JP4867887B2 - Fiber-reinforced resin gear and method for manufacturing the same - Google Patents

Description

  The present invention relates to a fiber reinforced resin gear and a manufacturing method thereof.

  Fiber reinforced resin gears are used in various fields because they have advantages such as low meshing noise, light weight and low rotational inertia. As a reinforcing fiber base material for forming a resin gear, it has been proposed to use a base material in which an aramid fiber yarn is knitted into a cylindrical shape (see Patent Document 1). In patent document 1, as shown to Fig.9 (a), the reinforcing fiber base material 61 is wound up to the axial direction, and it is used for manufacture of a gearwheel as the ring body 62. FIG. The ring body 62 and a metal bush (core metal) disposed at the center of the ring body are accommodated in a molding die, and the ring body 62 is impregnated with resin and integrally molded. Then, teeth are formed around the molded ring body by cutting or the like to complete the resin gear.

  In this configuration, the diameter of the reinforcing fiber base material knitted into a cylindrical shape is changed according to the diameter of the resin gear to be manufactured. Depending on the gear to be manufactured, the operation of knitting reinforcing fiber bases with various diameters is extremely complicated, and in some cases, reinforcing fiber bases with a required diameter may not be prepared. There has been proposed a resin gear improved in this problem (see Patent Document 2). In this resin gear, a flat sheet of aramid fiber yarn knitted so as to have a wale of 25 to 35 pcs / inch and a course of 16 to 26 pcs / inch is rolled up in a cylindrical shape, and the cylindrical body is temporarily molded. It is made into a ring body by folding it in a bellows shape in the axial direction, and used for the production of gears. The ring body and a metal bush arranged at the center of the ring body are accommodated in a molding die, and the ring body is impregnated with resin and integrally molded. Then, teeth are formed around the molded ring body by cutting or the like to complete the resin gear.

In addition, the fiber direction of the ring-shaped reinforcing fiber base is aligned with the direction of increasing the tooth strength over the entire circumference of the gear, and the strength of each tooth is greatly uniformed, and the ring-shaped reinforcing fiber base is configured. A resin gear has been proposed for the purpose of preventing the end material from being formed (see Patent Document 3). As shown in FIG. 9B, the ring-shaped reinforcing fiber base material used for this resin gear is prepared by laminating a long fiber base material 63 with a predetermined width by spiral winding and arranging it into a ring shape. The ring width is used. The long fiber base 63 having a predetermined width can be selected from a woven fabric, a paper-made non-woven fabric, and a felt, and can further be selected from a flattened tubular woven or knitted fabric or a solid string. It is said that.
JP-A-8-156124 Japanese Patent Laid-Open No. 2003-4119 JP 2001-241535 A

  However, as described in Patent Document 2, a ring body is manufactured by winding a reinforcing material in which fiber yarns are knitted into a flat sheet into a cylindrical shape and folding the cylindrical body into an accordion shape in the axial direction. difficult. In addition, Patent Document 2 defines the width of the stitches in the width direction and the pitch of the stitches in the longitudinal direction of the knitted fabric, but the preferable relationship between the size of the gear teeth and the pitch of the two stitches is described below. Not mentioned.

  In the case of Patent Document 3, since long fiber bases 63 having a predetermined width are laminated by spiral winding, for example, wefts of a woven fabric are easily arranged in the radial direction of a gear. However, it is difficult to stack a long woven fabric in a spiral winding without wrinkles due to a difference in path between the inside and outside of the ring. In the case of a knitted fabric, it is easy to expand and contract as compared with a woven fabric, and therefore, it is easier to laminate in a spiral winding than in the case of a woven fabric. However, in Patent Document 3, there is no description regarding the pitch of the stitches of the knitted fabric, and there is no description regarding the relationship between the size of the gear teeth and the stitches. Unlike woven fabrics, knitted fabrics are not arranged so that the fibers extend straight, but are arranged so that looped stitches are intertwined. Therefore, depending on the size of the stitches and the size of the gear teeth, the stitches are cut when the gear is cut, and the stitches are not completely present in the teeth, and the load is applied to the teeth when the gear is used. When this occurs, there is a problem that the strength, particularly the shear strength, decreases.

  The present invention has been made in view of the above-mentioned problems, and a first object is to form a fiber reinforced material by knitting, and in a fiber reinforced resin gear having a tooth portion formed by cutting, a tooth portion. It is in providing the fiber reinforced resin gear which can suppress the intensity | strength fall of this. Moreover, the 2nd objective is to provide the manufacturing method of the said fiber reinforced resin gear.

  In order to achieve the first object, according to the first aspect of the present invention, at least the tooth portion is formed of a fiber reinforced resin having a fiber reinforced material in which a plurality of layers of knitted fabrics are laminated in the axial direction of the gear. A fiber reinforced resin gear, wherein the height of each tooth portion or the width of the tooth tip of the gear is formed to be smaller than the distance of one stitch in the course direction of the knitting, and each tooth portion of the gear is knitted. At least one knitted layer in which at least one pair of intersecting portions of one loop of the stitches constituting the loop and two fiber bundles intersecting the loop exists.

