JPH0875007A - Seal ring of synthetic resin - Google Patents

Abstract

PURPOSE: To prevent local contact at abutment parts in a seal ring of synthetic resin provided with abutments facing each other at a specified interval from each other at a position in the circumferential direction of a ring main body. CONSTITUTION: In a seal ring provided with abutments 2, 2' facing each other at a specified interval from each other at a position in the circumferential direction of a ring main body 1, with linear end surfaces of the abutments 2, 2' formed as straight surfaces, chamfered parts 5 are formed at boundaries between tip surfaces 3 of the abutments 2, 2' and an outer surface 4 of the ring main body 1. The chamfered part 5 is formed in an arc form of a specified curvature, or as a chamfer of a curvature of 0, that is comprising diagonal surfaces. Protruded quantity of tip parts of the abutments 2, 2' is thus set at zero even when the curvature of the seal ring does not coincide with that of a counter member to eliminate local contact, thereby breakage of the abutments, etc., can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic resin seal ring for preventing leakage of liquids such as oil and water, fluids such as air and other gases, and mainly relates to automatic speed changers such as torque converters and hydraulic clutches. The present invention relates to a synthetic resin oil seal ring used for sealing hydraulic oil in a machine.

[0002]

2. Description of the Related Art As such a seal ring, a metal seal ring or a tetrafluoroethylene resin seal ring has been conventionally used. Recently, injection molding has been performed to improve wear resistance, oil sealability and cost reduction. The use of a synthetic resin seal ring according to US Pat.

These seal rings are separated at one position in the circumferential direction for the convenience of mounting, and are provided with straight cut type fitting ports 71, 71 'as shown in FIG. For example, a composite step cut type abutment 72, 72 'is provided.

The seal ring is mounted in the gap between the piston and the cylinder, rotates with the relative rotation of the two, and slides with these mating members with the relative movement of the two in the axial direction. To do. Therefore, the seal ring is required to have sufficient sealing property without damaging the sliding surface of the mating member.

[0005]

By the way, in order to facilitate the mold release, the seal ring of the injection molding die is in a state in which the gaps between the two abutments 72, 72 'are widened (in the radial direction) as shown in FIG. Injection molding in a substantially circular shape or in a state in which it is slightly wider than the circular shape (when there is no overlap with the above), and when this is mounted on the piston, it is mounted by fitting the mating ports 72, 72 'to each other and then inserted into the cylinder. It At this time, a and b ', a'and b, c and c'at the corners of the abutment may be caught, which may be an obstacle when fitting both abutments.

Further, as shown in FIG. 25, the entire injection-molded seal ring 73 is not necessarily a perfect circle, and the tips of the mating openings 72, 72 'protrude from the outer diameter surface of the seal ring 73, so that the piston 75 is moved into the cylinder. It becomes an obstacle when it is inserted into 74, and after the insertion, the seal ring 7
3 between the outer diameter surface and the inner diameter surface of the cylinder 74.
And the seal is incomplete.

Further, when the seal ring 73 rotates in this state, the tips of the abutments 72 and 72 'slide locally while hitting, so that the contact surface pressure becomes high and the oil film is cut off, and finally the cylinder 74 It leads to wear of the inner diameter surface.

The above-mentioned problem occurs similarly in the case of the straight cut type abutments 71 and 71 ', but in the case of the composite step cut type, one abutment 7 is used.
When the thickness of the protrusion 77 of the 2, 72 'is larger than the depth of the step 78 of the other abutment 72', the protrusion 77 portion protrudes to the outer peripheral surface, so that the same problem as described above occurs. .

In order to avoid such a problem, the cylinder 7
Although it is possible to design and mold it into a curvature that makes it a perfect circle when it is inserted in 4, it is difficult to make all the seal rings a perfect circle due to shrinkage of the material, processing tolerance of the mold, etc. It is difficult to completely eliminate local contact due to protrusion of the abutment tip.

Further, as one means for inserting the seal ring 73 into the cylinder 74 in a true circular shape, there is also a method in which the seal ring 73 injection-molded into a true circle is machined to provide the mating ports 72, 72 '. is there. However, even in this case, the dimensional tolerance of the outer diameter of the seal ring 73 and the cylinder 74
The curvature may not match due to the dimensional tolerance of the inner diameter of
It is difficult to completely prevent local contact between the abutments 72 and 72 '.

Therefore, an object of the invention according to this application is to provide a seal ring in which local contact at the abutment is prevented, and to provide a manufacturing method of the seal ring by injection molding.

[0012]

In order to achieve the above-mentioned object, the invention according to claim 1 is to provide an abutment facing each other at a certain interval at one position in the circumferential direction of the ring body, In a straight cut type synthetic resin seal ring formed by forming the front end surface of each of the aforesaid straight surfaces, a chamfered portion is provided at the boundary between the front end surface of each of the aforesaid opening and the outer diameter surface of the ring body. It is configured.

According to the second aspect of the present invention, an abutment facing each other is provided at one position in the circumferential direction of the ring body at a constant interval, and one abutment is provided on the outer diameter surface side of the ring body. The inner diameter of the ring body is formed by the outer diameter surface side projection and the inner diameter surface side step portion provided on the inner diameter surface side of the outer diameter surface side projection so that the other mating port complementarily fits with this. In the step cut type synthetic resin seal ring formed by the inner diameter surface side projection provided on the surface side and the outer diameter surface side step portion provided on the outer diameter surface side of the inner diameter surface side projection, the outer diameter surface side A chamfer is provided at each of the boundary between the tip surface of the projection and the outer diameter surface of the outer diameter surface side projection and the boundary between the step surface of the outer diameter surface side step and the ring body outer diameter surface. Of.

According to a third aspect of the present invention, there is provided an abutment facing each other at a certain interval in the circumferential direction of the ring body, and one abutment is provided on the outer diameter side projection and the outer diameter side. In the composite step-cut type synthetic resin seal ring, which is formed by a step portion, and the other abutment is formed by an outer diameter surface side projection and an outer diameter surface side step portion which complementarily fits with each other, A chamfer is provided at each of the boundary between the tip of the outer diameter surface side projection of the abutment and the outer diameter surface of the outer diameter surface side projection and the boundary between the step surface of the outer diameter surface side step and the ring body outer diameter surface. This is the configuration provided.

According to a fourth aspect of the present invention, an abutment facing each other is provided at a certain position in the circumferential direction of the ring body at regular intervals, and one abutment is provided at the tip on the inner diameter side of the ring body. An abutting surface is formed, and an outer diameter surface side protrusion and an outer diameter surface side step portion are provided adjacent to each other on the outer diameter surface side of the abutting surface, and the outer diameter surface side protrusion is the outer diameter surface side of the ring body. Is formed by a convex portion projecting from the abutting surface, and the outer diameter surface side step portion is closer to the side edge opposite to the outer diameter surface side projection, and An abutment formed by a recess recessed from the abutment surface, and the other abutment is formed so as to complementarily fit with the abutment surface, the outer diameter surface side protrusion and the outer diameter surface side step portion. Formed by the butt face, the outer diameter side protrusion and the outer diameter side step. In a composite step cut type synthetic resin seal ring formed from these abutments, the tip surface of the outer diameter side projection of each abutment, and The boundary of the outer diameter surface side projections of the abutment facing the inner surface of the outer diameter surface side projection, the tip surface of the outer diameter surface side projection of each of the abutment, and the outside of the one abutment when fitted. A boundary between the radial surface side projection and the outer diameter surface stepped portion inner surface facing the outer diameter surface stepped portion of the other mating opening, and the outer diameter surface side stepped portion inner surface of each of the mating openings, and the abutting surface. The chamfered portions are provided at the boundaries of each.

According to a fifth aspect of the present invention, in the synthetic resin seal ring according to the fourth aspect, a boundary between a tip end surface of the outer diameter surface projection of each of the mating ports and an outer diameter surface of the outer diameter surface projection is provided. Further, chamfered portions are provided at the boundaries between the stepped surface of the outer diameter surface side step and the outer diameter surface of the ring body.

