JPH07286670A - Oil seal ring - Google Patents

Abstract

PURPOSE:To provide an oil seal ring which employs soft material such as aluminum group alloy as material for a sliding counterpart, causes less abrasion in the counterpart, and itself, and is provided with excellent sealing property. CONSTITUTION:An oil seal ring is made of a molding body of resin composition containing 30-82% by weight of polyamide 4-6 resin, 5-45% by weight of carbon fiber or aromatic polyamide fiber, 2-25 % by weight of ethylene tetrafluoride resin, 10-40% by weight of powder talc or calcium group powder filling agent, and 1-10% by weight of molybdenum disulfide.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil seal ring which is slidably mounted inside an automatic transmission or the like to seal working oil.

[0002]

2. Description of the Related Art Generally, an oil transmission ring such as a torque converter or a hydraulic clutch for automobiles is equipped with an oil seal ring for sealing working oil. Such an oil seal ring is rotatable between the rotary shaft and the cylinder and is in sliding contact with them.

It is estimated that the operating oil has a temperature of about -40 ° C to 150 ° C and an instantaneous maximum temperature of about 170 ° C.

Therefore, such an oil seal ring has a low coefficient of friction and excellent wear resistance and heat resistance depending on the material of the cylinder material (counterpart material) with which it comes in sliding contact,
In addition, many properties are required, such as exhibiting sufficient oil sealability without damaging the mating material.

Recently, along with the demand for weight reduction of automatic transmissions, aluminum alloys have been used as materials for rotary shafts and cylinders, particularly aluminum alloys for die casting (for example, Al-Si-Cu alloys). ADC1
2) has come to be used frequently.

The Al-Si-Cu alloy improves mechanical properties by adding Cu to the Al-Si alloy, solid solution hardening of Cu, precipitation hardening of CuAl ₂ and precipitation hardening of Mg ₂ Si by adding a small amount of Mg. It is an alloy having good castability, machinability, weldability and the like.

Of these, the ADC 10 contains 7.5 to Si.
It contains 9.5% and Cu of 2.0 to 4.0%. The ADC 12 has a relatively large Si content of 9.6 to 12.0% and a Cu content of 1.5 to 3.5% in order to further improve the castability. These are excellent not only in castability but also in pressure resistance and heat resistance.

Cast iron or ethylene tetrafluoride resin has been used as a molding material for the oil seal ring which is in sliding contact with such an aluminum alloy.

[0009]

However, although the cast iron oil seal ring is excellent in wear resistance and does not wear the aluminum alloy mating member, it is inferior in sealability.

A ring made of tetrafluoroethylene resin (hereinafter abbreviated as PTFE) has excellent sealing properties, but the ring itself and an aluminum alloy mating material are slightly worn in a short time under sliding conditions where the PV value is high. There are drawbacks.

Further, in order to improve the wear resistance of the conventional PTFE ring, a seal ring has been developed in which carbon fiber and PTFE powder are filled with a polyether ether ketone resin as a main material. The amount of wear of the rotating shaft made of the aluminum-based alloy material, which is the counterpart material, is slightly larger than that of the cast iron oil seal ring, and it has become necessary to further improve the required sealing function.

In addition, under the sliding condition in which the aluminum-based alloy containing Cu and Si, which has relatively good castability as compared with the aluminum-based alloy containing Cu, is adopted as the sliding partner material, the resin composition which comes into contact therewith is used. It is presumed that it is relatively difficult to satisfy all of the low friction properties of a product, wear resistance, and damage property of a sliding mating material.

Therefore, the present invention solves the above-mentioned problems, and an oil seal ring mounted on an automatic transmission or the like is brought into sliding contact with a soft mating material such as an aluminum alloy used for weight reduction. In this case, it is an object to have excellent wear resistance, not to wear an aluminum-based alloy counterpart material, and to have excellent sealability.

A second object of the present invention is to provide an oil seal ring having a low friction characteristic, wear resistance and aluminum alloy which are superior to those of a conventional composition mainly composed of polyamide 4-6 resin. The above-mentioned good results can be obtained not only when using an aluminum-based alloy containing Cu and Si but also with an aluminum-based alloy containing Cu and Si as a sliding partner. It is to be a high performance oil seal ring.

