Double flanged pulley and method for manufacturing double flanged pulley

Abstract

To prevent welding burrs from blowing out even when a pulley body and a flange body are joined by ultrasonic welding.SOLUTION: A pulley body 2 includes: a first flange protruding radially outward RO at one end in an axial direction J; and a fitting protrusion 4 protruding in the axial direction J at the other end in the axial direction J. A flange body 3 includes: a second flange protruding radially outward RO; and a fitting concavity 5 fitted to the fitting protrusion 4. A radially inward RI portion of a deep surface 5C of the fitting concavity 5 is an inclined surface S1 that inclines so as to approach the one end in the axial direction J as it goes radially inward RI. The radially inward RI portion of a distal end surface 4A of the fitting protrusion 4 has an inclined surface S2 opposite to the inclined surface S1. An outer circumferential surface 6A of the flange body 3, which faces an inner circumferential surface 2C of the pulley body 2, has an endless protrusion A1 continuous in a circumferential direction. In a region including an annular range between the inclined surfaces S1 and S2, there is a junction E made of molten resin.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a double flanged pulley that meshes with a toothed belt. [Background technology]

[0002] The toothed pulley that meshes with the toothed belt is often a double-flanged pulley that has flanges on both sides in the width direction to prevent the toothed belt from coming off.

[0003] When a toothed pulley with double flanges is integrally molded using a synthetic resin material in an injection mold, the flanges get caught in the mold, making it impossible to remove the molded toothed pulley in the axial direction from the mold. Therefore, to enable removal in the axial direction, toothed pulleys with double flanges are molded using separate injection molds: a pulley body with one flange and a flange body with the other flange (see, for example, Patent Document 1). Ultrasonic welding is used to join the molded pulley body and flange body. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-96500 A Summary of the Invention [Problem to be solved by the invention]

[0005] When joining the pulley body and the flange body by ultrasonic welding, one of the problems is the weld burrs that shoot out from the joint (for example,

[0004] of Patent Document 1). The presence of the weld burrs can cause problems such as making it impossible to assemble parts, or the detached weld burrs becoming trapped between parts and leading to malfunctions. Therefore, the weld burrs must be removed, which increases manufacturing costs.

[0006] An object of the present invention is to provide a double-flanged pulley in which no welding burrs are produced even when a pulley body with one flange and a flange body with the other flange are joined by ultrasonic welding, and a method for manufacturing a double-flanged pulley. [Means for solving the problem]

[0007] A double flanged pulley according to a first aspect of the present invention comprises a pulley body and a flange body joined to the pulley body in a concave-convex fit state. The toothed belt is made of a metal core and a resin part integrated with the metal core. The resin part has teeth formed on its outer circumferential surface, which mesh with the teeth of the toothed belt. The pulley has a first flange at one axial end, which is parallel to the rotation axis, protruding outward in a radial direction, which is perpendicular to the rotation axis, and an annular mating protrusion at the other axial end, which protrudes in the axial direction. The flange body is located at the other axial end of the pulley body, has a second flange protruding outward in the radial direction, and has an annular mating recess recessed in the axial direction that fits with the mating protrusion. The radially inner portion of the annular rear surface of the mating recess is a first inclined surface shaped like a side surface of a truncated cone that slopes radially inward toward the axial end. The radially inner portion of the tip surface of the mating protrusion has a second inclined surface facing the first inclined surface. The outer peripheral surface of the flange body, which faces the inner peripheral surface of the pulley body and is connected to the radially inner end of the first inclined surface, has an endless circumferentially continuous ridge or groove. A cross section of the ridge cut along a plane including the rotation axis and a cross section of the groove cut along a plane including the rotation axis are arc-shaped or trapezoidal. In a region including an annular range between the first inclined surface and the second inclined surface, The pulley body and the flange body were ultrasonically welded together. There are joints made of molten resin.

