JP2003028275A - Fiber reinforced resin stuck gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gear capable of reducing gearing noise, improving strength, abrasion resistance and lubrication, transmitting high torque, and reducing thermal deformation. SOLUTION: This fiber reinforced resin stuck gear is provided with a tooth having a metallic tooth constituting a tooth frame part in the gear and a fiber reinforced resin covering at least a part of the surface of the metallic tooth. The fiber direction of the fiber reinforced resin is substantially parallel to the tooth flank of the tooth, while the metallic tooth is provided with a height larger than a pitch circle. In this way, in addition to great reduction of gearing noise similarly to a conventional resin gear, pitching strength and lubrication can be improved. As the metallic tooth has the height larger than the pitch circle, torque to the gear is transmitted mainly by means of the metallic tooth, and torque equivalent to that by a metallic gear can be transmitted. In comparison with a conventional gear having teeth fully formed of fiber reinforced resin, this gear has a fewer resin parts, and consequently, deformation due to heat can be reduced greatly.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gear, and more particularly to a fiber reinforced resin gear using a fiber reinforced resin.

[0002]

2. Description of the Related Art A resin gear or a fiber-reinforced resin gear in which all or some of the teeth of a gear are made of resin or fiber-reinforced resin is capable of reducing the sound at the time of gear engagement and is lightweight and has a rotational inertia force. It is being used in various fields due to its small size.

For example, Japanese Unexamined Patent Publication No. 11-192955 discloses a resin gear that reduces the metal contact noise during gear meshing by covering the metal surface of the gear teeth with resin. In such a resin gear, the tooth surface portion of the gear is formed of resin and the skeleton portion of the gear is formed of metal, and while sufficient strength of the gear is ensured, striking sound at the time of gear engagement and Sliding noise is reduced. However, in the gear disclosed in Japanese Unexamined Patent Publication No. 11-192955, the fiber-reinforced resin is not used for the resin portion of the metal surface of the tooth, so that when a high surface pressure is applied to the tooth surface during gear engagement, the resin There is a problem that pitching and peeling of the parts occur, which is not suitable for transmission of high torque.

On the other hand, a fiber-reinforced resin gear using a fiber-reinforced resin in which fibers are mixed with resin is disclosed in, for example, Japanese Patent Laid-Open No. 05-240325. Here, meta-aramid fiber (80% in volume%) has a low elastic modulus and is excellent in gear cutting property and reduction of hammering sound when meshing with gears.
Prepreg in which a phenolic resin is impregnated into a mixed woven fabric in which carbon fiber (20% in volume%) having high elasticity and excellent strength and abrasion resistance is orientated at 0 ° and 90 °. A fiber-reinforced resin gear manufactured by using is shown. However, in this gear, all the teeth are made of fiber reinforced resin, and the metal parts (that is, metal teeth) are inside the teeth.
Compared with a gear that has no metal and has a metal part inside the tooth,
It could not be said that the strength was sufficient. In addition, Japanese Patent Laid-Open No. 05-
In the fiber-reinforced resin gear disclosed in Japanese Patent No. 240325, since the direction of the fibers is along the circumferential direction of the gear, that is, the direction of the pressure applied to the teeth, the strength is sufficiently improved by mixing the fibers with the resin. However, there is a problem in that wear resistance, lubricity, etc. are not sufficiently obtained. Further, since the entire teeth are made of resin, they are more likely to be deformed by heat than a metal gear, and there is a problem in terms of accuracy.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is a gear capable of reducing a sound generated when the gears are meshed with each other, as compared with a conventional fiber-reinforced resin gear. In addition, it is possible to provide a gear that has improved strength, wear resistance and lubricity, can transmit high torque, and has a small amount of deformation due to heat.

[0006]

The present invention is a kind of a fiber reinforced resin gear using a fiber reinforced resin described in each of the claims as a means for solving the above problems. A fiber-reinforced resin-attached gear is provided.