[0015]

In order to solve the above problems, in the present invention, polyamide 4-6 resin 30 to
The oil seal ring was a molded body of a resin composition containing 82% by weight, 5 to 45% by weight of carbon fiber, and 2 to 25% by weight of fluororesin.

Alternatively, polyamide 4-6 resin 30-82
% By weight, 5 to 45% by weight of carbon fiber, 2 to 2 of fluororesin
The oil seal ring was a molded body of a resin composition containing 5% by weight and 10 to 40% by weight of powdered talc.

Alternatively, polyamide 4-6 resin 30-82
% By weight, 5 to 45% by weight of carbon fiber, 2 to 2 of fluororesin
The oil seal ring was a molded body of a resin composition containing 5% by weight, 10 to 40% by weight of powdered talc and 1 to 10% by weight of molybdenum disulfide.

In the above oil seal ring, 10 to 40% by weight of calcium powder filler may be blended instead of 10 to 40% by weight of powdered talc.

Further, instead of 5 to 45% by weight of carbon fiber,
You may mix | blend 5 to 45 weight% of aromatic polyamide fibers.

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 used in place of powdered talc of 10 to 40% by weight. An oil seal ring formed of a molded product of a resin composition containing the above may be used.

The details will be described below. The polyamide 4-6 resin used in the present invention is a straight-chain aliphatic polyamide represented by the following chemical formula 1, and a well-known resin industrially produced by a polycondensation reaction of diaminobutane and adipic acid is adopted. can do.

[0022]

[Chemical 1]

Such a polyamide 4-6 resin has lubricity, abrasion resistance, and chemical resistance that polyamide generally has, and at the same time, polyamide 6 resin and polyamide 6-
Compared with 6 resin, it is more excellent in mechanical strength such as tensile strength, bending strength, bending elastic modulus, and heat resistance. Commercially available products of polyamide 4-6 resin include: Japan Synthetic Rubber Co., Ltd .: Stanyl TW300, Unitika Co .:
F5001 and the like can be mentioned.

Typical physical property values of these standard resin molded products are shown in Table 1 below.

[0025]

[Table 1]

The polyamide 4-6 resin has a heat distortion temperature of about 150 ° C. to 220 ° C. by promoting crystallization.
It is thought that it can be pulled back and forth.

The spherulites of the polyamide 4-6 resin are about 1 to 2 μm, which is about 1 of the spherulites of the polyamide 6-6.
It is smaller than 0 to 20 μm by about 1/10, and it is considered that the strength of the polyamide 4-6 resin such as Izod impact strength is high. Further, the polyamide 4-6 resin has a relatively small molding shrinkage ratio in the flow direction when it is used as an injection-molded body, and the dimensional change due to water absorption in the flow direction is considerably smaller than that of the polyamide 6-6 resin.

The compounding ratio of the above polyamide 4-6 resin in the total composition is 30 to 82% by weight. Because 3
This is because if the amount is less than 0% by weight, the mechanical strength of the molded product will be reduced. If the amount is more than 82% by weight, the reinforcing effect will not be obtained even if the prescribed filler is added, and therefore the molded product will have an increased resistance. This is because it is not preferable because it results in poor abrasion resistance.

Next, the carbon fiber used in the present invention has an average fiber diameter of about 1 to 20 μm, preferably about 5 to 18 μm, and an aspect ratio of about 1 to 80, more preferably about 5 to 50. Is preferred. This is because if the average fiber diameter is less than about 1 μm, agglomeration between the fibers occurs and it becomes difficult to uniformly disperse, and if the average fiber diameter exceeds about 20 μm, the soft counterpart material is abraded, and the average fiber diameter is about 5 If it is -18 μm, such a tendency is lessened, which is preferable. On the other hand, if the aspect ratio is less than about 1, the reinforcing effect of the matrix itself is impaired and the mechanical properties are deteriorated. On the other hand, if it exceeds about 80, uniform dispersion during mixing becomes extremely difficult and wear characteristics are hindered. This is because the quality will deteriorate. When the aspect ratio is about 1 to 80, there is no such tendency, and preferable results are obtained.

The aromatic polyamide fiber used in the present invention is well known as a fibrous heat-resistant resin represented by the following chemical formula 2, wherein aromatic rings are bound 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.

[0031]

[Chemical 2]

Examples of the para-aromatic polyamide fiber include para-aromatic polyamide fiber containing a repeating unit represented by the following chemical formula 3.

