JPH0691770A - Fiber-reinforced resin gear - Google Patents

Abstract

PURPOSE:To provide a fiber-reinforced resin gear in which a strength of a toothed part and wear resistance of the vicinity of a pitch circle of an engaging surface are obtained while enhancing processability in the case of gear cutting. CONSTITUTION:A prepreg containing meta series aramid fiber and a prepreg containing carbon fiber are superposed, and wound in a rod state. Both ends of the rod state are matched in a doughnut state, molded and fixed in a ringlike material. Teeth are cut on an outer periphery of the material, and fibers are oriented in an annular ring state of a tree on an engaging surface 70 of a toothed part 7. A reinforced part 7a reinforced by aramid fiber is formed on an outermost periphery of the part 7, and a composite reinforced part 7b reinforced by aramid fiber and carbon fiber is formed at its central side. The part 7b is disposed at a position corresponding to a pitch circle 73.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a fiber-reinforced resin gear. This gear can be used, for example, as a camshaft timing gear of an automobile.

[0002]

2. Description of the Related Art Fiber-reinforced resin gears have been widely used in various fields in recent years because they have advantages such as low meshing noise, light weight and small rotational inertia. Here, JP-A-6
As disclosed in Japanese Unexamined Patent Publication No. 0-206628, a fiber reinforced resin gear is known in which a material obtained by kneading reinforcing short fibers and a thermosetting resin is loaded into a mold cavity and heat-pressed. Further, as disclosed in JP-A-60-206629, a denier prepreg composed of reinforcing short fibers and a thermosetting resin is circumferentially loaded into a mold cavity and heat-pressed. Fiber-reinforced resin gears are known.

Further, as disclosed in Japanese Patent Application Laid-Open No. 2-241729, a prepreg is spirally wound into a rod shape, and both ends of the rod shape are combined to form a doughnut-shaped preform. BACKGROUND ART A fiber-reinforced resin gear is known in which a ring-shaped material is solidified to form a ring-shaped material, and an outer peripheral portion of the ring-shaped material is gear-cut.

[0004]

Carbon fibers, glass fibers, aramid fibers, etc. are generally used as the reinforcing fibers in the above-mentioned fiber-reinforced resin gears. Although it has good wear resistance, carbon fiber is a difficult-to-cut material due to the small friction coefficient of the cutter because the blade edge of the cutter slips, workability is extremely poor, and it is not suitable for mass production. The effect of reducing the meshing noise, which is the original purpose of the fiber-reinforced resin gear, is small. Furthermore. Further, a fiber-reinforced resin gear reinforced only with glass fibers has extremely great aggression with respect to a mating gear, and therefore is fatal from the viewpoint of wear resistance of the mating gear particularly when aiming for high load applications. On the other hand, the fiber-reinforced resin gear reinforced with the meta-polyamide fiber has good workability, is effective in reducing noise, and has good wear characteristics including its own wear resistance and opponent attack.

By the way, in recent years, in fiber-reinforced resin gears,
It is desired to further improve the goodness of gear cutting, the wear resistance of the teeth, the strength of the teeth, and the load resistance. As a countermeasure, the present inventor has conceived a fiber reinforced resin gear in which the entire region is reinforced with both soft fibers such as meta-aramid fibers and hard fibers such as carbon fibers. However, such strengthening is not efficient. For example, to strengthen hard fibers such as carbon fibers uniformly over the entire meshing surface of the teeth,
Deteriorates gear cutting workability.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a fiber-reinforced resin gear that secures the strength and wear resistance of the tooth portion while improving the workability in gear cutting. To do.

[0007]

A fiber reinforced resin gear according to the present invention has a rod shape formed by winding a prepreg.
A ring-shaped preform that is made into a donut shape by combining both ends of the rod shape is molded and solidified. In the resin gear, the fibers oriented in the annual ring shape of the tree are arranged such that soft fibers having good workability are arranged on the outermost peripheral portion and relatively many hard fibers having high strength are arranged on the center side of the outermost peripheral portion. It is characterized by that.