  Unlike woven fabrics, knitted fabrics are not arranged so that the fibers extend straight, but are arranged so that looped stitches are intertwined. In the present invention, at least the tooth portion of the gear is formed of a fiber reinforced resin using a knitted fabric as a fiber reinforcing material, and each tooth portion of the gear has two loops intersecting the loop and one loop of the knitting constituting the knitted fabric. It has at least one knitted layer in which one or more pairs of intersections with the fiber bundle are present. Therefore, when a gear is used, if a load is applied to the tooth portion of the gear in the tooth thickness direction, the load is carried by the pair of intersecting portions, so compared to the case where there is no pair of intersecting portions. Strength is improved. That is, a reduction in the strength of the tooth portion can be suppressed.

  The invention according to claim 2 is the invention according to claim 1, wherein each tooth portion of the gear has at least one knitted layer in which only one pair of intersecting portions exists. In this invention, even if each tooth | gear part is small, the strength reduction of a tooth | gear part can be suppressed.

  The invention according to claim 3 is the invention according to claim 1 or 2, wherein the fiber reinforcement is formed in a band shape as the knitted fabric, and the vertical row of stitches is in the width direction of the band-shaped knitted fabric. In which the horizontal rows of the stitches are formed so as to extend in the longitudinal direction of the belt-like knitting, and the vertical rows of the stitches are arranged in a radial pattern so as to be circularly wound. Is formed. Therefore, it arrange | positions so that the vertical row | line | column of a stitch may line up along a radial direction over a perimeter, and the intensity | strength of each tooth | gear part of a gearwheel is equalized.

  The invention according to claim 4 is the invention according to claim 1 or 2, wherein the fiber reinforcing material is formed in a band shape as the knitted fabric, and the horizontal row of stitches is in the width direction of the knitted belt. In which the vertical rows of the stitches are formed so as to extend in the longitudinal direction of the belt-like knitting, and the horizontal rows of the stitches are arranged in a radial pattern so as to be circularly wound. Is formed. Therefore, the horizontal rows of the stitches are arranged along the radial direction over the entire circumference, and the strength of each tooth portion of the gear is made uniform.

  The invention according to claim 5 is the invention according to claim 1 or claim 2, wherein the fiber reinforcing material is formed by laminating knitted materials into outer circular shapes, and each laminated material is laminated. The knitting layers are stacked such that the arrangement direction of the vertical rows of stitches is shifted by a positive integer multiple of the angle formed between adjacent teeth of the gear. Here, the “outer circular shape” means an annular shape or a circular shape. In this invention, since the fiber reinforced material of the fiber reinforced resin constituting the tooth portion is formed by laminating a predetermined number of knitted materials that are punched out (cut out), it is easy to manufacture the fiber reinforced resin. is there.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the two fiber bundles are two loops. Depending on the type of knitting, there are cases in which one loop intersects with adjacent loops and a portion that extends in a straight line continuing to the loops. In this invention, since the loops intersect each other, the strength of the tooth portion is higher than that in the case of a fiber bundle extending linearly.

  In order to achieve the second object, in the invention according to claim 7, at least the tooth portion is formed of a fiber reinforced resin having a fiber reinforced material formed by laminating a plurality of layers in the axial direction of the gear. A method for manufacturing a fiber reinforced resin gear, wherein the height of each tooth portion of the fiber reinforced resin gear to be formed or the width of the tooth tip is smaller than the distance of one stitch in the course direction of the stitch as a reinforcing material, A step of manufacturing a fiber-reinforced resin molded body for gear cutting in which a plurality of layers of knitted fabrics are laminated in the axial direction of the gear, and a step of gear-cutting the fiber-reinforced resin molded body with a gear cutter. . Then, when gear cutting is performed on the fiber reinforced resin molded body, the gear cutting start position determined by the relationship with the stitch of the knitted fabric closest to the outer peripheral surface of the fiber reinforced resin molded body is instructed by the instruction means. Thus, the fiber reinforced resin molded body is fixed to the work mounting portion of the gear cutter, and gear cutting is started from the gear cutting start position by the cutting blade of the gear cutter.

  Here, “instruction means” means means for instructing the position at which the cutting blade starts gear cutting when the gear cutter performs gear cutting. In the manufacturing method of the present invention, when gear cutting is performed on the fiber reinforced resin molded body, the appropriate gear cutting start position of the fiber reinforced resin molded body matches the position where the cutting blade of the gear cutter starts gear cutting. As described above, the operator manually positions and fixes the workpiece to the workpiece mounting portion. Then, gear cutting by the cutting blade of the gear cutter is started from this state. Therefore, each tooth part of the fiber reinforced resin gear has a structure in which one or more pairs of intersections of one loop of a stitch constituting the knitted fabric and two fiber bundles intersecting the loop exist.

    The invention according to claim 8 is a method for manufacturing a fiber reinforced resin gear, in which at least the tooth portion is formed of a fiber reinforced resin having a fiber reinforced material in which a plurality of layers of knitted fabrics are laminated in the axial direction of the gear. The knitted fabric has a plurality of layers in the axial direction of the gear, using a knitted fabric in which the height of each tooth portion or the width of the tooth tip of the fiber reinforced resin gear to be formed is smaller than the distance of one stitch in the course direction of the stitch. A step of manufacturing a laminated fiber-reinforced resin molded body for gear cutting, and a step of gear-cutting the fiber-reinforced resin molded body by a gear cutter. Then, when gear cutting is performed on the fiber reinforced resin molded body, the reflected light of the light irradiated toward the outer peripheral surface of the fiber reinforced resin molded body mounted on the work mounting portion is detected, and the fiber reinforced Using a gear cutter equipped with a detection device capable of specifying the position corresponding to the stitch of the knitted fabric closest to the outer peripheral surface of the resin molded article, and fixing the fiber reinforced resin molded article to the work mounting portion of the gear cutter In this state, after the gear cutting start position determined by the relationship with the stitch of the knitted fabric closest to the outer peripheral surface of the fiber reinforced resin molded body is specified by the detection device, the cutting blade of the gear cutter is used from the gear cutting start position. Start gear cutting.