According to a sixth aspect of the present invention, there is provided the synthetic resin seal ring according to any one of the third to fifth aspects, in which the step surface of the outer diameter side step portion of each of the mating ports and the outer diameter projection are provided. A fillet is provided at each of the boundary with the inner surface and the boundary between the step surface of the outer diameter surface side step portion and the outer diameter surface side step portion inner surface.

According to a seventh aspect of the present invention, in the synthetic resin seal ring according to any one of the second to sixth aspects, the outer diameter surface projection of the one abutment and the other abutment of the other abutment are provided. A constant gap is provided between the surfaces facing the outer diameter surface side step portion.

According to an eighth aspect of the present invention, there is provided the synthetic resin seal ring according to any one of the third to seventh aspects, in which the outer diameter surface projection of the one abutment and the other abutment of the other abutment are provided. A constant gap is provided between the surfaces facing the outer diameter surface protrusions.

According to a ninth aspect of the present invention, there is provided a synthetic resin seal ring, wherein a ring-shaped main body is provided with facing gaps at one position in the circumferential direction of the ring body at regular intervals. Injection molding is performed in such a manner that the gap is expanded so that there is no overlapping portion when viewed in the radial direction, and then the gap between the aforesaid gaps is narrowed and the entire outer diameter surface is held in a perfect circle shape and heat fixed. It was done like this.

According to a tenth aspect of the present invention, the synthetic resin seal according to any one of the first to eighth aspects, in which a ring-shaped main body is provided at one position in the circumferential direction with facing openings facing each other at regular intervals. In the method for producing a ring, the injection molding is performed in such a manner that the gap between the two abutment portions is widened so that there is no overlapping portion when viewed in the radial direction, and then the gap between the abutment portions is narrowed to form a whole ring. The outer diameter surface is held in a perfect circle and heat-fixed.

[0022]

According to the present invention, since the chamfered portion is provided at the corner formed to face the outer diameter surface side, the protrusion amount of the protrusion at the abutment portion becomes zero or less. ,
It is possible to prevent local contact with the mating member.

Further, when the one abutment and the other abutment are fitted with each other, the chamfered portions are provided at the corners formed so as to contact each other when the two abutments are fitted together. The local contact that occurs in 1) is avoided or reduced, so that damage to the mutual abutment and the like can be prevented.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The first embodiment shown in FIGS. 1 (a) and 1 (b) is provided with facing ports 2 and 2 ', which are opposed to each other with a certain gap at one position in the circumferential direction of a ring body 1. The gap 2, 2 '
This is a seal ring having so-called straight cut type mating ports 2 and 2 ′ in which the front end surface 3 is formed into a straight surface.

A chamfered portion 5 is formed at the boundary between the tip surfaces 3 of the respective mating openings 2 and 2'of the seal ring and the outer diameter surface 4 of the ring body 1.
Is provided. The chamfered portion 5 may have an arcuate shape (also referred to as "R") having a predetermined curvature as shown in the drawing, but it has a curvature of 0, that is, a chamfered shape due to an inclined surface (also referred to as "chamfer"). However, this does not matter (this also applies to each of the following embodiments).
Such a chamfered portion is also called a crowning portion. Such a crowning portion can have, for example, a crowning shape in which the curvature continuously changes in various ways.

With such a shape, in the mounted state, even if there is a mismatch in the curvatures of the seal ring and the mating member, the amount of protrusion of the tips of the abutments 2 and 2 ′ becomes zero or small, and the local area Physical contact can be prevented.

The second embodiment shown in FIGS. 2 (a), (b) and (c) is a case where the step cut type abutments 9 and 9'are provided. The mating port 9 comprises an outer diameter surface side protrusion 10 and an inner diameter surface side step portion 11, and the mating port 9 ′ comprises an inner diameter surface side protrusion 13 and an outer diameter surface side step portion 14. Outer diameter side protrusion 10 of the abutment 9
And the outer diameter side step 14 of the abutment 9 ′, the inner diameter side step 11 of the abutment 9 and the inner diameter side projection 13 of the abutment 9 ′ are complementarily fitted with a certain gap. The following is a more detailed description.

That is, as shown in FIG. 6 (c), with respect to the abutment 9, the outer diameter side projection 10 projects from the ring body 1 in the circumferential direction, and this surface is referred to as a step surface 15. Then, the outer diameter surface side projection 10 is provided on the outer diameter side when divided into the inside and the outside of the step surface 15 (the inner diameter side and the outer diameter side of the ring body 1). Surface 8
Are continuous with the outer surface of the ring body 1 without any step and have the same curvature. Further, the inner diameter surface side step portion 11 is provided on the inner diameter surface side of the outer diameter surface side protrusion 10.

The other abutment 9'is formed in a form complementary to the aforesaid abutment 9, and the inner diameter surface side projection 13 is provided inside and outside of the step surface 15 '(the inner diameter side and the outer side of the ring body 1). It is provided on the inner diameter side when it is divided into two parts. Further, the outer diameter surface side step portion 14 is provided on the outer diameter surface side of the inner diameter surface side protrusion 13.

Both of the abutments 9 and 9'are fitted to each other with a certain gap, and the seal ring is shaped like a perfect circle as a whole.

A feature of the present invention is that a chamfered portion is provided at a corner portion having the outer diameter surface side. Specifically, in the seal ring having the step cut type mating ports 9 and 9'as described above, the chamfered portion 7 is provided at the boundary between the tip end surface 12 of the outer diameter surface side projection 10 and the outer diameter surface 8. Further, a chamfered portion 7'is also provided at the boundary between the step surface 15 'of the outer diameter surface side step portion 14 and the outer diameter surface 8'of the ring body 1.

Also in this case, the chamfered portions 7 and 7'can make the amount of protrusion at the abutting portions 9 and 9'become zero or less, so that local contact with the mating member should be prevented. You can

The third embodiment shown in FIGS. 3 (a), 3 (b) and 3 (c) is a case where the composite step cut type abutments 16 and 16 'are provided. The joints 16 and 16 'are composed of an outer diameter surface side projection 17 and an outer diameter surface side step portion 18,
The outer diameter side projections 17 and the outer diameter surface side step portions 18 and the outer diameter surface side step portions 18 and the outer diameter surface side projections 17 of 6 and 16 'are complementarily fitted with a certain gap. Yes, it will be described in more detail as follows.

That is, as shown in FIG. 6 (c), with respect to one of the mating openings 16 ', the outer diameter surface side projection 17 from the ring body 1
With reference to the surface of the tip on the inner diameter surface side of the portion where the concave portion that forms the circumferential direction and the recess that forms the outer diameter surface side step portion 18 extend in the opposite direction, this surface is called the abutting surface 19, The outer diameter surface side protrusion 17 is provided on one side surface side when the abutting surface 19 is divided into left and right sides, and on the outer diameter side when it is divided into the inside and the outside (the inner diameter side and the outer diameter side of the ring main body 11), The outer diameter surface 26 of the outer diameter surface side protrusion 17 is formed so as to be continuous with the outer surface of the ring body 1 without a step and to have the same curvature.

The outer diameter surface side step portion 18 is provided on the other side surface and the outer diameter side when the abutting surface 19 is similarly divided into left and right and inside and outside, and the outer diameter surface side step portion 18 is provided. The inner surface 22 of is formed to have the same curvature as the inner diameter surface of the ring body 1.

The other abutment 16 is the above-mentioned abutment 16 '.
Is formed in a shape complementary to that of both abutments 16, 16 '.
Are fitted to each other with a certain gap, and the seal ring has a substantially circular shape.

A feature of the present invention is that a chamfered portion is provided at a corner portion which faces the outer diameter surface side. Specifically, the composite step cut type abutment 16 as described above,
In the seal ring having 16 ', a chamfered portion 24 is provided at the boundary between the tip surface 23 of each outer diameter surface side projection 17 and its outer diameter surface 26, and the step surface 25 of each outer diameter surface side step portion 18 and the ring. A chamfer 24 ′ is also provided between the body 1 and the outer diameter surface 26.

