JP2011220463A - Resin gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin gear for reducing weight more than a resin gear of using a metallic bush.SOLUTION: The resin gear has an inorganic fiber resin layer including inorganic fiber having a through-hole in a central part and an organic fiber resin layer including organic fiber arranged on the outer periphery of this inorganic fiber resin layer. The through-hole has preferably a recess-projection on its inner peripheral surface, and is engaged with a rotary shaft by the mutual recesses-projections. The organic fiber resin layer is also provided with a tooth surface within a range of this layer.

Description

  The present invention relates to a resin gear that does not require a metal bush.

In order to comply with exhaust gas regulations that are becoming stricter year by year, and for the purpose of improving the fuel efficiency of automobiles, there is an increasing demand for lighter and more compact automotive parts. Yes.
Resin gears are used as mating gears that mesh with metal gears for the purpose of reducing weight and suppressing noise during meshing of teeth.

In the resin gear described above, a metal bush that engages with the rotation shaft is disposed at the central portion thereof, and an organic fiber resin cured layer containing organic fibers is provided on the outer peripheral portion thereof. Teeth are formed on the teeth (see Patent Document 1).
And since the request | requirement of the weight reduction with respect to resin gears has further strengthened, the improvement request | requirement with respect to a metal bush with a heavy mass has begun to appear.

JP 2005-121237 A

However, the assembly of the rotating shaft and the metal bush is fixed by press-fitting the shaft into the through-hole of the metal bush. Therefore, the metal bush provided with the through-hole resists press-fitting and is bonded to the rotating shaft. There is no need to find other materials that need to be good and can be reduced in weight.
Further, it is not practical to spread the organic fiber resin hardened layer provided with teeth to the center and abolish the metal bush because the material strength is weak.

  An object of this invention is to provide the resin-made gear reduced in weight rather than the resin-made gear using a metal bush.

The present invention relates to the following.
(1) Resin gear having an inorganic fiber resin layer containing an inorganic fiber having a through hole in the center and an organic fiber resin layer containing an organic fiber disposed on the outer periphery of the inorganic fiber resin layer .
(2) The resin gear according to item (1), wherein the through hole has irregularities on its inner peripheral surface and is engaged with the rotating shaft by the mutual irregularities.
(3) The resin gear in which the organic fiber resin layer is provided with a tooth surface in a range within this layer in the item (1) or the item (2).
(4) The resin gear according to any one of items (1) to (3), wherein the resin is a thermosetting resin or a thermoplastic resin.
(5) The resin gear according to any one of items (1) to (4), wherein an interface between the inorganic fiber resin layer and the organic fiber resin layer is a curved shape or a polygonal shape in plan view.

In the present invention, by placing an inorganic fiber resin layer containing inorganic fibers in a portion where a conventional metal bush has been used, it is possible to achieve a significant weight reduction and to withstand press-fitting into a rotating shaft. The bonding property with the rotating shaft can be improved.
When the inner surface of the through hole has irregularities and is engaged with the rotating shaft by mutual irregularities, it is possible to further improve the bondability with the high-speed and high-load rotating shaft compared to a simple cylindrical shape. it can.
When the organic fiber resin layer has a tooth surface within the range of this layer, the inorganic fiber resin layer and the mating gear (made of metal) are not in direct contact, and the mating mating gear is not damaged and durable. Property is improved.

  If the resin is a thermosetting resin, it is excellent in high heat resistance, mechanical strength, and dimensional stability. If it is a thermoplastic resin, the moldability is excellent and the resin can be reused.

  When the interface between the inorganic fiber resin layer and the organic fiber resin layer is a curved shape or a polygonal shape in plan view, peeling between the layers hardly occurs and a stronger resin gear can be obtained.

The outline of a reinforced fiber base material is shown. An outline of a method for producing a reinforcing fiber substrate is shown. An outline of a resin gear manufacturing method will be described. One Example of the through-hole of resin gears is shown.

