-linking adhesion.

[2] The sealing structure according to the above [1], wherein the pressure member has a smaller compression set than the compression set of the lip portion.

[3] A method for manufacturing a sealed structure according to the above [1] or [2].
A molding mold having the sealed structure is prepared, the pressure member is placed in the molding mold, and then the molding material of the seal lip is injected into the molding mold, and then the molding material in the molding mold is injected. A method for producing a sealed structure, wherein the pressure member is crosslinked and adhered to the lip portion to produce the sealed structure.

It is said that the sealed structure of the present invention reduces the labor of manufacturing, the difficulty of manufacturing the pressure member is low and easy to mold, and the eccentric followability and the difficulty of detachment of the pressure member are improved. It works.

According to the method for manufacturing a sealed structure of the present invention, the labor for manufacturing is reduced, the difficulty in manufacturing the pressure member is low, the pressure member is easy to mold, and the pressure member is eccentric followability and difficult to come off. It has the effect of being able to obtain a sealed structure with improved pressure.

It is a top view which shows typically one Embodiment of the sealed structure of this invention. FIG. 5 is a cross-sectional view schematically showing a state in which the AA cross section in FIG. 1 is viewed in the direction of the arrow. FIG. 5 is a cross-sectional view schematically showing a cross section corresponding to FIG. 2 in another embodiment of the sealed structure of the present invention. It is a partial cross-sectional view which shows typically the use state of one Embodiment of the sealed structure of this invention. FIG. 5 is a cross-sectional view schematically showing a cross section corresponding to FIG. 2 in another embodiment of the conventional sealed structure.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the present invention is not limited to the following embodiments, and it is understood that design changes, improvements, etc. may be appropriately made based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention. It should be.

(1) Sealed structure:
One embodiment of the sealed structure of the present invention is the sealed structure 100 shown in FIG. The sealing structure 100 is arranged on a seal lip 11 having an annular lip portion 10 in contact with the outer peripheral surface of the shaft member and the lip portion 10 of the seal lip 11, and is an annular shape that applies a force toward the shaft member to the lip portion 10. A pressure member 13 is provided, and the pressure member 13 is made of a rubber elastic material and is fixed to a lip portion 10 (seal lip 11) by cross-linking adhesion. The rubber elastic material is an elastic material (material having elasticity) made of a rubber material.

In this sealing structure 100, by cross-linking and adhering the pressure member 13 which is a rubber elastic material to the lip portion 10, the step of using an adhesive can be omitted, and the number of steps at the time of manufacturing can be reduced. Therefore, the labor for manufacturing is reduced, and it can be manufactured at low cost. The sealed structure 100 has a low degree of difficulty in manufacturing the pressure member 13 and is easy to mold, and further, the eccentric followability and the difficulty of coming off of the pressure member are improved.

Here, the sealing structure 100 includes an annular outer peripheral mounting portion 15 arranged on the outer peripheral portion, a seal lip 11 which is the outer peripheral mounting portion 15 and is arranged on the inner peripheral portion, and the seal lip 11 and the outer peripheral mounting portion. It has an annular (also referred to as "cylindrical") film portion 17 arranged between the fifteen. It is preferable that such a sealing structure 100 is mounted so that its central axis coincides with the insertion member (shaft member) 21 (see FIG. 4), but in reality, the sealing structure 100 The central axis may be arranged in an eccentric state with respect to the central axis of the insertion member 21. Therefore, the film portion 17 is provided in order to exhibit the sealing property even in this eccentric state. That is, even if the sealing structure 100 is arranged with some distortion, the film portion 17 is deformed to absorb the distortion of the sealing structure 100 as a whole, and the sealing property of the sealing structure 100 is ensured. Having such a property is called having "eccentric followability". An annular reinforcing ring 23 made of a rigid material such as metal may be embedded in the outer peripheral mounting portion 15.

In this way, the sealing structure is designed to have eccentricity followability, but if the degree of eccentricity is large or if the eccentric state continues for a long time due to long-term use, the pressurizing member will press the lip portion. There is also concern that it will deviate from. That is, since the pressure member is a part of the sealed structure, it is required to have eccentric followability and to be firmly fixed to the lip portion. As described above, the pressure member is required to have both properties of exhibiting a strong fixed state and being able to be flexibly deformed according to the degree of eccentricity. In this respect, in the sealing structure of the present invention, since the pressurizing member 13 is fixed to the lip portion 10 (seal lip 11) by cross-linking adhesion, the pressurizing member 13 has both the eccentric followability and the difficulty of coming off. It has properties.

