JP4478167B2 - Resin seal ring and manufacturing method thereof - Google Patents

Description

  The present invention relates to a resin seal ring and a method for manufacturing the same, and more particularly, to a synthetic resin seal ring that maintains a gap at a joint and stabilizes oil leak and a method for manufacturing the same.

In general, in an automatic transmission such as a torque converter or a hydraulic clutch such as an automobile, an oil seal ring for sealing hydraulic oil is attached to a key point. Such an oil seal ring is required to have sufficient oil sealability.
Conventionally, cast iron seal rings and fluororesin seal rings have been used as oil seal rings, but synthetic resins that have mating faces facing each other by injection molding are used to improve wear resistance, oil sealability, and cost. A seal ring made of PEEK resin, for example, a seal ring is often used.
There are straight cut shapes, step shapes, composite step shapes, and the like for the seal ring, but a composite step shape is known as an interface that can reduce oil leakage (for example, Patent Document 1).

A conventional resin seal ring having a composite step-shaped joint will be described with reference to FIG. FIG. 6 is a perspective view showing a state (a) in which the abutment portion is widened and a state (b) in which it is fitted.
The abutment portion divides the two sides of the rectangular cross section of the resin seal ring 1 into two parts, the ring inner surface 1a and the ring outer surface 1b. A butting surface 2 is formed. In addition, the rectangular cross-section portion 1b on the ring outer diameter surface side includes an outer-diameter surface-side protrusion 3 protruding from the abutting surface into one rectangular cross-section portion that further divides this portion into two in the radial direction, and the other rectangular cross-section portion. Is formed, and the outer diameter surface side stepped portion 4 that is retracted from the abutting surface 2 is formed. The peripheral surfaces of the outer diameter surface side protrusion 3 and the outer diameter surface side step 4 are formed to have a predetermined curvature of the resin seal ring 1.
When the mating port is fitted (FIG. 6B), the butted surfaces 2 and 2 'are fitted, and the outer diameter surface side protrusion 3, the outer diameter surface side step portion 4', and the outer diameter surface side step portion. 4 and the outer diameter surface side projection 3 ′ are complementarily fitted with a certain gap therebetween, and the resin seal ring 1 is substantially circular.

  A mold for producing the resin seal ring 1 by injection molding is shown in FIG. FIG. 7 is a cross section of the mold on the butting surface 2 of the resin seal ring 1 shown in FIG. The movable side template 9 and the fixed side template 10 are abutted at the abutting surface 12 to form the cavity 11. The cavity 11 in FIG. 7 is a portion where the outer diameter surface side protrusion 3 is formed. A broken line in the outer frame indicates a rectangular cross section of the seal ring 1. As described above, the mold of the resin seal ring has a complex mold structure in which the fixed-side mold plate 10 is also provided with the convex portion 13 in order to form a composite step-shaped joint having a complicated cross-sectional shape. .

However, when a resin seal ring is manufactured by injection molding using the above-described mold, the following problems occur.
That is, the mold is divided into a movable mold plate 9 and a fixed mold plate 10. The mold is molded in a state of abutting at the time of molding, and the mold plate is divided and taken out when taking out the product. By repeating this process, the mold interferes and wears or bites. In particular, the portion of the convex portion 13 of the fixed side mold plate 10 provided for forming the outer diameter surface side projection 3 is likely to cause interference with the corner portion 14 of the movable side mold plate 9, and this portion is galling and worn. To do. As a result, there is a problem that the gap at the joint portion of the resin seal ring becomes large and the sealing performance is deteriorated. In addition, since the mold must be repaired each time, there is a problem that work efficiency decreases or production cost increases.
JP-A-8-75007

  The present invention has been made in order to address such problems, and it is an object of the present invention to provide a resin seal ring having a shape that is excellent in gap accuracy at the joint and can improve productivity, and a method for manufacturing the resin seal ring. And

