JP2009250364A - Method for manufacturing of half-finished product for forming resin rotating body, method for manufacturing of resin rotating body, and resin gear - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a highly reliable resin rotating body with good workability, wherein bonding strength between rotation preventing parts provided on the outer periphery of a metal bush and a reinforcement fiber base material is improved even if only one reinforcement fiber base material is used. <P>SOLUTION: The method for manufacturing includes a first step of forming a reinforced fiber accumulation body 8 surrounding the outer periphery of the bush 2 by accumulating reinforced fiber around the outer periphery of the bush 2 by a papermaking method, and a second step of compressing the reinforced fiber accumulation body 8 in the axial direction of a rotating shaft so as to form the reinforcement fiber base material 5. The first step and the second step are continuously performed within the same device 7 containing the bush and the reinforcement resin accumulation body therein. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a semi-finished product for molding a resin rotating body, and the present invention relates to a method for manufacturing a resin rotating body. Furthermore, the present invention relates to a resin gear.

A resin rotating body using a reinforcing fiber base is excellent in durability and is suitable as a resin rotating body such as a resin gear used for vehicle parts, industrial parts and the like. As a reinforcing fiber base material for molding a resin gear, Patent Document 1 discloses a reinforcing fiber base material that is formed into a doughnut shape while turning a tubular body woven or knitted into a tubular shape while turning it over from the end. Are listed. Patent Document 1 also describes a resin gear in which the reinforcing fiber base material is impregnated with resin to form teeth. However, in this conventional technique, in order to improve the bonding strength between the reinforcing fiber base and the stopper provided on the metal bush, two reinforcing fiber bases are placed between the metal bushes in the molding die. In order to prevent the metal bush from coming off, the two layers are stacked (paragraphs [0013] to [0015] of Patent Document 1).
Patent Document 2 discloses a method for manufacturing a resin gear in which a plurality of paper-making paper sheet bodies obtained by pressing a paper-making sheet mainly composed of a thermosetting resin and a reinforcing fiber are stacked and heated and pressed in a molding die. 2.

  These resin gears have little fiber entanglement at the overlapping interface of the two reinforcing fiber bases or the lamination interface of the paper sheet body, and depending on the intended use, there is a concern that peeling may easily occur on the laminated surface. is there. Further, there is a concern that the bonding strength between the reinforcing fiber base and the metal bush is insufficient. For these reasons, depending on the intended use, there is a concern that the durability of the resin gear is insufficient.

  In order to solve these problems, it has also been proposed to make an aggregate using a papermaking mold using reinforcing fibers. Patent Document 3 discloses a production method in which a mixed slurry of reinforcing fibers and thermosetting resin is pressurized or dehydrated in a water-permeable mold to obtain an aggregate. However, a resin that can be dispersed in water has low fluidity and insufficient wetting at the interface between the resin and the fiber, so that durability that can withstand practical use cannot be obtained.

  Patent Document 4 discloses a method of forming a fiber reinforced resin composite by filling a fiber with a molding die having a fluid outlet and further performing resin injection with the same die and heating and pressing. Yes. However, with this method, it is difficult to place a metal bush at the center of the resin rotating body, and the injected resin leaks into the entire molding die made of a metal mesh or the like, and the molded product can be easily taken out after curing. In addition, since the mold is clogged, there is a problem that it cannot be used repeatedly.

  Furthermore, Patent Document 5 discloses a method for producing a resin gear, in which a reinforcing fiber base material formed seamlessly in a cylindrical shape obtained by a papermaking method is heated and pressed in a molding die. However, Patent Document 5 does not disclose any method for improving the bonding strength between the reinforcing fiber base and the metal bush.

JP 2001-295913 A JP-A-11-227061 Japanese Patent Laid-Open No. 2001-1413 JP 2005-96173 A JP 2007-138146 A

  In the resin rotating body in which the metal bush is arranged at the center, the metal bush is made up of two ring-shaped reinforcing fiber bases from above and below in order to fill the anti-rotation portion provided on the outer periphery of the metal bush with the reinforcing fiber. A method of sandwiching with a material and filling a fiber with a rotation stopper is a known technique (Patent Document 1). However, in this method, since there is no entanglement of fibers at the overlapping interface of the reinforcing fiber base material, there is a concern that the durability performance due to interfacial peeling may be lowered depending on the intended use. The problem of interfacial delamination can be solved by using a single reinforcing fiber substrate. However, since the anti-rotation part provided on the metal bush cannot be sandwiched, the fiber is caught in the anti-rotation part. A resin rotating body could not be produced.

  As a countermeasure against this, a metal bush is used in a paper making apparatus that can make paper into a cylindrical shape in order to produce a resin rotating body that uses a single reinforcing fiber base material and that has a fiber encroached into a detent. A method of collecting reinforcing fibers on the outer peripheral portion of the metal bush after the placement of the metal bush is conceivable. However, the reinforcing fiber base material after paper making is very bulky and weak in strength (easily loses its shape), so it can be taken out from the paper making apparatus while being integrated with the metal bush, or heated and pressed. There is a problem that it is difficult to arrange in a molding die for molding. In addition, when making the paper, since the slurry in which the reinforcing fibers are dispersed is added from above and the reinforcing fibers are accumulated, the detent portion itself becomes an obstacle, and it is difficult to fill the reinforcing fibers under the detent portion. There's a problem. Furthermore, when performing the compression operation in order to make the reinforcement fiber bite into the detent part more firmly, in order to perform from only one direction from the upper side or the lower side, the upper and lower reinforcement fibers of the detent part There is a problem that it cannot be compressed so that the density is uniform.