The sealing structure 100 has a plate shape as a whole, and a through hole 25 into which the insertion member 21 can be inserted is formed in the central portion thereof. The outer peripheral shape of the sealing structure 100 is not particularly limited, but may be, for example, a circular shape as shown in FIG.

(1-1) Seal lip:
The seal lip 11 has an annular lip portion 10 in contact with the outer peripheral surface of the shaft member (insertion member) 21. The seal lip 11 maintains a tightening allowance (tension force) with the insertion member 21 and the like. In FIG. 4, the tension force of the seal lip 11 is indicated by a white arrow. As shown in FIG. 4, the sealing structure 100 is arranged between a housing 31 such as a cylinder head cover and an insertion member 21 such as a plug tube or an injection pipe, and by applying surface pressure to both the housing 31 and the insertion member 21. The seal between them is ensured.

As the material of the seal lip 11, a conventionally known material can be appropriately selected and adopted, and can be made of resin, rubber, etc., for example, acrylic rubber, acrylonitrile-butadiene rubber (NBR), fluorine. Rubber and the like can be mentioned.

(1-2) Pressurizing member:
The pressurizing member 13 is an annular member that is arranged on the lip portion 10 of the seal lip 11 and applies a force toward the shaft member 21 to the lip portion 10. By making the pressure member 13 annular in this way, a tightening allowance (that is, a tense force) to the insertion member (counterpart member) 21 by the seal lip 11 is exhibited, and the sealed state can be maintained.

Further, the pressure member 13 is made of a rubber elastic material (that is, an elastic material made of a rubber material), and when the pressure member 13 is made of the rubber elastic material in this way, it is not made of metal like a conventional spring. The moldability is improved, and even a particularly complicated shape can be easily manufactured, and the difficulty of manufacturing the same is lowered. Then, since the difficulty level of manufacturing becomes low, the manufacturing cost can be kept low. Further, if the pressure member 13 is made of the same material as the material of the lip portion 10, the cross-linking adhesion with the lip portion 10 becomes stronger. From the viewpoint of manufacturing, it is easier to make materials of the same type.

By forming the pressure member 13 from a rubber elastic material, the degree of freedom in the shape of the pressure member 13 can be improved. That is, it is difficult for the conventional metal spring to adjust the surface pressure even when there is a request such as when it is desired to apply a surface pressure to a desired portion or when it is desired to reduce the surface pressure at a desired portion. However, since the shape of the pressure member can be freely designed by forming the pressure member from a rubber elastic material, the surface pressure at a desired portion can be appropriately adjusted.

Since the pressure member 13 is fixed to the lip portion 10 by cross-linking adhesion, it can be satisfactorily fixed even if the material is different from the material of the lip portion 10. According to the cross-linking adhesion, the adhesive strength (fixing strength) is increased, and further, the eccentricity followability and the difficulty of coming off from the lip portion 10 are improved.

As described above, the material of the pressurizing member 13 is not particularly limited as long as it is made of a rubber elastic material, but a material of the same type having a compressive permanent strain smaller than that of the seal lip 11 can be used, for example, acrylic rubber. Acrylonitrile-butadiene rubber (NBR), fluororubber and the like can be mentioned.

Further, the pressure member 13 is fixed to the lip portion 10 by cross-linking as described above. When it is fixed to the lip portion 10 by cross-linking adhesion in this way, the fixing strength thereof is increased, and further, the eccentric followability and the difficulty of coming off from the lip portion 10 are greatly improved.

More specifically, as described above, the pressure member 13 is required to have eccentric followability like the sealing structure 100 itself, and further, the fixed state with the lip portion 10 is strong. Is required. As described above, the pressure member 13 is required to have both properties of exhibiting a strong fixed state and being flexibly deformable according to the degree of eccentricity of the sealed structure 100. In the present invention, in order to satisfy both of these properties, attention is paid to fixing the pressure member 13 to the lip portion 10 by cross-linking adhesion. In addition, when fixing a metal spring or the like using an adhesive as in the conventional case, if the spring or the like is fixed more firmly, the boundary portion (that is, the adhesive portion) between the spring or the like and the lip portion is formed. It becomes stiff and tends to be inadequate for flexible deformation such as springs. On the other hand, when trying to secure flexible deformation of the spring or the like, the fixing strength of the spring or the like to the lip portion tends to be insufficient.