Also in this case, these chamfered portions 24, 2
By 4 ', the amount of protrusion of the portion of the abutment 16, 16' becomes zero or less, so that it is possible to prevent local contact with the mating member.

The fourth embodiment shown in FIGS. 4 (a), (b) and (c) is a local part which is produced when one of the compound step cut type fitting holes 16 and the other fitting port 16 'are fitted to each other. It prevents breakage and cracks due to static contact. The structure of the compound step cut type abutments 16 and 16 'is the same as that of FIGS. 3A, 3B and 3C except for the chamfered portions 24 and 24'.

The feature of the present invention is that the one abutment 16 and
The chamfered portion is provided at a corner portion that has a surface that comes into contact with each other when the other mating opening 16 'is fitted. Specifically, in the seal ring having the compound step cut type abutments 16 and 16 'as described above, the tip surfaces 23 of the outer diameter side projections 17 and the abutments 16 and 16' are provided.
When each of the outer diameter surface side projections 17 faces each other, a chamfered portion 30 is provided at the boundary with the inner surface 27 of the outer diameter surface projections that face each other.
The tip surface 23 of each outer diameter surface side projection 17 and the mating ports 16, 1
A chamfered portion 30 ′ is provided at the boundary between the outer diameter surface side step portion 18 and the outer diameter surface side step portion inner surface 22, which is a surface where the outer diameter surface side projection and the outer diameter surface side step portion 18 face each other when 6 ′ is fitted. A chamfered portion 30 ″ is provided at the boundary between the inner surface 22 of the step portion on the outer diameter surface side and the abutting surface 19 of the abutments 16 and 16 ′.

In this case, these chamfered portions 30, 3
By 0 ', 30'', local contact which occurs when fitting the abutments 16, 16' is avoided or reduced, so that the mutual abutment can be prevented from being damaged.

The fifth embodiment shown in FIGS. 5A, 5B and 5C is a combination of the constructions of the third embodiment and the fourth embodiment.

The features of the present invention are that a corner portion facing the outer diameter surface side, one abutment 16 and the other abutment 1 are provided.
6'is provided with a chamfered portion at the corners which are in contact with each other when fitted together. Specifically, in the seal ring having the compound step cut type mating ports 16 and 16 ′, the boundary between the tip end surface 23 of each outer diameter surface side projection and the outer diameter surface 26, and each outer diameter surface side Chamfered portions 24, 24 'are provided at the boundary between the tip surface 23 of the projection and the inner surface 27 of the outer diameter surface projection, and the tip surface 2 of each outer diameter surface side projection is formed.
3 and a chamfered portion 30 at a boundary between the outer diameter surface protrusion inner surface 27, and a chamfered portion 30 ′ at a boundary between the tip end surface 23 of each outer diameter surface side protrusion and the outer diameter surface side step portion inner surface 22. Furthermore, the outer diameter side step portion inner surface 22 and the abutting surface 1
A chamfered portion 30 ″ is provided at the boundary with 9.

In this case, the chamfered portions 24 and 24 'make the amount of protrusion of the portions of the abutments 16 and 16' zero, or
Or, since it is reduced, it is possible to prevent local contact with the mating member, and the chamfered portions 30, 30 ′, 30 ″.
As a result, local contact that occurs when fitting the abutments 16 and 16 'is avoided or reduced, so that damage to the abutments and the like can be prevented, and a synergistic effect can be obtained. .

Embodiment 6 shown in FIGS. 6A, 6B and 6C
Is obtained by adding the following configuration to the configuration of the above-described fifth embodiment. That is, in this case, the boundary between the step surface 25 of the outer diameter surface side step portion 18 of the abutment 16, 16 ′ and the outer diameter surface side projection inner surface 27 and the outer diameter surface side step portion inner surface 22 is rounded. Meat 3
2, 32 'are provided. Above fillet 32, 3
By providing 2 ', in addition to the above effects, the outer diameter surface side projection 17 and the outer diameter surface side step portion 18 are reinforced, and this occurs when the mating ports 16 and 16' are fitted together. Damage due to local contact can be prevented.

The sixth embodiment is the same as the fifth embodiment except that the fillets 32 and 3 are the same.
2'is added, but it can be used not only in the case of Example 5 but also in any of Examples 2 to 4, and the effect of adding the fillet exactly the same as in Example 6 Can be obtained.

Further, the chamfered portions 30 ', 30''and the fillet 32 of FIG. 2 are provided in the same manner as the chamfered portion and the fillet of the other embodiments described above, so that the chamfered portions 30', 30 '' at the time of fitting can be obtained. It is possible to prevent damage due to local contact.

The corners other than the above-mentioned corners may be chamfered or have a fillet.

By the way, the chamfered portion or the fillet portion may have a curvature or an inclined surface,
A more preferable shape is a chamfered shape having a curvature. The dimension of the chamfered portion or the fillet portion near the minimum value is about 5% to 50%, preferably about 5% to 25% of either the axial dimension or the radial dimension of the seal ring. . If this value is too small, it is conceivable that the mating member will be damaged if the amount of protrusion at the abutment portion is slight.

On the other hand, the dimension near the maximum value of the shape of the chamfered portion or the fillet portion of the curvature or the inclined surface is one of the outer diameter of the seal ring, the inner diameter, or the diameter of the intermediate portion thereof. It may be about 5 to 50%, preferably about 25 to 50%. If this value is too large, the effect of providing a chamfer is weakened, and only a chamfer that is substantially equivalent to the curvature of the outer diameter of the seal ring can be formed, and the protrusion amount of the abutment portion is set to zero, or I can't expect to reduce it. In any case, the dimensions of the chamfered portion may be in the range above or below these minimum values or above this value and below or below these maximum values.

The seventh embodiment shown in FIGS. 7A and 7B is as follows.
The following structure is added to the structure of the third embodiment. That is, in this case, between the inner diameter side surface of the outer diameter surface side projection 17 of one of the mating openings 16 or 16 'and the inner surface 22 of the outer diameter surface side cross section 18 of the other mating opening 16' or 16 facing this. A predetermined gap g ₁ is provided between them. By doing so, the amount of protrusion of the outer diameter surface side projection 17 toward the outer diameter surface side of the seal ring is further reduced. Also, the dimensional tolerance in the thickness direction of the outer diameter surface side projection 17 and the outer diameter surface side cross section 18 can be absorbed by the gap g ₁ , and the outer diameter surface side projections 17 are connected to the outer diameter surface side. Prevent protrusion.

Further, a predetermined gap g ₂ is also provided between the inner side surfaces 27 of the outer diameter surface side projections 17 of both the abutments 16 and 16 ′ which face each other. The gap g ₂ absorbs the dimensional tolerance of each outer diameter side protrusion 17 in the width direction, and prevents each outer diameter side protrusion 17 from projecting to both side surfaces.

The gaps g ₁ and g ₂ are the same as those in the other examples 1 to 1.
Even when it is provided at the abutment of No. 6, as in the case of the seventh embodiment, when the protrusions 17 of the outer diameter side are prevented from projecting to both sides and when the abutments 16 and 16 'are fitted. It is possible to prevent damage and the like due to local contact that occurs in the.

Next, a method for manufacturing the synthetic resin seal ring will be described with reference to the composite step cut type abutments 16 and 16 'of the third embodiment. This is Example 3
Not only this but also other Examples 1-2, 4-7 can be applied similarly.

