JP2019034438A - Gear box component, gear box, and method for producing the gear box component - Google Patents

Abstract

To provide a gear box component which has high dimensional precision and whose lightening of weight is possible while having strength and reliability equal to those of the conventional ones, a gear box, and a method for producing a gear box component.SOLUTION: Provided is a gear box component composing a gear box to store a gear mechanism, formed by a fiber-reinforced resin composition in which a fibrous filler with the average fiber length of 0.5 mm or more is dispersed into a resin material. The gear box component is produced by: a fiber opening step where a fibrous filler is opened in a solvent to obtain a fiber-containing slurry 149; a papermaking step where the fiber-containing slurry 149 is poured into a papermaking mold, and the solvent is removed from the inside of the papermaking mold to mold a preform 37A with a shape almost same as that of the gear box component; and a molding step where the preform 37A is charged into a molding die, and a resin material is impregnated into the preform 37A to mold a gear box component.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a gear box component, a gear box, and a manufacturing method of the gear box component.

In recent years, there has been a strong demand for the promotion of low fuel consumption to save automobile resources and energy and reduce CO ₂ emissions. The electric power steering device is also required to be further reduced in weight, and the possibility of realizing a reduction in the weight of the components of the gear box that houses the reduction gear mechanism has been studied. However, in order to realize this, it is necessary to greatly change the material and the structure constituting the gear box. Generally, the components of this gear box are manufactured by a metal press such as an aluminum alloy.

  For example, in the electric power steering device of Patent Document 1, a housing including a sensor housing that houses a steering state detection sensor and a gear housing that houses a reduction gear is made of a resin material. According to this, the electric power steering device can be reduced in weight. Further, in the electric power steering device of Patent Document 2, the housing member and the cover member of the gear box are manufactured by insert molding of a resin material in which a metal core is inserted.

JP 2009-298246 A JP 2013-67362 A

  The weight reduction of a conventional gearbox component formed of a metal material can be achieved by using a material having a specific gravity smaller than that of the metal material, for example, a resin material. However, it is difficult to ensure the same strength and quality as the conventional product simply by replacing only the material. For example, problems such as a decrease in impact resistance, creep characteristics, and rigidity as compared with metal materials occur, such as delamination of fiber sheets in the resin and variations in the amount of fibers in the fiber sheets. In addition, when a metal material is replaced with a resin material, it is actually difficult to ensure dimensional stability equivalent to that of a metal structure in a resin structure.

  According to the electric power steering apparatus of Patent Document 1, the sensor housing and the gear housing are all formed of a polyamide resin material or a polyamide resin filled with reinforcing fibers, and both are integrally welded by a laser. However, in order to perform laser welding, the fiber content must be lowered, and physical properties such as high-temperature strength, impact resistance, creep characteristics, and rigidity may not always be obtained sufficiently.

  Moreover, in the gear box of the electric power steering apparatus of Patent Document 2, a resin composition containing a thermoplastic resin and a fiber reinforcing material is fixed by inserting a bolt into a bolt hole of a core metal. However, in general, in injection molding, reinforcing fibers are oriented in the material flow direction during injection molding. For this reason, anisotropy occurs in the thermal expansion coefficient between the flow direction of the material and the direction perpendicular thereto, which causes “warping” and tends to reduce dimensional accuracy.

  The present invention has been made in view of the above matters, and its purpose is to provide gear box components and gear boxes that have high dimensional accuracy and can be reduced in weight while having the same strength and reliability as conventional ones. It is another object of the present invention to provide a method for manufacturing a gear box component.

The present invention has the following configuration.
(1) A gear box component constituting a gear box in which the gear mechanism is accommodated,
A gear box component formed of a fiber reinforced resin composition in which a fibrous filler having an average fiber length of 0.5 mm or more is dispersed in a resin material.
(2) A metal connecting member is embedded in at least a part of the gear box component,
A gear box in which a plurality of the gear box components are connected to each other by a fastening member.
(3) There is a method of manufacturing a gear box component constituting a gear box in which a gear mechanism is accommodated,
A fiber opening process in which a fibrous filler is opened in a solvent to obtain a fiber-containing slurry; and
Injecting the fiber-containing slurry into a papermaking mold, removing the solvent from the papermaking mold, and forming a preform that is substantially the same shape as the gearbox component,
A molding process in which the preform is loaded into a molding die and the preform is impregnated with a resin material to mold the gear box component.
A method of manufacturing a gearbox component having

  According to the present invention, the gear box in which the gear mechanism is accommodated can be configured to have high dimensional accuracy and be lightweight while having the same strength and reliability as the conventional one.

