JPH0663572B2 - Method for manufacturing sealing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention has a sealing device used for sealing between two concentrically assembled two rotating members, in particular, a resin sealing lip provided with a thread groove on the sealing surface. The present invention relates to a method for manufacturing a sealing device.

Conventionally, as a method of manufacturing this type of sealing device, for example, there is one as shown in FIGS. 9 to 11 (US Pat.
255,155). That is, reference numeral 100 denotes a sealing device, and an outer diameter side of a resin seal ring 101 is assembled to an annular support member 102. Seal ring 1
The inner diameter side of 01 is bent to the sealed fluid side so that the seal lip 1
03, and a thread groove 104a is engraved on the seal surface of the seal lip 103. In order to manufacture such a sealing device 100, first, as shown in FIG. After the screw is cut, the end portion of the resin cylindrical body 105 is cut out with a predetermined width by the cutting means 106 to form the thin plate-shaped seal ring 101. After that, as shown in FIG. 11, the inner diameter side of the seal ring 101 is bent at a predetermined angle by pressing to form the seal lip 103 and the seal ring 101 is assembled to the support member 102. For the bending of the seal ring 101, the lower die 107 is provided with a tapered surface 107a for forming the seal lip 103,
The upper mold 108 and the lower mold 107 were used for compression in the vertical direction.

(Problems to be Solved by the Invention) However, in the case of such a conventional example, there is a problem that the number of processes is large and the production efficiency is poor because the cutting is performed after the thread groove 104 is provided.

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 provide a method of manufacturing a sealing device capable of shortening the manufacturing process by grooving while cutting. Especially.

(Means for Solving Problems) In order to achieve the above object, in a method for manufacturing a sealing device according to the present invention, a resin cylindrical body is rotated with a central axis of the resin cylindrical body as a rotation axis, and After the end of the resin cylinder is cut into a plate shape from the inner diameter side to the outer diameter side by the cutting means, the cutting surface of the cutting piece in the middle of cutting is screwed to the inner diameter side of the cutting piece by the groove cutting means. Having a step of engraving a groove, a step of bending the seal ring cut off by the cutting means so that the screw groove faces inward, and a step of assembling the outer diameter side of the ring member with a support member It consists of

(Example) Below, this invention is demonstrated based on the Example shown in figure. 1 to 8 showing the method of manufacturing the sealing device according to the embodiment of the present invention, the same sealing device as the conventional example shown in FIG. 9 is manufactured also in this embodiment. In FIG. 1, reference numeral 1 denotes a resin cylindrical body made of PTFE (tetrafluoroethylene resin), which is rotatably attached to a lathe or the like with its central axis as a rotation axis. The inner diameter and the outer diameter of the resin cylindrical body 1 are preliminarily molded into predetermined dimensions. Around the periphery of the resin cylinder 1, a cutting means A for cutting the end of the resin cylinder 1 into a thin plate shape and a grooving means B for grooving the cutting piece 2 cut by the cutting means A are provided. ing. As the cutting means A, as shown in FIG. 2, a cutting tool arranged along the central axis direction of the resin cylindrical body 1 is used, and the cutting edge 3 has a knife shape in the present embodiment.
Is bent in a direction perpendicular to the central axis of the resin, and the end portion of the resin cylindrical body 1 is cut out from the inner diameter side to the outer diameter side in a thin plate shape. That is, the cutting means A is movable in the central axis direction of the resin cylindrical body 1 and in the direction perpendicular to the central axis, and is moved in the central axis direction by a predetermined thickness from the end surface of the resin cylindrical body 1 by a control mechanism (not shown). The thin plate is cut out by moving from the inner diameter side of the resin cylinder 1 to the outer diameter direction.

On the other hand, as the groove cutting means B, similarly to the above cutting means A, a cutting tool arranged along the central axis direction of the resin cylindrical body 1 is used, and the groove cutting part 4 at the tip thereof is bent into a substantially L shape to perform cutting. It is designed to cut into the gap between the pieces 2. Groove 4
A cutting edge 4a for grooving is provided on the surface of the tip portion facing the cutting piece 2. Further, a guide projection 4b is provided adjacent to the cutting edge 4a, and the cutting edge 4a extends from the guide surface of the projection 4b.
Is projected by the depth of the groove 5 in which is carved. The cross section of the protrusion 4b is substantially trapezoidal. That is, the groove cutting means B is moved outward in the radial direction and inserted into the gap of the cutting piece 2 cut by the cutting means A, and the outer surface side of the cutting piece 2 is held by the holding jig 6, The cutting edge 4a bites into the cutting surface of the cutting piece 2 and is moved inward or outward in the radial direction of the resin cylindrical body 1 from the inner diameter side of the cutting piece 2 at a constant speed at a constant speed, and the rotation of the resin cylindrical body 1 is compensated for. In addition, a spiral thread groove 5 is engraved. As described above, the groove surface of the cutting piece 2 is being cut by the cutting means A, and the thread groove 5 is formed by the groove cutting means B.
Since it is engraved, the shape of the thread groove 5 is not deformed. As the moving direction of the groove cutting means B, it is desirable to move the groove 4 from the inner diameter side of the cutting piece 2 radially outward so that the guide projection 4b does not interfere with the thread groove 5. The depth of the thread groove 5 can be adjusted by the biting amount of the groove cutting means B, and the shape of the thread groove 7 can be set to any desired shape by the shape of the cutting edge of the groove cutting means B. If a plurality of groove cutting means B are used, a plurality of thread grooves 5 can be formed. Blade end 4a of the thread cutting means B after grooving
Are separated from the cutting piece 2.