First, as shown in FIG.
The 6'portion is separated and injection-molded into a shape in which there is no radial overlap between the two. Next, as shown in FIG. 9, the above-mentioned molded product 28 is attached to the ring gauge 3 by using a jig including a cylindrical body 29 made of synthetic resin or rubber and a ring gauge 31.
1 is inserted into the inner diameter surface of the cylindrical body 1 and the cylindrical body 2 is placed inside the molded article 28.
Insert 9. The resin forming the columnar body 29 is a substance having a coefficient of thermal expansion higher than that of the ring gauge 31, for example, a resin having a coefficient of thermal expansion higher than that of the ring gauge 31 or a polymeric substance such as an elastomer, and is molded by thermal expansion when heated. Apply a force from the inside of item 28. In the case of an elastomeric polymer, it is considered preferable that the rubber hardness (Hs) is about 60 to 100, preferably about 65 to 90 because good elastic force can be obtained. If the rubber hardness is too high, it will be too hard, and it will be difficult to insert the columnar body 29 inside the molded product 28. If the rubber hardness is too low, it will be too soft, and it will be difficult to obtain an appropriate elastic force.

Next, the entire jig is placed in an electric furnace or the like,
The molded product 28 is heated to a temperature not lower than the glass transition point of the base resin of the molded product 28 to heat-fix the molded product 28. Thus, a composite step cut type seal ring as described above can be obtained.

In order to know the performance of the seal ring obtained by the above manufacturing, a durability comparison test was conducted.

(Test contents of experimental example) Polyetheretherketone resin was used as a main material, and carbon fiber and tetrafluoroethylene resin were mixed as a filler. A material having a vertical cross section of a substantially rectangular shape and an outer diameter of 50 mm was used. A seal ring having a ring width of 2.0 mm, a ring thickness of 1.8 mm, and the compound step cut type abutments 16 and 16 'shown in FIG. No. 8), injection-molded into a jig, and then forcedly deformed as shown in FIG. 9. The jig was placed in an electric furnace and heat-set at 200 ° C. for 2 hours.

The seal ring thus obtained was used in an automatic transmission oil for automobiles (DEXILON II (trade name) manufactured by Showa Shell Sekiyu) in a cylinder material S45C and a shaft material S45C mating material.
It was subjected to a durability test for 100 hours under the conditions of a hydraulic pressure of 1.5 MPa, a cylinder rotation speed of 8000 rpm (the shaft was fixed), and an oil temperature of 120 ° C., and the leak amount and the cylinder wear amount were measured. The obtained results are shown in FIG.

(Test contents of comparative example) Material, longitudinal sectional shape,
The outer diameter, ring width, ring thickness, and shape of the abutment are the same as in the experimental example, the abutment is widened, and a protrusion with no crowning portion is formed by injection molding and heat-fixed. Without being forced, it was forcibly deformed and mounted on the mating material, and subjected to a durability test under the same conditions as above. The obtained results are shown in FIG.

(Consideration of Test Results) As shown in FIG.
It was confirmed that the oil sealings of the examples have a small amount of leak and a significantly small amount of friction of the cylinder.

(Injection Molding of Seal Ring) The seal ring having the above-mentioned abutment can be obtained by using a usual method, but a more preferable method is as follows.

The seal ring 41 of the eighth embodiment shown in FIGS. 11 (a) and 11 (b) has a pair of facing facing openings 42 having the above-described structure, and is separated at this portion. There is. After the injection molding, this separated portion is heat-fixed by engaging the respective mating holes 42 with each other, and when assembling into the seal groove of the mating member, the mating holes 42 are widened.

There is an injection position 43 for injecting the material substantially at the center of the entire length of the seal ring 41. Since this injection position 43 usually remains as a trace of the gate 44 at the time of injection molding, the position can be known. Also,
Even if the gate 44 portion is processed to be smooth, the portion can be recognized by a magnifying glass or the like.

The outer diameter of the seal ring 41 is φ70.
The total length is about 220 mm. The injection position "almost in the center" means the central part of the entire length of the seal ring 1 within ± 3
A position within the range of 0 °.

The seal ring 41 is made of polyetherketone resin as a main material, and carbon fiber, fluororesin such as tetrafluoroethylene resin, and other solid lubricants are mixed as a filling material. An outer diameter of 70 mm, a width of 2 mm, and a wall thickness of 2 mm were determined so as to be rectangular, and injection molding was performed. The obtained results are shown in FIGS. 13 and 14.

FIG. 12 shows a ninth embodiment. In this case, the seal ring 41 is slightly displaced from the center of its entire length (± 10
The material injection position 43 is located at a position of (° to ± 30 °), and the material composition and dimensions are the same as in the eighth embodiment.

In this case, it is possible to avoid that the stress at the time of assembling into the seal groove of the mating member is concentrated in the center of the entire length and concentrated in the injection position 43 which is slightly displaced from the center. Especially in the step-cut type seal ring, the gate position is ± 10 from the center of the entire length of the seal ring.
If it deviates by about ± 30 °, a large force will be applied to the gate part even if it is expanded or closed by more than the length of the step cut protrusion when it is heat set after molding or the seal ring is installed in the piston. You can ease your participation.

With the same composition, size and shape as in the eighth embodiment, the injection position 43 was set in the vicinity of one of the mating holes 42 of the seal ring 41 and injection molding was carried out. Simultaneously with the eighth embodiment, the dimension measurement and the bending strength test were conducted. went. The results obtained are shown in FIG.
And also shown in FIG.

As can be seen from these results, it was confirmed that the strength decreases and the width dimension decreases when the distance exceeds 150 mm from the injection position.

It should be noted that although a decrease in strength is observed at the injection position 43, it is at a level where there is no functional problem.

Next, FIG. 15 shows a part of an injection molding die 45, in which a cavity 6 for molding the above-mentioned seal ring 41 is formed, and a gate 44 is provided at approximately the center of its entire length. There is.

The position of the gate 44 is selected within a range of ± 30 ° from the center of the entire length, preferably a position of about ± 10 °.
Injection molding of the seal ring of the embodiment is performed. By molding by injection molding, a seal ring having a complicated shape can be easily manufactured.

The seal ring manufactured in this manner is excellent in heat resistance and is therefore particularly suitable for an oil seal ring for an automatic transmission.

(Example of Seal Ring of Other Shape) Next, a seal ring having another shape of the present invention will be described.

FIGS. 16 (a) to 16 (f) show a seal ring 50 of the tenth embodiment having the above-mentioned structure of the abutment.
The sealing surface 51 on one side of the ring 50 has approximately 3
A lubricating groove 52 penetrating from the inner peripheral side to the outer peripheral side is formed at equal positions, and a similar lubricating groove 52 is formed on the seal surface 21 on the other side surface with a slight shift.

These lubricating grooves 52 are minute ones having a depth of about 0.1 mm and a width of about 0.1 mm, and even if they are provided in 1 to 5 places, preferably 1 to 3 places as shown in the drawing, the sealing performance is improved. It does not hurt. Further, a chamfered portion 53 is provided at the opening end of the lubricating groove 52 on the seal surface 51 side.

The sectional shape of the seal ring 50 is shown in FIG.
As shown in FIGS. 6 (d) and 6 (e), step portions 56 are provided between the both side seal surfaces 51 and the outer peripheral surface 54 and between the both side seal surfaces 51 and the inner peripheral surface 55, respectively. The step portion 56 is shown in FIG.
As shown in FIG. 6 (f), a right angle surface 57 with respect to the sealing surface 51 is formed.
And a slant surface 58 'formed between the right-angled surface 57' and the both right-angled surfaces 57, 57 'with respect to the outer peripheral surface 54, and the height h of the stepped portion 56 is higher than the depth of the lubricating groove 52.

The height h of the step portion 56 is not particularly limited, but the length of the rectangular cross section of the seal ring 50 in the radial direction,
Alternatively, each of the axial lengths is about 5 to 50%, preferably about 5 to 25%, and more preferably about 5 to 1%.
It is preferably about 0% and provided on one side or both sides of the seal ring 50. Any of the above numerical ranges may be selected so that it exceeds the lower limit and is less than the upper limit.

If the height h of the step is too small, there is a possibility of causing a defect when the displacement between the movable mold and the fixed mold occurs in a relatively short period when the mold is used for a long period of time. If the amount is too large, the area of the seal portion of the seal ring, that is, the so-called seal land is reduced, so that reliable and good sealing characteristics cannot be expected.