[0033]

[Chemical 3]

The para-aromatic polyamide fiber added to such a composition has high elasticity and high strength in the axial direction because the molecular chains are arranged in the axial direction of the fiber, but the molecular weight is increased in the perpendicular direction. The force is weak. 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 the soft sliding mating material is not damaged.

When an aromatic polyamide fiber other than the para-type is used, by adding a substance 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. The composition does not damage the moving partner material and has excellent wear resistance.

The para-aromatic polyamide fiber is composed of a polymer containing the repeating unit shown in Chemical formula 3, and has a different molecular structure from the meta-aromatic polyamide resin shown in Chemical formula 4 below. Examples of commercially available para-aromatic polyamide fibers include DuPont Toray Kevlar: Kevlar, Nippon Aramid: Twaron, Teijin: Technora.

[0037]

[Chemical 4]

When an aromatic polyamide fiber other than para type (that is, meta type aromatic polyamide fiber) is used, PTFE is adopted as the fluorine resin and a predetermined amount thereof is added. In this case, other fluorocarbon resin may be used together. Examples of commercially available meta-aromatic polyamide fibers include DuPont Toray Kevlar: Nomex and Teijin: Conex.

Such an aromatic polyamide fiber has a fiber length of about 0.15 to 3 mm and an aspect ratio of about 1 to 2.
It is in the range of about 30.

The form of the aromatic polyamide fiber is preferably one having an average fiber diameter of about 1 to 20 μm, more preferably about 5 to 15 μm. The aspect ratio is preferably about 1 to 60, more preferably about 15 to 40.

If the aromatic polyamide fiber has a fiber length of less than the predetermined range, the abrasion resistance becomes insufficient, and if it exceeds the above range, the dispersion in the composition is unsatisfactory, which is not preferable. Also,
If the aspect ratio is less than the above range, the shape of the powder is close to that of the powder, and the effect of improving wear resistance becomes insufficient. If the aspect ratio exceeds the above range, uniform dispersion in the composition is difficult, which is not preferable.

When the average fiber diameter is less 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.
This is because a composition having a large diameter exceeding μm causes the composition to slide and wear the soft counterpart material, and a composition having an average fiber diameter of about 5 to 15 μm does not show such a tendency at all and is very preferable. On the other hand, if the aspect ratio is less than about 1 μm, the matrix has no reinforcing effect and the mechanical properties are low, and
This is because if it exceeds 0, it becomes difficult to uniformly disperse upon mixing, and the wear characteristics of the composition are not uniform. As a commercially available aromatic polyamide fiber satisfying such conditions, there is Twaron (trade name) manufactured by Akzo.

The blending ratio of the above aromatic polyamide fiber or the above carbon fiber in the total composition is 5 to 45% by weight, preferably 10 to 30% by weight. Because
If it is less than 5% by weight, the wear resistance of the molded body is hardly improved and 4
This is because when the amount is more than 5% by weight, the melt fluidity is remarkably lowered and the moldability is deteriorated. The same mixture ratio is 10-30
If it is% by weight, there is no such tendency, and preferable results are obtained.

The fluororesin used in this 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 form of a mixture of two or more of them in the range of, for example, 1:10 to 10: 1.

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. , TLP-1
0, Asahi Glass Co., Ltd .: Fluon G163, Daikin Industries Co., Ltd .: Polyflon M15, Lubron L5, and the like. Alternatively, PTFE modified with an alkyl vinyl ether may be used. Generally, PTFE is
As a homopolymer of tetrafluoroethylene, a commercially available resin that can be compression-molded can be used, and for example, 400H manufactured by Kitamura Co. can be used.

As PFA, Teflon PFA-J and MP-10 manufactured by Mitsui-DuPont Fluorochemicals Co., Ltd .: Hostafuron TFA manufactured by Hoechst Co., Ltd., NEOFLON PFA manufactured by Daikin Industries, Ltd. and Mitsui DuPont Fluorochemical Co., Ltd. as FEP. : Teflon FEP-J, manufactured by Daikin Industries, Ltd .: NEOFLON FEP, ETFE manufactured by Mitsui DuPont Fluorochemicals: Tefzel, Asahi Glass Co., Ltd .: Aflon COP, and EPE manufactured by Mitsui DuPont Fluorochemicals: Teflon EPE-J, etc. can be mentioned.