[0008] In the double-flanged pulley according to the first aspect of the present invention, the outer peripheral surface of the flange body, which connects to the radially inner end of the radially inner first inclined surface of the fitting recess, has a circumferentially continuous endless ridge or groove, and the ridge or groove faces the inner peripheral surface of the pulley body. Because the ridge or groove is located in a path through which molten resin generated when the pulley body and the flange body are ultrasonically welded together mainly flows, migration of the molten resin beyond the ridge or groove can be suppressed. Therefore, no welding burrs are generated when the pulley body and the flange body are joined using an ultrasonic welding machine.

[0009] A double flanged pulley according to a second aspect of the present invention comprises a pulley body and a flange body joined to the pulley body in a concave-convex fit. The toothed belt is made of a metal core and a resin part integrated with the metal core. The resin part has teeth formed on its outer circumferential surface, which mesh with the teeth of the toothed belt. The pulley has a first flange at one axial end, which is parallel to the rotation axis, protruding outward in a radial direction, which is perpendicular to the rotation axis, and a ring-shaped mating protrusion at the other axial end, which protrudes in the axial direction. The flange body is located at the other axial end of the pulley body, has a second flange protruding outward in the radial direction, and has a ring-shaped mating recess recessed in the axial direction that fits with the mating protrusion. The radially outer portion of the annular inner surface of the mating recess is a first inclined surface shaped like a side surface of a truncated cone that slopes radially outward and approaches the axial end as it extends radially outward. The radially outer portion of the tip surface of the mating protrusion has a second inclined surface facing the first inclined surface. The inner peripheral surface of the flange body, which faces the outer peripheral surface of the mating protrusion of the pulley body and is connected to the radially outer end of the first inclined surface, has a circumferentially continuous endless ridge or groove. A cross section of the ridge cut along a plane including the rotation axis and a cross section of the groove cut along a plane including the rotation axis are arc-shaped or trapezoidal. In a region including an annular range between the first inclined surface and the second inclined surface, The pulley body and the flange body were ultrasonically welded together. There are joints made of molten resin.

[0010] In a double-flanged pulley according to a second aspect of the present invention, the inner peripheral surface of the flange body, which connects to the radially outer end of the radially outer first inclined surface of the mating recess, has a circumferentially continuous endless ridge or groove, and the ridge or groove faces the outer peripheral surface of the mating protrusion of the pulley body. Because the ridge or groove is located in a path through which molten resin generated when the pulley body and the flange body are ultrasonically welded together primarily flows, migration of the molten resin beyond the ridge or groove is suppressed. Therefore, no welding burrs are generated when the pulley body and the flange body are joined using an ultrasonic welding machine.

[0011] A double-flanged pulley according to a third aspect of the present invention is the double-flanged pulley according to the first aspect, further comprising a second circumferentially continuous, endless convex rib or second concave groove on the inner peripheral surface of the flange body that faces the outer peripheral surface of the fitting convex portion of the pulley body. The cross section of the second ridge taken along a plane including the rotation axis and the cross section of the second groove taken along a plane including the rotation axis are arc-shaped or trapezoidal.

[0012] In the double-flanged pulley according to the third aspect of the present invention, when the volume of molten resin is large during ultrasonic welding, the second ridge or second groove is present in the path of the molten resin that flows from the tip end surface of the fitting convex portion of the pulley body along the outer peripheral surface. This makes it possible to prevent the molten resin from moving beyond the second ridge or second groove. Therefore, even when the volume of molten resin is large when the pulley body and flange body are joined using an ultrasonic welding machine, no welding burrs are generated.

[0013] A double-flanged pulley according to a fourth aspect of the present invention is the double-flanged pulley according to the second aspect, further comprising a second endless convex rib or second concave groove that is continuous in the circumferential direction and is provided on the outer peripheral surface of the flange body that faces the inner peripheral surface of the pulley body. The cross section of the second ridge taken along a plane including the rotation axis and the cross section of the second groove taken along a plane including the rotation axis are arc-shaped or trapezoidal.

[0014] In the double-flanged pulley according to the fourth aspect of the present invention, when the volume of molten resin is large during ultrasonic welding, the second ridge or second groove is present in the path of the molten resin that flows from the tip end surface of the fitting convex portion of the pulley body along the inner circumferential surface of the pulley body. This prevents the molten resin from moving beyond the second ridge or second groove. Therefore, even when the volume of molten resin is large when the pulley body and flange body are joined using an ultrasonic welding machine, no welding burrs are generated.

