JP2003090438A - Sealing device and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reliable sealing device improving sealing performance by preventing generation of a foreign matter due to deterioration, pealing off or the like of molding burr. SOLUTION: A fitting part provided on one end of a contact part 11c of a reinforcing ring 11 is fitted to a lower die 51. Non-abutting area provided on another end of the contact part 11c and not contacting an end surface 4a of an abutting member 4 is loaded on only an annular projecting line part 51b provided in the lower die 51 under a condition that there is an opening S between the contact part 11c and the lower die 51 and the die is closed. Molding is performed with pressing the reinforcing ring 11 to the annular projecting line part 51b of the reinforcing ring 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sealing device manufactured by molding a rubber-like elastic member, and more particularly to a manufacturing method and a product thereof in which molding burrs do not occur on the surface of a reinforcing ring.

[0002]

2. Description of the Related Art Conventionally, as a sealing device for sealing between a housing member and a shaft inserted into the housing member,
There is a sealing device 101 as shown in FIG.

The sealing device 101 is applied to, for example, a power steering device, in which the housing 102 and the shaft 103 are relatively moved in the axial direction by the action of hydraulic oil such as high-pressure oil. On the sliding surface,
The lip portion 110 of the sealing device hits to prevent leakage of hydraulic oil.

The sealing device 101 comprises a reinforcing ring 1 having an L-shaped cross section.
A lip portion 110 is provided on the inner peripheral side of 11, and a fitting portion 112 is provided on the outer peripheral side thereof to maintain the hermeticity when fitted to the housing member 102. The lip portion 110 and the fitting portion 112 are formed by vulcanization molding.
At the time of molding, the rubber-like elastic member, which is a material inside the mold, is heated and fluidized, and gets over the axial portion 111a of the reinforcing ring 111 to be integrated.

Reference numeral 120 is a spring for maintaining the tightening force of the lip tip portion 110a of the lip portion 110.
In addition, 130 is a support ring that prevents the lip portion 110 from turning over and returning when sliding.

Such a sealing device 101 is fitted on the inner peripheral surface of the housing member 102, but the radial portion 111b of the reinforcing ring 111 is abutted against the end surface 104a of the abutting member 104 so as not to move due to the pressure of hydraulic oil. Is pressed against.

[0007]

However, in the sealing device 101 of this type, the rubber-like elastic member that wraps around the outside of the reinforcing ring 111 during molding flows to the radial portion 111b of the reinforcing ring 111. However, there is a problem that the radial direction portion 111b is covered as a thin film-shaped molding burr.

This problem is a general problem that occurs during rubber molding, and since there is no effective solution in the past, conversely, in anticipation of the anticorrosive effect of the reinforcing ring 111, the reinforcing ring 111 is expected.
It was necessary to take measures such as covering the entire circumference or manually removing a thin molding burr after molding.

However, as shown in FIG. 5 (b),
If this thin molding burr 113 is incorporated into the product with it left, the molding burr 113 is sandwiched between the reinforcing ring 111 and the end surface 104 a of the abutting member 104 and compressed.

In a use environment in which a constant compressed state is maintained, the molding burr 113 can be used so as to function as a joining member or a seal, and in some cases, there is no problem, but the sealing device 101 is arranged in the axial direction. In a use environment in which the molding burr 113 moves or vibrates, that is, when the pressure fluctuation of the hydraulic oil is large due to repeated high pressure during operation of the actual machine, a fluctuating load is applied to the molding burr 113 sandwiched and the molding burr 113 deteriorates. It will be damaged such as peeling or peeling.

The damaged molding burr 113 is formed by the reinforcing ring 1.
11 and the end surface 104a of the abutting member 104, when foreign matter is mixed into the sealing area, it mixes with the working oil to block the hydraulic path, or it is caught in the lip portion 110 of the sealing device 101 to deteriorate the sealing performance. It is thought that the problem of occurs.

As measures against this, for example, Japanese Patent Laid-Open No. 10-11
There is one disclosed in Japanese Patent No. 5373.