The shape of the abutment 60 is the same as in the first embodiment.
It may have any type of ~ 7. An example of using the sixth embodiment is shown in FIG.

FIG. 17 shows the position of the mating surface 61 of the mold 59 when the seal ring 50 is injection molded with synthetic resin. That is, the mating surface 61 is set at one end of the outer peripheral surface 54 on the side of the stepped portion 56. When the mating surface 61 is set in such a position, the burr 62 is generated at a position apart from the lubricating groove 52, so that the lubricating groove 52 is not closed.

FIGS. 18 (a) and 18 (b) show a seal ring 50 of the eleventh embodiment, in which the lubricating groove 52 is a circumferential groove 6 formed over the entire circumference in the central portion of the seal surfaces 51 on both sides.
3 and an outer diameter direction groove 64 and an inner diameter direction groove 65 respectively formed in the outer circumferential direction and the inner circumferential direction from the circumferential groove 63, and the positions of the outer diameter direction groove 64 and the inner diameter direction groove 65 are in the circumferential direction. Deviated.

The lubricating groove 52 of the seal ring of the twelfth embodiment shown in FIGS. 19 (a) and 19 (b) comprises an outer diameter direction groove 64 and an inner diameter direction groove 65 formed at the same position as the circumferential groove 63.

FIGS. 20 (a) and 20 (b) show various examples of the shapes of the various step portions 56 of the seal ring. In each case, there is a step between the mating surface 61 of the mold and the lubricating groove 52. Yes,
The burr prevents the lubricating groove 52 from being blocked. Also, in all of these, the mating surface 61 of the mold is a right angle surface 57 '.
Therefore, even if the mating surfaces of the fixed mold and the movable mold are slightly deviated from each other, there is no part protruding to the outer peripheral surface 54 or the inner peripheral surface 25 side.

(Material of Seal Ring and Molding Method) The seal ring of the present invention can be obtained by molding a resin composition comprising a heat resistant resin, a reinforcing fiber, a fluororesin and a filler.

The heat-resistant resin may be any resin as long as it has heat resistance. For example, a polycyanoaryl ether resin (hereinafter abbreviated as PEN), a polyether-etherketone resin ( Hereinafter, it will be abbreviated as PEEK.) Aromatic polyether ketone resin (hereinafter,
Abbreviated as PEK. ), An aromatic thermoplastic polyimide resin (hereinafter abbreviated as TPI), a polyamide 4-6 resin (hereinafter abbreviated as PA-46), a polyphenylene sulfide resin (hereinafter abbreviated as PPS). Etc. In addition to high heat resistance, these have high flame resistance, excellent mechanical properties, excellent electrical properties, and chemical resistance. These materials are used as the molding base material of the oil seal ring of the present invention. If the melting point of these heat-resistant thermoplastic resins is at least 280 ° C. or higher, they can be preferably used in the present invention.

PEEK such as PEEK used in the present invention
As the above, a ketone polymer having a melting point of 330 ° C. or higher can be used without limitation. PEK is a structural unit represented by the following (Chemical Formula 1) to (Chemical Formula 6), in which an aromatic ring is bonded to include both an ether bond (-O-) and a ketone bond (-CO-). Resins having All of these are crystalline resins. These PEK resins have excellent thermal dimensional properties, and even if they are used as oil seal rings at high temperatures such as heat shrinkage and heat shrinkage of automatic transmissions, there is little dimensional change, and such dimensional accuracy is required. It is suitable for use at a high temperature with a seal ring having a mating shape.

[0089]

Embedded image

(N represents an integer.)

[0091]

Embedded image

(N represents an integer.)

[0093]

[Chemical 3]

(N represents an integer.)

[0095]

[Chemical 4]

(N represents an integer.)

[0097]

[Chemical 5]

(N represents an integer.)

[0099]

[Chemical 6]

(N represents an integer.) Of the above resins, the resin of Chemical formula 1 has a glass transition point (Tg) of about 165.
C., melting point (Tm) is 365.degree. C., and as a typical example, VICTREX-PE manufactured by UK IC Corp.
K 220G (trade name) is included. Also, (Chemical formula 2)
The glass transition point (Tg) of the resin is about 150 ° C and the melting point (Tg)
m) is 334 to 337 ° C., and as a typical example, VICTREX-PEEK manufactured by British IC KK
150P (brand name) is mentioned. Further, the glass transition point (Tg) of the resin of (Chemical Formula 3) is about 160 ° C. and the melting point (Tm)
Is 360 to 380 ° C., and a typical example thereof is HOSTATEC (trade name) manufactured by Hoechst in Germany. Furthermore, the glass transition point (Tg) of the resin of (Chemical formula 4) is about 170 to 175 ° C, and the melting point (Tm) is 375 to 381 ° C.
And a typical example thereof is Ultrapek-A2000 (trade name) manufactured by Germany BSF.

As the heat resistant resin other than PEK such as PEEK, known resins which are commercially available can be adopted. As a specific example, PEN: Idemitsu Kosan Co., Ltd .: ID300 (trade name), TPI: Mitsui Toatsu Co., Ltd .: Aurum 450 (trade name), PA-46: Japan Synthetic Rubber Co., Ltd .: Stanil TW300 (trade name), P
Kureha Chemical Company as PS: Fortron KPS W21
4 (trade name) and the like can be exemplified.

The blending ratio of the above heat resistant resin is preferably 30 to 82% by weight based on the resin composition of the present invention,
˜78 wt% is more preferred. This is because a small amount of less than 30% by weight results in a decrease in strength, and a large amount of more than 82% by weight is not preferable because the reinforcing effect by the filler cannot be obtained and the abrasion resistance is deteriorated. Because.

The reinforcing fiber in the present invention is not particularly limited, but carbon fiber and aromatic polyamide fiber can be mentioned as examples.

The carbon fibers have an average fiber diameter of 1 to 20 μm.
m, preferably 5 to 18 μm, more preferably 5 to 1
It is 5 μm. Moreover, 1-80 are preferable and, as for an aspect ratio, 5-50 are more preferable. Because, when the average fiber diameter is less than 1 μm, agglomeration between fibers occurs,
This is because it becomes difficult to uniformly disperse the particles, and a thick material having a thickness of more than 20 μm causes abrasion of the soft counterpart material. When the average fiber diameter is in the above range, such a tendency is lessened, which is preferable. On the other hand, if the aspect ratio is less than 1, the reinforcing effect of the matrix itself is impaired and the mechanical properties are deteriorated. On the other hand, if it exceeds 80, uniform dispersion during mixing is extremely difficult and wear characteristics are hindered. This is because it is not preferable because it causes a decrease. When the aspect ratio is 1 to 80, such a tendency is relatively small, and favorable results are obtained.

The above-mentioned aromatic polyamide fiber is well known as a fibrous heat-resistant resin represented by the following formula (Chem. 7), wherein aromatic rings are bonded at the meta position by an amide bond, It may be any of those in which the group ring is linked by an amide bond at the para position.

[0106]

[Chemical 7]

Of these, the para-aromatic polyamide fiber is a para-aromatic polyamide fiber containing a repeating unit represented by the following formula (Formula 8).

[0108]

Embedded image

Since the para-aromatic polyamide fiber has molecular chains arranged in the axial direction of the fiber, it has high elasticity in the axial direction.
It has high strength, but weak intermolecular force in the perpendicular direction. As described above, the para-aromatic polyamide fiber can improve the abrasion resistance of the blended resin composition well due to the strength in the axial direction. On the other hand, when the compressive force is applied in the direction perpendicular to the fiber, the molecular chain buckles. Or, since it is easily broken, it is considered that it does not damage the soft sliding mating material.

When an aromatic polyamide fiber other than a para-based resin is used, by adding a resin containing a predetermined amount of a fluorine-based resin such as a tetrafluoroethylene resin, the same soft sliding property as that of the above composition can be obtained. It is possible to obtain a composition having excellent wear resistance without damaging the moving partner material.

