JP3247565B2 - Sealing device and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a first rubber-like elastic material.
A first sealing member having a sealing lip;
The present invention relates to a sealing device having a composite structure in which a second sealing member having a sealing lip is assembled, and a method of manufacturing the same.

[0002]

2. Description of the Related Art As a conventional sealing device having a composite structure of this kind, there is, for example, one shown in FIGS. 5 to 7 (FIG. 5; Japanese Utility Model Publication No. 3-32843; FIG. 6;
No. 46371, FIG. 7; see Japanese Utility Model Application Laid-Open No. 63-22467).

The example shown in FIG. 5 includes a first seal member 102 made of a rubber-like elastic material, and a second seal member 104 made of a resin disposed adjacent to the first seal member 102 on the atmospheric side. ing. The first and second seal members 102 and 104 are provided with first and second seal lips 100 and 106, respectively. Further, a reinforcing ring 110 is integrally embedded in the first seal member 102, and a second seal member 104 is sandwiched between the flange portion 108 of the reinforcing ring 110 and the first seal member 102.

A plurality of holes 112 into which a part 114 of the joint portion of the second seal member 104 bites are provided in the flange portion 108 of the reinforcing ring 110 in the circumferential direction to increase the joint strength of the second seal member 104. .

In this conventional example, when the first seal member 102 is molded, the reinforcing ring 110 and the second seal member 104 are formed.
And a resin material for molding are inserted into the molds 116 and 118 and integrally molded. A part 114 of the second seal member 104 is cut into the hole 112 of the flange portion 108 of the reinforcing ring 110 by molding pressure. I was

[0006] In the embodiment shown in FIG. 6, similarly to the example shown in FIG. 5, the second seal member 204 is sandwiched between the flange portion 208 of the reinforcing ring 210 and the first seal member 202 and provided on the flange 208. A part 214 of the second seal member 204 is cut into the hole 212, and a thread groove 220 is provided on the sliding surface of the second seal lip 206 made of resin.

In FIG. 7, a second sealing member 304 made of resin and a backup ring 310 made of metal are sequentially assembled on the atmosphere side of a first sealing member 302 made of a rubber-like elastic body, and the second sealing member 304 is made. To the first seal member 3
02 and the backup ring 310, a detent part 330 is provided to prevent the second seal member 304 from rotating by engaging the concave and convex parts with the contact part between the second seal member 304 and the backup ring 310. It is a thing.

[0008]

However, in the case of the prior art described above, in the example shown in FIGS. 5 and 6, the second sealing member made of resin such as PTFE is provided in the holes 112 and 212 of the reinforcing rings 110 and 210. Part of 104, 204 114, 21
4 is sufficient as a fixing force in the rotation direction of the shaft, but when the second seal lip 106, 206 is bent or formed, or when the shaft is inserted from the atmosphere side, the second seal lip 106 is pressed. , 206 and the second sealing members 104, 20 from the reinforcing rings 110, 210 in the axial direction.
4 is applied, and the entire waist portion is easily lifted toward the sealed fluid side, that is, easily moved in a direction in which the second seal members 104 and 204 come out of the holes 112 and 212. For this reason, the contact positions of the second seal lips 106 and 206 with the shaft fluctuate, and the sealing performance is not stable.
Also, since the second seal members 104, 204 are displaced, the first and second seal members 102, 104, 202, 2
In this case, the adhesion between the joints 04 is reduced, and the sealing performance of the joint becomes unstable. This tendency is remarkable when the product size is large.

Also in the case of FIG. 7, a detent portion 330 is provided at the contact portion between the resin-made second seal member 304 and the backup ring 310 so as to engage and recess with each other. There is a problem that the fixing force is good in the rotation direction but not reliable in the axial direction.

On the other hand, there is a method of bonding and fixing each member by using a special bonding technique. However, a process such as a base surface treatment for bonding each member and a coating process of an adhesive is required, and the airtightness of the bonded portion is required. There is a problem that it takes time to check the properties and the cost is high.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems of the prior art, and an object of the present invention is to connect a first seal member made of a rubber-like elastic body and a second seal member made of a resin. An object of the present invention is to provide a sealing device and a manufacturing method thereof that can be reliably performed at low cost.

[0012]

In order to achieve the above object, according to the present invention, an annular first seal member having a first seal lip made of a rubber-like elastic body, and the first seal member is provided with a first seal member. a metal reinforcing ring embedded, a sealing device comprising a second sealing member annular, a having a second seal lip made of a resin which is assembled to the first seal member, said first
1 When molding the seal member, the metal reinforcing ring and the
The second seal member is inserted into a mold and integrally molded.
In the sealing device , the mold clamping pressure is
The second seal member is fixed by caulking a part of the metal reinforcing ring using a force .