  Therefore, in the present invention, when gear cutting is performed on the fiber reinforced resin molded body, the fiber reinforced resin molded body for gear cutting is used, and the appropriate gear cutting start position of the fiber reinforced resin molded body is the cutting of the gear cutting machine. It is not necessary for the operator to manually position and fix the blade to the work mounting portion of the gear cutter so that the blade coincides with the position where gear cutting starts. When the worker fixes the fiber reinforced resin molded body to the workpiece mounting portion, an appropriate cutting start position of the cutting blade of the gear cutter is automatically detected, and gear cutting is started from an appropriate position.

  ADVANTAGE OF THE INVENTION According to this invention, while comprising a fiber reinforcement with a knitting, the fiber reinforced resin gear by which the tooth part was formed by cutting can suppress the strength reduction of a tooth part.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described with reference to FIGS. As shown in FIG. 1A, the fiber reinforced resin gear 11 has a resin part 13 formed on the outer periphery of the core metal 12 and a fiber reinforced resin part 14 formed on the outer periphery of the resin part 13. A tooth portion 15 is formed in the fiber reinforced resin portion 14. The fiber reinforced resin portion 14 is formed of a fiber reinforced resin having a fiber reinforced material in which a plurality of layers of knitted fabrics made of continuous fibers are laminated in the axial direction of the fiber reinforced resin gear 11. More specifically, the fiber reinforcing material is formed in an annular shape by spirally winding a knitted fabric formed in a band shape in the axial direction of the fiber reinforced resin gear 11. The knitted fabrics are laminated so that the outer portion of the annular portion is stretched, and in a straight belt-like state, the vertical rows of stitches arranged in parallel are arranged so as to extend in the radial direction.

  And the width W of the tooth tip of each tooth part 15 of the fiber reinforced resin gear 11 is formed smaller than the distance T of one stitch in the course direction of the stitch of the knitted fabric. As shown in FIG. 1 (b), the distance T for one stitch in the course direction is a straight line in contact with the loop tip of one stitch and a common tangent of two curved portions on the opposite side of the loop of the stitch. Means distance. Moreover, the height H of each tooth part 15 is formed the same as 1 course. As shown in FIG. 1B, one course of the stitch is a length of one pitch in the vertical row 20a of the stitch, and one wal is a length of one pitch in the horizontal row 20b of the stitch. . Further, each tooth portion 15 of the fiber reinforced resin gear 11 includes at least one knitted layer in which one or more pairs of intersections of one loop of a stitch constituting the knitting and two loops intersecting the loop exist. Have a layer.

  A pair of intersecting portions refers to a pair of straight lines L1a and L1b that extend in the course direction through both ends in the wale direction of one loop, and a wale that passes through the tip of the loop and the tip of the loop that intersects the loop, respectively. It refers to a portion surrounded by a pair of straight lines L2a and L2b extending in the direction. The reference loop may be upward or downward, and one of the two parts A and B surrounded by a rectangle in FIG. 1B is a pair of intersections. In this embodiment, each tooth part 15 has one part A or part B.

  The fibers constituting the reinforcing material are selected depending on the physical properties required for the fiber reinforced resin gear 11. In this embodiment, aramid fibers as organic fibers are used. A monomer cast nylon resin is used as a matrix resin for the resin portion 13 and the fiber reinforced resin portion 14.

  Next, the manufacturing method of the fiber reinforced resin gear 11 is demonstrated. In the manufacturing process of the fiber reinforced resin gear 11, the height of each tooth part or the width of the tooth tip of the fiber reinforced resin gear to be formed is a knitted material smaller than the distance T of one stitch in the course direction of the stitch, A step of manufacturing a fiber-reinforced resin molded body for gear cutting, in which a plurality of layers of knitted fabrics are laminated in the axial direction of the gear, and a step of gear-cutting the fiber-reinforced resin molded body by a gear cutter. In this embodiment, the step of manufacturing a fiber-reinforced resin molded body includes a step of forming a strip-shaped knitted fabric, a strip-shaped knitted fabric laminating step of laminating the knitted fabric spirally to form an annular body of a predetermined thickness, A fiber reinforced resin molded body forming step of manufacturing an annular fiber reinforced resin molded body by impregnating the body with resin. Further, as a pre-process of the step of cutting the fiber-reinforced resin molded body with the gear cutter, the process includes a step of heat-pressing the core metal 12 into the center of the annular fiber-reinforced resin molded body. A gear cutting process is performed on the fiber-reinforced resin molded body into which is pressed.

  In the step of forming the strip-shaped knitted fabric, as shown in FIG. 2, the vertical row 20a of the stitch extends in the width direction of the strip-shaped knitted fabric 20, and the horizontal row (course) 20b of the stitch is the longitudinal direction of the strip-shaped knitted fabric 20. A band-shaped knitted fabric 20 is formed so as to extend in the direction. In this embodiment, an annular body is not constituted by one belt-like knitted fabric 20, but an annular body is constituted by a plurality of belt-like knitted fabrics 20, so that the belt-like knitted fabric 20 is formed with a plurality of articles having a predetermined length. Is done. Further, when the band-shaped knitted fabric 20 is formed so that the width W of the tooth tip of each tooth portion 15 of the fiber reinforced resin gear 11 is smaller than the distance T of one stitch in the course direction of the knitted stitch, each tooth portion 15 is formed. In addition, the pitch of the vertical rows 20a and the pitch of the horizontal rows 20b in the knitted fabric are set so that one or more of the portions A or B are present. That is, the pitch of the vertical rows 20a and the horizontal rows 20b of the knitted fabric are such that there is at least one pair of intersecting portions of one loop of a stitch constituting the knitted fabric and two fiber bundles intersecting the loop. It is formed by setting the size of the pitch.