<Inorganic fiber resin layer>
(Through hole)
The inorganic fiber resin layer described in the present invention has a through hole at the center thereof. The through hole engages with the rotation shaft to rotate the resin gear, and the center axis of the through hole and the center axis of the inorganic fiber resin layer are made to coincide with each other.
The inner peripheral surface of the through hole is not particularly limited as long as it can be engaged with the rotating shaft, but the inner peripheral surface has irregularities and is engaged with the rotating shaft by the respective irregularities. In this way, the engagement force is further increased, and the resin gear is less likely to idle.
More specifically, when viewed in cross section so that the inorganic fiber resin layer and the rotating shaft can be seen simultaneously, the engaging portion can be a wavy line, a mountain valley line, an uneven line, or the like. In addition, it is preferable that a wave, a valley, and an unevenness | corrugation generate | occur | produce in each said line at equal intervals so that local stress may not generate | occur | produce easily. For example, a shape as shown in FIG. In addition, since the rotating shaft is inserted into the through hole and the inner peripheral surface of the through hole is engaged with the outer peripheral surface of the rotating shaft, the thickness direction of the through hole is preferably a straight line.

The through hole can be formed by cutting after forming the inorganic fiber resin layer, or can be formed simultaneously with the formation of the inorganic fiber resin layer.
The concave / convex shape of the inner peripheral surface can be formed by cutting as in the case of the above-described through holes, or can be formed simultaneously with the formation of the inorganic fiber resin layer.

(Inorganic fiber)
The inorganic fiber resin layer contains inorganic fibers therein. The inorganic fiber is not particularly limited, but it is preferable to use a combination of one or more fibers selected from carbon fiber, glass fiber, and metal fiber, thereby reducing the weight of the resin gear. The mechanical strength can be excellent. Among these, it is particularly preferable to use carbon fiber. When carbon fiber is used, it is particularly lightweight and has excellent mechanical strength.

  The inorganic fiber can be used in the form of a woven fabric, a knitted fabric or a non-woven fabric, and if it is a woven fabric or a knitted fabric, the woven fabric or the knitted fabric is made into a cylindrical shape and then turned inside out or inside. It can be used in a donut shape by wrapping around. Moreover, if it is a nonwoven fabric, it can be used close to the external shape of an inorganic fiber resin layer by laminating | stacking a planar nonwoven fabric. Furthermore, it can be used by diffusing inorganic fibers in a solvent and making it close to the outer shape of the inorganic fiber resin layer by papermaking. In addition, alcohol, hard water, etc. can be used as a solvent at the time of papermaking, and it is preferable to use water with little environmental influence.

The inorganic fiber is not limited in length, fiber diameter, content, etc., but when used in the form of a nonwoven fabric, the length is preferably 3 mm or less, and when exceeding 3 mm, Gradual dispersion of fibers during paper making does not succeed, making it difficult to produce a reinforcing fiber substrate, which is not preferable.
The fiber diameter is preferably 3 to 30 μm, and if it is less than 3 μm, impregnation and handling of the resin gradually become difficult, and if it exceeds 30 μm, the mechanical strength gradually decreases.
Although content rate is not specifically limited, It is preferable to set it as 30-50 volume% by making the whole inorganic fiber resin layer into 100 volume%, and when it is less than 30 volume%, mechanical strength falls gradually. When it is generated and exceeds 50% by volume, the resin gradually becomes difficult to impregnate, which is not preferable.

<Organic fiber resin layer>
(Organic fiber)
The organic fiber resin layer contains organic fibers therein. The organic fiber is not particularly limited, but it is preferable to use a combination of one or more fibers selected from aramid fiber, PBO fiber, polyimide fiber, polyphenylene sulfide fiber, and polyarate fiber. The resin gear can have high heat resistance and excellent mechanical strength. Among these, it is particularly preferable to use an aramid fiber. When an aramid fiber is used, it becomes particularly superior in terms of heat resistance, workability, and mechanical strength. When selecting a PBO fiber, a polyparaphenylene benzoxazole fiber is preferable.