Among the fluororesins, PTFE, PFA and FEP are preferable because they have a relatively high heat resistance temperature. Examples of PVDF include KF polymer manufactured by Kureha Chemical Industry Co., Ltd.

The aromatic polyester resin is, for example, a polyoxybenzoyl polyester represented by the formula (5) below, and a copolymer containing the polyoxybenzoyl polyester as a copolymerization component is further mixed in an amount of about 1 to 10% by weight. Good. As such an aromatic polyester resin, a commercially available product of polyoxybenzoyl polyester shown in Chemical formula 5 can be exemplified by Sumitomo Chemical Co., Ltd .: Econol E101.

[0049]

[Chemical 5]

The mixing ratio of the above-mentioned fluororesin is 2 to 2
It is 5% 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. . If the blending ratio is 5 to 25% by weight, such a tendency does not occur at all, and a preferable result is obtained.

Next, the powdery talc used in the present invention is
The average particle size is about 0.5-40 μm, preferably about 1-30
It is preferably μm. Small particles of less than about 0.5 μm cause agglomeration between particles, making uniform dispersion difficult.
This is because large particles exceeding m result in poor surface smoothness and are not preferred.

Examples of the calcium-based powder filler used in the present invention include calcium carbonate, sulfate, oxide and hydroxide, of which calcium carbonate or calcium sulfate is preferable. These calcium-based fillers have an average particle size of about 0.5 to 40 μm, preferably about 1 to 30 μm.
m is preferable. Small particles of less than about 0.5 μm cause agglomeration between particles, making uniform dispersion difficult.
This is because large particles exceeding μm are not preferable because the surface smoothness deteriorates.

The blending ratio of the above-mentioned calcium-based powder filler or the above-mentioned talc is 10 to 40% by weight, preferably 10 to 30% by weight, based on the total composition. Because
If it is less than 10% by weight, the soft counterpart material is abraded and 40% by weight
If it exceeds, the moldability will deteriorate and the mechanical properties will also deteriorate. 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 molybdenum disulfide used in the present invention is added as an essential component in order to improve wear resistance, and its compounding ratio is 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.

As additives other than the above-mentioned materials, solid lubricants and additives are added within the range that does not impair the effects of the present invention, for example, for the purpose of improving self-lubricating property, mechanical strength and thermal stability and coloring. A substance stable at a high temperature of about 350 ° C. or higher, such as an agent, a powder filler and a pigment, may be appropriately mixed. Further, it is preferable that the balance of the polyamide 4-6 resin when the additive is blended is not less than about 40% by weight.

The method of adding and mixing various additives to the polyamide 4-6 resin is not particularly limited, and a generally widely used method such as resin as a main component and other raw materials are used. Either individually or after dry-mixing appropriately with a mixer such as a Henschel mixer, a ball mill, a tumbler mixer, etc., supply them to an injection molding machine or a melt extrusion machine with good melt-mixing properties, or in advance a hot roll, kneader, Banbury mixer. A method such as melt mixing with a melt extruder may be used.

Further, when molding the composition of the present invention, the molding method is not particularly limited, and compression molding,
It is also possible to classify the composition to a desired particle size by a usual method such as extrusion molding or injection molding, or after melt-mixing the composition, pulverizing the composition with a jet mill, a freeze pulverizer, or the like.
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.

In the present invention, polyamide 4-
Various additives can be added to the lubricating composition containing 6 resin as a main component. For example, in order to further improve the lubricity of the composition, an abrasion resistance improver in an amount substantially equal to the amount of the aromatic polyester resin may be added. Specific examples of the 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. It can be illustrated.

The oil seal ring according to the present invention molded from the above-mentioned materials is not limited in its shape, and may take a form according to the specifications and conditions of the seal ring, the piston, the cylinder and the like.

The shape of the sealing abutment may be any of straight cut, angle cut, step cut, etc., preferably step cut, and more preferably shown in FIG. It is a step cut shape like that. This is a shape that is notched in steps in both the radial direction and the axial direction, and is intended to improve the sealing property of the hydraulic oil.

Further, within a range that does not impair the sealing property,
Oil groove 1 with a depth of about 0.1 mm on the side of the seal ring
2 may be provided on at least the side surface of the seal ring on the sliding side, for example, at about 1 to 10 places, preferably at 2 to 5 places.