A fiber-reinforced resin-bonded gear according to a first aspect of the present invention includes a metal tooth that forms a bone portion of a tooth of the gear, and a fiber-reinforced resin that covers at least a part of the surface of the metal tooth to form a tooth surface. A toothed wheel having teeth, wherein the fiber direction of the fiber-reinforced resin is substantially parallel to the tooth surface of the tooth of the gear,
Moreover, the metal teeth have a height equal to or greater than the pitch circle. With this structure, the striking sound during gear meshing is greatly reduced as in conventional resin gears and fiber-reinforced resin gears, and the fiber direction of the fiber-reinforced resin is almost parallel to the tooth surface. Therefore, the pitching strength is improved as compared with the conventional fiber-reinforced resin gear.
Further, by running the fibers of the fiber reinforced resin along the slip direction of the tooth surface of the gear, the lubricity and wear resistance can be improved. Furthermore, since the metal teeth inside the teeth have a height equal to or greater than the pitch circle, the torque to the gear is transmitted mainly by the metal teeth, and it is possible to transmit the torque comparable to that of the metal gear. Further, since the teeth of the gear of the present invention are formed by covering the surfaces of the metal teeth with the fiber-reinforced resin, the tooth has less resin portion than the conventional gear in which all the teeth are formed of the fiber-reinforced resin, and thus it is not deformed by heat. It can be significantly suppressed, and the accuracy of the tooth shape can be improved.

The fiber-reinforced resin-bonded gear according to a second aspect is the gear according to the first aspect, in which the thickness of the layer forming the tooth surface of the fiber-reinforced resin is substantially constant. is there. With such a configuration, the amount of change in the thickness of the fiber reinforced resin layer due to the tooth surface pressure becomes substantially constant over the entire tooth surface, and it is possible to further reduce the tooth biting noise. Further, since the fiber density is substantially constant over the entire tooth surface, the surface pressure strength is substantially the same over the entire tooth surface. Furthermore, in order to make the thickness of the fiber reinforced resin layer almost constant,
Since the shape of the metal tooth is such that the surface is almost parallel to the tooth surface of the final tooth, when applying the fiber reinforced resin for forming the tooth, a sheet is formed along the surface of the metal tooth. Since it is sufficient to attach a fiber-shaped resin, the processing becomes easy.

A fiber-reinforced resin-bonded gear according to claim 3 is the gear according to claim 1 or 2, wherein the metal teeth are
It has a height of 75% or more of the tooth height of the gear measured from the root of the metal tooth. With such a structure, the strength of the tooth tip is increased, and the deformation of the fiber-reinforced resin layer forming the tooth tip can be suppressed to the minimum.

Further, in the fiber-reinforced resin-bonded gear according to the fourth aspect, the metal teeth are provided with a means for preventing the fiber-reinforced resin from peeling off. With this construction, the metal teeth are bonded to the surface of the metal teeth and the metal teeth. Adhesion with the fiber reinforced resin is improved, and pitching and peeling of the fiber reinforced resin layer that occur when a high surface pressure is applied to the fiber reinforced resin layer on the tooth surface during gear engagement are suppressed.

[0011]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings. In the drawings,
The same or similar components are given common reference numbers.

FIG. 1 shows the structure of the teeth 10 of the fiber-reinforced resin-bonded gear according to the first embodiment of the present invention. As shown in FIG. 1, this gear includes a metal tooth 2 forming a bone portion of a tooth 10 of the gear, and a fiber-reinforced resin 1 forming a tooth surface by covering a part of the surface of the metal tooth 2. It is a fiber-reinforced resin pasted gear having teeth 10 provided with. Here, the fiber direction of the fiber-reinforced resin 1 is substantially parallel to the tooth surfaces of the gear teeth 10, and the metal teeth 2 have a height of a pitch circle 3 or more.

In the present embodiment, two facing surfaces (hereinafter, referred to as circumferential surfaces) of the metal teeth 2 facing in the circumferential direction of the gear are substantially parallel to each other, and face outward in the radial direction of the gear. It is extended. Therefore, the circumferential width t of the metal tooth 2 is t.
Is almost constant. Further, as is apparent from FIG. 1, the above-mentioned "metal tooth 2 has a height of pitch circle 3 or more" means that height l measured from the root of metal tooth 2 is
Means that the end surface (that is, the surface of the metal tooth 2 facing the radially outer side of the gear) is more outward than the pitch circle 3 in the radial direction.