  In the belt-like knitting lamination step, as shown in FIG. 3A, the belt-like knitting 20 is laminated while being spirally deformed to form an annular body 21 having a predetermined thickness as shown in FIG. 3B. To do. At this time, the strip-shaped knitted fabric 20 is spirally laminated along the periphery of a cylindrical guide (not shown). Therefore, the band-shaped knitted fabric 20 is easily arranged in a spiral with a constant width while one side in the width direction is in contact with the peripheral surface of the guide.

  For example, when the inner diameter of the annular body 21 to be formed is 60 mm, the length of the belt-shaped knitted fabric 20 for one layer that is spirally stacked is about 190 mm, and the length of 1.9 m is 10 layers. I need it. Moreover, when the number of layers is 20, a length of 3.8 mm is required. Therefore, when one annular body 21 is formed by one belt-shaped knitted fabric 20, a device having a particularly wide width is required as a flat knitting machine. However, since one annular body 21 is formed by a plurality of strip-shaped knitted fabrics 20, it is not necessary to use a device having a particularly wide knitting width as a flat knitting machine.

  In the fiber reinforced resin molded body forming step, for example, a resin transfer molding (RTM) method is employed. In the RTM method, the annular body 21 is disposed in a resin impregnation mold (molding mold). Then, after closing the molding die, a polyamide (nylon) monomer is injected into the molding die and impregnated in the annular body 21 and heated and polymerized. An annular fiber-reinforced resin molded article for cutting is obtained. As the polyamide monomer, for example, ε-caprolactam is used. The fiber reinforced resin molded body is formed in a state having a resin portion 13 having no fiber layer on the inside.

  Next, the metal core 12 is heated and press-fitted into the center portion of the fiber-reinforced resin molded body to form a gear molded body having the metal core 12 at the center portion. And the fiber reinforced resin gear 11 is formed by forming the gear tooth part 15 by cutting in the outer peripheral part of this molded article for gears. The tooth portion 15 is processed by cutting the fiber-reinforced resin molded body with a gear cutter.

  When gear cutting is performed on a fiber reinforced resin molded body, the fiber reinforced resin molded body is cut so that gear cutting starts from a gear cutting start position set at a predetermined position of the fiber reinforced resin molded body. Fix to the work mounting part of the board and start gear cutting with the gear cutting device. The above-mentioned gear cutting start position is a position determined by the relationship with the stitch of the knitted fabric closest to the outer peripheral surface of the fiber reinforced resin molded body, and if gear cutting is started from that position, a pair of intersections are formed on all the tooth portions. Is calculated and set from the shape of the teeth, the shape of the stitches, etc. so that at least one exists. As a method of fixing the fiber reinforced resin molded body to the work mounting portion of the gear cutting machine so that gear cutting is started from the gear cutting start position, for example, a laser as an instruction means for irradiating the outer surface of the fiber reinforced resin molded body A beam pointer is provided on the gear cutter. Then, the fiber reinforced resin molded body is fixed to the gear cutter so that the gear cutting position of the fiber reinforced resin molded body matches the irradiation position of the laser beam pointer, and gear cutting is started from the irradiation position. . Alternatively, a protrusion may be provided as an instruction means on the gear cutter, the gear cutting start position of the fiber reinforced resin molded body may be aligned with the position of the protrusion, and gear cutting may be started from the position of the protrusion by the gear cutter. By doing so, a fiber reinforced resin having a structure in which at least one pair of intersecting portions of one loop and two loops intersecting the loop exists in the row next to the stitches constituting the knitted fabric in each tooth portion. A gear 11 is formed.

According to this embodiment, the following effects can be obtained.
(1) The fiber reinforced resin gear 11 has at least the tooth portion 15 formed of a fiber reinforced resin in which a plurality of layers of knitted fabrics are laminated in the axial direction of the gear. Each tooth portion 15 of the fiber reinforced resin gear 11 is formed with a width W of the tooth tip smaller than a distance T corresponding to one stitch in the course direction of the knitted stitch, and in the row 20b next to the stitch constituting the knitted fabric, It has at least one layer of knitting in which one or more pairs of intersections of one loop and two loops intersecting the loop exist. Therefore, when the fiber reinforced resin gear 11 is used, as shown by the arrow F in FIG. 1B, when a load is applied to the tooth portion 15 in the tooth thickness direction, a pair of intersecting portions (part A or Since the load is carried by the part B), the strength is improved as compared with the case where there is no pair of intersections. That is, the strength reduction of the tooth portion 15 can be suppressed.

  (2) The fiber reinforced resin used for the fiber reinforced resin portion 14 of the fiber reinforced resin gear 11 is formed in a band shape as a knitted fabric, and is also formed into a ring shape by being spirally wound. In each tooth portion 15, a vertical row 20a of knitting stitches is arranged along the radial direction. Therefore, the strength of each tooth portion 15 of the fiber reinforced resin gear 11 is made uniform.