  The first problem to be solved by the present invention is that a detent provided on the outer periphery of a metal bush is used even when a single reinforcing fiber substrate having no overlapping interface is used. This is to manufacture a highly reliable resin-made rotating body half-processed product or resin-made rotating body with improved workability, in which the bonding strength of the reinforcing fiber base material is improved. Further, the second problem to be solved by the present invention is to manufacture a resin-made rotating body half-processed product or a resin-made rotating body in which the upper and lower reinforcing fiber densities of the anti-rotation portion are made uniform. is there.

  In the method for manufacturing a resin-made rotating body half-finished product to be improved by the present invention, first, a step of preparing a bush that has one or more anti-rotation portions formed on the outer peripheral portion and rotates around the rotation axis is prepared. carry out. Next, a step of forming a reinforcing fiber base material, which is formed of reinforcing fibers and arranged so as to surround one or more detents on the outer periphery of the bush, is performed.

  In the present invention, the step of forming the reinforcing fiber base is constituted by the following two steps. In the first step, a reinforcing fiber assembly surrounding the outer periphery of the bush including one or more detents is formed by collecting reinforcing fibers around the outer periphery of the bush by papermaking. When the reinforcing fiber assembly is manufactured by the papermaking method, a boundary portion that causes peeling is not formed in the central portion of the reinforcing fiber assembly. In addition, since there is no need for a work of fitting a reinforcing fiber assembly made in advance into the bush, the number of work steps can be reduced. In addition, when making paper, the reinforcing fibers surely wrap around the one or more detents. Therefore, compared to the case where the pre-made reinforcing fiber assembly is fitted into the bush, The bond strength with the stopper can be increased. In the second step, the reinforcing fiber base is formed by compressing the reinforcing fiber assembly in the axial direction of the rotating shaft using the same apparatus as in the first step. This compression ensures that the reinforcing fibers are biting into the anti-rotation portion, increases the density of the reinforcing fiber substrate in the anti-rotation portion, and further increases the bond between the bush and the reinforcing fiber substrate.

  In this invention, the said 1st step and said 2nd step are continuously performed within the same apparatus which accommodates a bush and a reinforcement fiber assembly. Since the reinforcing fiber base material made by paper is continuously compressed using the same equipment, it is not necessary to handle the reinforcing fiber base material after paper making that is bulky and weak (easy to lose shape). Fewer steps are required. In addition, since the density of the reinforcing fiber base is increased by the compression performed in the second step, the strength of the reinforcing fiber base can be increased, and workability (handleability) is greatly improved.

  In the second step, it is preferable that the reinforcing fiber assembly is compressed from above and below in the axial direction of the rotation shaft in a state where the bush is positioned at the center between the pair of compression molds. Thereby, it can compress so that the reinforcement fiber density of the upper side and lower side of a rotation prevention part may become uniform, and the dispersion | variation in the mechanical strength of a resin-made rotary body can be reduced. Further, the compression is preferably performed in a heated state. As a result, it is possible to shorten the time for removing moisture contained in the reinforcing fiber base material after papermaking, and to suppress a change in thickness due to a change with time of the reinforcing fiber base material after compression. Moreover, it is preferable to perform the said compression in the state which vacuum-sucked the accommodation space of the bush and the reinforcement fiber integration body. Thereby, the time which removes the water | moisture content contained in the fiber base material for reinforcement after papermaking can be shortened.

The configuration of the apparatus that performs the first step and the second step is arbitrary. For example, when a device that compresses the reinforcing fiber assembly in the axial direction in a state in which the reinforcing fiber assembly is restricted from spreading radially outward and radially inward of the bush, the reinforcing fiber has a diameter of the bush in the compression process. It will move inward. As a result, the reinforcing fibers are pressed against the outer peripheral portion of the bush, and the density of the reinforcing fibers around the one or more detent portions can be increased.
Note that such an apparatus includes, for example, a cylindrical mold that restricts the reinforcing fiber base material from spreading outward in the radial direction of the bush during the compression operation, and an inner portion of the cylindrical mold that is disposed from the outer periphery of the bush. A pair of bushing molds that sandwich the portion located on the inner side from both sides in the axial direction and restrict the reinforcing fiber assembly from spreading inward in the radial direction of the bush during the compression operation, and the cylindrical mold and the pair of bushes A pair of compression molds positioned between the support molds and compressing the reinforcing fiber assembly from both sides in the axial direction during the compression operation, and at least the lower compression mold has water permeability. It is preferable.

  When a pair of bush supporting molds is used in such an apparatus, positioning and supporting of the bush can be easily performed. The shape of the outer peripheral surface of the reinforcing fiber assembly is determined by the shape of the inner peripheral surface of the cylindrical mold. As a result, by forming the inner peripheral surface of the cylindrical mold into a gear shape, it is possible to form gear-shaped irregularities on the outer peripheral surface of the reinforcing fiber assembly. Of course, the peripheral wall portion of the cylindrical mold may have water permeability. In this case, water permeability can be imparted by forming a plurality of water permeable holes in the cylindrical mold and the lower compression mold. If the slurry in which the reinforcing fibers are dispersed in water is sucked through the cylindrical mold and the lower compression mold, the reinforcing fibers are accumulated on the lower compression mold to form a reinforcing fiber assembly. Good.