Such aromatic polyamide fiber preferably has a fiber length of about 0.15 to 3 mm and an aspect ratio of about 1 to 230. The average fiber diameter is about 1 to 20μ.
It is preferably m, and more preferably about 5 to 15 μm. The aspect ratio is preferably about 1 to 60, more preferably about 15 to 40. If the fiber length of the aromatic polyamide fiber is less than the predetermined range, the abrasion resistance becomes insufficient, and if the fiber length exceeds the above range, the dispersion in the composition is unsatisfactory, which is not preferable. On the other hand, if the aspect ratio is less than 1, the shape is close to that of powder, the effect of improving the wear resistance is insufficient, the reinforcing effect of the matrix is lost, and the mechanical properties are lowered. On the other hand, when it exceeds 60, it becomes difficult to uniformly disperse it during mixing, and the wear characteristics of the composition are not uniform.

When the average fiber diameter is smaller than about 1 μm, the fibers are aggregated when mixed into the matrix, and uniform dispersion is difficult, and the average fiber diameter is about 20 μm.
If the diameter is larger than m, the composition may slide and wear the soft counterpart material. Those having an average fiber diameter of about 5 to 15 μm are extremely preferable because such a tendency is not observed at all.

The content of the reinforcing fiber in the total resin composition is 5 to 45% by weight, preferably 10 to 45% by weight, more preferably 10 to 30% by weight. Because 5
If it is less than 5% by weight, the wear resistance of the molded body is hardly improved and
This is because if the amount is more than 10% by weight, the melt fluidity is significantly reduced and the moldability is deteriorated. When the blending ratio is 10 to 30% by weight, such a tendency does not occur at all, and a preferable result is obtained.

The fluororesin used in the present invention is
For example, polytetrafluoroethylene (hereinafter abbreviated as PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (abbreviated as PFA),
Tetrafluoroethylene-hexafluoropropylene copolymer (abbreviated as FEP), ethylene-tetrafluoroethylene copolymer (abbreviated as ETFE), tetrafluoroethylene-fluoroalkyl vinyl ether-fluoroolefin copolymer (abbreviated as EPE) ), Polychlorotrifluoroethylene (abbreviated as PCTFE), ethylene-chlorotrifluoroethylene copolymer (abbreviated as ECTFE), polyvinylidene fluoride (P).
Examples thereof include VDF) and polyvinyl fluoride (abbreviated as PVF). These may be used alone or in the range of 1:10 to 10: 1, for example, fluorinated polyolefins such as the above-mentioned two or more copolymers and terpolymers, and the like. The characteristics as an agent are shown.

Of these, PTFE has a melting point of about 327 ° C. and a melt viscosity of about 10 ¹¹ -1 even at about 340-380 ° C.
It is considered to be a resin having the highest heat resistance among fluororesins because it has a high value of 0 ¹² poise and is hard to flow even if it exceeds the melting point. When such PTFE is adopted, it may be a powder for molding or a so-called fine powder for a solid lubricant, and a commercially available product is Teflon 7J manufactured by Mitsui DuPont Fluorochemicals. (Product name), T
LP-10 (trade name), Asahi Glass Co., Ltd .: FLUON G163
(Trade name), manufactured by Daikin Industries, Ltd .: polyflon M15 (trade name), Lubron L5 (trade name), and the like. Alternatively, PTFE modified with an alkyl vinyl ether may be used. Generally, PTFE is a homopolymer of tetrafluoroethylene, and a commercially available resin can be used as a compression-moldable resin, for example, manufactured by Kitamura:
400H (trade name) or the like can be adopted.

As PFA, Teflon PFA-J (trade name) and MP-1 manufactured by Mitsui DuPont Fluorochemicals Co., Ltd.
0 (commercial name), Hoechst: Hostafuron TFA (commercial name), Daikin Industries, Ltd .: Neoflon PFA (commercial name), FEP as Mitsui DuPont Fluorochemicals Co., Ltd .: Teflon FEP-J (commercial name), Daikin Industries, Ltd .: Neoflon FEP (trade name), ETFE: Mitsui DuPont Fluorochemicals: Tefzel (trade name), Asahi Glass Co .: Aflon COP (trade name), and EPE: Mitsui DuPont Fluorochemical Co .: Teflon EPE-J (trade name) and the like can be mentioned.

The perfluoro fluororesin such as PTFE, PFA, FEP, etc. is a state in which the carbon base paper as the skeleton is entirely surrounded by the fluorine base paper or a trace amount of oxygen atoms. Among the fluorine-based resins, the heat resistance temperature is relatively high, and various characteristics such as low friction coefficient, non-adhesiveness, and chemical resistance are excellent, which are preferable. PVD
Examples of F include KF polymer (trade name) manufactured by Kureha Chemical Industry Co., Ltd.

The blending ratio of the above-mentioned fluorine resin is 2 to 25% by weight, preferably 5 to 25% by weight. This is because if it is less than 2% by weight, the sliding characteristics such as self-lubricating property and abrasion resistance are not significantly improved, and if it exceeds 25% by weight, the formability is deteriorated and the mechanical properties are deteriorated. . When the blending ratio is 5 to 25% by weight, such a tendency is hardly seen and a preferable result is obtained.

The filler used in the present invention is, for example,
Examples thereof include powder talc and calcium-based powder filler.

The powdered talc has an average particle size of about 0.5 to
40 μm is preferable, and about 1 to 30 μm is more preferable.
This is because small particles of less than about 0.5 μm cause agglomeration between particles to make uniform dispersion difficult, and large particles of more than about 40 μm result in poor surface smoothness, which is not preferable.

Examples of the above calcium-based powder filler include calcium carbonate, sulfate, oxide and hydroxide, of which calcium carbonate or calcium sulfate is preferable. The average particle size of the calcium-based filler is about 0.
5-40 micrometers is preferred and about 1-30 micrometers is more preferred. This is because small particles of less than about 0.5 μm cause agglomeration between particles to make uniform dispersion difficult, and large particles of more than about 40 μm result in poor surface smoothness, which is not preferable.

The blending ratio of the above filler is preferably 10 to 40% by weight, more preferably 10 to 30% by weight based on the total resin composition. This is because if it is less than 10% by weight, the soft counterpart material is abraded, and if it exceeds 40% by weight, the formability is deteriorated and the mechanical properties are deteriorated. The same mixture ratio is 10-30
If it is% by weight, there is no such tendency, and preferable results are obtained.

In addition to the above, molybdenum disulfide or the like can be used as the antiwear agent. This molybdenum disulfide is added in order to improve wear resistance, and its mixing ratio is preferably 1 to 10% by weight. Because, in the compounding amount less than the above predetermined range, the improvement of sliding characteristics such as self-lubricating property and abrasion resistance is not significantly recognized, and in the compounding amount exceeding the above predetermined range, the mechanical strength decreases, and This is because the wear resistance is not improved in proportion to the blended amount.

The following can be mentioned as examples of combinations in the resin composition used for the seal ring of the present invention.

TPI, PEEK, PEK, PEN,
A resin composition containing 30 to 82% by weight of any one resin selected from the group consisting of PA-46 and PPS, 5 to 45% by weight of carbon fiber, and 2 to 25% by weight of a fluororesin.

PEN, PEEK, PEK, TPI,
30 to 82% by weight of any one resin selected from the group consisting of PPS and PA-46, 5 to 45% by weight of carbon fiber,
Fluorine resin 2-25% by weight, powdered talc 10-40
A resin composition whose main component is wt%.

PEN, PEEK, PEK, TPI,
Mainly contains 30 to 78% by weight of any one resin selected from the group consisting of PPS and PA-46, 10 to 45% by weight of carbon fiber, 2 to 25% by weight of fluororesin, and 10 to 40% by weight of powdered calcium compound. A resin composition as a component.

PEN, PEEK, PEK, TPI,
30 to 82% by weight of any one resin selected from the group consisting of PPS and PA-46, 5 to 45% by weight of carbon fiber,
Fluorine resin 2-25% by weight, powdered talc 10-40
A resin composition comprising 1 wt% and 1-10 wt% molybdenum disulfide.