The shape of such an oil groove is not particularly limited and may be a continuous groove from the inner peripheral surface to the outer peripheral surface of the seal ring as shown in FIG. You may provide the groove of the shape from a surface to the middle. The number and shape of such grooves may be determined so that the hydraulic oil can be appropriately supplied to the sliding surface, but when the number of such grooves is too small to stop the hydraulic oil supply to the sliding surface. However, it is not possible to expect the cooling effect and wear resistance of the sliding surface by the hydraulic oil. Further, when the number of oil grooves is too large and the amount of oil leakage increases, the sealing performance is impaired and the performance as a seal ring cannot be exhibited.

Further, as shown in FIG. 2, the injection position 13 of the molten resin at the time of injection molding of the seal ring is set to the mating portion 1.
It is preferable to set the position by shifting the position within a range of ± 30 ° from the position of 180 ° facing from 1. Since the seal ring formed in this way can prevent stress from concentrating in the injection position 13 when the mating portion 11 is expanded and assembled in the seal groove of the mating member,
The seal ring has excellent mechanical strength and is free from problems such as chipping. In addition, the number 14 in the drawing indicates the gate opening. Since the polyamide 4-6 resin has a relatively small dimensional change in the flow direction, it is considered that the polyamide 4-6 resin has a long development length such as a seal ring and is suitable for an elongated body as a whole.

Further, as shown in FIGS. 3 (a) and 3 (b),
By forming the crowning portion 15 at the abutment portion of the seal ring, it is possible to prevent the abutment end portion from projecting toward the outer peripheral surface when the diameter of the seal ring is slightly widened during assembly to the piston or cylinder. Can be done relatively easily.

Such a molded body has a strength of about 100 in order to secure dimensional stability during high temperature use, excluding strain during molding.
It is desirable to perform annealing heat treatment at about 250 ° C. for about 0.1 to 24 hours.

The annealing heat treatment temperature is about 230 ° C. or lower,
It is suitable to carry out at about 150 to 220 ° C. Polyamide 4-6 resin is a resin that has high rigidity over a wide temperature range, excellent impact resistance, is resistant to distortion such as creep, and is resistant to most types of oils and chemicals. is there. Further, this resin is crystalline, its crystallization rate is high, and its water absorption rate is larger than that of the polyamide 6-6 resin, but the amount of dimensional change due to water absorption is considered to be smaller than that of the polyamide 6-6 resin. There is. It also has properties such as increased strength and rigidity due to increased crystallinity, improved wear resistance and lubricity, and decreased thermal expansion coefficient and water absorption.

When the heat treatment temperature is lower than about 150 ° 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.

The annealing heat treatment temperature exceeds about 230 ° C.,
In particular, when the heat distortion temperature of the standard product exceeds about 220 ° C., the influence of the heat history applied to the resin becomes large, which is considered to be unfavorable. During the heat treatment, before reaching the predetermined temperature, for example, room temperature, about 80 ° C, about 130 ° C, about 180 ° C, about 22 ° C.
0 ℃, about 230 ℃, divided into several steps, about 1
The temperature may be gradually raised in the range of about 5 to 180 minutes every about 15 to 60 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 may be about 15 to 480 minutes.
If the maximum temperature retention time is shorter than the specified time,
The crystallization of the resin becomes insufficient and the dimensional stability deteriorates,
If the time is longer than the specified time, improper thermal deformation such as "sledding" will occur, and the production cost will be reduced from the viewpoint of increasing the energy consumption of the electric furnace and increasing the production time. Becomes difficult.

Further, when the temperature is raised to about 90 to 120 ° C., it may be held 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 over a period of 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 surely and gradually progressed 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 material, it may be inefficient or affected by the formation of the transition film of the resin material. It is presumed that the range may be about 3 to 8 μm or less under the above conditions.

[0075]

The oil seal ring according to the present invention comprises a fluorine-based resin, carbon fiber or aromatic polyamide fiber, which is added to polyamide 4-6 resin in a predetermined mixing ratio, powdered talc or calcium-based powder filler, and Molybdenum disulfide is the original sliding property of polyamide 4-6 resin,
Since the mechanical strength is synergistically increased, the abrasion resistance is enhanced while satisfying the non-damage property of the soft sliding mating material, which was insufficient with the conventional resin composition in which carbon fiber and PTFE are used in combination. It has excellent sealing properties.

[0076]

EXAMPLES The raw materials used in Examples and Comparative Examples of the present invention are summarized below.