It is a schematic block diagram of an electric power steering device. It is a fragmentary sectional view of the II-II line shown in FIG. FIG. 3 is a partial cross-sectional view taken along line III-III shown in FIG. 2. (A) is a perspective view which shows schematic structure of a gear box cover, (B) is a perspective view which shows schematic structure of the back side of the gear box cover shown to (A). FIG. 4 is a schematic perspective view of a papermaking mold for papermaking a preform of a gear box cover. FIG. 6 is a cross-sectional view of the lower mold VI-VI line shown in FIG. 5. (A), (B) is process explanatory drawing which shows a mode that a fiber containing slurry is produced at a fiber opening process. (A)-(E) are process explanatory drawings explaining a papermaking process in steps. It is explanatory drawing which shows the flow direction of the fiber containing slurry which flows in into a boss | hub formation part. It is the elements on larger scale which show typically the boss | hub of a gear box cover.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
Here, the gear box in which the gear mechanism of the present invention is accommodated will be described as a gear box used in an electric power steering apparatus, but the present invention is not limited to this.

<Configuration of electric power steering device>
FIG. 1 is a schematic configuration diagram of an electric power steering apparatus.
The electric power steering device 100 transmits the auxiliary output from the electric motor 11 to the steering mechanism 15 of the vehicle via the reduction gear mechanism 13. In addition, the electric power steering apparatus 100 of the example of illustration is an example, Comprising: Another kind of mechanism may be sufficient.

  In the electric power steering apparatus 100 shown in FIG. 1, a steering shaft 17 having a steering wheel (not shown) fixed to an upper end portion is rotatably supported inside a steering shaft housing 19. Further, the steering shaft housing 19 is fixed at a predetermined position in the vehicle interior with its lower portion inclined toward the front of the vehicle.

  The rack and pinion mechanism 21 that converts the rotation of the steering shaft 17 into the movement of the left and right steering wheels includes a rack 23 that is movable in the axial direction, a pinion shaft 25, and a cylindrical rack that supports the rack 23 and the pinion shaft 25. And the housing 27. The pinion shaft 25 is supported in an oblique direction with respect to the axis of the rack 23 and has a pinion provided with gear teeth that mesh with the gear teeth of the rack 23.

  The rack and pinion mechanism 21 is disposed substantially horizontally in the engine room at the front of the vehicle so that the longitudinal direction thereof is along the width direction of the vehicle. The upper end portion of the pinion shaft 25 and the lower end portion of the steering shaft 17 are connected by two universal joints 29 and 31. Further, steered wheels (not shown) are connected to both ends of the rack 23.

  When steering torque (rotational force) is applied to the steering wheel by the driver, the steering shaft 17 rotates, and the steering torque is detected by a torque sensor attached to the steering shaft 17. Based on the detected steering torque, the output of the electric motor 11 (rotational force assisting steering) is controlled. The output of the electric motor 11 is supplied to the intermediate portion of the steering shaft 17 via the reduction gear mechanism 13, and combined with the steering torque, is converted into a motion for turning the steered wheels by the rack and pinion mechanism 21.

2 is a partial cross-sectional view taken along line II-II shown in FIG. 1, and FIG. 3 is a partial cross-sectional view taken along line III-III shown in FIG.
As shown in FIGS. 2 and 3, the gear box 33 that houses the reduction gear mechanism 13 of the electric power steering apparatus 100 attached to the vehicle body (not shown) is a bottomed cylindrical gear box main body shown in FIG. 35 and a gear box cover 37 (gear box component). The gear box cover 37 is fixed to the gear box body 35 by closing the opening of the gear box body 35. That is, the bolt 39 is inserted into an opening provided on the gear box cover 37 side and fastened to a screw hole provided on the gear box body 35 side. Thereby, the gear box 33 in which the gear box body 35 and the gear box cover 37 are integrated by fastening the bolt 39 is obtained.

  An intermediate steering shaft 47 is rotatably supported by rolling bearings 51 and 53 inside the gear box 33. The gear box 33 houses the reduction gear mechanism 13 and a torque sensor 59 as a steering state detection sensor.