  Further, when compression is performed with such an apparatus, when the reinforcing fiber assembly is compressed with a pair of compression molds, it is ensured that the reinforcing fibers bulge in both the radially inner and outer directions of the bush. Can be blocked. In this case, the contact surface that contacts the reinforcing fiber substrate of at least one compression mold of the pair of compression molds is between the contact surface that contacts the reinforcing fiber assembly of the other compression mold. The inclined surface may be inclined such that the distance becomes longer as the distance from the cylindrical mold approaches the pair of bush supporting molds.

  If a step of impregnating the reinforcing fiber substrate with resin and curing the resin to form a resin molded body is added, a resin rotating body can be manufactured.

  As the reinforcing fiber, various materials can be used. However, as the reinforcing fibers, those containing fine fibers obtained by fibrillation of aramid fibers, the freeness of the fine fibers being 100 ml or more and 400 ml or less, and the content of the fine fibers being 30% by mass or less in the reinforcing fibers are used. Is preferred. When such a reinforcing fiber is used, compression is easy, and necessary and sufficient bonding strength can be obtained between the reinforcing fiber base and the rotation stopper.

  The number and shape of the one or more anti-rotation portions provided on the outer peripheral portion of the metal bush are arbitrary. For example, the one or more anti-rotation portions can be composed of a plurality of protrusions that protrude from the central portion of the metal bush toward the radial direction of the shaft. In this case, a recess is formed between two adjacent protrusions. That is, the protrusions and the recesses are arranged alternately in the circumferential direction. These protrusions and recesses can be configured such that the protrusion dimensions of the protrusions are different from the height dimension of the bottom part of the recess formed between the two protrusions. In this case, when the projecting dimension of the projecting part is h1, the height of the bottom part of the recessed part is h2, and h1> h2, the lengths of the reinforcing fibers are 0.5 × h1 mm and 1 × h2 mm. It is preferable to set it to be not less than the smaller value of 5 × h1 mm and 10 × h2 mm or less (refer to FIG. 2 for h1 and h2). When the reinforcing fiber having such a length is used, even when the reinforcing fiber enters between adjacent protrusions, no tear is generated in a part of the reinforcing fiber base, and the reinforcing fiber base A decrease in mechanical strength can be suppressed.

  The ratio of the reinforcing fibers to the resin molded body is desirably 30% by volume or more and 50% by volume or less. If it is the value of this range, the mechanical strength required for a resin molding can be obtained reliably.

  If the resin molded body is machined to form a plurality of teeth, a gear having high mechanical strength and less noise during use can be obtained. Of course, rotating parts such as pulleys may be manufactured in addition to gears using the resin rotating body of the present invention.

  Moreover, what was manufactured by the sintering method can be used for metal bushes. Further, the protrusion used as the rotation stopper has an undercut shape in which the thickness of the top measured along the axial direction is larger than the thickness of the base, and a cross section of a pair of side surfaces facing the axial direction of the metal bush The angle with respect to is preferably 5 ° or more and 40 ° or less.

  The reinforcing fiber base formed by the method of the present invention has no overlapping interface with the reinforcing fiber base and does not peel off. From these things, the durability performance of resin-made rotary bodies, such as a resin-made gearwheel, improves significantly.

  According to the present invention, in the process of forming the reinforcing fiber assembly on the outer peripheral portion of the bush by papermaking, a necessary amount of reinforcing fiber is accumulated around the bush detent and the bush detent portion is formed by the reinforcing fiber aggregate. Can be completely enclosed. Furthermore, by compressing this, it is possible to ensure that the reinforcing fibers bite into the non-rotating portion of the bush and to increase the density of the reinforcing fiber base in the vicinity of the outer peripheral portion of the bush. For this reason, as in the prior art, without forming the boundary surface of the fiber layer inside the reinforcing fiber base, the bonding strength between the reinforcing fiber base and the detent portion of the bush can be improved, There is an advantage that the durability performance of a resin rotating body such as a resin gear can be greatly improved.

  In addition, by continuously performing the paper making and the compression using the same apparatus, it is possible to omit the work of handling the reinforcing fiber base material after paper making which is bulky and weak (easy to lose shape). The process can be greatly shortened. Further, by performing the compression in the state where the bush is located at the center, the reinforcing fiber assembly is vertically operated in the axial direction of the rotation shaft, so that the density of the reinforcing fibers on the upper side and the lower side of the anti-rotation part becomes uniform And the variation in mechanical strength of the resin rotating body can be reduced.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a longitudinal sectional view of an example of an embodiment of a resin rotating body of the present invention schematically shown. The resin rotating body 1 includes a metal bush 2 that rotates about a rotating shaft (not shown). A through hole 3 into which a shaft (not shown) is fitted is formed at the center of the metal bush 2. Further, on the outer peripheral portion of the metal bush 2, projecting portions 4A constituting a plurality of detent portions are integrally formed with a predetermined interval in the circumferential direction. The shaft may be integrally formed with the metal bush 2. The thickness dimension L2 measured in the axial direction of the plurality of protrusions 4A is smaller than the thickness dimension L1 measured in the axial direction of the metal bush 2. The metal bush 2 used in the present embodiment is manufactured by a sintering method. And the protrusion part 4A which comprises a rotation prevention part is an undercut shape with a thick top part and a thin base part. The metal bush 2 has an angle θ with respect to the cross section of 5 ° or more and 40 ° or less. As shown in FIG. 2, in order to enhance the action of the anti-rotation portion that can withstand a load in the rotational direction, preferably, the protrusion 4A serving as the anti-rotation portion includes at least the protrusion 4A having a height h1 and two It is preferable that the recesses 4B formed between the protrusions 4A and having the bottoms having the height h2 are alternately arranged. When the projecting portion 4A having such an undercut shape and having an angle θ of 5 ° or more and 40 ° or less is used, a plurality of projecting portions 4A as detents are completely formed in the reinforcing fiber base 5 described later. It becomes a buried state, and the strength of mechanical coupling between them can be made sufficient. Note that the mechanical strength described above naturally increases when a part of the reinforcing fiber substrate 5 enters the recess 4B formed between the two adjacent protrusions 4A.