  (3) As for the fiber reinforcement used for the fiber reinforced resin part 14, the vertical row 20a of the stitch extends in the width direction of the strip-shaped knitted fabric 20, and the horizontal row 20b of the stitch extends in the longitudinal direction of the strip-shaped knitted fabric 20. The belt-shaped knitted fabric 20 formed as described above is formed into an annular annular body 21 by overlapping a plurality of spirals. Therefore, the belt-like knitted fabric 20 can be formed with a general width apparatus without using a specially wide apparatus as a flat knitting machine.

  (4) Organic fibers are used as the fibers forming the knitted fabric. Depending on the tooth height and the tooth thickness that determine the size of the tooth portion 15 of the fiber reinforced resin gear 11, the pitch of the vertical row 20a and the horizontal row 20b of the stitch becomes as small as about 1 mm, for example. In such a case, the organic fiber is less likely to be damaged than the inorganic fiber such as carbon fiber or glass fiber.

  (5) The fiber reinforced resin gear 11 is configured to have a resin portion 13 in which no reinforcing fiber exists between the core metal 12 and the fiber reinforced resin portion 14. Therefore, the core metal 12 can be manufactured in a state where it is accurately arranged at the center of the fiber reinforced resin gear 11, and the centering when the fiber reinforced resin gear 11 is fixed to the rotating shaft can be accurately performed. Further, the fiber reinforced resin gear 11 can be manufactured without increasing the volumes of the core metal 12 and the fiber reinforced resin portion 14 more than necessary, and the fiber reinforced resin gear 11 constituted by the core metal 12 and the fiber reinforced resin portion 14. This is advantageous in terms of weight reduction and cost reduction.

(Second Embodiment)
Next, a second embodiment will be described with reference to FIGS. This embodiment is different from the first embodiment in the manufacturing method of the annular body 21 as a fiber reinforcing material used for the fiber reinforced resin portion 14 of the fiber reinforced resin gear 11. Hereinafter, a different part from 1st Embodiment is demonstrated. In addition, the same code | symbol is attached | subjected about the part similar to 1st Embodiment, and detailed description is abbreviate | omitted.

  When the fiber reinforced resin gear 11 is manufactured, first, a step of forming a sheet-like knitted fabric, a step of punching the knitted fabric into an annular shape, and laminating the punched annular knitted sheet, an annular body having a predetermined thickness is formed. A knitting layer forming step to be formed; and a fiber reinforced resin molded body forming step of manufacturing an annular fiber reinforced resin molded body by impregnating the annular body with a resin. Moreover, it has the process of heat-pressing the metal core 12 in the center part of an annular | circular shaped fiber reinforced resin molded object, and the process of gear-cutting to the fiber reinforced resin molded object in which the metal core 12 was heat-pressed.

  In the step of forming the sheet-like knitted fabric, when the width W of the tooth tip of each tooth portion 15 of the fiber reinforced resin gear 11 to be formed is smaller than the distance T corresponding to one stitch in the course direction of the knitted stitch. The pitch of the vertical row 20a and the pitch of the horizontal row 20b in the knitting is set so that one or more of the portions A or B are present in each tooth portion 15, and the knitting is formed.

  As shown in FIG. 4A, an annular knitted fabric 31 (shown by a two-dot chain line in FIG. 4A) is punched out from a rectangular sheet-shaped knitted fabric 30. Next, as shown in FIG. 4B, a predetermined number of annular knitted fabrics 31 are laminated to form an annular body 32 in the knitting lamination step. When the annular body 32 is formed, the arrangement direction of the vertical rows 30a of the stitches in the layers of the laminated knitted fabrics 31 is shifted by a positive integer multiple of the angle θ formed between the adjacent teeth of the fiber reinforced resin gear 11. Are stacked. Specifically, as shown in FIG. 5, if the arrangement direction of the vertical rows 30 a of the (n−1) -th layer knitted fabric 31 is the vertical direction in FIG. 5, the vertical rows 30 a of the n-th knitted fabric 31. The layers are stacked in a state where the angle θ is inclined with respect to the arrangement direction. In addition, the arrangement direction of the vertical row 30a of the (n + 1) -th layer knitting 31 is stacked in a state inclined by an angle 2θ from the arrangement direction of the vertical row 30a of the (n−1) -layer knitting 31. The number of layers is set so that at least one layer of knitted fabric having at least one part A or part B exists at least in each tooth part 15 of the fiber reinforced resin gear 11.

  And after manufacturing an annular fiber reinforced resin molded object by using the annular body 32 as a fiber reinforcing material in the fiber reinforced resin molded object forming step as in the first embodiment, the center part of the annular fiber reinforced resin molded object The fiber reinforced resin gear 11 is manufactured by performing the step of heat-pressing the cored bar 12 and the step of cutting gears on the fiber-reinforced resin molded body into which the cored bar 12 is heat-pressed.