  The reduction gear mechanism 13 includes a worm wheel 55 and a worm shaft 57 shown in FIG. The worm wheel 55 is fixed to an intermediate portion in the axial direction of the intermediate steering shaft 47 shown in FIG. A worm shaft 57 shown in FIG. 2 is connected to the rotating shaft 61 of the electric motor 11 via a spline joint 63 and meshes with the worm wheel 55.

  As shown in FIG. 3, the worm wheel 55 includes a disk portion 55a fixed to the intermediate steering shaft 47 so as to be integrally rotatable, and synthetic resin teeth 55b formed on the outer diameter portion of the disk portion 55a. . The intermediate steering shaft 47 is rotatably supported by a first rolling bearing 51 and a second rolling bearing 53 that are disposed on both axial sides of the worm wheel 55.

The torsion bar 67 is disposed through the shaft centers of the steering shaft 17 and the intermediate steering shaft 47, the left end portion in the figure is fixed integrally with the intermediate steering shaft 47 by a connecting pin 69, and the right end portion in the figure is further fixed. Is press-fitted and fixed to the steering shaft 17.
Therefore, the rotational force (steering torque) of the steering shaft 17 is transmitted to the intermediate steering shaft 47 via the torsion bar 67.

  As shown in FIG. 2, the worm shaft 57 that meshes with the worm wheel 55 is rotatably supported by a third rolling bearing 75 and a fourth rolling bearing 77 that are held by a gear housing 73. The base end side end of the worm shaft 57 is connected to the rotating shaft 61 of the electric motor 11 via a spline joint 63.

<Gearbox>
Next, the gear box 33 will be described in detail.
As shown in FIG. 3, the gear box 33 is composed of a plurality of gear box components including a gear box body 35 and a gear box cover 37. Each of the gear box main body 35 and the gear box cover 37 is a member in which long fiber fibrous fillers (reinforcing fibers) are mainly dispersed and arranged in a resin material. The reinforcing fiber is contained in the resin material in the range of 10 to 60% by weight depending on the purpose of use. Thereby, compared with the case where the gear box 33 is formed of a resin material alone, impact resistance, creep properties, rigidity, and dimensional stability are improved.

  In the illustrated example, the gear box 33 is composed of two parts, that is, the gear box body 35 and the gear box cover 37. However, the present invention is not limited to this, and other parts may be combined. In this case, the other part may be a resin material including the above-described long fiber fibrous filler.

  The gear box 33 is configured by fastening a resin gear box body 35 including reinforcing fibers and a gear box cover 37 with bolts 39. The fastening portion of the gear box main body 35 and the gear box cover 37 by the bolt 39 is formed by insert molding a metal core on the gear box main body 35 side and a metal core on the gear box cover 37 side. Also good. The gear box 33 of this configuration is lighter than that of a conventional metal product and has the same durability and reliability as the conventional product.

  Although not shown, an O-ring groove in which an O-ring is mounted is provided on a surface to be fastened with bolts, that is, a joint surface between the gear box body 35 and the gear box cover 37, and enclosed in the gear box 33. It is preferable to prevent leakage of the grease that has been removed.

The gear box body 35 and the gear box cover 37 (hereinafter also referred to as a gear box component) having the above-described configuration are manufactured as follows, although details will be described later.
First, reinforcing fibers having an average fiber length of 0.5 mm or more are opened in a solvent. The fiber-containing slurry containing the reinforcing fibers is filled in a mold and made to form a preform. The formed preform is set in a mold, and a liquid or powder thermosetting resin is injected into the mold to impregnate the preform with a resin material. Thereby, the gearbox component based on a fiber reinforced resin composition is obtained.

  The gearbox component is preferably manufactured by producing a preform by the above-described three-dimensional papermaking technology, but is not limited thereto. For example, a fiber-containing slurry containing reinforcing fibers having an average fiber length of 0.5 mm or more is inserted into a mold together with a liquid or powder thermosetting resin, and the reinforcing fibers and the resin material are integrated by heating. Gearbox components may be manufactured. Also by this, the gearbox component of the fiber reinforced resin composition in which the reinforcing fiber is dispersed in the resin material is obtained as in the case of papermaking. In any case, the compounding amount of the reinforcing fibers contained in the fiber reinforced resin composition is preferably 10 to 60% by weight.