[0015] A method for manufacturing a double-flanged pulley according to a fifth aspect of the present invention is a method for manufacturing a double-flanged pulley comprising a pulley body made of synthetic resin and a flange body made of synthetic resin joined to the pulley body in a concave-convex fit state.

[0016] The pulley body is The toothed belt is made of a metal core and a resin part integrated with the metal core. The resin part has teeth formed on its outer circumferential surface, which mesh with the teeth of the toothed belt. The pulley has a first flange at one axial end, which is parallel to the rotation axis, protruding outward in a radial direction, which is perpendicular to the rotation axis, and an annular mating protrusion at the other axial end, which protrudes in the axial direction. The flange body is located at the other axial end of the pulley body, has a second flange protruding outward in the radial direction, and has an annular mating recess recessed in the axial direction that fits into the mating protrusion. The radially inner portion of the annular rear surface of the mating recess is a first inclined surface shaped like a side surface of a truncated cone that slopes radially inward and approaches the axial one end. The mating protrusion of the pulley body has a circular corner that faces the first inclined surface. The outer peripheral surface of the flange body, which connects to the radially inner end of the first inclined surface, has an endless circumferentially continuous ridge or groove. A cross section of the ridge cut along a plane including the rotation axis and a cross section of the groove cut along a plane including the rotation axis are arc-shaped or trapezoidal.

[0017] A method for manufacturing a double flanged pulley according to a fifth aspect of the present invention comprises: The core metal is used as an insert workpiece. Molded by injection molding The pulley body is molded by integrating the core metal and the resin portion. and a step of molding the flange body by injection molding; placing the molded pulley body with the first flange facing downward and the axial direction aligned vertically; placing the molded flange body on the pulley body so that the fitting recess fits into the fitting protrusion of the pulley body; and pressing the flange body downward with a horn of an ultrasonic welding machine, while transmitting ultrasonic vibrations from the horn to the inside of the flange body and the inside of the pulley body, thereby melting mainly the corners of the pulley body, thereby joining the flange body to the pulley body.

[0018] In the method for manufacturing a double-flanged pulley according to the fifth aspect of the present invention, the radially inner portion of the annular rear surface of the fitting recess of the flange body is formed as the first inclined surface shaped like a side surface of a truncated cone, and the fitting protrusion of the pulley body has a circular corner facing the first inclined surface. The outer peripheral surface of the flange body connected to the radially inner end of the first inclined surface has an endless ridge or groove that continues in the circumferential direction, and the ridge or groove faces the inner peripheral surface of the pulley body.

[0019] The molded flange body is placed on the pulley body so that the mating recess fits into the mating protrusion of the pulley body, and while the flange body is pressed downward by the horn of an ultrasonic welding machine, ultrasonic vibrations from the horn are propagated into the interior of the flange body and the interior of the pulley body, melting mainly the corners of the pulley body. As a result, the ridges or grooves are present in the path along which the molten resin mainly flows, preventing the molten resin from moving beyond the ridges or grooves. Therefore, no welding burrs are produced when the pulley body and flange body are joined using an ultrasonic welding machine.

[0020] A method for manufacturing a double-flanged pulley according to a sixth aspect of the present invention is a method for manufacturing a double-flanged pulley comprising a pulley body made of synthetic resin and a flange body made of synthetic resin joined to the pulley body in a concave-convex fit state.

[0021] The pulley body is The toothed belt is made of a metal core and a resin part integrated with the metal core. The resin part has teeth formed on its outer circumferential surface, which mesh with the teeth of the toothed belt.The pulley has a first flange at one axial end, which is parallel to the rotation axis, protruding outward in a radial direction, which is perpendicular to the rotation axis, and an annular mating protrusion at the other axial end, which protrudes in the axial direction. The flange body is located at the other axial end of the pulley body, has a second flange protruding outward in the radial direction, and has an annular mating recess recessed in the axial direction that fits into the mating protrusion. The radially outer portion of the annular inner surface of the mating recess is a first inclined surface shaped like a side surface of a truncated cone that slopes radially outward and approaches the axial one end. The mating protrusion of the pulley body has a circular corner that faces the first inclined surface. The inner peripheral surface of the flange body, which connects to the radially outer end of the first inclined surface, has an endless circumferentially continuous convex rib or concave groove. A cross section of the ridge cut along a plane including the rotation axis and a cross section of the groove cut along a plane including the rotation axis are arc-shaped or trapezoidal.