Preferably, the metal reinforcing ring is provided with a plurality of tongue-shaped protrusions for fixing the second seal member in a circumferential direction.

The tongue-shaped projection is preferably formed by providing a plurality of holes in the metal reinforcing ring in the circumferential direction, and bending a cutout portion of the hole toward the second seal member.

In the method of manufacturing a sealing device according to the present invention, when the first sealing member made of rubber-like elastic material is molded, the metal reinforcing ring and the second sealing member made of resin are inserted into the mold. The second seal member is fixed by caulking a part of the metal reinforcing ring by utilizing a mold clamping pressure simultaneously with the molding.

[0016]

According to the present invention, the second seal member having the second seal lip is fixed by caulking to the reinforcing ring.
Even if external force acts in the axial direction during bending of the seal lip or when inserting the actual machine shaft, the caulking fixing portion with the reinforcing ring is securely fixed without loosening, and the sliding position of the second resin seal lip is stable. I do.

Further, since the second seal member is securely fixed, the adhesion between the first seal member and the second seal member is also ensured.

As a specific method, a plurality of tongue-shaped projections are provided on the reinforcing ring in the circumferential direction, the second seal member is placed inside the tongue-shaped projection, and the reinforcing ring is overlaid, and the tongue-shaped projection is bent inward again. Thereby, the second seal member is caulked and fixed.

Further, if the tongue-shaped projection is formed by bending a cutout portion of a hole provided in the metal reinforcing ring toward the second seal member, the structure can be made simple and inexpensive.

In addition, the first seal lip made of rubber-like elastic material also has a stable characteristic that it does not rise even if an axial load is applied to the first seal lip because the tongue-like projection forms a reinforcing portion. Can be obtained.

On the other hand, according to the manufacturing method of the present invention, the second seal member is caulked and fixed to the reinforcing ring using the mold clamping pressure. Therefore, it can be caulked and fixed at the same time as the molding, and the number of steps can be reduced.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the illustrated embodiments.

FIGS. 1 to 4 show a sealing device according to an embodiment of the present invention.

In FIG. 1, reference numeral 2 denotes an oil seal as a sealing device embodying the present invention. The oil seal 2 is composed of three members, that is, a first rubber-made elastic body made of a material. A seal member 4, a metal reinforcing ring 30 embedded in the first seal member 4, and a second seal member 20 made of resin such as PTFE (ethylene tetrafluoride resin) assembled to the first seal member 4. Have been.

The first seal member 4 is an annular member having a substantially U-shaped cross section which opens toward the fluid side O to be sealed, and has an outer cylindrical fitting portion 6 which is press-fitted and fixed to the shaft hole 3 of the housing 1, End face 8 extending inward in the radial direction from the atmosphere-side end of the shape fitting portion 6
And a first seal lip 10 extending from the inner end of the end face portion 8 toward the fluid side O to be sealed in the axial direction. A dust lip 12 that extends obliquely toward the atmosphere is also provided at the inner diameter end of the end face portion 8.

The first seal lip 10 is a main lip having a function of sealing a fluid to be sealed which has pressure and leaks along the rotating shaft 5. On the other hand, the dust lip 12 has an auxiliary function of preventing dust, dust and the like from entering the sliding surface of the first seal lip 10 from the outside of the atmosphere.

The second sealing member 20 is an annular member having a substantially inverted L-shaped cross section. The second sealing member 20 is formed by bending a washer-shaped plate portion 22 extending in the radial direction from the inner end of the plate portion 22 toward the fluid to be sealed. And a second seal lip 24 that is provided. Second seal lip 24
Is located adjacent to the atmosphere side of the first seal lip 10 and extends along the inner periphery of the first seal lip 10 to the fluid side O to be sealed in the axial direction to near the lip tip 14 of the first seal lip 10. .

The main function of the second seal lip 24 is to back up the first seal lip 10 made of a rubber-like elastic material from the atmosphere side, to enhance the double sealing effect, and to make the contact surface of the fluid to be sealed under high pressure. An object is to suppress an increase in pressure to suppress an increase in sliding resistance between the first seal lip 10 and the rotating shaft 5, reduce wear of the first seal lip 10, and improve durability.