This is because when the reinforcing ring 111 is fitted into the molding die, as shown in FIG. 6, the annular protrusion 131 and the positioning portion 132 of the molding die (the lower die 151 and the middle die 153) have radial portions. 111b is supported, and the radial direction portion 111b is pressed against the annular ridge portion 131 and the positioning portion 132 of the molding die by the pressure of the rubber-like elastic member softened by heat to perform molding.

However, even in such a case, it has been feared that thread-like rubber around the annular protrusion 131 may occur.

The present invention has been made in order to solve the above-mentioned problems of the prior art. The object of the present invention is to prevent the generation of foreign matter due to deterioration or peeling of molding burrs and improve the sealing property. Another object of the present invention is to provide a highly reliable sealing device and a manufacturing method of the sealing device.

[0016]

In order to achieve the above object, the present invention provides a sealing device for sealing an annular gap between two members which are concentrically and relatively movably assembled with each other. A method for manufacturing a sealing device, comprising: a reinforcing ring having an abutting portion that abuts against one of the two members and integrally formed with an annular seal body attached to the one member; The fitting portion provided on one end side of the contact portion is swingably fitted to the molding die, and is provided on the other end side of the contact portion with the corresponding contact portion having a gap with the molding die. The non-contact region that does not contact the one member is placed only on the protrusion provided on the mold to perform mold closing,
It is characterized in that the reinforcing ring is molded while being pressed against the protruding portion side of the molding die.

As a result, since the non-contact area of the reinforcing ring is pressed against only the ridges of the mold during molding, contact pressure can be generated, and the contact pressure causes the rubber-like elastic member to flow during molding. Can be obtained. Therefore, the rubber-like elastic member that flows at the time of molding is molded without protruding to the abutting portion side with the portion where the annular protruding portion abuts as the boundary portion.

A sealing device for sealing an annular gap between two members which are concentrically and relatively movable to each other, and which has a contact portion for contacting one of the two members, and In a sealing device provided with a reinforcing ring integrally formed with an annular seal body attached to the member, the reinforcing ring is provided on one end side of the abutting portion and can swing on a forming die during molding. And a non-contact region that is provided on the other end side of the corresponding contact part and does not contact the one member, wherein the fitting part is fitted to the molding die. With the contact portion having a gap with the mold, the non-contact region is placed only on the protrusion provided on the mold to close the mold, and the reinforcing ring is projected onto the mold. It is characterized in that it is molded while being pressed against the striation side.

As a result, since the rubber-like elastic member does not exist at the abutting portion of the sealing device, the generation of foreign matter due to deterioration or peeling of the molding burr is eliminated, and the sealing property and the reliability are improved. Is possible.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be illustratively described in detail below with reference to the drawings. However, the dimensions of the components described in this embodiment,
The material, the shape, and the relative arrangement of them should be appropriately changed depending on the configuration of the device to which the invention is applied and various conditions, and the scope of the invention is not limited to the following embodiments.

The sealing device 1 according to the embodiment of the present invention is
It is used in a shaft seal portion of various devices under relatively high pressure, and is applied to, for example, a power steering device.

FIG. 1 is a cross-sectional explanatory view showing a state in which the sealing device 1 according to the embodiment of the present invention is incorporated in the inner peripheral portion of the housing member 2. The sealing device 1 seals between a housing member 2 which is one of the two members and a shaft 3 which is inserted into the housing member 2.

The housing member 2 and the shaft 3 move relatively in the axial direction by the action of hydraulic oil such as high-pressure oil.
The lip portion 10 of the sealing device 1 abuts on the sliding surface of the shaft 3 to prevent the hydraulic oil from leaking.

The sealing device 1 comprises a reinforcing ring 11 having an L-shaped cross section.
And a seal body integrally formed with the reinforcing ring 11. The seal body is provided with a lip portion 10 provided on the inner peripheral side of the reinforcing ring 11, a fitting portion 12 provided on the outer peripheral side for maintaining a sealing property when fitted to the housing member 2.
Is equipped with.

The lip portion 10 and the fitting portion 12 are
For example, it is formed by vulcanization molding, and the rubber-like elastic member which is a material inside the mold at the time of molding is heated and fluidized, and it crosses the axial direction portion 11a of the reinforcing ring 11 to be integrated.