In the fiber-reinforced resin gear according to the present invention, the fibers are oriented on the meshing surfaces of the teeth in the shape of a tree ring. Here, the annual ring shape of a tree means that the fibers are multi-oriented, and includes a ring-oriented shape, a semi-ring shape, and a partial ring shape. Fibers oriented in the shape of tree rings have relatively many soft fibers with good workability arranged at the outermost periphery, and relatively many hard fibers with high strength are arranged at the center side of the outermost periphery. It is set up.

The soft fiber used in the fiber-reinforced resin gear of the present invention means a fiber having an elastic modulus lower than that of the hard fiber. The soft fiber is basically not limited to any particular one as long as it can form a gear, but a meta-aramid fiber is preferable in terms of its machinability and reduction of meshing noise. The hard fiber means a fiber having a higher elastic modulus than the soft fiber and poor machinability. Carbon fibers, para-aramid fibers, and glass fibers can be used as the hard fibers. Carbon fiber has a high elastic modulus, high strength, and excellent wear resistance.

In the meshing surface of the tooth portion, the portion corresponding to the pitch circle or the portion between the pitch circle and the tooth root in the height direction of the tooth portion has a relatively large amount of hard fibers. preferable. The main reason for this is that among the meshing surfaces of the teeth, the part where wear resistance is particularly required is near the pitch circle,
Alternatively, in many cases, the diameter is slightly inside the pitch circle.

In the fiber-reinforced resin gear of the present invention, the total amount of fibers is not particularly limited and may be arbitrarily set according to the required characteristics of the gear. Considering this, the total volume ratio of the fibers is preferably about 50%, and particularly preferably about 40 to 60%. Of these, the main fibers can be soft fibers. The hard fiber having high strength and high abrasion resistance (for example, carbon fiber or para-aramid fiber) can be, for example, 5 to 50% of the total amount of the fiber.

However, in the region where the carbon fibers are locally concentrated, the carbon fiber content is 30% or more of the total amount of the fibers in the region from the viewpoint of improving wear resistance.
From the viewpoint of workability, it is preferably 70% or less.
Examples of the matrix resin used in the fiber-reinforced resin gear of the present invention include various thermosetting resins such as phenol resin, epoxy resin, and polyimide resin, or PES and PEE.
Various thermoplastic resins such as K and PAI may be used. That is,
Any resin can be used as long as it can be combined with the soft fiber or the hard fiber by some method.

[0013]

With respect to the fibers oriented in a tree ring shape, soft fibers having good workability are arranged on the outermost peripheral portion, and relatively many hard fibers having high strength are arranged on the center side of the outermost peripheral portion. Therefore, a relatively large amount of hard fibers is arranged in a portion closer to the center than the outermost peripheral portion of the tooth portion, that is, a portion where the tooth portion of the mating gear easily contacts, for example, near the pitch circle. In addition, during the gear cutting process, the soft fiber is processed.

[0014]

【Example】

(Example 1) (1) Production of prepreg Using a phenol resin melted in a varnish form with a solvent, a plain woven aramid fiber cloth was impregnated with the phenol resin, and then the solvent was dried and removed. . Thus, a prepreg sheet made of aramid fiber cloth and phenol resin was prepared. Then, this prepreg sheet was cut into parallelogram shapes as shown in FIG. The prepreg 1 has sides 1a to 1d, and the side 1a is inclined at an angle θ (5 °) with respect to the direction perpendicular to the side 1c.
Here, the prepreg 1 has a length L1 of 235 mm and a width L.
2 is 228 mm and the thickness is 0.2 mm. In this prepreg 1, as shown in FIG. 2, the fiber orientations of the aramid fibers 1x and 1y are 0 ° and 90 ° with respect to the side 1c.

Further, a plain weave carbon fiber cloth was impregnated with the above-mentioned phenol resin and the solvent was removed by drying, whereby a prepreg sheet composed of the carbon fiber cloth and the phenol resin was prepared. Then, this prepreg sheet is shown in FIG.
As shown in (1), it was cut into parallelogram shapes to obtain prepreg 2. The prepreg 2 has sides 2a to 2d, and the side 2a is inclined at an angle θ (5 °) with respect to the direction perpendicular to the side 2c.
Here, the prepreg 2 has a length L3 of 235 mm and a width L.
4 is 40 mm and the thickness is 0.3 mm. Prepreg
In G2, as shown in FIG. 3, the fiber orientations of the carbon fibers 2x and 2y are 0 ° and 90 ° with respect to the side 2c.