  The organic fiber can be used in the form of a woven fabric, a knitted fabric or a non-woven fabric in the same manner as the inorganic fiber described above. If the fabric is a woven fabric or a knitted fabric, the woven fabric or the knitted fabric is formed into a cylindrical shape. Then, it can be made into a donut shape by winding it while turning it inside out or turning it inside. Moreover, if it is a nonwoven fabric, it can be used close to the external shape of an inorganic fiber resin layer by laminating | stacking a planar nonwoven fabric. Furthermore, it can be used by diffusing inorganic fibers in a solvent and making it close to the outer shape of the inorganic fiber resin layer by papermaking. In addition, alcohol, hard water, etc. can be used as a solvent at the time of papermaking, and it is preferable to use water with little environmental influence.

The organic fiber is not limited in its length, fiber diameter, content, etc., but when used in the form of a nonwoven fabric, the length is preferably 2 to 6 mm, and less than 2 mm. When the thickness exceeds 6 mm, the fibers are not well dispersed during papermaking, and it becomes difficult to produce a reinforcing fiber substrate, which is not preferable.
When used in the form of a nonwoven fabric, the fiber diameter is preferably 7 to 14 μm, and if it is less than 7 μm, it takes time to manufacture the reinforcing fiber base gradually due to the filter effect of the fibers laminated at the time of papermaking, If it exceeds 14 μm, the mechanical strength and durability gradually decrease, which is not preferable.
The content rate is preferably 30 to 50% by volume, based on 100% by volume of the entire organic fiber resin layer, and when the content is less than 30% by volume, a decrease in mechanical strength gradually occurs, and when the content exceeds 50% by volume, The resin gradually becomes difficult to impregnate, which is not preferable.

<Resin>
The resin to be impregnated into the inorganic fiber resin layer and the organic fiber resin layer of the present invention is not particularly limited, but a thermosetting resin or a thermoplastic resin can be used, so long as it is used at a high temperature. It is preferable to use a thermosetting resin having high heat resistance.
Moreover, although the various resins are held by inorganic fibers and organic fibers to form a resin layer, the resin layer can be formed by infiltrating various resins into a base material composed of inorganic fibers and organic fibers. . Further, the above-described thermosetting resin or thermoplastic resin filled with inorganic fibers or organic fibers may be injection molded or compression molded.

(Thermosetting resin)
As the thermosetting resin, a cross-linked polyaminoamide resin, an epoxy resin, a polyimide resin, a phenol resin, or the like can be used. Thus, high heat resistance and excellent mechanical strength can be obtained. Among them, it is particularly preferable to use a crosslinked polyaminoamide resin because it has excellent heat resistance, flexibility, and mechanical strength.
Moreover, a filler, an additive, etc. can be added in a thermosetting resin.

As the filler, rubber particles or the like can be used, and it is preferable to add 5% by mass or less based on 100% by mass of the entire thermosetting resin. If it exceeds 5% by mass, mechanical strength and heat resistance other than impact strength gradually decrease, which is not preferable.
As the additive, molybdenum disulfide, PTFE (polytetrafluoroethylene), polyethylene powder, or the like can be used. It is preferable to add 10% by mass or less based on 100% by mass of the entire thermosetting resin. If it exceeds 10% by mass, the mechanical strength gradually decreases, which is not preferable.

(Thermoplastic resin)
As the thermoplastic resin, an ABS resin, a PPS resin, a PEEK resin, or the like can be used, and thereby, the abrasion resistance and the mechanical strength can be excellent. Among these, it is particularly preferable to use PEEK resin because of its excellent mechanical strength.
Moreover, a filler, an additive, etc. can be added in a thermoplastic resin.

As the filler, rubber particles or the like can be used, and it is preferable to add 5% by mass or less based on 100% by mass of the entire thermosetting resin. If it exceeds 5% by mass, mechanical strength and heat resistance other than impact strength gradually decrease, which is not preferable.
As the additive, molybdenum disulfide, PTFE, polyethylene powder or the like can be used, and it is preferable to add 10% by mass or less based on 100% by mass of the entire thermosetting resin. If it exceeds 10% by mass, the mechanical strength gradually decreases, which is not preferable.

The resin used for the inorganic fiber resin layer and the organic fiber resin layer may be the same or different. If they are the same, the resin is impregnated and cured simultaneously in the inorganic fiber resin layer and the organic fiber resin layer. Work time can be shortened.
Moreover, when using different resin, the resin layer match | combined with the intended use can be formed.