  In the present embodiment, one reinforcing fiber base 5 is disposed at a position outside the outer peripheral portion 4 of the metal bush 2 in a state of being fitted to the outer peripheral portion 4. A resin molded body 6 is formed in which the reinforcing fiber base 5 is impregnated with resin and cured.

  As schematically shown in FIG. 3, the reinforcing fiber base 5 is formed by collecting reinforcing fibers at a position outside the outer peripheral portion of the metal bush 2 using a papermaking compression device 7 that can continuously perform papermaking and compression. The body 8 is formed, and the reinforcing fiber assembly 8 is compressed in the axial direction of the rotation shaft.

First, a description will be given of a first step of forming a reinforcing fiber assembly surrounding the outer periphery of the bush including one or more detents by collecting the reinforcing fibers around the outer periphery of the bush by papermaking.
As shown in FIG. 3 (A), the mold used in the paper making compression device 7 includes a cylindrical mold 10 that restricts the reinforcing fiber assembly 8 from spreading outward in the radial direction of the metal bush 2 during the compression operation. Further, a portion disposed inside the cylindrical mold 10 and positioned on the inner side of the outer periphery of the metal bush 2 is sandwiched from both sides in the axial direction, and the reinforcing fiber assembly 8 is in the radial direction of the metal bush 2 during the compression operation. The reinforcing fiber assembly 8 is positioned between the pair of bush supporting molds 11 and 12 for restricting the inward spreading and the cylindrical mold 10 and the pair of bush supporting molds 11 and 12 during the compression operation. Is provided with a pair of compression molds 13 and 14 for compressing by sandwiching them from both sides in the axial direction. In this mold, in order to impart water permeability to the lower compression mold 14, a through hole 15 for draining water is formed in the lower compression mold 14. It is preferable to attach a pump for vacuum suction to the through-hole 15 because drainage can be completed in a short time. In this example, a bottom member 16 is disposed on the lower compression mold 14 to prevent the reinforcing fibers from flowing out during drainage.

  The pair of bush supporting molds 11 and 12 is a cylindrical mold 10 having a portion located inside the outer peripheral part of the metal bush 2 so that the reinforcing fibers do not enter inside the outer peripheral part of the metal bush 2. Is supported by being sandwiched from both sides in the direction in which the center line extends. In this example, the lower bushing support mold 12, the upper bushing support mold 11, the lower compression mold 14, the upper compression mold 13, and the cylindrical mold 10 are each independent. It can be moved up and down.

  A metal mesh can be used for the bottom member 16. When the mesh size is larger than 250 mesh, the filtration resistance of water and fibers increases, and a slurry described later including reinforcing fibers placed inside the mold is pumped. Even if the moisture is drained from the mold by suction, the time required for separation of the fiber and the water becomes longer, and the production cycle becomes longer. On the other hand, if the mesh size is smaller than 10 meshes, even if reinforcing fibers having a long fiber length are used, the mesh (through hole) is large, so that most of the reinforcing fibers flow out with water. Therefore, there arises a problem that the fiber density of the reinforcing fiber assembly 8 is remarkably lowered. Therefore, the mesh size used is preferably 10 mesh or more and 250 mesh or less.

  When the metal bush 2 is sandwiched between the pair of bush supporting molds 11 and 12, the upper bush supporting mold 11 moves upward as shown in FIG. Then, after positioning the metal bush 2 on the lower bush supporting mold 12, the upper bush supporting mold 11 is moved downward as shown in FIG. The metal bush 2 is sandwiched between the bush supporting molds 11 and 12.

  The slurry formed by mixing the reinforcing fiber and water is supplied from the upper opening of the cylindrical mold 10 as shown in FIG. Then, vacuum reinforcement is performed, and moisture is discharged from the plurality of through holes 15 provided in the lower compression mold 14, thereby forming the reinforcing fiber assembly 8 surrounding the periphery of the metal bush 2. . When the pair of bush supporting molds 11 and 12 are used as described above, the metal bush 2 can be easily positioned and supported. In addition, the shape of the outer peripheral surface of the reinforcing fiber assembly 8 is determined by the shape of the inner peripheral surface of the cylindrical mold 10. As a result, by forming the inner peripheral surface of the cylindrical mold 10 into a gear shape, it is possible to form gear-shaped irregularities on the outer peripheral surface of the reinforcing fiber assembly 8. The slurry may be supplied from a plurality of locations in the opening.

Next, a second step of compressing the reinforcing fiber assembly in the axial direction of the rotating shaft to form a reinforcing fiber base will be described.
If it is a metal mold | die used with the paper-making compression apparatus 7 mentioned above, when the reinforcing fiber integration body 8 is compressed with a pair of compression metal molds 13 and 14, the metal bush 2 is reinforced in both the radially inner and outer directions. It is possible to reliably prevent the fibers from bulging.