As a constituent material of the gear box component, for example, a material obtained by blending a thermosetting resin such as an epoxy resin or a phenol resin as a resin material and a reinforcing fiber such as glass fiber or carbon fiber as a fibrous filler is preferable. Further, a part of the thermosetting resin may be replaced with a thermoplastic resin. By using a thermosetting resin as a constituent material, a configuration excellent in heat resistance and mechanical strength can be achieved.
In consideration of durability and reliability as a molded article, it is desirable to use a fiber reinforced resin composition in which a thermosetting resin is used as a base resin and the base resin is filled with reinforcing fibers. By using this fiber reinforced resin composition, the impact resistance performance of the gear box component can be sufficiently ensured.

  The reinforcing fiber is not particularly limited, and examples thereof include glass fiber, carbon fiber, metal fiber, aramid fiber, aromatic polyimide fiber, liquid crystal polyester fiber, silicon carbide fiber, alumina fiber, boron fiber, cellulose, and cellulose nanofiber. .

  In particular, glass fiber and boron fiber are preferable because of high tensile strength. Carbon fiber is excellent in wear resistance, heat resistance, thermal stretchability, acid resistance, and electrical conductivity. Metal fibers such as stainless steel, aluminum, iron, nickel, and copper can be used as the metal fiber. Aramid fibers have high tensile strength and friction resistance, and are excellent in high temperature and chemical resistance. Aromatic polyamide fibers have very good heat resistance and strength. Liquid crystal polyester fiber has rigidity higher than that of engineering plastic reinforced with filler even in an unreinforced state. Alumina fiber can be used even in a high temperature range and has fire resistance.

  Further, the fiber length of the reinforcing fiber is preferably an average fiber length of 0.5 mm or more, more preferably 1 mm or more. In the case of adding fibers having an average fiber length of less than 0.5 mm, the effect of improving impact resistance and dimensional stability is less than that of adding fibers having an average fiber length of 0.5 mm or more. By making the average fiber length 0.5 mm or more, the reinforcing effect of the resin material in the composite material can be obtained with certainty.

  Further, the blending amount of the reinforcing fiber in the fiber reinforced resin composition is preferably 10 to 60% by weight. When the blending amount of the reinforcing fiber in the fiber reinforced resin composition is less than 10% by weight, durability equivalent to that of the conventional product cannot be obtained. Moreover, when the compounding quantity of a reinforced fiber exceeds 60 weight%, the toughness of material will be impaired, for example, cold-heat shock resistance may be insufficient, and is unpreferable.

  The fiber reinforced resin composition can improve the affinity between the resin material and the reinforcing fiber by treating the reinforcing fiber with a coupling agent such as a silane coupling agent or a titanate coupling agent. Thereby, the adhesiveness of a resin material and a reinforced fiber and dispersibility can be improved. In addition, a coupling agent is not limited to a silane coupling agent or a titanate coupling agent.

  And in the range which does not impair the objective of this invention, you may mix | blend various additives with a fiber reinforced resin composition. Examples of additives include solid lubricants such as graphite, hexagonal boron nitride, fluorine mica, ethylene tetrafluoride resin powder, tungsten disulfide, and molybdenum disulfide, inorganic powder, organic powder, lubricating oil, plasticizer, Rubber, antioxidant, heat stabilizer, UV absorber, photoprotective agent, flame retardant, antistatic agent, mold release agent, fluidity improver, thermal conductivity improver, non-tackifier, crystallization promotion Examples thereof include agents, nucleating agents, pigments, dye agents and the like.

  When mixing these resin materials, reinforcing fibers, and various additives to produce gearbox components, the reinforcing fiber preform was impregnated with molten resin to which various additives other than reinforcing fibers were added. Then, it is cured by heating. The temperature at which the molten resin is impregnated is not particularly limited, but may be appropriately selected within a temperature range in which the melting of the resin as a base material sufficiently proceeds and does not deteriorate.

<Manufacture of gearbox components>
Next, the manufacturing method of the gear box component will be described in more detail. Here, the manufacture of the gear box cover 37 will be described as an example. The manufacturing of the gear box main body 35 is the same as that of the gear box cover 37, and therefore will be omitted.

(Gear box cover)
4A is a perspective view showing a schematic configuration of the gear box cover 37, and FIG. 4B is a perspective view showing a schematic configuration of the back side of the gear box cover 37 shown in FIG. 4A.
The gear box cover 37 is a substantially disk-shaped member having a bearing hole 81 for holding the second rolling bearing 53 at the center. A pair of protrusions 85 having bolt holes 83 are provided on the outer side in the radial direction of the bearing hole 81 along the diametrical direction. A bolt 39 shown in FIG. 3 is inserted into the bolt hole 83.

