JP2988214B2 - Manufacturing method of phenolic resin gears - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a phenolic resin gear suitable as an automobile part or the like.

[0002]

2. Description of the Related Art The above-mentioned resin gear is used as a mating gear that meshes with a metal gear in order to suppress the generation of noise when the teeth mesh with each other, and is required to have excellent wear resistance and high strength. Conventionally, there are the following two methods for manufacturing a resin gear. As shown in FIG. 5, a metal bush 5 is provided at the center, a molding material 8 for forming a web is disposed around the metal bush 5, and a molding material 3 for forming a tooth portion is disposed at the outermost periphery. A manufacturing method in which molding is performed, and after molding, the teeth are formed by machining to form a resin gear. Here, the molding material 3 for forming the tooth portion is shown in FIG.
As shown in the figure, a prepreg 10 in a semi-cured state (B stage) is impregnated and dried with a phenolic resin varnish on a woven fabric base material of cotton cloth or aramid fiber, and the rod-shaped body 11 is formed in a donut shape. It was made. Further, as shown in FIG. 7, the web forming molding material 8 is obtained by putting a chip piece 12 obtained by cutting a prepreg into a temporary molding die 13 and temporarily forming it into a donut shape. A phenolic resin and a reinforcing fiber such as aramid fiber are mixed and kneaded to prepare a granulated molding material, and the molding material is injected and molded into a mold having a metal bush disposed at the center. A manufacturing method in which resin gears are formed by machining.

[0003]

In the above manufacturing method,
The tooth portion forming molding material 3 is obtained by making the rod-shaped body 11 into a donut shape, and the direction of the weave of the woven fabric becomes irregular at a joint portion where the rod-shaped body 11 is made into a donut shape. as a result,
The strength of the tooth portion of the molded resin gear decreases at the portion corresponding to the joint. In addition, in the above-described manufacturing method, it is difficult to obtain a sufficient strength as the whole resin gear. This is because when the reinforcing fiber is mixed and kneaded with the phenol resin to form a molding material, the reinforcing fiber is broken or cut and becomes shorter. Further, when performing the injection molding, the reinforcing fiber is cut by the screw of the cylinder of the molding machine or the gate of the mold, so that the strength is greatly reduced. In addition, in the injection molding, the reinforcing fibers are oriented in the flow direction of the resin so that the strength is directional, and the strength is lower in a weld generated portion than in other portions.

[0004] The problem to be solved by the present invention is to increase the strength of the tooth portion of the molded resin gear and to make the strength different from place to place. Another object of the present invention is to adopt a heat and pressure molding method so as to prevent a decrease in the directionality of strength and a decrease in strength at a welded portion as in the case of employing an injection molding method.

[0005]

In order to solve the above-mentioned problems, a first method for producing a phenolic resin gear according to the present invention comprises dispersing a phenolic resin powder and a reinforcing fiber in a liquid as essential components. The sheet-shaped molding material thus formed is formed into a cylindrical shape, and the cylindrical body is pressed in the axial direction to obtain a molding material for forming a tooth portion. Then, the molding material for forming a tooth portion is arranged around the bush arranged at the center, and the two are subjected to a process of heating and pressing to integrate them. In the second production method according to the present invention, a phenolic resin powder and a reinforcing fiber are used as essential components, these are dispersed in a liquid, and a sheet-shaped molding material is formed into a tubular shape. A pressure is applied in the axial direction to obtain a molding material for forming a tooth portion. Separately, a doughnut-shaped forming material for forming a web is prepared by dispersing the phenol resin powder and the reinforcing fiber in a liquid as essential components and forming the dough. Then, the molding material for forming the web is arranged around the bush arranged at the center, and the molding material for forming the tooth portion is arranged at the outermost periphery, and the three members are subjected to a process of heating and pressing to integrate them. Features.