The aramid fiber cloth constituting the above prepreg 1 will be described. That is, the fiber material is meta-aramid (Teijin Co., Ltd. “Conex”), and the filament characteristics have an elongation of 27% and an elastic modulus of 1250 kg /
mm ^2, count as yarn properties 20Tex, basis weight as a cross characteristic is 130 g / m ^2. Further, the carbon fiber cloth constituting the above prepreg 2 will be described. That is, the fiber material was graphite (“Besfight” manufactured by Toho Rayon Co., Ltd.), and the filament characteristics were strength 380 kg / mm ² , elongation 1.6%, elastic modulus 23500 kg / mm ² , yarn count was 67 tex, and the fabric weight per unit area is 236 g / m ² .

Here, the meta-aramid fiber has a characteristic that it has a low elastic modulus, is excellent in machinability, and suppresses the sound generated at the meshing surfaces of gears and the like. Further, the carbon fiber has a high elastic modulus, excellent strength, a small friction coefficient, and excellent wear resistance. (2) Production of ring-shaped material Next, as shown in FIG. 1 (A), a carbon fiber prepreg 2 is superposed in a predetermined arrangement on an aramid fiber prepreg 1 cut into parallelogram shapes. At this time, the side 1b and the side 2b are aligned, and the side 2a and the side 1a are aligned. In this example, the prepreg 2 in the stacked state
One side 2c is a dimension L5 from one side 1c of the other prepreg 1.
(30 mm) apart. Figure 1 (B) after overlapping
Prepreg 1 from one side 1c to prepreg 2 as shown in
Along with this, it is wound into a spiral and made into a rod shape. Next, FIG.
As shown in (C), a mating portion 3a was formed so that one end and the other end of the rod-shaped prepreg 1 were aligned, and the prepregs 1 and 2 were curved to obtain a ring-shaped preform material 3. Here, the mating portion 3a (coil rod matching) of the ring-shaped preform material 3 has an overlapping structure in order to avoid a decrease in strength of the same portion. The length of the overlap can be arbitrarily set by devising the shape when cutting the prepregs 1 and 2 in FIG.

The cross-sectional structure of the preformed material 3 has an aramid fiber layer A at the center, as schematically shown in FIG.
An alternate laminated portion B of aramid fibers and carbon fibers is provided on the outer side thereof, and an aramid fiber layer A is again present on the outermost periphery to form a composite structure. As shown in FIG. 5, the two ring-shaped preforms 3 thus obtained are stacked so that the mating portions 3a face each other by 180 °, and the mold 4 shown in FIG.
Set to. At this time, a ring-shaped steel insert 5 having a central hole 5e is arranged in the mold 4. The mold 4 includes a lower die 40 having a positioning protrusion 40a at the bottom of the cavity, a cylindrical pressure punch 41 having a ring-shaped pressure surface 41a inserted into the cavity of the lower die 40, and a pressure punch. The core 42 is inserted through the central hole 41 b of the core 41. Then, the insert 5 is held by the core 42, and the ring-shaped preforms 3 vertically stacked in the cavity are pressed by the pressure punch 41 to the arrow E.
By pressing in the direction, heat compression molding was performed, thereby solidifying the resin components in the prepregs 1 and 2, and the ring-shaped material 6 shown in FIG. 7 was formed. The molding condition at this time is a temperature of 180.
° C., a pressure 250 kgf / cm ^2, is 15 minutes pressing time.