The method for producing a resin seal ring according to the present invention includes a joint where the resin seal rings face each other, and one joint connects the two sides of the resin seal ring in the rectangular cross section. When dividing into the inner diameter surface side and the ring outer diameter surface side, the abutting surface formed in the rectangular cross section portion on the ring inner diameter surface side and the rectangular cross section portion on the ring outer diameter surface side are divided into two in the radial direction. One rectangular cross-section portion has an outer diameter surface-side protrusion protruding from the abutting surface, and the other rectangular cross-section portion is deleted from the abutting surface and the outer diameter surface-side stepped portion, and the other abutment is The abutting surface, the outer diameter surface side protrusion, and the outer diameter surface side stepped portion formed to complementarily fit with the outer diameter surface side stepped portion. , One of the above and the other of the above At least one abutment of a plastic seal ring outer peripheral surface of the outer diameter surface side step has a radial inward facing slope toward the seal ring side,
The method for producing the resin seal ring includes a movable mold plate and a fixed mold plate, and the movable mold plate is formed with cavities and depressions at the time of die contact to form the one abutment. The recess has a depth that defines the thickness in the width direction of the resin seal ring, and the width of the outer diameter side and the inner diameter side of the recess forming the outer diameter surface protrusion of the resin seal ring is two. The substantially intermediate portion to be divided is provided with a predetermined gradient, and the convex portion forming the other abutment is formed from the bottom surface of the cavity to the substantially intermediate portion and the outer diameter side that divide the width of the outer diameter side and the inner diameter side into two. A protruding fixed mold plate side having a height approximately equal to the mold abutting surface and having a height substantially the same as the convex portion on which the other mating hole is formed on the fixed mold plate The resin composition is injection-molded using a mold having convex portions formed on the mold abutting surface.
Further, the fixed mold plate-side convex portion of the mold is provided with a gradient that is complementarily fitted to the inner diameter-side gradient of the concave portion.

The method for producing a resin seal ring according to the present invention is such that the gradient in the inner diameter of the resin seal ring has an angle of 2 to 30 ° with respect to the two-part dividing line between the ring inner diameter surface side and the ring outer diameter surface side. It is characterized by being.
In addition, the mold is a mold for forming the joints facing each other in a widened form without overlapping portions.
The resin seal ring of the present invention is a resin seal ring manufactured by the above manufacturing method.

The resin seal ring manufacturing method of the present invention has the above-mentioned structure of the mold for forming the abutment portion, and therefore, the phenomenon of galling / wearing between the fixed mold plate and the movable mold plate in the injection mold. Can be greatly reduced. For this reason, a resin-made seal ring can be manufactured stably. Further, there is no galling / wearing phenomenon of the mold, and the mold life is improved. In addition, since the inner diameter gradient has an angle of 2 to 30 °, the gap accuracy of the joint is excellent, and there is no galling / wearing phenomenon of the mold, and the productivity is further improved.
Also, the resin seal ring that is injection-molded from this mold has an outer peripheral surface of the outer diameter side step portion at the mating portion that has a gradient toward the inner diameter toward the side surface of the seal ring. Excellent accuracy.
Moreover, oil leak can be effectively suppressed by setting the gradient toward the inner diameter of the step portion on the outer diameter surface side to a gradient having an angle of 2 to 30 °.

The structure of the joint portion of the resin seal ring according to the present invention will be described with reference to FIG. FIG. 1 is an enlarged view showing an abutment portion having a predetermined radius of curvature, FIG. 1 (a) is a front view, and FIG. 1 (b) is an AA enlarged sectional view.
The resin seal ring 1 has a feature in the outer diameter surface side step portion 4 in the joint portion of the composite step shape shown in FIG.
That is, the outer peripheral surface 4a of the outer diameter surface side step portion 4 has a gradient toward the inner diameter toward the seal ring side surface 1d. Specifically, in the enlarged sectional view 1b of the resin seal ring, when the outer diameter side and the inner diameter side are divided into two by the broken line 1e, the angle θ of the inner diameter gradient is 2 to 30 ° from the broken line 1e, preferably Is characterized by a gradient with an angle of 2-15 °. If the angle θ is less than 2 °, the galling phenomenon of the mold may occur. If the angle θ exceeds 30 °, the oil leak will increase remarkably if the seal ring is displaced in the width direction during use.

FIG. 2 shows a state where the mating ends are fitted to each other. FIG. 2 is a cross-sectional view showing a state where the outer diameter surface side step portion 4 and the outer diameter surface side protrusion 3 ′ are fitted.
In the present invention, it is sufficient that the outer diameter surface side step portion 4 has the above-described gradient toward the inner diameter, but the outer diameter surface side projection 3 ′ that is fitted to the outer diameter surface side step portion 4 is further It is preferable to have a gradient toward the inner diameter that fits complementarily with the radial surface side step portion 4. That is, it is preferable to have a gradient in the inner diameter of 2 to 30 ° and substantially the same gradient angle as the gradient angle in the inner diameter of the outer diameter surface side step portion 4. By making the gradient angle of the outer diameter surface side projection 3 ′ and the outer diameter surface side stepped portion 4 substantially the same, galling and wear between the fixed mold plate and the movable mold plate can be reduced, and the seal ring is in the width direction. Even if it is shifted to, oil leakage is reduced.