In the first and second production methods, the sheet-like molding material forming the cylindrical body is preferably a parallelogram or a rectangle, and the two sides facing each other are preferably formed into a cylindrical shape. At that time, the number of sheet-shaped molding materials is not limited to one, and a plurality of sheets may be connected and used. The sheet-shaped molding material for forming the cylindrical body may be cut into a predetermined size and shape after being formed, or may be formed into a predetermined size and shape suitable for forming the cylindrical body from the beginning. Then, the cutting step may be omitted.

[0007]

In the method according to the present invention, since the molding material is prepared by forming reinforcing fibers dispersed in the liquid, the reinforcing fibers are prepared as in the case of the molding material prepared by conventional mixing and kneading. The initial fiber length can be kept almost as it is without being broken by external force. Further, the reinforcing fibers are not blended in a special direction, and a molding material in which the reinforcing fibers and the phenol resin powder are uniformly dispersed is obtained. As a result, the resin gear formed by heating and pressing the molding material retains the expected strength, and the directionality of the strength is lost. When the sheet-shaped molding material is formed into a tubular shape, seams are formed, but since the molding material prepared by papermaking easily flows the reinforcing fibers due to the flow of the resin at the time of molding, the reinforcing fibers at the seam portion are entangled with each other. , Approaching a seamless state. As a result, the difference in intensity from portions other than the joint portion is reduced. When a parallelogram is used as the sheet-like molding material to be formed into a tubular shape, the joint formed in the tubular body appears obliquely with respect to the axial direction of the tubular body. Therefore, the portion where the strength is likely to be low due to the presence of the joint does not appear linearly in the axial direction, but is dispersed in the circumferential direction of the gear, which is preferable.

[0008] The resin portion of the gear may be constituted only by the molding material for forming the tooth portion. However, if the molding material for forming the web is separately prepared by papermaking as in the second manufacturing method, the characteristic balance of the gear can be improved. The degree of freedom in selecting the reinforcing fibers to be used increases. For example, when using aramid fiber as the reinforcing fiber of the molding material for forming the tooth portion, in order to reduce the dimensional shrinkage of the gear, the reinforcing fiber of the molding material for forming the web is mixed with glass fiber and cotton fiber in addition to aramid fiber, Further, a filler powder having a small shrinkage can be blended.

[0009]

EXAMPLES In carrying out the production method according to the present invention, the phenol resin powder has a suitable particle size of 1 to 100 .mu.m, but is not particularly limited as long as it can be dispersed during papermaking. The reinforcing fibers are chopped, and para-aramid fibers (poly-p-phenyleneterephthalamide (PPTA)), meta-aramid fibers (poly-m-phenyleneisophthalamide (PMIA)), glass fibers,
Cotton fibers, carbon fibers and the like. At the time of papermaking, other fillers and additives may be appropriately blended. Hereinafter, embodiments according to the present invention will be described in detail.

Example 1 Phenol resin powder (particle size 1-20 μm) and para-aramid fiber chop (fiber diameter 5-20 μm, fiber length 3 mm)
And meta-type aramid fiber chops (fiber diameter 5-20μ)
m and a fiber length of 3 mm) are dispersed in water at a weight ratio of 60/20/20, and this is sheet-formed to obtain a sheet-shaped molding material 1. As shown in FIG. 1, this is 140 mm wide and 46 mm long.
It was punched into a parallelogram of 0 mm and one opposite angle of 60 °. The shorter two opposite sides of this molding material are abutted to form a cylindrical body 2. Then, it was put into a temporary molding die 13 and was compressed in the axial direction of the cylindrical body 2 and was temporarily molded to obtain a donut-shaped molding material 3 for forming a tooth portion. In the molding material 3 for forming a tooth portion, the joint 4 appears at one position obliquely to the axial direction. As shown in FIG. 2, a metal bush 5 is disposed at the center of the main molding die 9, and the molding material 3 for forming the tooth portion is disposed around the metal bush 5, and heat and pressure molding is performed at 190 ° C. Was integrated. After molding, the teeth were formed by mechanical cutting on a portion molded with the molding material 3 for forming a tooth portion to obtain a resin gear. The characteristics are shown in Table 1.