In the ring-shaped material 6 shown in FIG. 7, the concave portions 5a and the convex portions 5b of the steel insert 5 and the inner peripheral portion of the fiber reinforced resin portion are firmly bonded. The ring-shaped material 6 in FIG.
The cross section of is shown. As shown in FIG. 8, the radial direction, that is, the arrow Y
In the outermost peripheral portion of the ring-shaped material 6 in the direction, a reinforced portion 7a reinforced with aramid fiber is formed. Further, a composite reinforced portion 7b having a ring-shaped cross section reinforced with aramid fibers and carbon fibers is formed at a portion Y3 closer to the center than the reinforced portion 7a. Further, a reinforced portion 7c reinforced with aramid fibers is formed in the portion of the composite reinforced portion 7b surrounded by the ring. Further, a reinforced portion 7d reinforced with aramid fiber is formed on the center side of the composite reinforced portion 7b, that is, on the shaft core K side.

That is, in FIG. 8, the black filled area is the composite reinforced portion 7b reinforced with aramid fibers and carbon fibers, and the unfilled area is reinforced with only aramid fibers. The parts 7a, 7c and 7d. Here, the ring-shaped material 6 has an inner diameter L7 of 40.0 m.
m, the outer diameter L9 is 79.0, the thickness t is 10 mm, and the outer diameter L8 of the insert 5 is 55 mm. Ring material 6
The total amount of fibers in the fiber-reinforced portion is 50% by volume, of which 80% is aramid fibers and 20% is carbon fibers.

(3) Gear cutting processing The ring-shaped material 6 shown in FIG.
Tooth cutting was performed by cutting the outer peripheral portion with a cutter to obtain a fiber reinforced resin gear 8 having tooth portions 7 on the outer peripheral portion as shown in FIGS. 9 to 11. At this time, some of the fibers are cut. The specifications of the fiber-reinforced resin gear 8 are as follows. That is, the type is an involute helical gear, the tip diameter is 79.0 mm, and the root diameter is 6
6.9 mm, pitch circle diameter 73.9 mm, total tooth depth 6.05 mm, number of teeth 32, right angle module 2.0,
The pressure angle at right angles to the teeth is 18.0 °, and the twist angle is 30 °.

The orientation form of the fibers according to this embodiment is shown in FIG.
As shown in FIG. FIG. 9 mainly shows the meshing surface 70 of the tooth portion 7.
Shows the annual ring-shaped fiber orientation of the tree in. Further, in FIG. 10, fibers oriented in a tree ring shape are omitted and other fiber orientations in the meshing surface 70 are shown. As shown in FIG. 9, in the fiber-reinforced resin gear 8 according to this embodiment, the meshing surface 7 of the tooth portion 7 is
At 0, the fibers 100 are oriented like tree rings. Further, on the tooth crest surface 75 as the outermost peripheral surface of the tooth portion 7, the fibers 101 extending substantially in the circumferential direction and the fibers 102 extending along the axis K of the gear intersect and are oriented. Further, on the shaft end surface 76 of the tooth portion 7, a fiber 103 extending substantially in the circumferential direction and a fiber 104 extending substantially in the radial direction with respect to the shaft axis K of the gear are intersecting and oriented. Further, as shown in FIG.
In the meshing surface 70 of, the end portion 103a of the fiber 103 extending in the circumferential direction, which is cut during gear cutting, is meshed with the meshing surface 7
It is exposed on the surface of 0. Here, in the present embodiment, as described above, the fibers 104 extending substantially in the radial direction with respect to the axis of the gear are oriented, which is advantageous for increasing the strength of the tooth portion 7 near the root 72.

In the fiber-reinforced resin gear 8 according to this embodiment, as shown in FIG. 11, the tooth portion 7 is formed in the radial direction.
In the height direction of, the reinforced portion 7a reinforced with aramid fiber is formed on the outermost peripheral portion of the tooth portion 7. Further, a composite reinforced portion 7b reinforced with aramid fiber and carbon fiber is formed at a portion Y3 closer to the center than the reinforced portion 7a. Further, as shown in FIG. 12, a reinforced portion 7c reinforced with aramid fibers is formed in the portion of the composite reinforced portion 7b surrounded by the ring. Furthermore, the reinforced portion 7d reinforced with aramid fiber is located closer to the center than the composite reinforced portion 7b.
Are formed.