It is preferable that a part of the surface 41 of the pressure member 13 is exposed as shown in the sealing structure 101 shown in FIG. That is, the pressure member 13 has an adhesive region in which a part of the surface 41 on the inner surface side thereof is fixed to the lip portion 10 by cross-linking adhesion, while the pressure member 13 is exposed to the outside without contacting the lip portion 10. It can have an exposed area. In other words, the pressure member 13 is not entirely embedded in the lip portion 10, but a part of the surface 41 is crosslinked and fixed to the lip portion 10, and the other parts are exposed. Can be In this way, the mobility of the pressure member 13 is improved, and the sealing structure 101 can be deformed more flexibly according to the degree of eccentricity.

As described above, the pressurizing member 13 may be fixed to the lip portion 10 in a partially exposed state, but in that case, the pressurizing member 13 is stronger in order to prevent the pressurizing member 13 from coming off. It is important to exert a stable fixed state. On the other hand, it is necessary to exert stronger fixing strength, but flexibility is also important. When a part of the pressure member 13 is exposed in this way, it is more effective to fix it by cross-linking adhesion.

The ratio of the area of the exposed portion in the pressure member can be 45% or less of the total area of the pressure member, and may be about 5 to 45% of the total area. By setting such a range, the mobility of the pressure member 13 is further improved, the pressure member 13 can be deformed very flexibly according to the degree of eccentricity of the sealing structure 100, and the pressure member 13 is hard to come off from the lip portion 10. It also becomes. For the "ratio of the area of the exposed portion", the entire length of the outer peripheral edge of the pressure member was set to 100% in the cross section (see FIG. 3) obtained by cutting the annular pressure member in a plane including the central axis thereof. At this time, the ratio of "the length of the outer peripheral edge of the portion where the pressurizing member is not in contact with the lip portion" shall be referred to.

The pressure member 13 can have a compression set smaller than the compression set of the lip portion 10. In this way, it is possible to secure the same sealing characteristics as the conventional metal spring. That is, even if the seal lip 11 is exposed to a high temperature for a long period of time, the tightening allowance (that is, the tense force) to the insertion member 21 (the mating member) by the seal lip 11 can be maintained, and the sealing property is maintained.

The pressure member 13 can be appropriately set with respect to its compression set.

The shape of the pressurizing member 13 is not particularly limited as long as it is annular, and for example, an O-ring (an annular member having a circular or elliptical cross section) or a square ring (a polygonal cross section (chamfered corners)). It can be an annular member) or the like.

Further, if the pressure member 13 is an O-ring or a square ring, the lip angle of the lip portion can be appropriately changed, and the sealing characteristics of the sealing structure 100 can be changed as desired.

The size and thickness of the pressurizing member 13 are not particularly limited and may be a conventionally known size and thickness.

(2) Manufacturing method of sealed structure:
The sealed structure of the present invention can be manufactured as follows. The manufacturing method will be described below.

First, a molding mold having a sealed structure is prepared. As the molding die, a conventionally known molding die can be appropriately adopted. Then, after that, an annular pressure member is arranged in the molding mold. The pressurizing member is the same as the pressurizing member already described above, and is made of a rubber elastic material. Therefore, the shape can be made into a desired shape, the difficulty of manufacturing is low, and the moldability is high. Then, the molding material of the seal lip is injected into the molding mold in which the annular pressure member is arranged, and then the molding material in the molding mold is pressurized and heated. In this way, the pressure member described above can be crosslinked and adhered to the lip portion of the seal lip to produce a sealed structure (sealed structure of the present invention).

When manufactured in this way, the labor of manufacturing is reduced, the difficulty of manufacturing the pressure member is low, the pressure member is easy to mold, and the eccentric followability and the detachment difficulty of the pressure member are improved. The structure can be obtained.

(3) How to use the sealed structure:
The sealing structure of the present invention is a sealing such as a plug tube seal (PTS) or an injection pipe seal (IPS) that seals a gap between an insertion member such as a plug tube or an injection pipe and a housing such as a cylinder head cover. Can be used as a structure.