Reference numeral 20 denotes a lip tip portion 10 of the lip portion 10.
It is a spring for maintaining the tension force of a. Also,
Reference numeral 30 denotes a support ring that prevents the lip portion 10 from turning over and returning when sliding.

The sealing device 1 is fitted to the inner peripheral surface of the housing member 2, but the abutting portion 1 of the radial portion 11b of the reinforcing ring 11 is prevented from moving axially by the pressure of the hydraulic oil.
1c is brought into pressure contact with the end surface 4a of the butting member 4 provided on the housing member 2 as one member.

In the radial portion 11b of the reinforcing ring 11, an abutting portion 11c that abuts the end surface 4a of the abutting member 4 is provided on the surface opposite to the lip portion 10. Further, the connecting portion 11d between the axial portion 11a and the radial portion 11b is provided so as to be inclined from the contact portion 11c, and constitutes a non-contact area that does not contact the end surface 4a of the butting member 4. In the present embodiment, it has a rounded shape.

The boundary portion 12a of the fitting portion 12 is
It is located at this connecting portion 11d and is not in contact with the end surface 4a of the abutting member 4.

Further, at the inner diameter side end which is one end side of the radial direction portion 11b of the reinforcing ring 11, an inner diameter end portion as a fitting portion which swingably fits in the molding die at the time of molding. 11e is provided.

Therefore, the sealing device 1 can be positioned in the axial direction by the contact portion 11c in which the rubber-like elastic member does not exist, and the sealing device 1 moves in the axial direction and vibrates. Even in the environment in which it is used, the contact portion 11c does not have a thin molding burr like the conventional one.
It is possible to prevent problems due to the generation of foreign matter and deterioration of the sealing property, and improve the reliability of the sealing device 1.

Next, a method of manufacturing the sealing device 1 will be described.

FIG. 2 is a view for explaining the method of manufacturing the sealing device 1 according to the embodiment of the present invention, in which the sealing device 1 is molded in the mold 50 with the mold closed.
FIG. 3 is a diagram for explaining a state in which the pressure (arrow A2) of the rubber-like elastic member R is generated during molding in FIG.

The feature of the manufacturing method according to the present invention resides mainly in the molding die 50 used when molding the sealing device 1, and the state in which the reinforcing ring 11 of the sealing device 1 is placed on the molding die 50 before molding ( There is a contact relationship between the reinforcing ring 11 and the molding die 50).

The basic structure of the molding die 50 is the same as the conventional one, and is composed of a lower die 51, an upper die 52 and a middle die 53.

The lower die 51 is a fitting portion 12 of the sealing device 1.
And an annular axial wall 51a forming a base, and a base portion 51c continuous from the rising portion of the axial wall 51a in the inner diameter direction,
An annular protrusion 51b provided on the base portion 51c and supporting the connecting portion 11d of the reinforcing ring 11, and a radial portion 1 of the reinforcing ring 11.
A cylindrical positioning stud 51d to which the inner diameter end portion 11e of 1b is fitted is provided.

In the base portion 51c of the lower die 51, there is a concave portion between the annular projection 51b and the positioning stud 51d, and when the reinforcing ring 11 is fitted into the lower die 51, the lower die 51 is formed. Abutment portion 1 between the base portion 51c and the reinforcing ring 11
1c forms a gap S, and due to the pressure during molding,
As the inner diameter end 11e extends along the outer circumference of the positioning stud 51d, the radial portion 11b is bent.

Here, the size of this concave portion is the same as that of the reinforcing ring 11.
It is preferable to limit the elastic deformation area in which the radial direction portion 11b returns to the original shape even when the radial direction portion 11b is bent by the pressure during molding. Further, when the radial portion 11b of the reinforcing ring 11 is bent by the pressure at the time of molding, the material of the reinforcing ring 11 and the radial portion of the reinforcing ring 11 are arranged so that the fitting gap between the inner diameter end 11e and the positioning stud 51d is substantially eliminated. 11b thickness, inner diameter end 11e
It is advisable to set the fitting between the positioning stud 51d and the positioning stud 51d.