As a comparative example, a combination of the outer diameter surface side protrusion 3 ′ and the outer diameter surface side step 4 will be described with reference to FIG. 3. FIG. 3A shows the case where the outer diameter surface side protrusion 3 ′ and the outer diameter surface side step 4 are not inclined, and FIG. 3B shows the outer diameter surface side protrusion 3 ′ and the outer diameter surface side step. 4 is a diagram illustrating a case where the difference in gradient angle from 4 exceeds 30 °. In the case of an abutment-shaped seal ring shown in FIG. 3A, galling and wear occur between the fixed mold plate and the movable mold plate during injection molding. As a result, the shape of the joint shown in FIG. 3A is likely to vary within the production lot, and oil leakage is likely to occur.
In the case of the abutment-shaped seal ring shown in FIG. 3B, there is little galling or wear between the fixed mold plate and the movable mold plate, but a gap is formed in the abutment portion, and oil leakage is likely to occur.

The resin seal ring 1 of the present invention is obtained by injection-molding a resin composition using a mold that can be molded in a form in which an abutment portion is widened without an overlapping portion.
The seal ring mold will be described with reference to FIG. 4A is a plan view of the mold of the mating part when the movable mold plate is viewed from the front side when the mold is opened, and FIG. 4B is a mold of the mating part when the fixed mold plate is viewed from the back side when the mold is opened. Each plan view is shown. Moreover, sectional drawing of each part of the resin-made seal ring 1 obtained with this metal mold | die is shown in FIG.
As shown in FIG. 4 (a), the movable mold plate is formed with uneven portions that become cavities when the molds are brought together. The recesses 5 and 5 ′ are recesses having the same depth and define the thickness of the resin seal ring 1 in the width direction. A predetermined gradient is provided on the inner diameter side of the recess 5. The convex portion 6 from the bottom surface of the cavity is a convex portion having a height approximately halfway between the mold abutting surface and the concave portion 5, and 7 is a die abutting surface.
On the other hand, as shown in FIG. 4B, the fixed mold plate is formed with protruding convex portions 8 having substantially the same height as the convex portions 6 on the mold abutting surface. The convex portion 8 is also provided with a gradient that is complementarily fitted with the inner diameter side gradient of the concave portion 5. Thus, it is preferable to provide the gradient of the convex part 8 and the concave part 5 over the whole area | region which forms the outer diameter surface side protrusion 3 and the outer diameter surface side step part 4. FIG. Further, it is possible to provide a gradient only in the portion of the outer diameter surface side projection 3 where galling of the mold occurs.
The fixed mold plate and the movable mold plate are abutted to form a cavity, and a resin seal ring having a cross-sectional shape shown in FIG. 5 at each cut surface is obtained by injection molding the resin composition. In addition, each cut surface location is shown in FIG. When the seal ring is used, the cross section (a) and the cross section (c) are fitted to each other, and the cross section (b) and the cross section (d) are fitted to each other.

  The resin seal ring of the present invention is obtained by injection-molding a resin composition using the mold shown in FIG. 4 and then using a jig comprising a resin or rubber cylinder and a ring gauge. The composite step-cut type seal ring as described above can be obtained by heat-fixing by inserting and fixing inside and heating to a temperature equal to or higher than the glass transition point of the base resin of the resin composition.

The resin composition according to the present invention comprises at least a heat resistant resin, a reinforcing fiber, and a fluorine resin.
The heat-resistant resin may be any thermoplastic resin having a melting point of at least 280 ° C. Examples thereof include aromatic polyether ketone resins such as polycyanoaryl ether resins and polyether ether ketone resins, aromatic thermoplastic polyimide resins, polyamide 46 resins, and polyphenylene sulfide resins. In addition to high heat resistance, they are excellent in flame retardancy, mechanical properties, electrical properties and chemical resistance.
As a preferred resin composition according to the present invention, a heat-resistant resin composed of an aromatic polyetherketone resin or a polyphenylene sulfide resin is blended with a fluorine-based resin such as a fibrous reinforcing material or polytetrafluoroethylene. It is preferable because the complex shape of the composite step-cut seal ring can be easily formed and the characteristics required for the resin seal ring can be easily obtained.