  In this embodiment, the annular knitted fabric 31 constituting the annular fiber-reinforced resin molded body is formed by punching the rectangular sheet-shaped knitted fabric 30. Therefore, the vertical rows 30a of the stitches of the knitted fabrics 31 to be stacked are formed. When the arrangement direction is the same, the vertical row 30a of the stitches included in each tooth portion 15 does not always coincide with the tooth height direction. For example, in the tooth portion 15 in which the tooth height direction is orthogonal to the direction of the vertical row 30a of the stitch, the horizontal row 30b of the stitch matches the direction of the tooth height. In other tooth portions 15, depending on the tooth thickness and the pitch of the stitches, the vertical row 30a or the horizontal row 30b of the stitches do not coincide with the tooth height direction. Therefore, at least one part A or part B does not necessarily exist in each tooth part 15. However, in this embodiment, since the arrangement direction of the vertical rows 30a of the stitches of each knitted fabric 31 is laminated with each layer being shifted, each knitted fabric 15 has one or more portions A or B in each tooth portion 15. There will be at least one layer. Therefore, when a load is applied to the tooth portion 15 in the tooth thickness direction, a portion in which at least one pair of intersecting portions of one loop and two loops intersecting the loop exists in the row 30b next to the stitch. Since the load is carried by A or the portion B, the strength is improved as compared with the case where there is no pair of intersecting portions. That is, the strength reduction of the tooth portion 15 can be suppressed.

This embodiment has the following effects in addition to the same effects as the effects (4) and (5) in the first embodiment.
(6) The fiber reinforcement is formed by laminating knitted fabrics cut into an annular shape, and the arrangement direction of the vertical rows of stitches in each of the laminated knitted layers is between adjacent teeth of the gear. Are stacked so as to be shifted by a positive integer multiple of the angle formed by. Therefore, when the fiber reinforced resin gear 11 is used and the load is applied to the tooth portion 15 in the tooth thickness direction, the load is carried by the pair of intersecting portions (part A or part B). The strength is improved compared to the case where there is no intersection. That is, the strength reduction of the tooth portion 15 can be suppressed.

(7) Since the fiber reinforced material is formed by laminating a predetermined number of knitted fabrics cut into a ring shape by punching or cutting, it is easy to manufacture a fiber reinforced resin.
The embodiment is not limited to the above, and may be embodied as follows, for example.

  When the belt-like knitted fabric 20 is spirally stacked to form the annular annular body 21, the belt-shaped knitted fabric 20 has a vertical row 20 a of stitches extending in the width direction of the strip-shaped knitted fabric 20, and a row next to the stitches. 20b does not necessarily extend to the longitudinal direction of the strip-shaped knitted fabric 20. For example, as shown in FIG. 6A, the horizontal rows 20b of the stitches extend in the width direction of the strip-shaped knitted fabric 20, and the vertical rows 20a of the stitches are formed to extend in the longitudinal direction of the strip-shaped knitted fabric 20. Also good. In this case, since the obtained annular body 21 is arranged so that the horizontal rows 20b of the knitted stitches are arranged along the radial direction, as shown in FIG. The horizontal rows 20b of the stitches are arranged along the radial direction. Therefore, the strength of each tooth portion 15 of the fiber reinforced resin gear 11 is made uniform. In addition, regardless of the length of the belt-like knitted fabric 20 to be formed, the knitting machine having a narrow apparatus width can be used as a flat knitting machine, and one annular body 21 can be easily formed with one belt-shaped knitted fabric 20. be able to.

  The fiber reinforced resin gear 11 is formed such that the height of each tooth portion 15 or the width of the tooth tip is smaller than the distance T of one stitch in the course direction of the knitting of the knitting constituting the fiber reinforcing material, and each tooth The portion 15 may have at least one knitted layer in which one or more pairs of intersecting portions of one loop of a stitch constituting the knitted fabric and two fiber bundles intersecting the loop exist. That is, the crossing portion is not limited to the configuration in which the loops cross each other, and depending on the type of knitting, the crossing with one loop may be a portion of a fiber bundle that extends continuously in a straight line instead of the loop. However, the strength of the tooth portion is higher in the case where the loops intersect than in the case of the fiber bundle extending in a straight line.

  The size of each tooth portion 15 is not limited to the fact that both the height of the tooth portion 15 and the width of the tooth tip are smaller than the distance of one stitch in the course direction of the knitting stitch. For example, as shown in FIG. 7A, the width W of the tooth tip is not more than half of the distance T for one stitch in the course direction, and the distance between the height of the tooth portion 15 and the width of the base end of the tooth portion 15 is a distance. It may be formed larger than T so that one of the part A and the part B exists.

  ○ When the width W of the tooth tip is smaller than the distance T of one stitch in the course direction, the cutting start position when cutting the gear is accurately determined depending on the direction of the stitch of the knitting existing in the tooth portion 15. Must be set. For example, when the course direction of the stitch is the width direction of the tooth tip and the width of the base end of the tooth portion 15 is equal to the distance T, as shown in FIG. When the tooth portion 15 is cut so that there is almost one stitch, the tooth portion 15 does not completely include a pair of intersecting portions. Even if the tooth portion 15 has the same size, when the waling direction of the stitch is parallel to the width direction of the tooth tip, the tooth portion 15 completely includes a pair of intersecting portions. Further, when the height of the tooth portion 15 is made smaller than the distance T for one stitch in the course direction, the cutting start position when the gear is cut depends on the direction of the stitch of the knitting existing in the tooth portion 15. It is necessary to set it correctly. For example, when the waling direction of the stitch is the width direction of the tooth tip, even if the width of the base end of the tooth portion 15 is larger than the distance T, as shown in FIG. When the tooth portion 15 is cut so that there is almost one stitch along the tooth portion 15, the tooth portion 15 does not completely include a pair of intersecting portions. That is, the cutting start position and the position of the tooth tip and the stitch when the gear is cut are determined by the width W of the tooth tip and the width of the base end of the tooth portion 15 and the height of the tooth portion 15 depending on the direction of the stitch. There is a need to.