10-40% by weight of the powdered talc
In place of the above, 10 to 40% by weight of calcium powder filler is blended.

A material in which 5 to 45 wt% of aromatic polyamide fiber is blended in place of 5 to 45 wt% of the carbon fiber.

Aromatic polyamide fibers of 5 to 45% by weight are blended in place of the carbon fibers of 5 to 45% by weight, and calcium powder fillers of 10 to 40% by weight are substituted for powdered talc of 10 to 40% by weight. A resin composition containing

The resin composition of the present invention has the purpose of improving the self-lubricating property, the mechanical strength, the thermal stability, and the like, and coloring, as long as the additives other than the above do not impair the effects of the present invention. Then, solid lubricants, fillers, powder fillers, pigments, and other substances that are stable at a high temperature of about 350 ° C. or higher may be appropriately mixed. For example, in order to further improve the lubricity of the resin composition, a wear resistance improver can be added. Specific examples of this wear resistance improver include carbon, graphite, mica, wollastonite, powders of metal oxides, whiskers such as calcium sulfate, phosphates, carbonates, stearates, and ultra-high molecular weight polyethylene. Can be illustrated. The balance of the heat resistant resin when adding such an additive is preferably not less than about 40% by weight.

The method for adding and mixing various additives to these heat resistant resins is not particularly limited, and a method that is generally widely used, for example, a resin as a main component,
Other various raw materials are individually or individually dry-mixed by a mixer such as a Henschel mixer, a ball mill, a tumbler mixer, and then supplied to an injection molding machine or a melt extrusion molding machine having a good melt-mixing property, or a hot roll in advance. , Kneader, Banbury mixer, melt extruder, and the like may be used.

Further, when molding the above composition,
The molding method is not particularly limited, and a usual method such as compression molding, extrusion molding, or injection molding, or after melt-mixing the composition, the composition is pulverized by a jet mill, a freeze pulverizer, or the like to obtain a desired particle size. It is also possible to classify into. Among them, the injection molding method has excellent productivity and can provide an inexpensive molded body.

The particles such as pellets thus obtained may be subjected to a drying treatment to the same extent as the heat treatment described later before molding. It is considered that the swelling and strength reduction of the molded body can be prevented by sufficiently evaporating the water content from the grains such as pellets.

The molded body thus obtained is heated at about 100 to 280 ° C. for about 0.1 to 24 hours in order to secure dimensional stability during high temperature use by removing heat distortion and strain during molding. It is desirable to perform the annealing heat treatment of.

The annealing heat treatment temperature depends on the material,
Approximately 280 ° C or lower, for example, approximately 140 to 270 ° C, and approximately 140 to 230 ° C or approximately 140 to 200 depending on the material.
It is suitable to carry out at about ° C. These heat-resistant resins have high rigidity over a wide temperature range, excellent impact resistance, are strong against distortion such as creep, and are resistant to almost all types of oils and chemicals. . Further, these resins are crystalline, and have properties such as an increase in crystallinity and an increase in strength and rigidity, an improvement in wear resistance and lubricity, and a decrease in thermal expansion coefficient and water absorption.

When the heat treatment temperature is lower than about 140 ° C.,
It is considered that it takes a lot of time for the crystallization to proceed, the efficiency is low, it is difficult to remove a slight strain of the molded body, and it is difficult to obtain the dimensional stability.

When the annealing heat treatment temperature exceeds the heat deformation temperature by about 20 to 30 ° C., the influence of the heat history applied to the resin is considered to be unfavorable, which is not preferable. During the heat treatment, before reaching the predetermined temperature, for example, at room temperature, about 80 ° C., about 130 ° C., about 180 ° C., about 220 ° C., about 230 ° C., about 280 ° C. The temperature may be gradually raised every about 15 to 60 minutes in the range of about 15 to 180 minutes, and the temperature may be kept constant at the optimum temperature within the temperature range within the time range. In that case, the maximum temperature holding time is about 15
It may be about 480 minutes. If the holding time at the maximum temperature is shorter than the specified time, the crystallization of the resin will be insufficient and the dimensional stability will be poor, and if it is longer than the specified time, "warping" will be inappropriate. It is difficult to reduce the manufacturing cost in view of an increase in the energy consumption of an electric furnace and an increase in the manufacturing time.

Further, when the temperature is raised to about 90 to 120 ° C., it may be maintained at such a constant temperature. By doing so, it is possible to dry the water taken in a little in the molded body and then crystallize it. On the other hand, it is not preferable to rapidly heat and finish the heat treatment in a short time. This is because the water content above the boiling point is vaporized, and the volume expansion at that time increases the possibility that defects such as “swelling” occur in the molded body.

The cooling after the crystallization step may be carried out through the steps opposite to the above-mentioned temperature rising, or may be continuously gradually cooled for about 60 to 180 minutes.

By performing the heat treatment process as described above, the occurrence of defects such as swelling of the molded body can be prevented as much as possible, and the crystallization of the resin can be reliably and gradually advanced to improve the dimensional stability of the molded body. It is possible to provide a molded product with high dimensional accuracy.

The surface roughness of the sliding surface of at least one of the molded body and the mating member is JI such as Rmax, Ra, or Rz.
According to the evaluation method defined by S, it is about 3 to 25 μm or less, preferably about 8 μm or less, more preferably about 3 μm.
m or less. This is because when the surface roughness exceeds the predetermined range, the sliding surface is often scratched, which is considered to cause wear.

Since it takes a long time to finish the surface of the mating member, it may be inefficient or affected by the formation of the transfer film of the resin material. It is presumed that the range may be about 3 to 8 μm or less under the above conditions.

The mating material for the piston, cylinder, etc. is carbon steel such as S45C, SCM420H, or FCD45.
It may be a hard material such as spheroidal graphite cast iron or the like, or a hardened material thereof, or a soft material such as an aluminum alloy such as ADC12.

[0146]

According to the invention of the seal ring described in claims 1 to 5, the presence of the chamfer can prevent the abutment part from locally contacting the mating material.
There is little leakage and there is little wear on the mating member.

Further, in the seal ring inventions according to claims 4 to 6, the presence of the chamfered portion can prevent the contact of both abutment portions at the time of fitting, so that the abutment portion is not damaged. effective.

Further, in addition to this, in the invention according to claim 7, the protrusion in the outer peripheral surface direction is avoided by the gap between the protrusion and the pocket, and the invention according to claim 8 is Due to the gap between the inner side surfaces, the protrusion of the projections on both side surfaces is avoided, and the above effect is further promoted.

The invention described in claims 9 to 10 makes it possible to easily manufacture an injection-molded seal ring in which the compound step cut type abutments are fitted to each other. There is an effect that it is possible to provide a seal ring that exhibits various effects such as those of the invention described in item 8 at a low cost.

[Brief description of drawings]

FIG. 1A is a partial front view of the first embodiment, and FIG. 1B is a partial plan view of the same.

2A is a partial front view of the second embodiment, FIG. 2B is a partial plan view of the same, and FIG. 2C is a partial perspective view of the same.

3A is a partial front view of the third embodiment, FIG. 3B is a partial plan view of the same, and FIG. 3C is a partial perspective view of the same.

4A is a partial front view of the fourth embodiment, FIG. 4B is a partial plan view of the same, and FIG. 4C is a partial perspective view of the same.

5A is a partial front view of the fifth embodiment, FIG. 5B is a partial plan view of the same, and FIG. 5C is a partial perspective view of the same.

6A is a partial front view of the sixth embodiment, FIG. 6B is a partial plan view of the same, and FIG. 6C is a partial perspective view of the same.

FIG. 7A is a partial front view of the seventh embodiment. FIG. 7B is a partial plan view of the same.

[FIG. 8] (a) Partial front view of the molded product (b) Partial plan view of the same

FIG. 9 is a sectional view showing a heat setting process.

FIG. 10 Chart of test results

FIG. 11A is a plan view of the eighth embodiment. FIG. 11B is a partially enlarged front view of the eighth embodiment.