(1) Polyamide 4-6 resin [PA46]
(Nippon Synthetic Rubber Co., Ltd .: Stanyl TW300) (2) Carbon fiber (Kureha Chemical Co., Ltd .: M107T, average fiber diameter 18.0 μm, aspect ratio 38) (3) Aromatic polyamide fiber (Aczo Co., Ltd .: Twaron)
Micro 1088, average fiber diameter 13.0 μm, aspect ratio 19) (4) PTFE (made by Kitamura: 400H) (5) Talc (Matsumura Sangyo: crown talc, average particle diameter 11 μm) (6) Calcium carbonate (day) Nitto Kogyo Co., Ltd .: NA600, average particle size 7 μm) (7) Wholly aromatic polyester resin (Sumitomo Chemical Co., Ltd .: Econol E101) (8) Mica (Shiraishi Calcium Co., Ltd .: HAR325
A) (9) Polyimide (manufactured by Ube Industries, Ltd .: Upilex R) (10) Molybdenum disulfide (manufactured by Dow Corning: Moricoat Z powder) [Examples 1 to 4] Ratio of the above raw materials shown in Table 1 (weight) %), Dry mixed using a Henschel mixer, and melt-extruded by an extruder to granulate, which is injected at a pressure of about 1000 kgf / cm ² and a cylinder temperature of about 30.
Injection molding under conditions of 0 ℃, outer diameter 21mm, inner diameter 17mm,
A cylindrical test piece having a height of 10 mm was used. The following test was performed on the obtained test piece.

(A) Thrust wear test Using a thrust wear tester, the mating material was an aluminum alloy for die casting (ADC12), and the sliding speed was 128 per minute.
m, surface pressure 18 kg / cm ² , and the lubricating coefficient was determined by selecting the forced lubrication condition of an automatic transmission oil for automobiles (Showa Shell Sekiyu KK: Dexylon II) as a lubricating oil. The obtained results are also shown in Table 2.

[0079]

[Table 2]

[0080]

[Table 3]

[Comparative Examples 1 to 7] Cylindrical test pieces having the composition shown in Table 3 were produced in exactly the same manner as in Example 1, and thrust wear tests were carried out on these, and the obtained results are shown in Table 3. Also described in.

As is clear from the measurement results of Tables 2 and 3, Comparative Examples 2 and 3 in which the addition amount of the talc or calcium-based filler was less than the predetermined range, or the comparison in which the predetermined powdery filler was not added In Example 1 and Comparative Examples 4 to 7, both the wear damage property of the mating member and the wear coefficient of self were significantly inferior to the Examples. In Comparative Example 6 in which the carbon fiber or the aromatic polyamide fiber was not mixed, mica was used instead of the predetermined powdery filler, but the wear coefficient was much higher than that in the Examples.

On the other hand, the molded bodies of Examples 1 to 4 all had extremely small wear coefficients of the self and sliding mating materials, and had desired wear characteristics.

Next, the seal rings of Examples 1 to 4 (external diameter φ4), which had excellent test results in the above-mentioned thrust wear test,
0 x inner diameter φ36 x width 2) injection molded,
Using this as a test product, the following sealing property test was conducted.

(B) Sealability test The oil seal rings 3 and 3'are mounted in the ring grooves 2 and 2'of the shaft 1 made of aluminum alloy for die casting (ADC12) of the rotary tester shown in FIG. When you rotate
Sides of ring grooves 2, 2'and cylinder 12 made of ADC12
The inner surface of the sliding contact. Further, at this time, oil was pressure-fed from an oil pressure generator (not shown) above the cylinder 4 through the oil supply pipe 5, and the oil pressure was measured by the oil pressure gauge 6. A discharge pipe 7 for discharging the leaked oil was provided below the cylinder 4, the amount of oil leakage was measured by a graduated cylinder 8, and the oil temperature at this time was measured by a thermocouple 9.

The test conditions are as follows: Automatic transmission oil for automobiles (manufactured by Showa Shell Sekiyu KK:
Dexilon II) is used and the hydraulic pressure is about 10 kgf / cm ²
And the shaft rotation speed is 4000 rpm and the oil temperature is about 120 ° C.
It was carried out continuously for 0 hours. Oil leak rate (ml / min)
^{2 at} hydraulic pressure of 10 kgf / cm ² and shaft speed of 4000 rpm
The measurement was performed every 0 hours, and the results are shown in Table 4.