Using the mold shown in Fig. 4, a composite step-cut seal ring with a ring width of 2.0 mm, ring thickness of 1.8 mm, and ring outer diameter of 50 mmφ is injection-molded, and then from a rubber cylinder and a ring gauge. The jig was forcibly deformed so that the mating part was fitted, and the jig was placed in an electric furnace and heat fixed at 200 ° C. for 2 hours to obtain a resin seal ring. The resin composition was blended with an aromatic polyether ketone resin, carbon fiber, and polytetrafluoroethylene resin.
Even when the production of the resin seal ring of the present invention was continuously produced for 200,000 shots or more, there was no change in the cross section of the resin seal ring.
On the other hand, in the case of the resin seal ring having the cross-sectional shape of the joint shown in FIG. 3 (a) as a comparative example, the galling and wear phenomenon of the mold occurred in the production of 5,000 shots, and the mold needs to be repaired. .

It is a figure which shows the structure of an abutment part. It is a figure which shows the state which the fitting part mutually fitted. It is a figure which shows the state which the joint in the comparative example fitted. It is a figure explaining the metal mold | die of a seal ring. It is a figure which shows the cross-sectional shape of a seal ring. It is a perspective view which shows the conventional seal ring. It is a figure explaining the metal mold | die of the conventional seal ring.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin sealing ring 2 Butting surface 3 Outer surface side protrusion 4 Outer surface side step part 5 Recessed part 6 Convex part 7 Mold | die abutting surface 8 Convex part of a stationary mold plate 9 Movable side mold board 10 Fixed side template 11 Cavity 12 Abutting surface 13 Convex part 14 Corner part

Claims (3)

In the method for producing a resin seal ring having a rectangular cross section ,
The resin seal ring has a abutments facing each other, one of the abutments is said by connecting side two sides of the resin seal rings in rectangular section ring inner diameter surface side and the ring outer diameter surface side , The abutting surface formed in the rectangular cross-section portion on the ring inner diameter surface side and the rectangular cross-section portion in the radial direction of the rectangular cross-section portion on the ring outer diameter surface side from the abutting surface into one rectangular cross-section portion The outer diameter surface side protrusion which protruded, and the other rectangular cross-section part are deleted, and it has the outer diameter surface side step part which retreated from the abutting surface, and the other abutment is the abutting surface, the outer diameter surface side formed abutment surfaces so as to complementarily mate with the projections and the outer diameter surface side step, a resin-made seal ring to have a an outer diameter surface side projection and the outer diameter surface side step,
The manufacturing method of the resin seal ring includes a movable mold plate and a fixed mold plate, and the movable mold plate is configured such that one side surface of the resin seal ring is located on the mold abutting surface at the time of mold abutting. in the manufacturing method for injection-molding the resin composition by using the concave and convex portions of the plate, said fixed die plate and die portion to be a cavity Ru is formed to have a shape of the resin sealing ring with its convex portion Yes,
The concave part of the movable mold plate is a ring-shaped part for forming the joint part of the resin seal ring in a widened form without an overlapping part, and the thickness in the width direction of the resin seal ring. It is a shape that is recessed from the mold abutting surface,
In the recess, an intermediate step for forming the abutting surface and the outer diameter surface side projection of the one abutment at one ring end, and the abutting of the other abutment at the other ring end Each having an intermediate step part forming a surface and the outer diameter surface side protrusion,
The convex part of the movable mold plate is formed in the concave part with an intermediate height from the cavity bottom surface to the mold abutting surface at the ring end part forming the other abutment,
The convex portion of the fixed mold plate is formed on the mold abutting surface of the fixed mold plate to have the same height as the convex portion of the movable mold plate,
At the time of die collision, the convex part of the fixed mold plate is fitted to the one ring end part in the concave part of the movable mold plate, and the intermediate step part of the one ring end part in the concave part is A method for manufacturing a resin seal ring, wherein a slope of the concave portion toward the inner diameter of the ring is provided on a fitting surface with the convex portion of the fixed mold plate toward the die abutting surface . 2. The mold according to claim 1, wherein the convex portion of the fixed mold plate is provided with a gradient that is complementarily fitted to the gradient of the intermediate step portion of the one ring end portion in the concave portion . A method for producing a resin seal ring according to claim 1. 3. The resin product according to claim 1 , wherein the gradient is a gradient having an angle of 2 to 30 ° with respect to a two-part dividing line between a ring outer diameter surface side and a ring inner diameter surface side of the concave portion . A manufacturing method of a seal ring.

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