FIG. 12 is a plan view of the ninth embodiment.

FIG. 13: Test result diagram regarding bending strength change

FIG. 14 is a diagram showing test results regarding changes in width dimension.

FIG. 15 is a cross-sectional plan view showing a part of the embodiment of the injection molding device.

16A is a front view of the tenth embodiment, FIG. 16B is a partially enlarged front view of the same, and FIG. 16C is a partially enlarged plan view of the same. ) (B) sectional view taken along the line ee (f) (d) partially enlarged cylinder sectional view

FIG. 17 is a sectional view of the tenth embodiment during molding.

FIG. 18 (a) is a partially enlarged front view of the eleventh embodiment. FIG.

FIG. 19 (a) is a partially enlarged front view of the twelfth embodiment. FIG. 19 (b) is a sectional view of the above.

FIG. 20A is a sectional view of another example of the seal ring. FIG. 20B is a sectional view of another example of the seal ring.

FIG. 21 is a perspective view of the abutment of Example 10.

FIG. 22 (a) Partial front view of a conventional example (b) Partial plan view of the same

23A is a partial front view of another conventional example, and FIG. 23B is a partial plan view of the same.

FIG. 24 is a partial front view of the conventional example of FIG. 23 after molding.

FIG. 25 is a sectional view of the usage pattern of the conventional example of FIG.

[Explanation of symbols]

 1 Ring body 2, 2'Mating opening 3 Tip surface 4, 4'Outer diameter surface 5 Chamfering portion 7, 7'Chamfering portion 8, 8'Outer diameter surface 9, 9'Mating opening 10 Outer diameter surface side protrusion 11 Inner diameter surface Side step portion 12, 12 'Tip surface 13 Inner diameter surface side protrusion 14 Outer diameter surface side step portion 15, 15' Step surface 16, 16 'Abutment 17 Outer diameter surface side protrusion 18 Outer diameter surface side step portion 19 Butt surface 22 Outer diameter side stepped inner surface 23 Tip surface 24, 24 'Chamfered portion 25 Stepped surface 26 Outer diameter surface 27 Outer diameter side protrusion inner surface 28 Molded product 29 Columnar body 30, 30', 30 '' Chamfered portion 31 Ring gauge 32 , 32 'Fillet 41 Oil seal ring 42 Abutment 43 Injection position 44 Gate 45 Mold 46 Cavity 50 Seal ring 51 Seal surface 52 Lubrication groove 53 Chamfer 54 Outer peripheral surface 55 Inner peripheral surface 56 Step 57, 57' Right-angled surface 58 Inclined surface 59 Mold 60 Fitting 61 Fitting surface 62 Burr 63 Circumferential groove 64 Outer radial groove 65 Inner radial groove 71, 71 'Fitting 72, 72' Fitting 73 73 Seal ring 74 Cylinder 75 Piston 76 Clearance 77 Protrusion 78 step

Claims (10)

[Claims] 1. A straight cut type synthetic resin in which a ring-shaped main body is provided with facing openings facing each other at regular intervals in a circumferential direction, and the front end surfaces of the respective facing openings are formed into straight surfaces. A seal ring made of synthetic resin, characterized in that a chamfered portion is provided at a boundary between the tip end surface of each of the above-mentioned mating ports and the outer diameter surface of the ring body. 2. A ring main body is provided with an abutment facing each other at a certain position in the circumferential direction with a constant interval, and one abutment is provided with an outer diameter surface side protrusion provided on the outer diameter surface side of the ring body. , The inner diameter provided on the inner diameter surface side of the ring body so that the other mating opening is formed by the outer diameter surface side projection and the inner diameter surface side step portion provided on the inner diameter surface side In a step-cut type synthetic resin seal ring formed by a surface side projection and an outer diameter side step provided on the outer diameter side of the inner diameter side projection, a tip surface of the outer diameter side projection and its A synthetic resin seal characterized in that chamfers are provided at the boundary between the outer diameter surface side projection and the outer diameter surface, and at the boundary between the step surface of the outer diameter surface side step and the ring body outer diameter surface. ring. 3. A ring main body is provided with an abutment facing each other at a certain position in the circumferential direction at regular intervals, and one abutment is formed by an outer diameter side projection and an outer diameter side step. In a composite step cut type synthetic resin seal ring formed by an outer diameter side projection and an outer diameter side step which complementarily fit the other abutment, the outer diameter surface of each abutment At the boundary between the tip surface of the side projection and the outer diameter surface of the outer diameter surface side projection, and the boundary between the step surface of the outer diameter surface side step and the ring body outer diameter surface,
Synthetic resin seal rings, each of which has a chamfer. 4. A ring main body is provided with an abutment facing each other at a certain position in the circumferential direction at regular intervals, and one abutment is formed with an abutment surface at the tip on the inner diameter side of the ring body. An outer diameter surface side protrusion and an outer diameter surface side step portion are provided adjacent to each other on the outer diameter surface side of the abutting surface, and the outer diameter surface side protrusion is located near one side edge of the ring body on the outer diameter surface side. And formed by a convex portion protruding from the abutting surface,
Further, the outer diameter surface side step portion is an abutment formed by a recess recessed from the abutting surface, which is close to a side side opposite to the outer diameter surface side protrusion, and the other abutment is The butt surface, the outer diameter surface side projection, and the outer diameter surface side step portion are formed so as to complementarily fit with each other, and the outer diameter surface side projection and the outer diameter surface side step portion are formed. In the composite step cut type synthetic resin seal ring formed from these abutments,
Boundary between the tip surface of the outer diameter surface side projection of each of the mating openings and the outer diameter surface side projection inner surface of the outer diameter surface projections of the two mating openings that face each other when fitted, A tip end surface of the outer diameter surface side projection and an outer diameter surface step portion inner surface where the outer diameter surface side projection portion of the one abutment and the outer diameter surface step portion of the other abutment face each other when fitted. A seal ring made of synthetic resin, characterized in that chamfered portions are provided at a boundary and a boundary between the outer diameter surface side step portion inner surface of each of the mating openings and the abutting surface. 5. A boundary between a tip end surface of the outer diameter surface projection and an outer diameter surface of the outer diameter surface projection of each of the mating ports, and a step surface of the outer diameter surface side step portion and an outer diameter surface of the ring body. The synthetic resin seal ring according to claim 4, wherein chamfered portions are provided at boundaries between the seal rings. 6. The boundary between the step surface of the outer diameter surface side step portion and the inner surface of the outer diameter surface protrusion of each of the mating ports, and the step surface of the outer diameter surface side step portion and the outer diameter surface side step portion. The synthetic resin seal ring according to any one of claims 3 to 5, wherein a fillet is provided at each boundary with the inner surface. 7. A constant gap is provided between the surfaces of the outer diameter surface projection of the one abutment and the outer diameter surface side step portion of the other abutment facing each other. The synthetic resin seal ring according to any one of claims 2 to 6. 8. A constant gap is provided between the surfaces of the outer diameter surface projection of the one abutment and the outer diameter surface projection of the other abutment facing each other. Item 3
7. The seal ring made of synthetic resin according to any one of 1 to 7. 9. A seal ring made of synthetic resin, wherein a gap is provided at one position in the circumferential direction of the ring body at a constant interval so as to face each other, and the gap between the two gap parts is viewed in the radial direction. Injection molding into an expanded form so that there are no overlapping parts, and then the outer diameter surface of the whole is held in a perfect circle shape and heat-fixed by narrowing the gap between the aforesaid joints. A method for manufacturing a resin seal ring. 10. The method for producing a synthetic resin seal ring according to claim 1, wherein the ring main body is provided with facing openings facing each other at regular intervals in one circumferential direction. , Injection molding is performed in such a manner that the gap between both of the aforesaid joints is expanded so that there are no overlapping portions when viewed in the radial direction, and then the gap between the aforesaid joints is narrowed so that the entire outer diameter surface is A method of manufacturing a synthetic resin seal ring, which is characterized by holding in a circular shape and thermally fixing.