  Further, the gear box cover 37 has a plate-like rib 87 on one side in a direction orthogonal to a line connecting the pair of protrusions 85 (downward in FIG. 4A, FIG. 4B). ) Protruding upward). A pair of bosses 91 having bolt holes 89 are provided on the other side so as to protrude in the same direction as the ribs 87.

(Making paper box cover)
FIG. 5 is a schematic perspective view of a papermaking mold for papermaking the preform of the gear box cover 37, and FIG. 6 is a sectional view taken along the line VI-VI of the lower mold 113 shown in FIG.

  As shown in FIGS. 5 and 6, the papermaking mold 111 includes a lower mold 113 and an upper mold 135. The lower mold 113 is provided with a bowl-shaped concave portion 115 into which a fiber-containing slurry, which will be described later, is injected, a protruding surface forming portion 117, a protruding portion forming portion 119, a rib forming portion 121, and a boss forming portion 123. The projecting surface forming portion 117 forms one surface of the gear box cover 37, that is, the surface on the side from which the rib 87 and the pair of bosses 91 project. Further, the protruding portion forming portion 119 forms the protruding portion 85, the rib forming portion 121 forms the rib 87, and the boss forming portion 123 forms the pair of bosses 91. The protruding surface forming portion 117 is a main concave portion that forms a main surface that becomes a base of the gear box cover 37, and a bearing hole forming portion 118 projects in the center to form a bearing hole. The protruding portion forming portion 119, the rib forming portion 121, and the boss forming portion 123 are branched from a portion of the main recessed portion to form branched protruding portions.

  Here, for simplification of description, the accompanying mechanisms such as a core and a slide core that form the bolt holes 83 and 89 of the gear box cover 37 are omitted.

  Below the rib forming portion 121 and the boss forming portion 123, drain holes 125 and 127 for discharging the solvent of the fiber-containing slurry injected into the bowl-shaped recess 115 are provided. The drainage hole 125 allows the rib forming part 121 to communicate with the outside of the lower mold 113, and the drainage hole 127 allows the boss formation part 123 to communicate with the outside of the lower mold 113.

  The reinforcing fiber and the solvent contained in the fiber-containing slurry are respectively between the lower tip portion of the rib forming portion 121 and the drainage hole 125 and between the lower tip portion of the boss forming portion 123 and the drainage hole 127. And mesh-shaped filter portions 129 and 131 (see FIG. 6) are provided. The filter parts 129 and 131 allow only the solvent to pass through while preventing the reinforcing fibers from flowing out of the fiber-containing slurry.

  Further, the upper mold 135 has a convex portion 136 corresponding to the bowl-shaped concave portion 115 of the lower mold 113. The convex part 136 has a mesh-like filter part 133 at the convex tip. This filter part 133 should just be the mesh size which prevents the outflow of a reinforced fiber and allows only a solvent to pass through.

  These filter units 129, 131, and 133 may be configured via a porous filter. Examples of the porous filter include porous bodies such as sponge and zeolite, non-woven fabric, fibrous masses such as cotton, and the like. Further, the filter parts 129, 131, 133 may be in a form in which a mesh (fine) part is formed in the mold itself, and further, a porous filter such as a sponge is loaded in the mesh gap. May be.

(Gearbox cover manufacturing process)
Next, the manufacturing process of the gear box cover 37 will be described.
The manufacturing process of the gear box cover 37 includes a reinforcing fiber opening process, a paper making process for making the preform 37A of the gear box cover 37, a resin material impregnated into the paper preform 37A, and a core material is insert-molded. Forming steps to be performed in this order.

FIGS. 7A and 7B are process explanatory views showing a state in which a fiber-containing slurry is produced in the fiber opening process.
In the opening process, as shown in FIG. 7A, a large number of pellets 141 containing carbon fibers that are reinforcing fibers are put into a container 145 containing a solvent 143, and the stirrer 147 is driven. As a result, as shown in FIG. 7B, a homogeneous fiber-containing slurry 149 is obtained in which the carbon fibers contained in the fillet 141 are opened in a solvent 143. The solvent 143 is preferably water (white water) from the viewpoint of stability, handleability, and cost, but may be a solvent such as ethanol or methanol, or a mixture thereof.

  The average fiber length of the fibrous filler to be input is preferably 1 mm or more. Thereby, a part of carbon fiber breaks during the opening and becomes shorter, and the average fiber length after opening can be made 0.5 mm or more.