The reinforcing ring 30 is an annular member having a substantially L-shaped cross section, and comprises a cylindrical portion 32 on the outer periphery and a flange portion 34 extending inward from the atmospheric end of the cylindrical portion 32. The reinforcing ring 30 is inserted into the cylindrical fitting portion 6 and the end face 8 of the first seal member 4 together with the second seal member 20 during vulcanization molding.

Here, the second seal member 20 is connected to the reinforcing ring 3
By caulking a part of the flange portion 34 of the
Is one of the features of the present invention.

Referring to FIG. 2, the shape of the reinforcing ring 30 before insert molding will be described.
A tongue-shaped projection 38 for caulking and fixing the second seal member 20 to the flange portion 34 of the reinforcing ring 30 is provided on the surface 36 on the side (the fluid side O to be sealed) where the second seal member 20 contacts at the time of insertion. Have been. The tongue-shaped projection 38 is formed by forming a hole 35 in a part of the flange portion 34, cutting the cutout portion of the hole 35 from the inner diameter side while the outer diameter side is connected, and bending and raising the cutout portion toward the second seal member 20. And a plurality of such components are arranged on the same circumference with respect to the axis.

On the other hand, as shown in FIG. 3, the second seal member 20 is a disk-like member having a circular hole at the center in the state of the washer-shaped resin material 21 before the second seal lip 24 is bent. You are. Then, when placed on the surface 36 on the sealed fluid side of the flange surface 34 of the reinforcing ring 30, the resin material 21
The outer periphery of the plurality of tongues 38 of the flange portion 34
It has a dimensional relationship that fits inside.

As shown in FIG. 3A, a plurality of tongue-shaped projections 38 are bent inward while the resin material 21 is superimposed on the reinforcing ring 30, so that the reinforcing ring 30 and the second seal member 20 are bent.
Can be combined by caulking. This caulking process,
In the present invention, it is performed at the time of vulcanization molding of the oil seal 2.

As shown in FIG. 3 (b), a backup portion 37 may be provided at the inner end of the flange portion 34 of the reinforcing ring 30 so as to be bent in the axial direction. The backup portion 37 has a tapered waist portion of the second seal lip 24 for functionally lowering the tension force, improving durability and wear resistance, and improving reinforcement against internal pressure. .

In the present invention, since the second seal member 20 is fixed by caulking to the reinforcing ring 30, even if an external force acts in the axial direction when the second seal lip 24 is formed by bending or when the shaft of the actual machine is inserted. The fixing portion for caulking with the reinforcing ring 30 is securely fixed without loosening, and the sliding position of the second seal lip 24 made of resin is stabilized.

Further, since the second seal member 20 is securely fixed, the adhesion between the first seal member 4 and the second seal member 20 is also ensured.

Also, the first seal lip 10 made of a rubber-like elastic body is buried in the end face 8 continuous with the first seal lip 10 so as to bite into the tongue-shaped projection 38 to form a reinforcing portion. Even if an axial load acts on the first seal lip 10, stable characteristics without lifting can be obtained. In particular, the tongue 38 is connected to the flange 3
4 is formed by cutting and raising the hole 35 formed in the hole 3.
5, the rubber-like elastic body is firmly fixed.

A method for manufacturing the oil seal 2 of the present invention having the above-described structure will be described with reference to FIG.

Reference numeral 40 denotes a molding die as a die, which is roughly divided into an upper die 42 and a lower die 44. Upper mold 42 and lower mold 4
The space formed by closing the oil seal 4 has the same shape as the oil seal 2, and the oil seal 2 is formed.

With the mold open, the reinforcing ring 30 and the second seal member 20 are placed in the lower mold 44 in the state shown in FIG. 3A with the sealed fluid side up and the air side down. (See FIG. 4A). The reinforcing ring 30 is positioned by fitting the hole inside the flange portion 34 into the lower mold 44, and
The sealing member 20 has a central hole in the lower mold 44 and an outer periphery in the reinforcing ring 3.
Positioning is performed by fitting the inside of a plurality of zero tongue-shaped projections 38. The reinforcing ring 30 is press-formed in advance into the shape shown in FIG.

The resin material 21 of the second seal member 20
Is a disk shape having a round hole at the center, and the second seal lip 22 is not yet formed.

As shown in FIG. 4B, the upper mold 42 is pressed from above the plurality of tongues 38 of the reinforcing ring 30 during vulcanization molding, so that the tongues 38 are pressed inward. Then, the outer diameter end of the resin material 21 is sandwiched and fixed between the tongue-shaped projection 38 and the flange 34. At the same time, by pouring the rubber material, the resin material 21 of the first seal member 4, the reinforcing ring 30, and the second seal member 20 is surely integrated.