In other words, in this embodiment, a relatively large amount of aramid fiber is arranged at the outermost peripheral portion of the tooth portion 7, and a relatively large amount of carbon fiber is arranged at the center side of the outermost peripheral portion. ing. Here, in the composite reinforced portion 7b, the fiber ratio is aramid fiber: carbon fiber = 50: 50 (volume ratio). The fiber composition ratio of the composite reinforced portion 7b can be changed by changing the basis weight of the fiber cloth used.
It can be set arbitrarily.

By the way, when using the gear, the tooth portion 7
The most severe part of the stress is the root 72. Further, the portion requiring wear resistance is a portion of the meshing surface 70 of the tooth portion 7 near the pitch circle 73 or a portion slightly inward of the pitch circle 73, that is, the pitch circle 73 and the root 72 in the radial direction. It is the part between. In this respect, in this example, as can be understood from FIG. 11, a composite reinforced with both carbon fiber and aluminide fiber, which is excellent in wear resistance and strength, is provided in the vicinity of the root 72 and the pitch circle 73 of the tooth portion 7. Strengthening part 7
b is located. Therefore, it is possible to increase the strength of the tooth base 72 of the tooth portion 7, and further, the composite strengthening portion 7b is located at a portion corresponding to the pitch circle 73 and a portion slightly inward of the pitch circle 73. Therefore, the wear resistance of the meshing surface 70 can be improved.

Here, the composite reinforcing portion 7b having a ring-shaped cross section made of aramid fiber and carbon fiber is shown in FIG.
When the two types of prepregs 1 and 2 are superposed in the step shown in (A), the position can be arbitrarily adjusted by changing the arrangement. (Other Examples) Just as in Example 1, a prepreg 1 made of aramid fibers and a prepreg 2 made of carbon fibers were used, and only the cutting lengths of both prepregs 1 and 2 were changed. The total volume ratio of the fibers is 50% as in the case of Example 1, but only the ratio of the aramid fibers to the carbon fibers in the fibers is changed as shown in Table 1, and the same as in Example 1. After the molding process and the gear cutting process, the fiber reinforced resin gear (NO.
a-NO. f) was created.

[0027]

[Table 1] Here, NO. a-NO. Also in the fiber-reinforced resin gear according to f, the aramid fibers and the carbon fibers are oriented in a tree ring shape at the meshing surface 70 of the tooth portion 7. Further, as in the case of Example 1, a strengthened portion 7a reinforced with aramid fiber is formed on the outermost peripheral portion of the tooth portion 7, and the composite strengthened portion 7 is located closer to the center than the strengthened portion 7a.
b is formed, and the reinforced portion 7c reinforced with aramid fiber is formed in the portion of the composite reinforced portion 7b surrounded by the ring.

(Comparative Example) As Comparative Example 1, a fiber reinforced resin gear having exactly the same appearance as that of Example 1 was used, in which the total volume percentage of fibers was 50% and the fibers were aramid fibers only. Formed (NO.g). In addition, Comparative Example 2
As a result, a gear having only carbon fibers was prepared (NO.h). Further, as Comparative Example 3, aramid fiber is 80% and carbon fiber is 20% at a total volume ratio of 50%.
A fiber-reinforced resin gear was prepared by using a mixed woven fabric in which carbon fibers and aramid fibers were integrally mixed and woven so that the ratio became% (NO.i). Further, as Comparative Example 4, the prepreg 1 and the prepreg 2 described above were superposed so that the ratio of aramid fiber was 40% and carbon fiber was 60% at a total volume ratio of fiber of 50%. A fiber-reinforced resin gear was prepared in the same manner as in (NO.j).

Comparative Example 3 and Comparative Example 4 differ from Example 1 in that the carbon fibers are compounded over the entire meshing surface of the tooth portion. Table 2 shows Comparative Examples 1 to 4.