8A to 8E are process explanatory views for explaining the paper making process step by step.
In the papermaking process, first, the fiber-containing slurry 149 is injected through the nozzle 151 into the lower mold 113 of the papermaking mold shown in FIG. Thereafter, as shown in FIGS. 8B and 8C, the upper mold 135 is moved toward the lower mold 113 (arrow P). As a result, only the solvent 143 in the fiber-containing slurry 149 passes through the mesh-shaped filter part 133 by the pressing of the upper mold 135 and is discharged out of the papermaking mold cavity. Similarly, the solvent 143 of the fiber-containing slurry 149 is discharged from the drainage holes 125 and 127 to the outside of the papermaking mold via the filter parts 129 and 131.

FIG. 9 is an explanatory diagram showing the flow direction of the fiber-containing slurry 149 flowing into the boss forming portion.
The reinforcing fibers in the fiber-containing slurry 149 when the solvent is discharged are aligned in parallel with the flow direction by the flow of the fiber-containing slurry 149 in the fiber longitudinal direction. That is, when the fiber-containing slurry 149 flows into the boss forming portion 123, as indicated by an arrow F in the drawing, the fiber-containing slurry 149 wraps around the edge portion 113 a of the lower mold 113 in a circular arc shape, thereby Head to part 131. That is, in the fiber-containing slurry 149 of this configuration, the fiber longitudinal direction is aligned in parallel with the flow direction by the flow caused by the solvent discharge. Thereby, the thickness of the boss | hub formation part 123 can be made uniform with high precision, without producing the anisotropy of a thermal expansion coefficient.

  Then, the upper mold 135 shown in FIG. 8 (C) is further moved and pressurized toward the lower mold 113, so that a preform (fiber laminated layer) having the same shape as the gear box cover 37 is obtained as shown in FIG. 8 (D). Body) 37A is made.

  Next, as shown in FIG. 8E, the wet preform 37A is taken out from the lower mold 113, and the preform 37A is dried.

  In the molding step, the dried preform 37A is placed in a known molding die not shown. At this time, a cover side metal core 43 (see FIG. 3), which is a connecting member, may be attached to the preform 37A. Then, a thermosetting resin is poured into a molding die and impregnated into the preform 37A for molding.

  Here, it is preferable to preheat the mold before injecting the thermosetting resin into the mold. As a result, the thermosetting resin is heated uniformly, and molding defects are less likely to occur, the curing time is shortened, and productivity is improved. Further, it is preferable that the cover side metal core 43 is bonded to the preform 37A with an adhesive. In that case, coupled with the strength of the adhesive, the bonding strength of the cover-side metal core 43 with the resin material is improved, and misalignment during molding is less likely to occur.

  FIG. 10 is a partially enlarged view schematically showing the boss 91 of the gear box cover 37 formed by the manufacturing method described above. In the boss 91 of the gear box cover 37, the reinforcing fiber 155 is arranged with the fiber longitudinal direction along the outer surface of the boss 91. That is, at the root portion 157 where the boss 91 rises, the reinforcing fiber 155 is disposed along the arc direction of the bending of the boss outer surface. In addition, the reinforcing fiber 155 is disposed in parallel with the outer surface over the entire boss 91.

  Therefore, even if a tensile force or a bending moment is applied to the boss 91, the direction in which the maximum stress is generated in the boss 91 and the fiber direction substantially coincide with each other, so that the reinforcing effect by the reinforcing fiber 155 is enhanced. As a result, the strength (resistance to tearing) of the boss 91 is improved as compared with the case where the reinforcing fibers 155 are arranged in a direction perpendicular to the arc direction of the bending. This reinforcing effect is obtained not only for the boss 91 but also for other parts such as the rib 87 (see FIG. 4B). Similarly, the filter part 133 of the upper mold 135 contributes to aligning the fiber direction of the gear box cover 37 where a particularly high stress is applied in a desired direction.

  In the above example, the filter portions 129 and 131 are provided corresponding to the ribs 87 and the bosses 91, but the present invention is not limited to this. For example, you may provide in other parts, such as projection part 85 (refer to Drawing 4 (A) and (B)). Moreover, although the filter part is arrange | positioned at the downward front-end | tip part of the rib 87 or the boss | hub 91, it is not restricted to this. For example, the boss 91 may be configured to be provided at an arbitrary position such as the axial end surface of the bolt hole 89 of the boss 91 and the arc-shaped outer surface of the boss 91 shown in FIG.

