JP5564856B2 - Fiber base material and resin gear using the fiber base material - Google Patents

Description

  The present invention relates to a fiber base material for a resin molded body and a resin gear using the fiber base material.

Conventionally, many gears used in automobiles have been made of metal gears in terms of strength and heat resistance. However, between metal gears, the meshing noise is increased, which is disadvantageous for the quietness that is a user's need.
In recent years, automobile manufacturers have been developing environmentally-friendly cars, and are focusing on improving fuel efficiency and reducing CO _2, and the weight of automobile parts has been reduced in order to achieve the purpose.
It has been proposed to use resin gears as a countermeasure against the above-described quietness and weight reduction.

  As a specific configuration of the resin gear, there is one using an aramid fiber as a reinforcing fiber base material. As shown in FIG. 1, the aramid fiber is woven or knitted to form a tubular body 1, and this tubular body. Patent Document 1 discloses a ring-shaped fiber base material 2 that is rolled up while being turned upside down and formed into a donut shape.

JP-A-8-156124

  However, when the above-described ring-shaped fiber base material is used, as shown in FIG. 2, the shape after impregnating and curing the resin (form 3 before cutting) becomes a circle in plan view. If the teeth 4 are cut, there is a problem that the machining allowance 5 becomes large.

  More specifically, the ring-shaped fiber base material 2 described with reference to FIG. 1 is difficult to use as it is, so that it is slightly flattened by applying pressure. As shown in FIG. Preparing a preforming mold 9 comprising a body part 6, a housing part 7 for the ring-shaped fiber base material 2, and a compression means 8 for compressing the ring-shaped fiber base material 2 in the axial direction of the cylindrical body part 6, After the ring-shaped fiber substrate 2 is inserted into the cylindrical body portion 6 and installed in the accommodating portion 7, the ring-shaped fiber substrate 2 is preformed by the compression means 8 to produce a flat preform substrate.

  When using a preformed base material produced by such a method, since it will be a lot of processing allowance as described above, in order to reduce the processing allowance as much as possible, at the stage of preforming, Although it is conceivable to make the shape close to the final gear shape, when the ring-shaped fiber base material is forcibly compressed into a housing portion having a shape other than the ring shape in plan view, as shown in FIG. The fibers of the ring-shaped fiber base material 2 are sandwiched between the accommodating portion 7 and the compression means 8, and the fibers are cut, making it difficult to produce a preformed base material.

  An object of this invention is to provide the fiber base material and the resin-made gears using this fiber base material which can reduce processing cost as much as possible.

The present invention relates to the following.
(1) A fiber substrate knitted with a cloth knitted into a cylindrical shape while being turned inside out or folded back inside, and a doughnut-shaped fiber base material, the inner diameter circular shape being maintained, and the outer diameter circular shape being Deformed by an external force, the deformed shape of the outer diameter circular shape is a protruding portion that contacts the original circumscribed circle at equal intervals, and the distance between the protruding portion and the protruding portion is separated from the original circumscribed circle A fiber substrate that is shaped by a dent.
(2) term Oite to (1), an external force is, the fiber substrate is an external force toward the axial compressive force or radial center of the cylindrical shape.
( 3 ) A resin gear in which the fiber base material according to (1) or (2) is impregnated with a thermosetting resin and cured to form teeth.

According to the present invention, it is possible to reduce the machining allowance when performing gear machining.
In addition, the deformed shape of the outer diameter circular shape is formed by a protruding portion that contacts the original circumscribed circle at equal intervals, and a hollow portion that is spaced from the original circumscribed circle between the protruding portion and the protruding portion. Thus, it is possible to follow the final gear shape and further reduce the machining allowance.
When the external force is a cylindrical axial compressive force or an external force toward the radial center, the ring-shaped fiber base material can be compressed into a deformed shape having a circular outer diameter after being introduced into the housing portion. It is possible to prevent the fibers from being sandwiched and cut by the accommodating portion and the compression means.
The resin gear using the fiber base material of the present invention can reduce production time and production cost by reducing the machining allowance.

The manufacturing process figure of the ring-shaped fiber base material which is a prior art example is shown. The gear tooth cutting process figure which is a prior art example is shown. The preforming process figure of the ring-shaped fiber base material which is a prior art example is shown. The preforming process of the other ring-shaped fiber base material which is a prior art example is shown. The preforming process which deform | transforms a fiber base material using an axial direction compression force is shown. The preforming process which deform | transforms a fiber base material using the external force which goes to radial direction center is shown. An example of preforming in which a fiber base material is deformed by using an external force toward the radial center will be described.