Example 2 Phenol resin powder (particle size 1-20 μm) and para-type aramid fiber chop (fiber diameter 5-20 μm, fiber length 3 mm)
And meta-type aramid fiber chops (fiber diameter 5-20μ)
m and a fiber length of 3 mm) are dispersed in water at a weight ratio of 60/20/20, and this is sheet-formed to obtain a sheet-shaped molding material 1. As shown in FIG. 3, this is 140 mm wide and 23 mm long.
It was punched into two parallelograms of 0 mm and one opposite angle of 60 °. The shorter sides of the two molding materials are joined to form a cylindrical body 2. Then, it was put into a temporary molding die 13 and was compressed in the axial direction of the cylindrical body 2 and was temporarily molded to obtain a donut-shaped molding material 3 for forming a tooth portion. In the molding material 3 for forming a tooth portion, the joints 4 appear at two positions obliquely to the axial direction. Hereinafter, a resin gear was formed in the same manner as in Example 1. The characteristics are shown in Table 1.

Example 3 Phenol resin powder (particle size 1 to 20 μm) and para-aramid fiber chop (fiber diameter 5 to 20 μm, fiber length 3 mm)
And meta-type aramid fiber chops (fiber diameter 5-20μ)
m and a fiber length of 3 mm) are dispersed in water at a weight ratio of 60/20/20, and this is formed into a sheet-like molding material. This was punched into a rectangle having a width of 140 mm and a length of 460 mm. The shorter two opposite sides of the molding material are butted to form a cylindrical body. Then, it was put into a temporary molding die, compressed in the axial direction of the cylindrical body, and temporarily molded to obtain a donut-shaped molding material for forming a tooth portion. In the obtained molding material for forming a tooth portion, a joint where two opposing sides of a rectangle are joined,
It appears at one location in the axial direction. Hereinafter, a resin gear was formed in the same manner as in Example 1. The characteristics are shown in Table 1.

Example 4 Phenol resin powder (particle size 1 to 20 μm) and para-type aramid fiber chop (fiber diameter 5 to 20 μm, fiber length 3 mm)
And meta-type aramid fiber chops (fiber diameter 5-20μ)
m and a fiber length of 3 mm) are dispersed in water at a weight ratio of 60/20/20, and this is formed into a sheet-like molding material. This was punched into two rectangles 140 mm wide and 230 mm long. The shorter sides of the two molding materials are joined to form a cylindrical body. Then, it was put into a temporary molding die, compressed in the axial direction of the cylindrical body, and temporarily molded to obtain a donut-shaped molding material for forming a tooth portion. In the obtained molding material for forming a tooth portion, joints in which the sides of the rectangle are butted together appear at two places in the axial direction. Hereinafter, a resin gear was formed in the same manner as in Example 1. The characteristics are shown in Table 1.

Example 5 Phenol resin powder (particle size 1-20 μm) and para-type aramid fiber chop (fiber diameter 5-20 μm, fiber length 3 mm)
And meta-type aramid fiber chops (fiber diameter 5-20μ)
m and a fiber length of 3 mm) are dispersed in water at a weight ratio of 60/20/20, and this is sheet-formed to obtain a sheet-shaped molding material 1. As shown in FIG. 1, this is 140 mm wide and 46 mm long.
It was punched into a parallelogram of 0 mm and one opposite angle of 60 °. The shorter two opposite sides of this molding material are abutted to form a cylindrical body 2. Then, it was put into a temporary molding die 13 and was compressed in the axial direction of the cylindrical body 2 and was temporarily molded to obtain a donut-shaped molding material 3 for forming a tooth portion. In the molding material 3 for forming a tooth portion, the joint 4 appears at one position obliquely to the axial direction. Separately, phenol resin powder (particle size 1-2)
0μm) and glass fiber chop (fiber diameter 10-30μ)
m, fiber length 3 mm and 6 mm) and cotton fiber chop (fiber diameter 5 to 20 μm, fiber length 3 mm and 6 mm) at a weight ratio of 50
It was dispersed in water at a ratio of / 25/25, and this was sheeted to obtain a sheet-shaped molding material 6. This is shown in FIG.
It was punched into a doughnut shape of 115 × φ55 mm to obtain a molding material 8 for web construction. Next, as shown in FIG. 5, the metal bush 5 is arranged at the center of the main molding die 9, and the above-described molding material 8 for forming the web is arranged around the metal bush 5, and the molding material 3 for forming the tooth portion is arranged around the outermost periphery. The three members were placed and subjected to heat and pressure molding at 190 ° C. to integrate the three members. Hereinafter, a resin gear was formed in the same manner as in Example 1. The characteristics are shown in Table 1.