In general, in the injection molding method, when reinforcing fibers are mixed in a resin, the fluidity of the resin pellets is small, so the fluidity of the resin in the mold is lowered. If it is forced to mold in this state, excessive cutting of the reinforcing fibers will be caused, and the shapeability of the gear box will be reduced. Further, when the resin is melted and mixed with a stirrer (screw) and when the injection-molded material passes through the mold gate, the reinforcing fibers are cut by shearing. For this reason, in the gear box manufactured by the injection molding method, the deterioration of the mechanical characteristics is inevitable.
However, in the case of this configuration, after forming a preform in which reinforcing fibers are arranged by papermaking, the preform is impregnated with a resin material. Decrease can be avoided. In addition, since the gear box of this configuration is formed with a curved surface in order to accommodate the gear, there is little stagnation of the resin material, and good resin fluidity can be obtained.

  As described above, the present invention is not limited to the above-described embodiments, and those skilled in the art can make changes and applications based on combinations of the configurations of the embodiments, descriptions in the specification, and well-known techniques. This is also the scope of the present invention, and is included in the scope for which protection is sought.

  The gear box of the present invention is a gear box applied to various transport machines such as automobiles, motorcycles, railway vehicles, airplanes, ships, etc. that are required to be reduced in weight in addition to the gear box provided in the electric power steering device described above. Further, it may be a building equipment such as an elevator or a gear box applied to various manufacturing apparatuses.

As described above, the following items are disclosed in this specification.
(1) A gear box component constituting a gear box in which the gear mechanism is accommodated,
A gear box component formed of a fiber reinforced resin composition in which a fibrous filler having an average fiber length of 0.5 mm or more is dispersed in a resin material.
According to this gear box component, the weight can be reduced with high dimensional accuracy as compared with a conventional metal gear box component, and the impact resistance, creep characteristics, and rigidity can be improved.

(2) The gear box component according to (1), wherein the resin material is a thermosetting resin.
According to this gear box component, by using a thermosetting resin such as an epoxy resin or a phenol resin, a configuration excellent in heat resistance and mechanical strength can be achieved.

(3) The gearbox component according to (1), wherein a blending amount of the fibrous filler in the fiber reinforced resin composition is 10 to 60% by weight.
According to this gear box component, when the fiber filler is blended in an appropriate amount, durability equivalent to that of the conventional product is obtained and the toughness of the material is maintained.

(4) The fibrous filler is at least one of glass fiber, carbon fiber, metal fiber, aramid fiber, aromatic polyamide fiber, liquid crystal polyester fiber, silicon carbide fiber, alumina fiber, boron fiber, cellulose, and cellulose nanofiber. The gear box component according to (3), which is selected from one type.
According to this gear box component, the strength of the fiber-reinforced resin composition can be improved due to the high fiber strength.

(5) The said fibrous filler in the said fiber reinforced resin composition is a gear box component of any one of (1)-(4) arrange | positioned with the fiber longitudinal direction aligned.
According to this gear box component, the fiber longitudinal direction of the fibrous filler tends to be along the direction in which the stress is generated, and the mechanical strength is improved.

(6) A metal connecting member is embedded in at least a part of the gear box component according to any one of (1) to (5),
A gear box in which a plurality of the gear box components are connected to each other by a fastening member.
According to this gear box, since the gear box components are connected by the metal connecting members, the connection strength can be improved.

(7) There is a manufacturing method of a gear box component constituting a gear box in which a gear mechanism is accommodated,
A fiber opening process in which a fibrous filler is opened in a solvent to obtain a fiber-containing slurry; and
Injecting the fiber-containing slurry into a papermaking mold, removing the solvent from the papermaking mold, and forming a preform that is substantially the same shape as the gearbox component,
A molding process in which the preform is loaded into a molding die and the preform is impregnated with a resin material to mold the gear box component.
A method of manufacturing a gearbox component having
According to this gear box component manufacturing method, a gear having a high dimensional accuracy and weight reduction as compared with a conventional metal gear box component and having excellent impact resistance, creep characteristics and rigidity. Can manufacture box components.

(8) The molding step is a step in which a metal connecting member is disposed in a cavity of the molding die, and the preform and the connecting member are insert-molded with the resin material. Method for manufacturing the gearbox component of the present invention.
According to this gear box component manufacturing method, the connecting member can be easily insert-molded.