  ○ As shown in FIG. 8A, the height of each tooth portion 15 of the fiber reinforced resin gear 11 is formed to be smaller than one course of the knitting stitch, and the width of the tooth tip is formed to be a multiple of one course. A plurality of portions A and portions B may be present in each tooth portion 15. Further, as shown in FIG. 8B, the horizontal row 20b of the stitch may be arranged in the tooth height direction.

  In the case where the annular body 21 is formed by using the belt-like knitting 20 in which the vertical row 20 a of the stitch extends in the width direction of the belt-like knitting 20 and the horizontal row 20 b of the stitch extends in the longitudinal direction of the belt-like knitting 20. Alternatively, it may be formed by one strip-shaped knitted fabric 20.

  ○ The knitting structure is not particularly limited. For example, flat knitting, rubber knitting, pearl knitting, etc., a structure that intersects with one loop becomes an adjacent loop, or a knitting structure intersects with one loop like Denby knitting. May be a structure that is not a loop but a linearly extending portion of a fiber bundle.

  The fiber reinforced resin gear 11 has a configuration in which the fiber reinforced resin portion 14 is directly continuous with the outer periphery of the core metal 12 without providing the resin portion 13, or the entire fiber reinforced resin gear 11 is not provided with the core metal 12. You may comprise only the fiber reinforced resin part 14. FIG.

In the fiber reinforced resin gear 11, the fiber reinforced resin portion 14 is not limited to an annular shape, and may be a disk shape.
O The number of tooth portions 15 of the fiber-reinforced resin gear 11, the tooth height, the tooth thickness, and the like may be appropriately changed according to the purpose.

○ Not limited to spur gears, it may be applied to, for example, worm wheels and inclined gears.
○ Continuous fibers used for reinforcing materials are not limited to aramid fibers, but high-strength organic fibers such as ultrahigh molecular weight polyethylene fibers and polyparaphenylene benzobisoxazole fibers (PBO fibers), and polyesters as organic fibers depending on the required physical properties. Fiber may be used. Moreover, you may use not only an organic fiber but inorganic fibers, such as carbon fiber and glass fiber.

  The matrix resin is not limited to the monomer cast nylon resin, but may be other thermoplastic resins or thermosetting resins. As the thermoplastic resin, polycarbonate, polybutylene terephthalate, polyacetal, or the like, which is an engineering plastic other than polyamide, may be used. Moreover, as a thermosetting resin, an epoxy resin and vinyl ester-type resin are used, for example. In the case where the annular body 21 made of a knitted material is impregnated with the polymer thermoplastic resin, the molten thermoplastic resin is injected under pressure in a state where the mold is heated to a temperature higher than the melting temperature of the matrix resin.

  When the annular body 32 is formed by stacking the annular knitted fabrics 31 formed by punching (cutting) the rectangular sheet-shaped knitted fabric 30 as in the second embodiment, the annular structure constituting each layer The knitted fabric 31 is not limited to a configuration in which the arrangement direction of the vertical rows 30a of the stitches is shifted by an angle θ between adjacent layers. It is only necessary that the knitted layers arranged at different angles exist in the laminated annular body 32 as a whole. In this case, the same effect as that of the second embodiment can be obtained.

  ○ When gear cutting is performed on a fiber reinforced resin molded body, the operator fixes the fiber reinforced resin molded body to the workpiece mounting part without positioning, and sets the appropriate gear cutting start position of the fiber reinforced resin molded body. The gear cutting may be started after the cutting machine automatically detects. For example, the gear cutter receives light reflected from the surface of the fiber reinforced resin molding that is irradiated from the light irradiator and the light irradiation unit that irradiates the fiber reinforced resin molded body mounted on the workpiece mounting portion. And a detection device capable of detecting the state of the stitches of the knitted fabric constituting the fiber reinforced resin molded body from the light receiving state. For example, the detection device can specify the position of the loop of the stitches constituting the knitted fabric by reflected light from the fiber-reinforced resin molded body. Then, when performing the gear cutting process on the fiber reinforced resin molded body, when the operator mounts the fiber reinforced resin molded body on the work mounting portion and presses the switch, first the gear cutting of the fiber reinforced resin molded body is performed by the detection device. After the start position is specified, gear cutting by the cutting blade of the gear cutter is automatically started from the gear cutting start position. Therefore, in this embodiment, when gear cutting is performed on the fiber reinforced resin molded body, the appropriate gear cutting start position of the fiber reinforced resin molded body matches the position at which the cutting blade of the gear cutter starts gear cutting. Thus, it is not necessary for the operator to manually position and fix to the work mounting portion of the gear cutter.

  ○ When gear cutting is performed on the fiber reinforced resin molding, after fixing the fiber reinforced resin molding to the work mounting part, the operator manually operates the tip of the cutting blade of the gear cutting machine. The gear cutting may be started by moving to the gear cutting start position.

The following technical idea (invention) can be understood from the embodiment.
(1) In the invention described in any one of claims 1 to 8, the knitted fabric is knitted with organic fibers.