  After the moisture is discharged from the plurality of through holes 15 provided in the lower compression mold 14, the metal bush 2 is disposed between the pair of compression molds 13 and 14 as shown in FIG. The upper compression die 13 is lowered to a position that is in the center. Thereafter, as shown in FIG. 3 (D), the pair of compression molds 13 and 14 are moved in a state where the metal bush 2 is located at the center of the pair of compression molds 13 and 14, respectively. Compression is performed until the accumulated body 8 has a predetermined thickness. The time and temperature for compression are arbitrary depending on the type of reinforcing fiber to be used. At the time of compression, a heater is attached to the upper compression mold 13 and compressed in a heated state, thereby reinforcing after paper making. The time for removing the moisture contained in the fiber base material can be shortened, and the change with time of the thickness of the reinforcing fiber base material 5 after compression can be suppressed. Preferably, the reinforcing fiber base material 5 having almost no change with time in thickness can be obtained by compressing for 0.5 to 10 minutes at a temperature of 100 to 180 ° C. above the boiling point of water in the solvent used, in this example. . Further, at the time of the compression, the time for removing moisture contained in the reinforcing fiber base material after paper making can be shortened by compressing in a state of being vacuum sucked from the through hole 15 of the lower compression mold 14. .

  As described later, various types of reinforcing fibers can be used for forming the reinforcing fiber substrate 5 or the reinforcing fiber assembly 8. The length of the reinforcing fiber is determined as follows when, for example, a metal bush 2 as shown in FIG. 2 is used. That is, the protrusion dimension of the protrusion 4A (the height of the protrusion 4A measured in the radial direction from the central portion 2A of the metal bush 2) is h1, and the height of the bottom of the recess 4B (the diameter from the central portion 2A of the metal bush 2). When the height of the bottom of the recess 4B measured in the direction is h2, the length of the reinforcing fiber is not less than the smaller value of 0.5 × h1 mm and 1 × h2 mm, and 5 × h1 mm and 10 × h2 mm. It is preferable that it is below the larger value of. Here, when the height dimensions h1 and h2 are the same, the effect of rotation prevention becomes weak. For the height dimension h1 or h2 of the bottom of the protrusion 4A or the recess 4B, a fiber length sufficient to cover the reinforcing fiber is necessary, and the length of the reinforcing fiber is 0.5 × h1 mm and 1 It is appropriate that the value is smaller than the smaller value of x2 mm. Further, if the reinforcing fiber is too long, it causes the uniform dispersion of the slurry, resulting in a non-uniform fiber distribution that does not contribute to strength enhancement. Therefore, the length of the reinforcing fiber is suitably less than the larger value of 5 × h1 mm and 10 × h2 mm. Needless to say, as the protrusions, protrusions (projections having two or more different protrusion dimensions) in which the height of the bottom of the protrusion recesses is h3 larger than h1 may be used in combination.

  The fiber length of the reinforcing fiber thus determined is preferably 2 mm to 5 mm, and more preferably 3 mm. When the fiber length is less than 2 mm, the mechanical properties of the fiber-reinforced resin molded product are deteriorated. On the other hand, when the fiber length exceeds 6 mm, it becomes difficult to dissociate the fiber bundle when the fiber bundle is dissociated and dispersed in water. In addition to the reinforcing fibers (fiber chops) described so far, pulp such as aramid fibers may be used in combination. Thereby, the entanglement of the fibers increases, and the handleability of the reinforcing fiber base material is improved, which is preferable.

  Further, in order to strengthen the connection between the anti-rotation portion provided on the outer peripheral portion 4 of the metal bush 2 and the resin portion, the anti-rotation portion has an undercut shape with a thick top portion and a thin base portion. It is effective that the angle with respect to the cross section of the metal bush 2 is 5 ° or more and 40 ° or less, preferably 10 ° or more and 35 °. This acts to prevent removal in the outer diameter direction.

  The protrusion 4A that constitutes the anti-rotation portion having the undercut shape can be accurately produced as designed if it is molded by a sintering method. For example, in the case of a resin gear having an outer diameter of 60 mm, the optimum structure of the protrusion 4A is 30 protrusions (crests) and 29 recesses or valleys formed between the protrusions. Of course, these numbers are appropriately changed according to the diameter and thickness of the resin gear and the tooth structure.

  The reinforcing fiber used is preferably made of fibers having a melting point or decomposition temperature of 250 ° C. or higher. By forming the reinforcing fiber assembly 8 using such reinforcing fibers, the reinforcing fibers in the resin rotating body do not undergo thermal deterioration at the molding temperature and processing temperature during molding, and the ambient temperature during actual use. And a resin rotating body having excellent heat resistance. Such fibers include para-aramid fibers, meta-aramid fibers, carbon fibers, glass fibers, boron fibers, ceramic fibers, ultra-high strength polyethylene fibers, polyketone fibers, polyparaphenylene benzobisoxazole fibers, wholly aromatic polyesters. It is preferable to use at least one fiber selected from fibers, polyimide fibers, and polyvinyl alcohol fibers.

  The reinforcing fiber preferably contains at least 20% by volume of high-strength and high-modulus fiber having a tensile strength of 15 cN / dtex or more and a tensile modulus of 350 cN / dtex or more. The resin rotating body using the reinforcing fiber assembly 8 thus obtained can withstand a high load applied during use.