(9) The gear box component includes a mother body and a protrusion provided to protrude from a part of the mother body to the outer side of the mother body,
The papermaking mold has a main recess that forms the base body, and a branch recess that branches from the main recess and forms the protrusion.
The gear box according to (7) or (8), wherein only the solvent in the fiber-containing slurry injected into the branch recess is discharged out of the papermaking mold from a discharge path connected to the branch recess. Manufacturing method of component parts.
According to this gear box component manufacturing method, the fiber-containing slurry flows into the branch recesses, and the solvent is discharged from the discharge path. As a result, the fiber longitudinal direction of the fibrous filler can be aligned in the direction toward the discharge path, and papermaking can be made in the fiber direction in which mechanical strength is easily obtained intentionally.

(10) The discharge route is
A filter part that is arranged facing the tip of the branching recess and separates the fibrous filler and the solvent;
A drainage hole for discharging the solvent separated by the filter unit out of the mold;
(9) The manufacturing method of the gearbox component as described in (9).
According to this gear box component manufacturing method, the filter portion can reliably separate the fibrous filler and the solvent from the fiber-containing slurry, leaving only the fibrous filler and discharging the solvent.

DESCRIPTION OF SYMBOLS 11 Electric motor 13 Reduction gear mechanism 15 Steering mechanism 33 Gear box 35 Gear box main body (Gear box component)
37 Gearbox cover (Gearbox component)
37A Preform 39 Bolt (fastening member)
43 Cover side core (connecting member)
DESCRIPTION OF SYMBOLS 100 Electric power steering apparatus 111 Papermaking type | mold 113 Lower type | mold 117 Projection surface formation part (main recessed part)
118 Bearing hole forming part 121 Rib forming part (branch concave part)
123 Boss forming part (branch recess)
125,127 drainage hole (discharge path)
129, 131, 133 Filter section (discharge path)
141 Pillette (fibrous filler)
143 Solvent 149 Fiber-containing slurry 155 Reinforced fiber (fibrous filler)

Claims (10)

A gear box component constituting a gear box in which the gear mechanism is accommodated,
A gear box component formed of a fiber reinforced resin composition in which a fibrous filler having an average fiber length of 0.5 mm or more is dispersed in a resin material.   The gear box component according to claim 1, wherein the resin material is a thermosetting resin.   The gearbox component according to claim 1 or 2, wherein a blending amount of the fibrous filler in the fiber reinforced resin composition is 10 to 60% by weight.   The fibrous filler is at least one of glass fiber, carbon fiber, metal fiber, aramid fiber, aromatic polyamide fiber, liquid crystal polyester fiber, silicon carbide fiber, alumina fiber, boron fiber, cellulose, and cellulose nanofiber. The gearbox component according to claim 3, wherein the gearbox component is selected.   The gear box component according to any one of claims 1 to 4, wherein the fibrous filler in the fiber reinforced resin composition is arranged with the fiber longitudinal direction aligned. A metal connecting member is embedded in at least a part of the gear box component according to any one of claims 1 to 5,
A gear box in which a plurality of the gear box components are connected to each other by a fastening member. There is a method of manufacturing a gear box component constituting a gear box in which a gear mechanism is accommodated,
A fiber opening process in which a fibrous filler is opened in a solvent to obtain a fiber-containing slurry; and
Injecting the fiber-containing slurry into a papermaking mold, removing the solvent from the papermaking mold, and forming a preform that is substantially the same shape as the gearbox component,
A molding process in which the preform is loaded into a molding die and the preform is impregnated with a resin material to mold the gear box component.
A method of manufacturing a gearbox component having   The gear box according to claim 7, wherein the molding step is a step of disposing a metal connecting member in a cavity of the molding die and insert-molding the preform and the connecting member with the resin material. Manufacturing method of component parts. The gear box component includes a mother body and a protrusion provided to protrude from a part of the mother body to the outer side of the mother body,
The papermaking mold has a main recess that forms the base body, and a branch recess that branches from the main recess and forms the protrusion.
The gearbox according to claim 7 or 8, wherein only the solvent in the fiber-containing slurry injected into the branch recess is discharged out of the papermaking mold from a discharge path connected to the branch recess. Manufacturing method of component parts. The discharge route is
A filter part that is arranged facing the tip of the branching recess and separates the fibrous filler and the solvent;
A drainage hole for discharging the solvent separated by the filter unit out of the mold;
The manufacturing method of the gearbox component of Claim 9 which has these.

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