The grooving is performed before the cutting is completely completed by the cutting means A, and after the grooving is completed, the plate-shaped seal ring 101 is formed by the cutting means A as shown in FIGS. 5 and 6.

Next, the seal ring 10 cut off as shown in FIG.
1 is assembled to the support member 102. That is, the seal ring 101 is fitted from the end of the outer cylinder 102a constituting the support member 102 on the side of the sealed fluid, and the inner cylinder 102b is further fitted so that the outer diameter side end portion of the seal ring 101 is connected to the outer cylinder 102a and the inner cylinder 102b. The atmosphere side flanges 102c and 102d are pressed against each other, and the outer fluid side edge of the outer cylinder 102a is caulked inward in the radial direction to assemble.

Further, the seal ring 1 assembled as shown in FIG.
The inner diameter side of 01 is bent at a predetermined angle so that the thread groove 5 faces inward, and the seal lip 103 is molded, thus completing the sealing device. Bending is performed, for example, by pressing the side surface of the seal ring 101 on the engraved side of the thread groove 5 with a rod-shaped rotating roll 7 that is rotatable along the central axis while rotating the seal ring 101. In this case, the rotating roll 7 is pressed against the screw groove 5, but since the rotating roll 7 is rotatable, it rolls on the seal ring 101 and the screw groove 5 is crushed by rubbing of the contact portion of the rotating roll 7. Etc. are prevented. If the surface of the rotating roll 7 is made of a flexible material, it is possible to prevent the screw groove 5 from being crushed during pressure contact.

The order of the assembling process and the bending process of the seal ring 101 may be that the seal ring 101 is bent and then assembled.

Further, as in the conventional example shown in FIG. 11, the bending step and the assembling step may be simultaneously performed by press working.

As the material of the resin cylinder 1, in addition to PTFE, FEP (tetrafluoroethylene hexafluoropropylene copolymer), PFA (tetrafluoroethylene / perfluoroalcooxide), EPFE (ethylene tetrafluoride) Various resins such as ethylene copolymer), polyether ether ketone, and high molecular weight polyethylene may be used, and glass short fibers, carbon short fibers, metal fibers, ceramic short fibers, whiskers, graphite powder, metal Powder, glass powder, ceramic powder, resin powder, etc., alone or 2
A mixture of more than one type that has been given wear resistance and low wear resistance, etc.
Various materials can be applied.

(Effects of the Invention) The present invention has the above-described configuration and operation. Since the cutting piece in the middle of cutting is grooved by the groove cutting means, it is necessary to perform the groove processing after the conventional cutting. The production process can be shortened and the production efficiency can be improved. Further, since the shape of the groove processed is not deformed, the shape of the groove can be maintained.

[Brief description of drawings]

FIG. 1 is a schematic perspective view in the vicinity of a resin cylindrical body showing a cutting and grooving step of a method for manufacturing a sealing device according to the present invention, FIG. 2 is a schematic sectional view showing a cutting state of FIG. 1, and FIG. 1 is a schematic sectional view showing a groove processing state, FIG. 4 is a schematic perspective view of the groove cutting means of FIG. 3, FIG. 5 is a schematic sectional view showing a state in which a resin cylindrical body is cut off, and FIG. 5 is a schematic perspective view of the cut-off seal ring, FIG. 7 is a longitudinal cross-sectional view of an essential part showing a state in which the seal ring of FIG. 6 is assembled, and FIG. 8 is bending of the seal ring of the apparatus of FIG. FIG. 9 is a schematic perspective view showing a processed state, FIG. 9 is a longitudinal sectional view of a main part of a conventional sealing device, and FIG. 10 is a schematic perspective view showing a seal ring molding state of the conventional sealing device.
FIG. 1 is a longitudinal sectional view of a main part of a press die showing a conventional seal ring bending process and an assembled state. DESCRIPTION OF SYMBOLS 1 ... Resin cylindrical body, 2 ... Cutting piece 4 ... Groove cutting portion, 5 ... Screw groove 6 ... Holding jig, 9 ... Outer diameter holding ring A ... Cutting means, B ... Groove cutting means

Claims (1)

[Claims] 1. A resin cylindrical body is rotated about a central axis of the resin cylindrical body as a rotation axis, and an end portion of the resin cylindrical body is cut into a plate shape from an inner diameter side to an outer diameter side by a cutting means, A step of engraving a thread groove on the inner diameter side of the cutting piece by a groove cutting means on the cutting surface of the cutting piece in the middle of cutting, and a sealing ring cut off by the cutting means so that the thread groove faces inward. A method of manufacturing a sealing device, comprising a bending step and a step of assembling the outer diameter side of the ring member with a support member.