  In addition, in order to give strength to maintain the shape when moving or transporting the one formed by integrating the reinforcing fiber assembly 8 with the metal bush 2 using the paper making compression device 7 to the next process. The reinforcing fiber contains fine fibers obtained by fibrillation of aramid fibers, and the freeness of the fine fibers is 100 ml or more and 400 ml or less, and the fine fiber content is 30% by mass or less in the reinforcing fibers. Is desirable. As a desirable embodiment, it is preferable to mix fibrillated aramid fine fibers which are cleaved in the fiber axis direction by mechanical shearing of para-aramid fibers. When the freeness exceeds 400 ml, the fibrillation is insufficient, which is not preferable for imparting strength for maintaining the shape of the reinforcing fiber base material. Further, when the freeness is less than 100 ml, not only the fiber axis direction is cleaved but also the powder is crushed in the radial direction and the entanglement of the fibers deteriorates, and the shape of the reinforcing fiber base is maintained. Therefore, it is not preferable in giving strength for the purpose. Further, the drainage is deteriorated, which impedes resin impregnation. When the fibrillated aramid fine fibers exceed 30% by mass, the fibrillated fine fibers are filled in the gaps between the fibers, and the resin impregnation of the resin is hindered during resin injection molding, resulting in defects such as poor impregnation. End up. It is preferable to blend 5 to 10% by mass of fibrillated fine fibers that impart moderate strength and do not impair resin impregnation.

  The concentration when the reinforcing fiber is dispersed in water is preferably 0.3 g / liter or more and 20 g / liter or less. When fibers having a short fiber length are used, there is little entanglement between the fibers and good dispersion makes it possible to disperse with a high concentration slurry having a concentration of 20 g / liter. On the other hand, when a fiber having a long fiber length is used, the fiber length is too long and cannot be sufficiently dispersed unless the concentration is as low as 0.3 g / liter.

  Incidentally, in the case where the above-mentioned reinforcing fibers include fine fibers obtained by fibrillating aramid fibers, the thickness dimension (axial dimension) of the reinforcing fiber assembly 8 used when the diameter of the metal bush 2 is 5 cm is about 8 cm. The reinforcing fiber assembly 8 is compressed to about 1.5 cm and formed into the reinforcing fiber base 5 by a compression operation described later.

Next, the step of impregnating the reinforcing fiber substrate with resin and curing the resin to form a resin molded body will be described.
As shown in FIG. 4, a resin-made rotating body molding workpiece 21 provided with a reinforcing fiber substrate 5 is placed in a mold 23, and then a liquid resin is injected into the mold 23 to reinforce the fiber substrate. 5 is impregnated with resin and then cured to form a resin rotating body provided with a resin molded body. The mold 23 is a fixed mold 25, a movable mold 27 that is disposed at the center of the fixed mold 25 and is displaced in the vertical direction, and an upper mold that holds the metal bush 2 in pairs with the movable mold 27. A mold 29 is provided. When the pressing portion 29 </ b> A of the upper mold 29 is inserted into the fixed mold 25 and presses the metal bush 2, the moving mold 27 is displaced downward according to the amount of insertion of the upper mold 29. After the upper mold 29 completely closes the opening of the fixed mold 25, the liquid resin is injected into the fixed mold 25. After that, when the resin is cured, the resin rotating body including the resin molded body formed with the reinforcing fiber base 5 as the core is taken out from the mold 23 to complete the production of the resin rotating body.

  A resin gear can be obtained by forming the teeth by machining the outer periphery of the resin molded body of the molded resin rotating body. If a groove is formed along the outer peripheral surface, a pulley can be obtained.

  The liquid resin may be any of thermosetting resin, thermoplastic resin, etc., and epoxy resin, polyaminoamide resin, phenol resin, unsaturated polyester resin, polyimide resin, polyether sulfone resin, polyether ether ketone. A combination of at least one resin selected from a resin, a polyamideimide resin, a polyamide resin, a polyester resin, a polyphenylene sulfide resin, a polyethylene resin, a polypropylene resin, and the like and a curing agent according to the type of the resin can be used.

  Among these, a polyaminoamide resin is preferable from the viewpoint of the strength and heat resistance of the cured resin, and a mixture 100 of 2,2 ′-(1,3 phenylene) bis-2-oxazoline and an amine curing agent having excellent heat resistance and strength. It is preferable to use a resin composed of 5 parts by mass or less of the catalyst with respect to parts by mass. When 5 parts by mass or more of this catalyst is added, the curing time is shortened, and the resin is cured before the reinforcing fiber base 5 is sufficiently impregnated with the resin, which causes a problem of poor resin impregnation.

  The ratio of the reinforcing fibers contained in the resin molded body varies depending on the desired strength of the resin rotating body, but is preferably 30% by volume or more and 50% by volume or less. When the proportion of the reinforcing fiber in the resin molded body is less than 30% by volume, the effect of reinforcing the resin with the fiber is hardly seen, and the fiber is not sufficiently filled in the detent portion of the metal bush 2. . In addition, when the proportion of the reinforcing fiber exceeds 50% by volume, the proportion of the fiber is too high, which causes problems such as insufficient resin impregnation of the resin during resin injection molding. Therefore, the ratio of the fibers contained in the resin molded body has the strength of the resin rotating body, and the fibers are surely filled in the recesses 4B for rotation prevention formed between the two protrusions 4A. More preferably, it is 35 to 45% by volume which does not inhibit impregnation.