[0030]

[Table 2] (Test) Using the fiber-reinforced resin gear of Example 1, the fiber-reinforced resin gear of other Examples, and the fiber-reinforced resin gears of Comparative Examples 1 to 4, (1) gear cutting workability and (2) teeth are described below. The bending strength of the tooth tip of the tooth portion and the wear resistance of the meshing surface of the tooth portion (3) were tested. (1) Test of workability of gear cutting The workability was determined by the number of pieces that can be processed with one tooth using a gear cutting machine having a tooth having a cutting edge made of a diamond tip. The judgment is based on JI based on the initial machining accuracy of the gear.
It was set to S4 grade, and when it was out of this accuracy range, it was set as the processing limit. The test results are shown in FIG. Here, the vertical axis of FIG. 13 represents the number of machinable materials, and the horizontal axis represents the carbon fiber content volume ratio in the fiber. That is, FIG. 13 shows the case where the left end is only aramid fibers and the right end is only carbon fibers. As shown in Fig. 13, the best workability for gear cutting is NO. It is g. And NO. a, NO. b, NO. c, NO. d, NO.
e, NO. f, NO. The processable number decreases in the order of j, that is, as the carbon fiber content increases. Among them, NO. In h, the number that can be processed is the smallest. In addition, as compared with Example 1 and NO. The ratio of carbon fiber is the same as that of i (20%), but N
O. In i, since the carbon fibers are arranged in the entire meshing surface of the teeth using the mixed woven fabric, the number of processable pieces is 150.
In the first embodiment, the outer peripheral portion is the reinforced portion 7a reinforced only with the aramid fiber, while the number of the reinforced portion 7a is about the
The number that can be processed has increased to around 170. That is, it is understood that Example 1 has good gear cutting workability. In addition, NO.
In j, since the carbon fibers were arranged all over the meshing surface of the tooth portion, the number of machinable was around 50, and the gear cutting workability was poor. From this, it is understood that not providing the carbon fiber as the difficult-to-cut material on the outer peripheral portion of the tooth portion 7 is effective in improving the gear cutting workability. (2) Bending Strength Test of Tooth Tip of Tooth 7 In this test, the gear was fixed and a bending load was applied to the vicinity of the pitch circle of the tooth 7 to measure the breaking load. The result is shown in FIG. The vertical axis in FIG. 14 represents the bending load, and the horizontal axis represents the carbon fiber content volume ratio in the fiber.

According to the test result shown in FIG. 14, the bending load is the smallest, that is, NO.
It is g. And NO. a, NO. b, NO. c, N
O. d, NO. e, NO. f, NO. The bending load increases in the order of j, that is, as the carbon fiber content increases. Among them, NO. In h,
The bending load is the largest.

(3) Abrasion resistance test In this test, a drive gear made of steel (SCr20) whose surface was nitrided was used, and a driving torque of 3 kg-m was applied to the above various gears at a rotation speed of 2000 rpm. The amount of wear of the meshing surface 70 of the tooth portion 7 after driving for 50 hours was measured. The test results are shown in FIG. The vertical axis of FIG. 15 represents the amount of wear of the meshing surface, and the horizontal axis represents the carbon fiber content volume ratio in the fiber.

From the test results shown in FIG. 15, NO. In g, the wear amount exceeds 80 μm, and the wear amount is the largest. And NO. a, NO.
b, NO. c, NO. d, NO. e, NO. f, NO.
The wear amount decreases in the order of j, that is, as the carbon fiber content increases. Among them, the NO. At h, the amount of wear is the smallest.

Here, the first embodiment and NO. The carbon fiber content is the same for i. However, the carbon fiber is arranged all over the meshing surface of the tooth part by using the mixed woven fabric. For i, the amount of wear is about 50 μm, whereas in Example 1 in which carbon fibers are intensively compounded near the pitch circle, the amount of wear is extremely small, about 18 μm. Therefore, it can be seen that the amount of wear is drastically reduced by concentrating the carbon fibers in the vicinity of the pitch circle.

(Comprehensive Evaluation) Considering gear cutting workability and gear meshing noise (backlash noise), it is preferable that the amount of high elastic modulus carbon fiber is small. Considering the bending strength of the tooth portion 7 and the wear resistance of the tooth portion 7, the larger the amount of carbon fiber, the better. Therefore, when the total amount of fibers is 50% by volume, the carbon fiber content is preferably 60% or less in the total amount of fibers from the viewpoint of reducing gear meshing noise, and from the viewpoint of good gear cutting, The carbon fiber content is preferably 50% or less in the total fiber amount.