The upper mold 52 is provided with a protrusion 52a forming a shape on the side of the lip 10 where the spring 20 is fitted in the mold closed state. The lower die 5 is on the outer diameter side.
The first axial wall 51a is in contact with the upper end surface 51e, and the inner diameter side is in contact with the outer peripheral upper end portion 53a of the middle die 53. still,
In order to easily open the mold, the upper mold 52 is appropriately divided into a plurality of pieces radially.

The middle die 53 is a lip tip portion 1 of the sealing device 1.
0a and the groove 10 into which the support ring 30 is fitted
Form the shape of b. Further, the middle die 53 is removably positioned at the center of the lower die 51 by fitting with an anchor.

Therefore, when the mold is closed, the axial wall 51a of the lower mold 51, the lower surface of the upper mold 52 and the outer periphery of the middle mold 53 form the lip portion 10 as the seal body of the sealing device 1 and the fitting portion 12. The annular cavity C is formed.

The molding process of the sealing device 1 is as follows.

First, the mold is opened and the abutting portion 11 of the reinforcing ring 11 is opened.
With c facing downward, the inner diameter end 11e of the radial portion 11b is
The lower mold 51 is fitted into the cylindrical positioning stud 51d.

Then, the connecting portion 11d of the reinforcing ring 11 is supported by the annular protruding portion 51b of the lower die 51. In this state, the base portion 51c of the lower mold 51 and the contact portion 1 of the reinforcing ring 11
There is a gap S between 1c and the reinforcing ring 11, and
0, the connecting portion 11d is supported by abutting against the annular protrusion 51b, and the inner diameter end 11e is positioned by the positioning stud 51d.
Is fitted to.

Next, the middle die 53 is fitted into the lower die 51, and the upper side formed by the lower die 51 and the middle die 53 is fluidized and expanded at the time of molding into an annular cavity C having an open upper side, and the cavity C is filled. A rubber-like elastic member R, which is a material forming the seal body of the sealing device 1, is placed at a predetermined position (position indicated by a chain double-dashed line in the figure).

Then, the upper mold 52 is closed in the direction of arrow A1, and molding is performed with pressurization and heating. In this case, while heating the entire molding die 50, the upper die 52 is closed at a predetermined speed to fluidize and mold the rubber material.

At the time of molding, the rubber-like elastic member R is softened by heat and generated by the pressure of the upper mold 52 which is closed.
The pressure (arrow A2) causes the reinforcing ring 11 to be pressed only against the annular protrusion 51b of the lower mold 51.

At this time, the inner diameter end 11e of the radial portion 11b of the reinforcing ring 11 fitted to the positioning stud 51d.
On the side, since the gap S is provided with respect to the base portion 51c of the lower mold 51, the pressure of the rubber-like elastic member R (arrow A
By 2), it bends in the elastic deformation region (dotted line shown in FIG. 3).

That is, the radial direction portion 11b of the reinforcing ring 11 which receives the pressure (arrow A2) of the rubber-like elastic member R is attached to the lower die 5
A high contact pressure (surface pressure) can be generated by supporting only one annular protrusion 51b.

At this time, the molding pressure is 200 to 40
Since a pressure of about 0 kgf / cm ² (1960 to 3920 N / cm ² ) is applied, the connecting portion 11 d of the reinforcing ring 11 abuts the annular protruding portion 51 b so as to be gazed and is in a sealed state with a high contact pressure. Has become.

Therefore, when the rubber-like elastic member R flows outward to form the fitting portion 12, the boundary portion 12a enters further than the contact portion between the connecting portion 11d and the annular protruding portion 51b. It is possible to eliminate the formation of molding burrs on the contact portion 11c. As a result, deburring work can be eliminated, and moldability can be improved.

Here, the radial portion 11b of the reinforcing ring 11 elastically deforms with respect to the magnitude of the molding pressure and bends due to the pressure during molding, whereby the inner diameter end 11e and the positioning stud 51 are formed.
Since the clearance for fitting with d is set to be substantially eliminated, the rubber-like elastic member R does not sneak into the contact portion 11c from the inner diameter end 11e side during molding.

After the flow and cross-linking and hardening of the rubber-like elastic member R are completed, the upper mold 52 is divided and the mold is opened, the middle mold 53 is extracted, and the molded sealing device 1 is taken out.