When the thermosetting resin is held on the fiber, the resin can be injected more quickly by lowering the pressure in the mold in which the fiber is arranged.
Moreover, although the temperature and pressure at the time of curing vary depending on the type of thermosetting resin to be used, the temperature is preferably 180 to 200 ° C., the pressure is preferably 0.05 MPa or more, and can be molded in a short time. Can be suppressed.

<Interface between inorganic fiber resin layer and organic fiber resin layer>
The interface between the inorganic fiber resin layer and the organic fiber resin layer is not particularly limited as long as it is in close contact, but in a plan view, a curved shape or a polygonal shape may cause interface breakdown. It is difficult to cause, and is preferable.

Specifically, the curved shape is a wavy line, and it is particularly preferable that the curved shape is a wavy line having a uniform period so that stress is not concentrated on a specific portion.
The polygonal shape is a shape such as a triangle, a quadrangle, a pentagon, a hexagon, and the like, and it is also preferable that the polygonal shape be a regular polygon so that stress is not concentrated on a specific part.
In addition, protrusions can be formed on the outer peripheral portion of the inorganic fiber resin layer. The protrusions are preferably provided at equiangular intervals as viewed from the center of the inorganic fiber resin layer so that stress is not concentrated on a specific part.

Embodiments of the present invention will be described below with reference to the drawings.
(Example 1)
The following were prepared as thermosetting liquid resins (crosslinked polyaminoamide resins). 2,2 ′-(1,3-phenylene) bis-2-oxazoline (component A) and 4,4′-diaminodiphenylmethane (component B) in a molar ratio: 2/1 (mass ratio: 69/31) Mix and dissolve at 150 ° C. for 10 minutes at a blending ratio to obtain a liquid material.
To this liquid, n-octyl bromide is blended as a curing accelerator. The compounding quantity of a hardening accelerator is 1 mass part by making the total amount of A and B component into 100 mass parts.

  As a reinforcing fiber base impregnated with the thermosetting liquid resin, a reinforced inorganic fiber base material 1 (left figure in FIG. 1) by papermaking and a reinforced organic fiber base material 2 integrated in the periphery thereof (right figure in FIG. 1). Is used. The reinforced inorganic fiber substrate 1 is a cylinder (height 12 mm) having an inner diameter of 32 mm and an outer diameter of 55 mm, and 30 protrusions are provided on the outer peripheral portion thereof at equal angular intervals when viewed from the center. The shape of the protrusions is a bottom diameter of 55 mm and a top width of 2 mm (height of 5 mm). The reinforced organic fiber base material 2 is on the outer periphery of the reinforced inorganic fiber base material 1 and has a shape of a cylinder (height 20 mm) having an outer diameter of 82 mm.

First, 15.1 g of carbon fiber having an inorganic fiber length of 3 mm and a fiber diameter of 10 μm is dispersed in 10 liters of water to prepare a slurry.
Then, as shown in the left diagram of FIG. 2, the slurry is injected into the papermaking mold, and at the same time, the vacuum dehydration treatment is performed by the vacuum pump, and the reinforcing inorganic fiber substrate 1 is formed by pressing from above and below. The reinforced inorganic fiber base material 1 was adjusted so as to have an amount of 50% by volume, with the entire inorganic fiber resin layer being 100% by volume.

Next, meta-type aramid fibers (made by Teijin Techno Products Co., Ltd., trade name: Conex) / para-type aramid fibers (made by Teijin Techno Products Co., Ltd., trade name: Technora) / para-type aramid fibers (Toray), which are organic fibers -A DuPont Co., Ltd. brand name: Kevlar pulp) = 50/45/5 (mass%) is weighed in a total amount of 20 g and dispersed in 10 liters of water to prepare a slurry.
And as shown in the right figure of FIG. 2, the reinforcement inorganic fiber base material 1 is arrange | positioned to the center part of a papermaking metal mold | die, slurry is inject | poured into the reinforcement inorganic fiber base material 1 outer peripheral part, and a vacuum dehydration process is carried out with a vacuum pump simultaneously. And press from above and below to make the reinforced organic fiber substrate 2. The reinforced organic fiber base material 2 was adjusted so that the whole organic fiber resin layer was 100% by volume and the amount was 50% by volume.