In this embodiment, the sheet-shaped fiber reinforced resin 1 is attached to the circumferential surface and the upper surface of the metal teeth 2 along the surfaces thereof in a multilayer structure, and the meshing surface of the gear is the fiber reinforced resin 1. Covered with. At this time, as described above, the fiber reinforced resin 1 is attached so that the fiber direction thereof is substantially parallel to the tooth surfaces of the gear teeth 10.
Since the fibers are running along the sheet surface in the sheet of the sheet-shaped fiber-reinforced resin 1, it can be achieved by forming the tooth flank portion by stacking and laminating the sheet-shaped fiber-reinforced resin 1 together. . The fiber-reinforced resin used is, for example, a meta-aramid fiber (80% in volume%) having a low elastic modulus and excellent in gear cutting property and meshing noise reduction property as described in JP-A-5-240325. )
Manufactured by impregnating a mixed woven fabric of carbon fiber (20% in volume%) having high elasticity and strength and abrasion resistance at 0 ° and 90 ° with a phenol resin. Examples of the sheet-shaped prepregs include In addition, tooth 10
The molding is performed by pressing the tooth mold before the resin is hardened.

With the structure as described above, in the fiber-reinforced resin-bonded gear of this embodiment, since the meshing surfaces of the gear teeth are covered with the fiber-reinforced resin 1, the conventional resin gear and the fiber-reinforced resin gear are used. In addition to significantly reducing the hitting sound when meshing with the gears, the fiber-reinforced resin 1 is pasted so that the fiber direction thereof is substantially parallel to the tooth surfaces of the teeth 10, so that the conventional fiber-reinforced resin gear The pitching strength is improved more than that. Further, since the fibers of the fiber reinforced resin 1 run along the slip direction of the tooth surface of the gear, lubricity and wear resistance are improved. Furthermore, since the metal teeth 2 inside the teeth 10 have a height equal to or greater than the pitch circle 3, the torque to the gear is mainly transmitted by the metal teeth 2, and it is possible to transmit the torque comparable to that of the metal gear. Further, in the case of a general metal gear, the heat treatment of the tooth surface, which is indispensable for preventing tooth surface pitting wear at the time of meshing, becomes unnecessary, which is very advantageous in terms of cost. Further, in the gear of the present embodiment, since the teeth 10 of the gear are formed by covering the surfaces of the metal teeth 2 with the fiber reinforced resin 1, compared with the conventional gear in which all the teeth are formed of the fiber reinforced resin, There are few parts,
Deformation due to heat can be greatly suppressed, and the accuracy of the tooth shape can be improved.

Next, a fiber-reinforced resin-bonded gear according to a second embodiment of the present invention will be described. FIG. 2 shows the tooth configuration of the fiber-reinforced resin-bonded gear of the second embodiment of the present invention,
It is a figure similar to FIG. The basic configuration of the tooth 10 is the same as the tooth 10 of the gear of the first embodiment, and therefore description thereof will be omitted.
As shown in FIG. 2, the two circumferential surfaces of the metal tooth 4 are inclined so that the circumferential width t of the metal tooth 4 forming the bone portion of the tooth 10 becomes smaller toward the outer side in the radial direction. The shape of the metal tooth 4 is applied to the metal tooth 4 to cover the surface thereof, and the thickness h of the layer of the fiber reinforced resin 1 forming the tooth surface of the tooth 10 is to be made substantially constant over the tooth surface. It is a thing.
When the tooth 10 of the gear of the present embodiment and the tooth 10 of the gear of the first embodiment are compared, the metal tooth 4 of the present embodiment has a large width t in the circumferential direction at the root of the tooth. Accordingly, the thickness h of the fiber reinforced resin layer is smaller than that of the gear teeth 10 of the first embodiment.