[0087]

[Table 4]

A sealability test was conducted under exactly the same conditions except that the oil temperatures shown in Table 5 were used.
The oil leakage rate (ml / min) after 100 hours at 0, 60, 80, 100, 120 ° C, and the wear amount (μm) of the ring side surface, ring outer peripheral surface, ring groove or cylinder after 100 hours of rotation test The measurement was performed, and the results are shown in Table 5 and Table 6, respectively.

[0089]

[Table 5]

[0090]

[Table 6]

Comparative Example 8 A seal ring made of cast iron (outer diameter φ40 mm × inner diameter φ36 mm × width 2 mm), which has good wear characteristics with respect to an aluminum material, was adopted as Comparative Example 8. Using this as a test piece, the above-mentioned sealability test (temporal and oil temperature distinction) and the amount of wear during the test were measured under exactly the same conditions as in the examples. The results are also shown in Table 4, Table 5 or Table 6, respectively.

As is clear from the results of Tables 4 and 5, the oil seal rings of Examples 1 to 4 showed less change in sealing property over time than the cast iron seal ring (Comparative Example 8), and had low temperature (about The oil leakage rate was low from 27 ° C) to a high temperature (about 120 ° C), and the sealing property was extremely excellent. In addition, the results of Table 6 show that the oil seal rings of Examples 1 to 4 showed less wear amount of the ring itself and less wear amount of the aluminum cylinder, and showed favorable wear resistance characteristics and sealability as an oil seal ring.

[0093]

[Effect] As described above, the oil seal ring of the present invention has excellent wear resistance under the sliding conditions against a soft material such as an aluminum alloy, and does not cause the aluminum alloy alloy mating material to wear. In addition, there is an advantage that it exhibits excellent sealing properties.

Therefore, if the oil seal ring of the present invention is used as the seal ring of the rotary shaft of an automatic transmission such as an automobile, the oil leak amount is small and the capacity of the oil pump can be set small. It can be said that it is extremely useful for reducing the size and weight of the device.

[Brief description of drawings]

FIG. 1 is a vertical sectional view illustrating a rotation tester.

FIG. 2A is a front view of an embodiment. FIG. 2B is a front view of another embodiment.

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

[Explanation of symbols]

 1 shaft 2, 2'ring groove 3, 3'oil seal ring 4 cylinder 5 oil supply pipe 6 oil pressure gauge 7 discharge pipe 8 graduated cylinder 9 thermocouple 10 oil seal ring 11 joint part 12 oil groove 13 injection position 14 gate 15 , 15 'Crowning section

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area // (C08L 77/00 27:18)

Claims (7)

[Claims] 1. A polyamide 4-6 resin 30 to 82% by weight, carbon fibers 5 to 45% by weight, and a fluorine resin 2 to 2.
An oil seal ring made of a molded product of a resin composition containing 5% by weight. 2. A molded product of a resin composition containing 30 to 82% by weight of polyamide 4-6 resin, 5 to 45% by weight of carbon fiber, 2 to 25% by weight of fluorine resin and 10 to 40% by weight of powdered talc. Oil seal ring. 3. Polyamide 4-6 resin 30 to 82% by weight, carbon fiber 5 to 45% by weight, fluorine resin 2 to 25% by weight, powdered talc 10 to 40% by weight and molybdenum disulfide 1 to 10% by weight. An oil seal ring formed of a molded product of a resin composition containing 4. The oil seal ring according to claim 2 or 3, wherein 10 to 40% by weight of powdered talc is used.
An oil seal ring comprising a molded product of a resin composition containing 10 to 40% by weight of a calcium-based powder filler instead of. 5. The oil seal ring according to any one of claims 1 to 4, comprising a resin composition containing 5 to 45% by weight of aromatic polyamide fibers instead of 5 to 45% by weight of carbon fibers. An oil seal ring made of a molded body. 6. The oil seal ring according to claim 2 or 3, wherein 5 to 45% by weight of aromatic polyamide fibers are blended in place of 5 to 45% by weight of carbon fibers, and powdered talc 10 to 40 is added. An oil seal ring comprising a molded body of a resin composition containing 10 to 40% by weight of a calcium-based powder filler in place of the weight%. 7. The oil seal ring according to claim 1, wherein the fluororesin is a tetrafluoroethylene resin.