The method of flowing the rubber cloth is as follows.
The mold may be placed on the outer periphery or the annular portion and compression molded at the same time as the mold clamping, or may be injected into the inner surface or the outer peripheral surface by injection or transfer after clamping.

The second seal member 20 forms the second seal lip 24 by bending the inside of the second seal member 20 toward the sealed fluid in a subsequent step. However, by changing the molding die from that shown in FIG. 4 and forming a movable mandrel at the center of the lower die 44 and extruding it upward, the same molding die can be used to perform lip formation. . Also, a lip may be formed before vulcanization molding.

[0045]

As described above, according to the present invention,
Since the second seal member was caulked to the reinforcing ring and fixed,
Even if external force acts in the axial direction during bending of the seal lip or insertion of the actual machine shaft, the caulking fixing portion with the reinforcing ring is securely fixed without loosening, and the sliding position of the second resin seal lip is stable. And the sealing performance is stabilized.

Further, since the second seal member is securely fixed, the adhesion between the first seal member and the second seal member is ensured, and the seal between the first and second seal members is also stabilized.

If the reinforcing ring is provided with a tongue-shaped protrusion and fixed by caulking, the caulking operation is easy.

Further, if the tongue-shaped projection is formed by bending a cutout portion of a hole provided in the metal reinforcing ring toward the second seal member, the structure can be made simple and inexpensive.

Also, the reinforcing portion is formed by the tongue-shaped projections of the first seal lip made of a rubber-like elastic material, so that even if an axial load is applied to the first seal lip, the first seal lip has a stable characteristic without lifting. Can be obtained.

On the other hand, according to the manufacturing method of the present invention, the second seal member is caulked and fixed to the reinforcing ring using the mold clamping pressure. Therefore, it can be caulked and fixed at the same time as the molding, the number of steps can be reduced, and it can be manufactured at low cost.

[Brief description of the drawings]

FIG. 1 is a sectional view of an oil seal as a sealing device according to one embodiment of the present invention.

FIG. 2 is a partial perspective view of a reinforcing ring of the oil seal of FIG.

3 (a) is a cross-sectional view showing a state in which a sheet-shaped resin material is superimposed on the reinforcing ring of FIG. 1, and FIG. 3 (b) is a sheet-like resin material on another type of reinforcing ring. It is sectional drawing which shows the state which overlapped.

FIGS. 4A and 4B are explanatory views showing a vulcanization molding method according to one embodiment of the present invention.

FIG. 5 is a cross-sectional view of a conventional sealing device during vulcanization molding.

FIG. 6 is a cross-sectional view of another conventional sealing device.

FIG. 7 is a sectional view of still another conventional sealing device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Housing 2 Oil seal (sealing device) 3 Shaft hole 4 1st seal member 5 Rotating shaft 6 Cylindrical fitting part 8 End surface 10 1st seal lip 12 dust lip 14 Lip tip part 20 2nd seal member 21 Resin material 22 Plate part 24 Second seal lip 30 Reinforcement ring 32 Cylindrical part 34 Flange part 35 Hole 36 Surface 38 Tongue-shaped projection 40 Mold 42 Upper mold 44 Lower mold O Sealing fluid side

Claims (4)

(57) [Claims] 1. An annular first seal member having a first seal lip made of a rubber-like elastic body, a metal reinforcing ring embedded in the first seal member, and a resin-made ring attached to the first seal member. a second sealing member annular having a second sealing lip, a sealing device provided with a, when molding the first sealing member, the metal reinforcing ring
And the second seal member are inserted into a mold and integrated.
In the sealing device to be molded , the second molding is performed simultaneously with the molding by utilizing the mold clamping pressure of the mold .
A sealing device, wherein a sealing member is fixed by caulking a part of the metal reinforcing ring. 2. The sealing device according to claim 1, wherein the metal reinforcing ring is provided with a plurality of tongue-shaped protrusions for fixing the second seal member in a circumferential direction. 3. The tongue-like projection according to claim 2, wherein a plurality of holes are provided in the metal reinforcing ring in a circumferential direction, and a cutout portion of the hole is bent toward the second seal member. The sealing device as described. 4. A mold for molding a first seal member made of a rubber-like elastic body, wherein a metal reinforcing ring and a resin material for a second seal member made of a resin are inserted into a mold and integrally molded. A method of manufacturing a sealing device, wherein a part of the metal reinforcing ring is fixed by caulking the resin material by using a mold clamping pressure at the same time as molding.