The fibers used in the cloth used in the present invention are not particularly limited, but natural fibers such as cotton and hemp, organic fibers such as aramid fibers (aromatic polyamide fibers), polyamide fibers and the like are appropriately used depending on the intended use. be able to. These fibers may be used alone or as a plurality of kinds of blended yarns depending on applications. Among these, the use of a blended yarn of para-aramid fiber and meta-aramid fiber is particularly preferable in terms of machinability, heat resistance, and gear strength.
The cloth used in the initial state is knitted into a cylindrical shape. The cylindrical shape described here is a tube (tube) shape having open portions at both ends, and is knitted into a cylindrical shape from the beginning. A thing knitted in a flat shape or a cylindrical shape may be used later.
The size of the cylindrical shape is not particularly limited, and is appropriately selected depending on the size of the final resin gear.

The donut shape described in the present invention is a ring shape having a through-hole in the center, and is obtained by winding the cloth knitted into the cylindrical shape described above while turning it back to the outside of the cylindrical shape or turning it back to the inside. As shown in FIG. 1 described above, the cylindrical cloth may be wound while turning it over to the outside, or conversely, it may be wound while turning back inside. Then, it is preferable to wind it upside down.
The number of winding is not particularly limited, but it is necessary to wind at least once in order to obtain a donut shape.

The fiber base material having a donut shape has an inner diameter circular portion that forms a central through-hole shape, and the circular shape of the inner diameter circular portion needs to be maintained so that the circular shape seen in plan view does not collapse. is there. This is because the fiber base material is fitted into the outer peripheral portion of the cylindrical metal bush 10 used for the inner diameter portion of the resin gear as shown in FIG. 2 when the resin gear is manufactured. Moreover, when installing the bearing of a gear, it is preferable that it is circular.
In addition, the outer peripheral part (contact surface with a fiber base material) of the metal bush 10 does not necessarily need to make a planar view circular, and is provided with a protrusion or the like that bites into the circular inner diameter portion of the fiber base. The metal bush 10 can be more firmly fixed.

The doughnut-shaped fiber base material has an outer circular portion facing the inner circular portion described above. Immediately after winding the cloth knitted into a cylindrical shape, the outer circular portion has a circular shape similar to the inner circular shape portion in plan view, but is deformed by an external force.
The deformation is preferably a shape close to the final resin gear, but it is sufficient that at least a plurality of depressions are provided, and the protrusions project relatively between the depressions.
It is preferable that the projecting portion is in contact with the shape of the original outer circular portion in plan view (circumferential circle) at equal intervals. In other words, the hollow portion is the original outer circular portion between the projecting portion and the projecting portion. It is preferable to be spaced apart at regular intervals with respect to the plan view shape (circumferential circle).
When such deformations are made, the protrusions and depressions appear alternately and at even intervals, making it easy to match the tip and bottom of the final resin gear, reducing the machining allowance. easy.

The external force described in the present invention only needs to deform the outer circular shape of the fiber base material, and specifically means a cylindrical axial compression force or an external force toward the radial center.
The axial compressive force indicates a force (axial compressive force 11) applied in the thickness direction (C direction in FIG. 5) of the ring-shaped fiber base material 2 by the compressing means 8 as shown in FIG. The accommodating portion 7 shown in FIG. 5 is deformed so that the dent gradually becomes deeper from the ring-shaped fiber base inlet (near the cross section D) toward the bottom, and the outer diameter deformed shape is formed on the inner diameter bottom portion (cross section F). It shall have. When the ring-shaped fiber base material is put into the accommodating portion 7 and pushed into the bottom portion of the accommodating portion 7 by an axial compressive force, the ring-shaped fiber substrate 2 is deformed while conforming to the inner diameter shape of the accommodating portion 7.

The aforementioned external force toward the center in the radial direction indicates a force that is used only for deforming the outer diameter shape of the ring-shaped fiber substrate 2 when performing preforming. The generation method is not particularly limited, but a method of pressing a member that deforms the ring-shaped fiber base material 2 toward the radial center by air pressure, a motor, or the like is preferable because it is simple and easy to control.
FIG. 6 shows an apparatus in which a deformable member 12 for deforming the outer diameter shape is added to the accommodating portion 7.
The deformable member 12 is retracted from the inside of the housing portion 7 before the ring-shaped fiber base material 2 is charged, but after the ring-shaped fiber base material 2 is loaded into the housing portion 7 and before being compressed in the axial direction, The deformable member 12 is pushed out in the horizontal direction toward the radial center by using force, and the deformable member 12 is brought into contact with the ring-shaped fiber substrate 2 to deform the outer diameter shape of the ring-shaped fiber substrate 2.
The fiber base material is prepared by performing preforming using the compression means 8 in a state where the deformable member 12 is in contact with the ring-shaped fiber base material 2 and deforming the outer diameter shape.

  The thermosetting resin described in the present invention uses a liquid resin such as CP resin (cross-linked polyester amide, cross-linked polyaminoamide), epoxy resin, polyimide resin, or phenol resin. Among these, it is particularly preferable to use CP resin from the viewpoint of physical properties such as manufacturability, heat resistance and strength of the resin gear.