Examples of the present invention will be described below.
Example 1
In order to produce the slurry, a tank filled with water in an amount that gives a concentration of 4 g / liter when the fiber chop is charged is prepared. And in this tank, the reinforcement fiber of the quantity from which the fiber total amount of the reinforcement fiber in a resin molding becomes 40 volume% is put. Specifically, as a fiber chop used as a reinforcing fiber, 50% by mass of para-aramid fiber “Technola (trademark)” manufactured by Teijin Limited with an aspect ratio of 200, and meta-aramid fiber “Teijin (aspect ratio 200). "Conex (trademark)" made by Co., Ltd. is 45% by mass, and the fine fiber "Kevlar (trademark)" made by DuPont is fibrillated to a freeness value of 300ml. Next, the water in the tank is stirred with a stirrer to disperse the fiber chop.

  Next, the metal bush 2 is positioned on the lower bush supporting mold 12 by using the papermaking compression device 7 shown in FIG. The shape of the protrusion 4A and the recess 4B of the metal bush 2 to be used is h1 = 2 mm, h2 = 0.5 mm, an undercut shape, and between the virtual center cross section of the metal bush 2 and the side surface SF. The angle θ is 20 °. Then, as shown in FIG. 3B, the upper bush supporting mold 11 is moved downward, and the metal bush is sandwiched between the pair of bush supporting molds 11 and 12. Here, the position of the lower compression mold 14 was a position where the distance from the center in the axial direction of the metal bush 2 to the upper surface of the bottom member 16 was 40 mm. The papermaking compression device 7 is filled with a slurry containing dispersed fiber chops. Then, vacuum suction is performed to drain water from the plurality of through holes 15 provided in the lower compression mold 14, thereby separating the fiber chop and the water to obtain the cylindrical reinforcing fiber assembly 8. In order to prevent the fiber chop from flowing out of the through hole 15 during drainage, a bottom member 16 is disposed on the lower compression mold 14. As the bottom member 16, a metal 100 mesh wire net was used.

  Next, compression is performed so that the fibers are more firmly entrapped in the rotation stop portion of the metal bush 2. First, as shown in FIG. 3C, the upper compression mold 13 heated to 150 ° C. is positioned at a distance of 40 mm from the axial center of the metal bush 2 to the lower surface of the upper compression mold 13. To lower. This position is a position where the metal bush 2 is located in the center between the pair of compression molds 13 and 14. And as shown in FIG.3 (D), in the state which metal bush 2 is located in the center between a pair of compression metal molds 13 and 14, a pair of compression metal molds 13 and 14 are made into speed 1-each, respectively. It moves to the direction which mutually approaches at 5 mm / s, and it compresses until the reinforcement fiber integration body 8 becomes thickness 10mm. And the fiber substrate 5 for reinforcement integrated with the metal bush 2 was obtained by compressing for 2 minutes in the heated state. At the time of the compression, the compression is performed while being vacuum-sucked from the through hole 15 of the lower compression mold 14.

  Next, as shown in FIG. 4, the reinforcing fiber base 5 integrated with the metal bush 2 obtained in the above process is placed in a molding die 27 heated to 200 ° C. and clamped. Then, after reducing the pressure inside the molding die 27 to 90 kPa or less, a resin in which 69 parts by mass of 2,2 ′-(1,3 phenylene) bis-2-oxazoline and 31 parts by mass of 4,4′-diaminodiphenylmethane are mixed. A resin melted at a temperature of 140 ° C., added with 1 part by mass of octyl bromide and stirred is poured into the mold, impregnated into the reinforcing fiber base 5, and heated and cured in the mold 27 to obtain a gear material. A resin gear is obtained by forming teeth by cutting this gear material.

Example 2
In FIG. 3 (B), the position of the lower compression mold 14 is a position where the distance from the axial center of the metal bush 2 to the upper surface of the bottom member 16 is 10 mm,
3C, the upper compression mold 13 is lowered to a position where the distance from the center in the axial direction of the metal bush 2 to the lower surface of the upper compression mold 13 is 70 mm.
In FIG. 3D, a resin gear was manufactured in the same manner as in Example 1 except that only the upper compression mold 13 was moved and compressed.

Conventional example 1
A tank filled with water is prepared, and fiber chops are dispersed with the same fiber blending and concentration as in Example 1. As shown in FIG. 5A, the papermaking apparatus 307 includes a bottom surface portion 313 and a rectangular tube-forming cylinder 309. Only the bottom surface portion 313 is made of a wire mesh. The wire mesh used was a 100 mesh sheet metal mesh. And the slurry containing the above-mentioned dispersed fiber chop was introduced into the papermaking apparatus 307, and the accumulation 310 was obtained. The accumulation 310 was taken out and dehydrated and dried. Thereafter, as shown in FIG. 5B, a reinforcing fiber assembly 308 was obtained by punching into a donut shape having an outer diameter of 80 mm and an inner diameter of 55 mm.

  Next, as shown in FIG. 6 (A), two reinforcing fiber assemblies 308 obtained in the above process are used to sandwich the protruding portion 4A provided on the metal bush 2 and heated to form a mold 323. Placed inside and clamped. Subsequent steps were performed in the same manner as in Example 1 to produce a resin gear. FIG. 6B is a schematic longitudinal sectional view of the resin rotating body manufactured as described above. There is almost no entanglement of the reinforcing fibers at the overlapping interface BS of the two reinforcing fiber base materials 305 in the resin molded body 306 of the resin rotating body.