Further, when the axial portion 11a of the reinforcing ring 11 is used as the annular contact portion, the method of forming the rubber-like elastic member R by wrapping around the radial portion 11b is adopted. Can be applied.

Here, the annular projection 51b provided on the lower die 51 is replaced by a wedge-shaped annular projection 60 as shown in FIG.
By this, the area in contact with the reinforcing ring 11 can be reduced, and thus a higher contact pressure can be generated. Therefore, it is possible to more reliably suppress the formation of molding burrs on the contact portion 11c and improve the moldability.

As described above, since the moldability can be improved by the manufacturing method of this embodiment, since the rubber-like elastic member does not exist in the contact portion 11c of the sealing device 1, deterioration or peeling of the molding burr is caused. The generation of foreign matter due to such factors is eliminated, and it is possible to improve the sealing property and the reliability.

In this embodiment, the lower mold 51
Although the connecting portion 11d of the reinforcing ring 11 is supported by the annular protruding portion 51b, the reinforcing ring 1 that is supported by the annular protruding portion 51b.
The region 1 may be a region that does not contact the end surface 4a of the abutting member 4 when the sealing device 1 is fitted to the housing member 2, and is a partial region of the radial portion 11b of the reinforcing ring 11. It may be.

[0058]

As described above, according to the present invention,
Molding burrs generated on the surface of the reinforcing ring can be eliminated during molding, and moldability can be improved. Further, when the completed sealing device is used, foreign matters are not generated due to deterioration or peeling of the molding burr, so that it is possible to improve the sealing property and the reliability.

[Brief description of drawings]

FIG. 1 is a sectional explanatory view of a sealing device according to an embodiment of the present invention.

FIG. 2 is a diagram for explaining a method of manufacturing the sealing device according to the embodiment of the present invention.

FIG. 3 is a diagram for explaining a method of manufacturing the sealing device according to the embodiment of the present invention.

FIG. 4 is a diagram for explaining a method of manufacturing the sealing device according to the embodiment of the present invention.

FIG. 5 is an explanatory cross-sectional view of a sealing device according to a conventional technique.

FIG. 6 is a diagram illustrating a method for manufacturing a sealing device according to a conventional technique.

[Explanation of symbols]

1 Sealing device 2 Housing member 3 axes 4 Abutting member 4a end face 10 Lip part 10a Lip tip 10b groove 11 Reinforcement ring 11a Axial part 11b radial part 11c contact part 11d connection part 11e Inner diameter end 12 Fitting part 12a boundary 20 springs 30 Support ring 50 Mold 51 Lower mold 51a Axial wall 51b Annular protrusion 51c base 51d Positioning stud 51e Upper end surface 52 Upper mold 53 Medium 53a Outer peripheral upper end C cavity R Rubber-like elastic member

Claims (2)

[Claims] 1. A sealing device for sealing an annular gap between two members that are concentrically and relatively movable to each other, and has a contact portion that contacts one of the two members. In a method for manufacturing a sealing device including a reinforcing ring integrally formed with an annular seal body attached to the one member, a fitting portion provided on one end side of the abutting portion of the reinforcing ring is formed in a molding die. A non-contact region provided on the other end side of the corresponding contact part and not in contact with the one member in a state where the contact part has a gap with the mold and is fitted so as to be swingable. A method for manufacturing a sealing device, comprising: mounting only on a ridge provided on the mold, closing the mold, and molding the reinforcing ring while pressing the reinforcing ring against the ridge of the molding die. 2. A sealing device for sealing an annular gap between two members that are concentrically and relatively movable to each other, and has a contact portion that contacts one of the two members. In a sealing device provided with a reinforcing ring integrally molded with an annular seal body attached to the one member, the reinforcing ring is provided on one end side of the abutting portion and is shaken by a molding die during molding. A fitting portion that movably fits and a non-contact area that is provided on the other end side of the corresponding contact portion and does not contact the one member, and the fitting portion is fitted to the molding die. With the contact portion having a gap with the mold, the non-contact region is placed only on the protrusion provided on the mold, the mold is closed, and the reinforcing ring is formed into the mold. The sealing device is formed while being pressed against the ridge portion side of the.