As shown in FIG. 3, the reinforced inorganic fiber substrate 1 and the reinforced organic fiber substrate 2 arranged on the outer periphery thereof are arranged in a molding die whose surface temperature is maintained at 200 ° C., and the molding die is closed. Then, the inside of the molding die is brought to a reduced pressure state of 0 to 1.3 kPa, the liquid resin is injected into the closed molding die, and the reinforcing inorganic fiber base material 1 and the reinforcing organic fiber base material 2 arranged on the outer periphery thereof are applied. The infiltrated liquid resin is heated and cured for 5 minutes to form a fiber reinforced resin molded body.
Since the fiber-reinforced resin molded article has not yet formed teeth, cutting was performed using a hobbing machine to form helical teeth, and resin gears were produced.
The helical teeth were a module 2.5, a pressure angle of 20 °, and a twist angle of 30 °.

(Example 2)
A resin gear was produced in the same manner as in Example 1 except that the glass fiber was used as the inorganic fiber of the reinforced inorganic fiber substrate 1 of Example 1 described above.
The glass fiber used had a fiber length of 3 mm, a fiber diameter of 13 μm, and a fiber mass of 21.6 g.

(Example 3)
A resin gear was produced in the same manner as in Example 1 except that the organic fiber of the ring-shaped reinforcing fiber substrate 2 of Example 1 described above was PBO fiber.
The PBO fiber used was a fiber length: 3 mm, a fiber diameter: 13 μm, and a fiber mass: 26.0 g.

(Comparative Example 1)
Only the reinforcing organic fiber substrate was used as the reinforcing fiber substrate (FIG. 1) impregnated with the liquid resin of Example 1 described above. First, meta-type aramid fibers (trade name: Conex, manufactured by Teijin Techno Products Co., Ltd.) / Para-type aramid fibers (trade name: Technora, manufactured by Teijin Techno Products Co., Ltd.) / Para-type aramid fibers (Toray DuPont Co., Ltd., trade name: Kevlar pulp) = 50/45/5 (mass%) is weighed in a total amount of 20 g and dispersed in 10 liters of water to prepare a slurry. Then, as shown in FIG. 2, a metal bush (iron-based sintered alloy, shape: φ55-φ35 × t3, mass: 117 g) is arranged at the center of the papermaking mold, and slurry is placed on the outer periphery of the metal bush. At the same time as the injection, vacuum dehydration treatment is performed with a vacuum pump, and pressing from above and below makes a reinforced organic fiber substrate.
The molding method for infiltrating the liquid resin into this was the method of Example 1 described above.

(Mass evaluation)
The mass evaluation was made by weighing resin gears with an electronic balance (Shimadzu Corporation, trade name: LIBROR) in an environment of a temperature of 19 ° C. and a humidity of 53% for comparison. The results are shown in Table 1.
The values in Table 1 are expressed as an index when Comparative Example 1 is set to 100.

  As is clear from Table 1, resin gears (Example 1, Example 2, Example 3) made of inorganic fiber resin layers and organic fiber layers are resin gears using metal bushes (Comparative Example 1). The mass is lighter than that.

DESCRIPTION OF SYMBOLS 1 ... Reinforcement inorganic fiber base material, 2 ... Reinforcement organic fiber base material, 3 ... Metal bush, 4 ... Rotating shaft

Claims (5)

  A resin gear having an inorganic fiber resin layer containing an inorganic fiber having a through hole in the center and an organic fiber resin layer containing an organic fiber disposed on the outer periphery of the inorganic fiber resin layer.   The resin gear according to claim 1, wherein the through hole has irregularities on an inner peripheral surface thereof and is engaged with the rotating shaft by the mutual irregularities.   3. The resin gear according to claim 1, wherein the organic fiber resin layer is provided with a tooth surface within a range within the layer.   4. The resin gear according to claim 1, wherein the resin is a thermosetting resin or a thermoplastic resin.   5. The resin gear according to claim 1, wherein an interface between the inorganic fiber resin layer and the organic fiber resin layer is a curved shape or a polygonal shape in plan view.

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