Table 1 shows the results of measuring the boss punching strength and the motoring durability life of the resin gears obtained in Examples 1 and 2 and Conventional Example 1. The measuring method is as follows.
Boss removal strength: As shown in FIG. 7, the resin gear 51 is disposed on a cylindrical base 55 that is in contact with only the resin molded body portion and has an inner diameter larger than the outer diameter size of the metal bush 2. A metal fitting 56 that holds the metal bush 2 is attached from above, and a load is applied to the metal fitting 56 to measure the maximum load that causes the resin gear 51 to break.
Motoring durability life: The resin gear was continuously rotated under the test conditions shown in Table 1, and the time until the resin gear was broken was measured.

As is clear from Table 2, the resin rotating body according to the present invention can improve the bonding strength between the reinforcing fiber base and the anti-rotation portion of the bush, and the boss punching strength is improved. Moreover, since the boundary surface of a fiber layer is not formed inside the reinforcing fiber base, the motoring durability life is greatly improved (contrast with Examples 1 and 2 and Conventional Example 1). In addition, when compressing the reinforcing fiber base material after papermaking, the reinforcing fiber assembly is performed from above and below in the axial direction of the rotating shaft in a state where the bush is positioned at the center between the pair of compression molds. Further, it is possible to compress the upper and lower reinforcing fiber densities of the rotation preventing portion so as to be uniform, and the variation in mechanical strength of the resin-made rotating body is reduced (contrast between Example 1 and Example 2). .

It is the longitudinal cross-sectional view of an example of embodiment of the resin-made rotary body of this invention typically shown. (A) And (B) is the top view and longitudinal cross-sectional view of metal bushes. (A) thru | or (D) is a figure which shows the papermaking and compression process of the fiber base material for a reinforcement in order. It is a schematic sectional drawing which shows an example of the metal mold | die for resin casting. (A) And (B) is a figure which shows an example of the papermaking apparatus used in order to manufacture a prior art example, and the example of manufacture of the conventional reinforcing fiber base material. (A) is a schematic sectional drawing which shows an example of the metal mold | die for resin casting used in order to manufacture a prior art example, (B) is a longitudinal cross-sectional view of the resin-made rotary body manufactured by the prior art example. It is a figure which shows the structure of the apparatus which measures the boss punch strength.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Resin rotating body 2 Metal bush 3 Through-hole 2B Outer peripheral part 4A Protrusion part (rotation prevention part)
4B Concave part 5 Reinforcing fiber base material 7 Paper-making compression device 8 Reinforcing fiber assembly 10 Cylindrical mold 11, 12 Bush supporting mold 13, 14 Compression mold 15 Through hole 16 Bottom member

Claims (8)

Providing one or more detents on the outer periphery and providing a bush that rotates about the rotation axis;
Forming a reinforcing fiber base formed on the outer peripheral portion of the bush with reinforcing fibers and disposed so as to surround the one or more detents; A method of manufacturing a semi-processed product,
Forming the reinforcing fiber substrate comprises:
A first step of forming a reinforcing fiber assembly surrounding the outer peripheral portion of the bush including the one or more detents by stacking the reinforcing fibers around the outer peripheral portion of the bush by papermaking;
A second step of forming the reinforcing fiber base by compressing the reinforcing fiber assembly in the axial direction of the rotating shaft;
The first step and the second step are continuously performed in the same apparatus containing a bush and a reinforcing fiber assembly, and a method of manufacturing a resin-made rotating body half-processed product . An apparatus for performing the first step and the second step is:
A cylindrical mold for restricting the reinforcing fiber assembly from spreading radially outward of the bush during compression operation;
A portion that is disposed inside the cylindrical mold and is located on the inner side of the outer peripheral portion of the bush is sandwiched from both sides in the axial direction, and the reinforcing fiber assembly spreads radially inward of the bush during the compression operation. A pair of bushing support molds for regulating
A pair of compression molds positioned between the cylindrical mold and the pair of bush supporting molds and compressing the reinforcing fiber assembly from both sides in the axial direction during compression operation, The manufacturing method of the resin-made rotary body shaping | molding half-finished product of Claim 1 in which the lower mold for compression has water permeability.   The second step is to compress the reinforcing fiber assembly from above and below in the axial direction of the rotating shaft in a state where the bush is positioned at the center between a pair of compression molds. Item 3. A method for producing a semi-finished product for molding a resin rotating body according to Item 1 or 2.   The said 2nd step compresses the said reinforcement fiber integration body in the said axial direction in the state heated, The semi-process for resin-made rotary body shaping | molding of any one of Claims 1-3 characterized by the above-mentioned. Product manufacturing method.   5. The method according to claim 1, wherein the second step compresses the reinforcing fiber assembly in the axial direction in a state where the housing space of the bush and the reinforcing fiber assembly is sucked under reduced pressure. The manufacturing method of the semi-finished product for resin-made rotary body shaping | molding of description.   The method for producing a semi-finished product for molding a resin rotating body according to any one of claims 1 to 5, wherein the reinforcing fiber assembly is in the shape of a gear. Providing one or more detents on the outer periphery and providing a bush that rotates about the rotation axis;
Forming a reinforcing fiber base formed on the outer peripheral portion of the bush by a reinforcing fiber and arranged so as to surround the one or more detents; and
A step of impregnating the reinforcing fiber base material with a resin and curing the resin to form a resin molded body, comprising the steps of:
The method for producing a resin rotating body, wherein the step of forming the reinforcing fiber base material is the method according to any one of claims 1 to 6.   A resin gear formed by performing gear cutting on a resin molded body of a resin rotating body manufactured by the method according to claim 7.

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