From the above results, in the fiber reinforced resin gear, the total amount of fibers is 50% in view of good gear cutting, strength of teeth, wear resistance of meshing surfaces, gear meshing noise, etc. In the case of, the carbon fiber content is 5 out of the total fiber amount.
0% or less is preferable.

[0037]

According to the fiber-reinforced resin gear of the present invention, in the tooth portion, the fibers are soft fibers having good workability in the outermost peripheral portion, and hard fibers having high strength are relatively disposed in the center side of the outermost peripheral portion. Many are installed in. Therefore, a relatively large amount of hard fibers will be disposed in a portion closer to the center than the outermost peripheral portion of the tooth portion, that is, in a portion where the tooth portion of the mating gear easily contacts, for example, in the vicinity of the pitch circle, and wear resistance is increased. It is advantageous in terms of securing the sex. In addition, during the gear cutting process, cutting is performed from soft fibers, so that the gear cutting workability can be improved.

[Brief description of drawings]

1 (A), (B), and (C) are diagrams showing a process of forming a doughnut-shaped reinforcing body with an aramid fiber-based prepreg and a carbon fiber-based prepreg.

FIG. 2 is a development view of an aramid fiber-based prepreg.

FIG. 3 is a development view of a carbon fiber-based prepreg.

FIG. 4 is a view schematically showing a VV cross section of the ring-shaped preform material.

FIG. 5 is a perspective view showing a state where two ring-shaped preforms are stacked.

FIG. 6 is a cross-sectional view at the time of compression molding two ring-shaped preforms stacked in a mold.

FIG. 7 is a perspective view of a ring-shaped material.

FIG. 8 is a diagram schematically showing a cross section of a ring-shaped material.

FIG. 9 is a partial perspective view of a tooth portion of a fiber-reinforced resin gear, showing the orientation of annual ring-shaped fibers of a tree.

FIG. 10 is a partial perspective view of a tooth portion of a fiber-reinforced resin gear showing a part of fiber orientation.

FIG. 11 is a perspective view of the vicinity of a tooth portion.

FIG. 12 is a perspective view of the vicinity of a tooth portion shown with a tooth root removed.

FIG. 13 is a graph showing the relationship between the number of machinable and the carbon fiber content.

FIG. 14 is a graph showing the relationship between bending load and carbon fiber content.

FIG. 15 is a graph showing the relationship between the amount of wear and the carbon fiber content.

[Explanation of symbols]

In the figure, 1 is a prepreg, 2 is a prepreg, 3 is a ring-shaped preforming material, 4 is a mold, 6 is a ring-shaped material, 7 is a tooth portion,
Reference numeral 70 denotes an engaging surface.

[Procedure amendment]

[Submission date] October 8, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Figure 1

[Correction method] Change

[Correction content]

FIG. 1 is a diagram showing a step of forming a doughnut-shaped reinforcing body with an aramid fiber-based prepreg and a carbon fiber-based prepreg.

Claims (2)

[Claims] 1. A prepreg is wound into a rod shape, and
A doughnut-shaped ring-shaped preform formed by combining both ends of the rod-shaped material is solidified and cut into pieces, and the reinforcing fibers that make up the prepreg on the meshing surface of the teeth are oriented in the shape of a tree ring. Reinforced resin gears, in which the fibers oriented in a tree ring shape, soft fibers with good workability are arranged on the outermost peripheral portion, and relatively many hard fibers having high strength are arranged on the center side of the outermost peripheral portion. Fiber-reinforced resin gears characterized by being used. 2. The soft fiber is a meta-aramid fiber, the hard fiber is a carbon fiber, and the pitch circle and the tooth are at least in a portion corresponding to the pitch circle in the meshing surface of the tooth portion and in the height direction of the tooth portion. The fiber-reinforced resin gear according to claim 1, wherein the portion between the root and the base has a relatively large amount of hard fibers.