In the above embodiment, the sheet-like molding material thus formed was cut into a predetermined size and shape to obtain a material for forming a cylindrical body. Since the remaining cut off pieces are easily loosened when immersed in water, they can be dispersed again and provided for sheet-like molding material. However, if the paper is formed into a predetermined size and shape from the beginning, the cutting step can be omitted. The same applies to the case where a doughnut-shaped molding material for web construction is manufactured by papermaking. Further, in the above embodiment, the shape of the sheet-shaped molding material forming the cylindrical body is a parallelogram or a rectangle, but the shape is not particularly limited as long as it can be formed in a cylindrical shape. Joints may be engaged with each other by unevenness.

Conventional Example 1 Meta-type / para-type composite aramid fiber woven fabric (fiber thickness: 2 denier, yarn thickness: cotton yarn standard No. 20, yarn driven per inch length: 55, width: 55) The prepreg 10 is obtained by impregnating with a phenol resin and drying. As shown in FIG. 6, the prepreg 10 was heated on a hot plate to be softened and wound into a rod, and the rod 11 was made into a donut shape to obtain the molding material 3 for forming a tooth portion. Separately, as shown in FIG. 7, a phenol resin-impregnated aramid woven prepreg and a phenol resin-impregnated cotton prepreg are each cut into 5 mm squares to form chip pieces 12, and a phenol resin impregnated glass woven prepreg is cut into 10 mm squares. To form a chip piece 12. These chip pieces 12 were mixed, put into a temporary molding die 13 and temporarily molded at 100 ° C. to obtain a donut-shaped molding material 8 for web construction. Hereinafter, similarly to the fifth embodiment, the metal bush 5 is arranged at the center of the main molding die 9, the molding material 8 for forming the web is arranged around the metal bush 5, and the molding material 3 for forming the teeth is arranged around the outermost periphery. Then, heat and pressure molding was performed at 180 ° C. to integrate the three members. Hereinafter, a resin gear was formed in the same manner as in Example 1. The characteristics are shown in Table 1.

Conventional Example 2 Phenol resin and para-type aramid fiber (fiber diameter 5 to 20)
μm, fiber length 3 mm) and meta-type aramid fiber (fiber diameter 5
２０20 μm, fiber length 3 mm) by weight ratio of 50/25/2
The mixture was mixed and kneaded at a ratio of 5 to obtain a granular molding material. The molding material was injected and molded into a metal mold having a metal bush at the center, and after molding, the teeth were formed by machining to obtain a resin gear. The characteristics are shown in Table 1.

In Table 1, each characteristic was measured as follows. The column A of the bending strength is a resin gear cut out from a portion corresponding to the abutting portion of the sheet-shaped molding material (the joint in which the rod-shaped body is formed into a donut in Conventional Example 1 and the weld-generating portion in Conventional Example 2). 2 shows the bending strength of the tooth portion of FIG. Column B shows the bending strength of the tooth portion of the resin gear cut out from other parts. The mounting durability time was measured by a cam gear acceleration test of an automobile engine (rotation speed: 3000 rpm, oil temperature 130 ° C., tooth root load stress 18 kg / mm ² ). The dimensional change rate is 200 ° C by putting the resin gears into a hot air circulation dryer.
It was subjected to a heat treatment of × 500 h, and the dimensional change rate of the tooth outer diameter before and after the treatment was measured.