(A) is a schematic side view of the fiber reinforced resin gear in 1st Embodiment, (b) is a schematic diagram which shows the arrangement | sequence state of the stitch in a tooth part. The schematic top view of a strip-shaped knitting. (A) is a schematic perspective view of a state in which a belt-like knitted fabric is deformed in a spiral shape, and (b) is a schematic perspective view of an annular body. (A) is a model top view of the knitting in 2nd Embodiment, (b) is a model perspective view which shows the state which forms an annular body from a circular knitting. The schematic diagram which shows the relationship of the arrangement direction of the vertical row | line | column 20a of the stitch in each knitted layer laminated | stacked. (A) is a schematic top view of the strip | belt-shaped knitting in another embodiment, (b) is a schematic diagram which shows the relationship between a tooth | gear part and a stitch. (A), (b), (c) is a schematic diagram which shows the relationship between the tooth | gear part and stitches in another embodiment. (A), (b) is a schematic diagram which shows the relationship between the tooth | gear part and stitches in another embodiment. (A) is a schematic perspective view which shows a mode that a ring body is formed from the fiber reinforced base material of a prior art, (b) is a schematic perspective view of another prior art.

Explanation of symbols

  θ ... Angle, H ... Height, T ... Distance, W ... Width, 11 ... Fiber-reinforced resin gear, 15 ... Tooth part, 20 ... Striped knitting, 20a, 30a ... Vertical row of stitches, 20b, 30b ... Kitch Next, 30 ... sheet-like knitting, 31 ... annular knitting.

Claims (8)

At least the tooth portion is a fiber reinforced resin gear formed of a fiber reinforced resin having a fiber reinforced material formed by laminating a plurality of layers in the axial direction of the gear,
The height of each tooth part of the gear or the width of the tooth tip is formed smaller than the distance of one stitch in the course direction of the knitting stitch,
Each tooth portion of the gear has at least one knitted layer in which one or more pairs of intersecting portions of one loop of a stitch constituting the knitted fabric and two fiber bundles intersecting the loop exist. Fiber reinforced resin gear.   2. The fiber-reinforced resin gear according to claim 1, wherein each tooth portion of the gear has at least one knitted layer in which only one pair of intersecting portions exists.   The fiber reinforcement is formed in a band shape as the knitted fabric, and is formed such that a vertical row of stitches extends in the width direction of the strip-shaped knitted fabric and a horizontal row of stitches extends in the longitudinal direction of the strip-shaped knitted fabric. The fiber reinforced resin gear according to claim 1 or 2, wherein the fiber reinforced resin gear is formed in an annular shape by being spirally wound so that a string is used and the vertical rows of stitches are arranged radially.   The fiber reinforcement is formed in a band shape as the knitted fabric, and is formed such that a horizontal row of stitches extends in a width direction of the strip-shaped knitted fabric and a vertical row of stitches extends in a longitudinal direction of the strip-shaped knitted fabric. The fiber reinforced resin gear according to claim 1 or 2, wherein the fiber reinforced resin gear is formed in an annular shape by being spirally wound so that a thing is used and a horizontal row of stitches is radially arranged.   The fiber reinforcement is formed by laminating knitted fabrics cut into outer circular shapes, and the arrangement direction of the vertical rows of stitches in each of the laminated knitted layers is between adjacent teeth of the gear. The fiber reinforced resin gear according to claim 1 or 2, wherein the fiber reinforced resin gears are laminated so as to be shifted by a positive integer multiple of an angle formed.   The fiber reinforced resin gear according to any one of claims 1 to 5, wherein the two fiber bundles are two loops. At least the tooth part is a method for producing a fiber reinforced resin gear formed of a fiber reinforced resin having a fiber reinforced material formed by laminating a plurality of knitted layers in the axial direction of the gear,
A plurality of layers of knitted fabrics are laminated in the axial direction of the gear using a knitted fabric whose height or tooth tip width of the fiber reinforced resin gear to be formed is smaller than the distance of one stitch in the course direction of the stitch. A step of manufacturing a fiber-reinforced resin molded body for gear cutting, and a step of gear-cutting the fiber-reinforced resin molded body with a gear cutter, and performing a gear-cutting process on the fiber-reinforced resin molded body In this case, the fiber reinforced resin molded product is placed on the gear cutting machine so that the gear cutting start position determined by the relationship with the stitch of the knitted fabric closest to the outer peripheral surface of the fiber reinforced resin molded product is instructed by the instruction means. A method for manufacturing a fiber-reinforced resin gear, wherein the gear is fixed to a work mounting portion and gear cutting is started by a cutting blade of a gear cutter from the gear cutting start position. At least the tooth part is a method for producing a fiber reinforced resin gear formed of a fiber reinforced resin having a fiber reinforced material formed by laminating a plurality of knitted layers in the axial direction of the gear,
A plurality of layers of knitted fabrics are laminated in the axial direction of the gear using a knitted fabric whose height or tooth tip width of the fiber reinforced resin gear to be formed is smaller than the distance of one stitch in the course direction of the stitch. A step of manufacturing a fiber-reinforced resin molded body for gear cutting, and a step of gear-cutting the fiber-reinforced resin molded body with a gear cutter, and performing a gear-cutting process on the fiber-reinforced resin molded body In this case, the reflected light of the light irradiated toward the outer peripheral surface of the fiber reinforced resin molded body mounted on the work mounting portion is detected and corresponds to the stitch of the knitted fabric closest to the outer peripheral surface of the fiber reinforced resin molded body. The fiber reinforced resin molded body is fixed to a work mounting portion of the gear cutter, and the fiber reinforced resin molded body is fixed by the detection device in that state. On the outer peripheral surface of After identifying the toothed start position determined in relation to the stitch near knitting method for producing a fiber reinforced resin gear, characterized in that to start the gear cutting by the cutting blade gear cutting machine from the gear cutting starting position.

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