With such a structure, the amount of change in the thickness of the fiber reinforced resin layer on the tooth surface due to the tooth surface pressure during gear engagement can be made substantially constant over the entire tooth surface.
That is, the fiber reinforced resin layer thickness is h, the change amount of the fiber reinforced resin layer thickness is Δh, and the proportional constant including the reciprocal of the elastic coefficient is k.
Then, if constant pressure is applied to these, Δ
There is a relationship of h = k × h (see FIG. 4). Therefore, in the case of the gear 5 in which the thickness h of the fiber reinforced resin layer along the tooth surface is not constant as shown in FIG. 3A, the variation Δh in the thickness of the fiber reinforced resin layer during gear engagement is Is not constant, and since there is a portion where the thickness h of the fiber reinforced resin layer is thick, the amount of change also becomes large, and the tooth biting noise tends to increase accordingly. On the other hand, the thickness h of the fiber reinforced resin layer along the tooth surface like the gear of the present embodiment shown in FIG.
In the case of the gear 6 in which is substantially constant, the amount of change Δh in the thickness of the fiber reinforced resin layer due to the tooth surface pressure is substantially constant over the entire tooth surface, and it is possible to reduce tooth biting noise.
Further, as is clear from the relationship between the fiber-reinforced resin layer thickness h and the variation amount Δh of the fiber-reinforced resin layer thickness described above and FIG. 4 showing it, the thickness h of the fiber-reinforced resin layer is set on the tooth surface. By making the thickness constant and thin, the variation amount Δh of the fiber reinforced resin layer thickness also becomes constant and small over the tooth surface,
As a result, the amount of change Δh in the thickness of the fiber reinforced resin layer does not differ depending on the meshing parts of the teeth, so that a substantially constant torque is applied to all meshing teeth. Furthermore,
Since the fiber density is almost constant over the entire tooth surface, the surface pressure strength is almost the same over the entire tooth surface.

In the tooth 10 of the gear according to the second embodiment, the surface of the metal tooth 4 has a final shape so that the thickness h of the fiber-reinforced resin layer to be applied is substantially constant. It is shaped so as to be substantially parallel to the tooth surface of the tooth 10. Therefore, when the fiber reinforced resin 1 is applied to form the tooth 10, the sheet-shaped fiber reinforced resin 1 may be applied mainly along the surfaces of the metal teeth 4, and the fiber reinforced resin layer may be formed depending on the portion of the metal teeth. Since the frequency of processing such as cutting the fiber reinforced resin 1 to change the thickness of the
Processing becomes easy.

Next, a fiber-reinforced resin-bonded gear according to a third embodiment of the present invention will be described. FIG. 5 shows the tooth configuration of the fiber-reinforced resin-applied gear of the third embodiment of the present invention,
FIG. 3 is a view similar to FIGS. 1 and 2. In the tooth 10 of the gear according to the third embodiment shown in FIG. 5, the height 1 of the metal tooth 7 constituting the skeleton thereof is higher than that of the other embodiments described above. This is because in the resin-applied gear of the present invention, the tip end of the tooth 10 of the gear has a structure like a resin beam extending from a metal tooth, so that the strength is weak, and the tip of the tooth 10 is engaged during gear engagement. When a large torque is applied to the part,
This corresponds to the possibility that the tip portion made of resin may be greatly deformed. That is, as in the structure shown in FIG. 5, by extending the tips of the metal teeth 7 inside the teeth 10 to increase the height l, the strength of the tips is increased and the fiber-reinforced resin layer forming the tips is formed. The deformation of the can be minimized. More specifically, the height l of the metal tooth 7 is preferably 75% or more of the height L of the tooth of the gear measured from the root of the metal tooth 7. In the embodiment shown in FIG. 5, the metal tooth 7 has an extension in which the width t in the circumferential direction is substantially constant at the tip of the base portion in which the width t in the circumferential direction decreases toward the outer side in the radial direction. A portion is provided to increase the height l, but if the height l is sufficient, the width t in the circumferential direction is gradually reduced to the tips of the metal teeth 7. Shape (that is, the shape of the metal tooth 4 shown in FIG. 2) or a shape in which the width t in the circumferential direction up to the tip of the metal tooth 7 is almost constant (that is, the metal tooth shown in FIG. 1). It may have a shape similar to the tooth 2.

Furthermore, in each of the above-described embodiments, the metal teeth may be provided with a peeling prevention means for the fiber reinforced resin 1 that covers the surfaces of the metal teeth. FIG. 6 is a partially enlarged schematic view showing the configuration of the teeth of the fiber-reinforced resin-bonded gear according to the fourth embodiment of the present invention. In this embodiment, the surface of the metal tooth 8 serves as a peeling prevention means for the fiber-reinforced resin 1. The uneven portion 12 is provided on the. Further, FIG. 7 is a partially enlarged schematic view showing the configuration of the teeth of the fiber-reinforced resin pasted gear of the fifth embodiment of the present invention,
In this embodiment, through holes 13 are provided in the metal teeth 9 as means for preventing the fiber reinforced resin 1 from peeling off. Metal teeth 8,
By providing the peeling prevention means having such a configuration in 9, the adhesiveness between the surfaces of the metal teeth 8 and 9 and the fiber reinforced resin 1 attached thereto is improved, and the fiber reinforced resin layer on the tooth surface is formed during gear meshing. Pitching and peeling of the fiber-reinforced resin layer that occur when a high surface pressure is applied are suppressed. still,
When providing the metal teeth with the concave-convex portions 12 and the through holes 13 as a means for preventing the peeling of the fiber-reinforced resin 1, care must be taken not to reduce the strength of the metal teeth and to cause insufficient strength of the teeth. is necessary.