Specifically, it can be attached and used as follows. First, the annular sealing structure 100 is inserted into the insertion member (shaft member) 21. At this time, a jig for expanding the lip portion 10 of the sealing structure 100 is attached to the tip of the inserting member 21, and the diameter of the lip portion 10 of the sealing structure 100 can be expanded by this jig. Then, the sealing structure 100 is arranged on the outer peripheral surface of the inserting member 21, and the sealing structure 100 is moved along the inserting member 21 and arranged at a desired position (a position between the housing 31 and the inserting member 21). .. At this time, the seal lip 11 and the pressure member 13 apply a tense force to the insertion member 21, and a surface pressure is applied from the outer peripheral mounting portion 15 to the housing 31. In this way, in the sealing structure 100, the outer peripheral mounting portion 15 is in close contact with the housing 31, and the seal lip 11 is in close contact with the insertion member 21, so that the gap between the insertion member 21 and the housing 31 is formed. Can be sealed.

Here, as described above, when the sealing structure 100 is arranged at a desired position, the sealing structure 100 may be arranged in a state in which the central axis thereof is eccentric with respect to the central axis of the insertion member 21. However, the film portion 17 absorbs the strain and ensures good sealing performance. Since the sealing structure 100 includes the pressure member 13 described above, the pressure member 13 is satisfactorily deformed (exhibits eccentric followability) with respect to the strain of the seal structure 100, and the pressure member 13 further deforms. , It will be difficult to drop out.

Hereinafter, the present invention will be specifically described based on examples, but the present invention is not limited to these examples.

(Example 1)
A sealed structure as shown in FIGS. 1 and 2 was produced. The pressure member in this sealed structure was made of a rubber elastic material and was fixed to the lip portion by cross-linking adhesion.

Since this sealing structure is formed by cross-linking and adhering a pressure member made of a rubber elastic material to the lip portion, the labor of manufacturing is reduced, the difficulty of manufacturing is low, and the moldability is good. Met. Further, the pressure member made of the rubber elastic material has improved eccentric followability and resistance to detachment.

(Comparative Example 1)
As the pressure member in the sealed structure, a metal one was adopted, and this metal pressure member (metal spring) was fixed to the lip portion with an adhesive.

Since the sealed structure of Comparative Example 1 was fixed using an adhesive, it took a lot of time and effort to manufacture it. Moreover, the moldability was not sufficient.

(Comparative Example 2)
As the pressure member in the sealed structure, a member made of a rubber elastic material was adopted, and the pressure member made of the rubber elastic material was fixed to the lip portion with an adhesive.

In the sealing structure of Comparative Example 2, a pressure member made of a rubber elastic material was fixed to the lip portion by using an adhesive, so that it took time and effort to manufacture, and it was firmly fixed (difficult to come off) and flexible. There was still room for improvement in that it exhibited both properties of deformation (good eccentricity).

From the results of Examples 1 and Comparative Examples 1 and 2, it can be seen that the sealed structure of Example 1 has improved eccentricity followability and difficulty in coming off as compared with the sealed structures of Comparative Examples 1 and 2. Further, the pressure member having the sealed structure of Example 1 was made of a rubber elastic material, and was easy to manufacture and easy to mold.

The sealing structure of the present invention can be adopted as a sealing structure used as a plug tube seal or the like in an automobile or the like.

10: Lip part, 11: Seal lip, 13: Pressurizing member, 15: Outer peripheral mounting part, 17: Membrane part, 21: Inserting member (shaft member), 23: Reinforcing ring, 25: Through hole, 31: Housing, 41: Surface of pressure member, 100, 101, 200: Sealed structure, 113: Spring.

Claims (3)

A seal lip having an annular lip portion in contact with the outer peripheral surface of the shaft member,
An annular pressure member, which is arranged on the lip portion of the seal lip and applies a force toward the shaft member to the lip portion, is provided.
The pressure member has a sealed structure made of a rubber elastic material and fixed to the lip portion by cross-linking adhesion. The sealing structure according to claim 1, wherein the pressure member has a smaller compression set than the compression set of the lip portion. A method for manufacturing a sealed structure according to claim 1 or 2, wherein the sealed structure is manufactured.
A molding mold having the sealed structure is prepared, the pressure member is placed in the molding mold, and then the molding material of the seal lip is injected into the molding mold, and then the molding material in the molding mold is injected. A method for producing a sealed structure, wherein the pressure member is crosslinked and adhered to the lip portion to produce the sealed structure.

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