The teeth of the resin gear described in the present invention may be formed by a mold for curing a thermosetting resin or by cutting after demolding from the mold, but the accuracy can be improved. Therefore, it is preferable to perform the cutting process.
In the present invention, since the outer peripheral portion of the fiber base material is deformed, the amount of cutting can be reduced compared to using a preformed base material having a circular shape in plan view.

Hereinafter, one example of the present invention is described in detail using a drawing.
In this example, the fiber base material is preformed using the manufacturing apparatus shown in FIG.
As a manufacturing apparatus, the cylindrical body part 6 which penetrates a ring-shaped fiber base material, the accommodating part 7 which has the shape after a deformation | transformation of the ring-shaped fiber base material 2, and the ring-shaped fiber base material 2 arrange | positioned at this accommodating part 7 And a compression means 8 for compressing the cylindrical body portion 6 in the axial direction.
For production of the fiber base material, the ring-shaped fiber base material 2 is put into the accommodating portion 7 through the cylindrical body portion 6 in the manufacturing apparatus through the circular inner diameter portion which is a through hole. At this time, the cylindrical body portion 6, the accommodating portion 7, and the compression means 8 are heated to 120 ° C. using a heater.
After the ring-shaped fiber base material 2 is introduced, the ring-shaped fiber base material 2 is pushed in the axial direction from the top to the bottom in the drawing by the compression means 8, compressed at a press pressure of 5 MPa, and held for 30 seconds. Since the inside of the bottom part of the accommodating part 7 has a shape after the ring-shaped fiber base material 2 is deformed, the compressed ring-shaped base material 2 is formed in that shape and maintains its shape by heat pressure. The fiber base 13 is obtained.
Moreover, the manufacturing apparatus used in the present embodiment has the outer diameter of the input portion of the accommodating portion 7 larger than the outer diameter of the bottom portion, so that the ring-shaped fiber substrate 2 can be easily input.
Furthermore, the outer diameter of the accommodating portion 7 is gradually reduced by providing an inclination on the inner peripheral wall surface of the accommodating portion 7, and the shape after deformation at the bottom portion (shape approximating the gear teeth) is obtained. To have.

As another example of the present invention, a fiber substrate was manufactured using a manufacturing apparatus shown in FIG.
The manufacturing apparatus shown in FIG. 7 includes a cylindrical body portion 6 through which the ring-shaped fiber base material 2 is inserted, a storage portion 7 having a shape after the ring-shaped fiber base material 2 is deformed, and a ring disposed in the storage portion 7. Compression means 8 for compressing the fibrous fiber substrate 2 in the axial direction of the cylindrical body portion 6.
The accommodating portion 7 has a deformable member 12 for forming the outer diameter of the ring-shaped fiber substrate 2, and this deformable member 12 uses an air cylinder 14 to center the cylindrical body portion 6. With respect to 15, it has a structure that can move freely forward and backward (near-distance direction).
For producing the fiber base material 13, first, the ring-shaped fiber base material 2 is put between the cylindrical body portion 6 in the manufacturing apparatus and the accommodating portion 7 for accommodating the ring-shaped base material 2. At this time, the cylindrical body portion 6, the accommodating portion 7, and the compression means 8 are heated to 120 ° C. using a heater. After introducing the ring-shaped fiber base material 2, the air cylinder 14 is moved with an air pressure of 3 MPa, and the deformable member 12 protrudes in the direction of the central axis 15 of the cylindrical body portion 6 in the housing portion 7 and contacts the ring-shaped fiber base material 2. Touch and transform.
Thereafter, the ring-like fiber base material 2 is pushed in the axial direction from the top to the bottom on the drawing by the compression means 8, compressed at a press pressure of 5 MPa, and held for 30 seconds. The ring-shaped fiber base material 2 is deformed by the deformable member 12, and the fiber base material 13 is produced while maintaining its shape by hot pressure.

DESCRIPTION OF SYMBOLS 1 ... Cylindrical body, 2 ... Ring-shaped fiber base material, 3 ... Shape before cutting, 4 ... Teeth, 5 ... Processing allowance, 6 ... Cylindrical body part, 7 ... Accommodating part, 8 ... Compression means, 9 ... Pre-molding Metal mold, 10 ... Metal bush, 11 ... Axial compressive force, 12 ... Deformable member, 13 ... Fiber base material, 14 ... Air cylinder, 15 ... Central shaft

Claims (3)

A fiber substrate knitted with a cloth knitted in a cylindrical shape while turning it inside out or folded back inside to make a doughnut-shaped fiber base that maintains its circular inner diameter, and its outer circular shape is deformed by external force It is those that have been,
The fiber base in which the shape after deformation of the outer diameter circular shape is formed by a protruding portion that contacts the original circumscribed circle at equal intervals, and a hollow portion that is spaced from the original circumscribed circle between the protruding portion and the protruding portion Wood. Oite to claim 1, external force, the fiber substrate is an external force toward the axial compressive force or radial center of the cylindrical shape. A resin gear in which the fiber base material according to claim 1 or 2 is impregnated with a thermosetting resin and cured to form teeth.

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