[0022] A method for manufacturing a double flanged pulley according to a sixth aspect of the present invention comprises: The core metal is used as an insert workpiece. Molded by injection molding The pulley body is molded by integrating the core metal and the resin portion. and a step of molding the flange body by injection molding; placing the molded pulley body with the first flange facing downward and the axial direction aligned vertically; placing the molded flange body on the pulley body so that the fitting recess fits into the fitting protrusion of the pulley body; and pressing the flange body downward with a horn of an ultrasonic welding machine, while transmitting ultrasonic vibrations from the horn to the inside of the flange body and the inside of the pulley body, thereby melting mainly the corners of the pulley body, thereby joining the flange body to the pulley body.

[0023] In a manufacturing method for a double-flanged pulley according to a sixth aspect of the present invention, the radially outer portion of the annular inner surface of the fitting recess of the flange body is formed as the first inclined surface shaped like a side surface of a truncated cone, and the fitting protrusion of the pulley body has a circular corner facing the first inclined surface. The inner peripheral surface of the flange body connected to the radially outer end of the first inclined surface has an endless ridge or groove that continues in the circumferential direction, and the ridge or groove faces the outer peripheral surface of the fitting protrusion of the pulley body.

[0024] The molded flange body is placed on the pulley body so that the mating recess fits into the mating protrusion of the pulley body, and while the flange body is pressed downward by the horn of an ultrasonic welding machine, ultrasonic vibrations from the horn are propagated into the interior of the flange body and the interior of the pulley body, melting mainly the corners of the pulley body. As a result, the ridges or grooves are present in the path along which the molten resin mainly flows, preventing the molten resin from moving beyond the ridges or grooves. Therefore, no welding burrs are produced when the pulley body and flange body are joined using an ultrasonic welding machine. [Effects of the Invention]

[0025] As described above, according to the pulley with double flanges and the method for manufacturing a pulley with double flanges of the present invention, even when a pulley body with one flange and a flange body with the other flange are joined using an ultrasonic welding machine, no welding burrs are produced.

[0026] The cross section of the ridge taken along a plane including the rotation axis and the cross section of the groove taken along a plane including the rotation axis are arc-shaped or trapezoidal. Also, the cross section of the second ridge taken along a plane including the rotation axis and the cross section of the second groove taken along a plane including the rotation axis are arc-shaped or trapezoidal. Therefore, the molded flange body can be forcibly removed from the injection molding die, and the stress applied during forcible removal is reduced. [Brief explanation of the drawings]

[0027] [Figure 1] FIG. 1 is a perspective view of a double-flanged pulley according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a partial cross-sectional perspective view of the double flanged pulley of FIG. 1. [Figure 3] FIG. 2 is a vertical cross-sectional view of the double flanged pulley of FIG. 1. [Figure 4]FIG. 2 is an enlarged longitudinal sectional view of a main portion of the double-flanged pulley of FIG. 1. [Figure 5] FIG. 10 is an enlarged longitudinal sectional view of a main part showing a first modified example. [Figure 6] FIG. 10 is an enlarged longitudinal sectional view of a main part showing a second modified example. [Figure 7] FIG. 11 is an enlarged longitudinal sectional view of a main part showing a third modified example. [Figure 8] FIG. 10 is an enlarged longitudinal sectional view of a main part showing a fourth modified example. [Figure 9] 5 is an explanatory view of a process of joining the flange body to the pulley body by an ultrasonic welding machine in the double flanged pulley according to the first embodiment. FIG. [Figure 10] FIG. 10 is a vertical cross-sectional view of a double-flanged pulley according to a second embodiment of the present invention. [Figure 11] FIG. 11 is an enlarged longitudinal sectional view of a main portion of the double-flanged pulley of FIG. 10. [Figure 12] FIG. 13 is an enlarged longitudinal sectional view of a main part showing a fifth modified example. [Figure 13] 10 is an explanatory view of a process of joining the flange body to the pulley body by an ultrasonic welding machine in the double flanged pulley according to the second embodiment. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0029] In this specification, the direction parallel to the direction of the rotation axis (see symbol O in Figures 3 and 10) of the double-flanged pulley is called the "axial direction" (see arrow J in Figures 3 and 10), the direction perpendicular to the direction of the rotation axis is called the "radial direction" (see arrow R in Figures 3 and 10), and the "circumferential direction" (see arrow C in Figures 1 and 2) is defined relative to the direction of the rotation axis.