As described above, according to the present invention, it is possible to reduce the sound generated when the gears are meshed with each other, and the strength, wear resistance and lubricity are improved as compared with the conventional fiber reinforced resin gears. Provided is a fiber-reinforced resin-bonded gear that can transmit torque and has a small amount of deformation due to heat. Due to the characteristics as described above, the gear of the present invention is preferably used for, for example, a gear that is arranged in an internal combustion engine and is required to be quiet, more specifically, a balance shaft gear.

[Brief description of drawings]

FIG. 1 is a partially enlarged schematic view of a gear showing a tooth configuration of a fiber-reinforced resin-bonded gear according to a first embodiment of the present invention.

FIG. 2 is a partially enlarged schematic view of a gear showing a tooth configuration of a fiber-reinforced resin-bonded gear according to a second embodiment of the present invention.

FIG. 3 is a diagram showing how the thickness of the fiber-reinforced resin layer changes when the gears mesh with each other. FIG. 3A shows a state when the gears in which the thickness of the fiber-reinforced resin layer is not constant mesh with each other. And (b) shows a state during meshing of gears in which the thickness of the fiber reinforced resin layer is substantially constant.

FIG. 4 is a diagram showing a relationship between the fiber-reinforced resin layer thickness h and a change amount Δh of the fiber-reinforced resin layer thickness when a constant pressure is applied.

FIG. 5 is a partially enlarged schematic view of a gear showing a tooth configuration of a fiber-reinforced resin-bonded gear according to a third embodiment of the present invention.

FIG. 6 is a partially enlarged schematic view of a gear showing a tooth configuration of a fiber-reinforced resin-bonded gear according to a fourth embodiment of the present invention.

FIG. 7 is a partially enlarged schematic view of a gear showing a tooth configuration of a fiber-reinforced resin-bonded gear according to a fifth embodiment of the present invention.

[Explanation of symbols]

1 ... Fiber reinforced resin 2, 4, 7, 8, 9 ... Metal teeth 3 ... pitch circle 5 ... Gear with variable thickness of fiber reinforced resin layer 6 ... Gear in which the thickness of the fiber reinforced resin layer is substantially constant 10 ... Tooth 12 ... uneven portion 13 ... Through hole

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Fukuro Kitagawa             14 Iwatani Shimohakaku-cho, Nishio-shi, Aichi Stock Association             Company Japan Auto Parts Research Institute (72) Inventor Koichi Shimizu             1 Toyota Town, Toyota City, Aichi Prefecture Toyota Auto             Car Co., Ltd. F term (reference) 3J030 AC10 BC01 BC02                 4F205 HA14 HA25 HA33 HA35 HA45                       HB01 HB12 HC05 HK17 HT02                       HT08

Claims (4)

[Claims] 1. A fiber-reinforced resin-bonded gear having teeth, including metal teeth forming a bone portion of teeth of a gear, and fiber-reinforced resin forming a tooth surface by covering at least a part of surfaces of the metal teeth. Wherein the fiber direction of the fiber reinforced resin is substantially parallel to the tooth flanks of the gear teeth, and the metal teeth have a pitch circle or higher height. gear. 2. The fiber-reinforced resin-bonded gear according to claim 1, wherein a layer forming a tooth surface of the fiber-reinforced resin has a substantially constant thickness. 3. The fiber according to claim 1, wherein the metal tooth has a height of 75% or more of the height of the tooth of the gear measured from the root of the metal tooth. Reinforced resin pasted gear. 4. The fiber-reinforced resin-bonded gear according to claim 1, wherein the metal teeth are provided with means for preventing the fiber-reinforced resin from peeling off.