[0019]

[Table 1]

[0020]

As described above, in the method for manufacturing a phenolic resin gear according to the present invention, the reinforcing fiber in the resin of the molded gear does not become too short and retains the original fiber length. Further, there is no directionality in which the reinforcing fibers are oriented in a specific direction. Furthermore, the joint when the sheet-shaped molding material is formed into a cylindrical shape approaches a state where it disappears after the gear is formed. As a result, a resin gear having a large strength and a small difference in strength depending on the direction and location of the strength can be obtained.

[Brief description of the drawings]

FIG. 1 is an explanatory view showing an example of a step of preparing a molding material for forming a tooth portion in a manufacturing method according to the present invention.

FIG. 2 is an explanatory sectional view showing an example of a step of heating and pressing a resin gear in a manufacturing method according to the present invention.

FIG. 3 is an explanatory view showing another embodiment of the step of preparing a molding material for forming a tooth portion in the manufacturing method according to the present invention.

FIG. 4 is an explanatory view showing an example of a step of preparing a molding material for web construction in the production method according to the present invention.

FIG. 5 is an explanatory sectional view showing another embodiment of the step of heating and pressing a resin gear in the manufacturing method according to the present invention.

FIG. 6 is an explanatory view showing a step of preparing a molding material for forming a tooth portion according to a conventional method.

FIG. 7 is an explanatory view showing a step of preparing a molding material for web construction according to a conventional method.

[Explanation of symbols]

 1 is a sheet-shaped molding material 2 is a cylindrical body 3 is a molding material for forming a tooth portion 4 is a joint 5 is a metal bush 6 is a sheet-shaped molding material 8 is a molding material for forming a web 9 is a main molding die 13 is a temporary molding Mold

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FIB29L 15:00 (56) References JP-A-2-241729 (JP, A) JP-A-4-8956 (JP, A) Kaihei 5-240324 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) B29C 43/00-43/58 F16H 55/00-55/30 B29D 15/00

Claims (8)

(57) [Claims] 1. A sheet-like molding material formed by dispersing a phenolic resin powder and a reinforcing fiber as essential components in a liquid and forming the same into a cylinder, and pressing the cylinder in the axial direction thereof to form a tooth portion. A phenolic gear made of a phenolic resin gear, characterized by passing through a step of forming a molding material for the configuration, arranging the molding material for the tooth portion configuration around the bush arranged at the center, and heat-press molding the two to integrate them. Manufacturing method. 2. A sheet-shaped molding material formed by dispersing phenol resin powder and reinforcing fibers in a liquid as essential components and forming the same into a cylindrical shape, and pressing the cylindrical body in its axial direction to form a tooth portion. As a constituent molding material, a donut-shaped web forming material was prepared by dispersing these in a liquid separately as a phenol resin powder and a reinforcing fiber as essential components, and preparing the dough-shaped forming material for the web. A method for manufacturing a phenolic resin gear, comprising a step of disposing a molding material for molding and the molding material for forming a tooth portion on the outermost periphery, and heat and pressure molding the three members to integrate them. 3. A method for producing a phenolic resin gear according to claim 1, wherein the sheet-like molding material is a parallelogram, and two opposite sides thereof are abutted to form a cylindrical shape. 4. The method for producing a phenolic resin gear according to claim 1, wherein the sheet-shaped molding material is rectangular, and two opposite sides are abutted to form a cylindrical shape. 5. The method for producing a phenolic resin gear according to claim 1, wherein a plurality of parallelogram-shaped sheet-like molding materials are joined to form a cylindrical shape. 6. The method for producing a phenolic resin gear according to claim 1, wherein a plurality of rectangular sheet-like molding materials are joined to form a cylindrical shape. 7. A phenolic resin material according to claim 2, wherein a sheet-like molding material for forming a cylindrical body is formed into a sheet and then cut into a predetermined size and shape. Gear manufacturing method. 8. A sheet-shaped molding material for forming a cylindrical body is formed into a sheet having a predetermined size and shape suitable for forming the cylindrical body. 3. The method for producing a phenolic resin gear described in 1. above.