[0030] [Embodiment 1] <Double flanged pulley> A double-flanged pulley 1 according to a first embodiment of the present invention, shown in the perspective view of Fig. 1, the partial cross-sectional perspective view of Fig. 2, and the longitudinal cross-sectional view of Fig. 3, is used, for example, in a power transmission mechanism of an electric power steering device. The double-flanged pulley 1 includes a pulley body 2 and a flange body 3 joined to the pulley body 2 in a concave-convex fit state.

[0031] The pulley body 2 is made up of a resin part 2A and a core metal 2B. Helical teeth T are formed on the outer circumferential surface of the pulley body 2, and the teeth T mesh with the teeth of a toothed belt (not shown).

[0032] In the double flanged pulley 1 according to the first embodiment of the present invention, the resin portion 2A including the teeth T of the pulley body 2 and the flange body are made of synthetic resin, so that the double flanged pulley 1 can be made lightweight.

[0033] <Core> The inner peripheral surface I of the core metal 2B is exposed. The inner peripheral surface I is attached to the outer peripheral surface of a nut member of a ball screw in a power transmission mechanism of an electric power steering device (not shown), and is used to radially position the double-flanged pulley 1 relative to the ball screw nut. The core metal 2B is made by pressing a cold-rolled steel plate, a hot-rolled steel plate, a high-tensile steel plate, or the like.

[0034] <Resin part and flange body> The material of the resin portion 2A and the flange body 3 is, for example, a thermoplastic resin material such as PBT, PA6, PA66, PA46, PPS, or PEEK, and among these, a preferred embodiment is one in which PPS, which has excellent heat resistance, mechanical properties, flame retardancy, and dimensional stability, is blended with several tens of weight percent of glass fiber as a reinforcing material.

[0035] The pulley body 2 has a first flange F1 at one end J1 in the axial direction J that protrudes radially outward RO, and at the other end J2 in the axial direction J that has a circular engaging protrusion 4 that protrudes radially inward RI from the tooth surface of the tooth T with which the toothed belt engages.

[0036] The flange body 3 is located at the other end J2 of the pulley body 2 in the axial direction J, and has a second flange F2 protruding radially outward RO. The flange body 3 also has an annular mating recess 5 recessed in the axial direction J that fits into the mating protrusion 4, and an inward extending portion 6 that is connected to an outer peripheral surface 5A (Figure 4), which is the peripheral wall surface on the radially inner side RI of the mating recess 5, and extends in the axial direction J along the radial inner peripheral surface 2C of the pulley body 2.

[0037] As shown in the enlarged longitudinal cross-sectional view of a main portion in Figure 4, the radially inward RI portion of the annular rear surface 5C of the fitting recess 5 of the flange body 3 is formed as a first inclined surface S1 in the shape of a side surface of a truncated cone, which inclines toward one end J1 (Figure 3) in the axial direction J as it moves toward the radially inward RI. The radially inward RI portion of the tip end surface 4A of the fitting protrusion 4 of the pulley body 2 has a second inclined surface S2 facing the first inclined surface S1.

[0038] The radial outer surface 6A of the inward extending portion 6 of the flange body 3, i.e., the outer surface of the flange body 3 that connects to the radially inner RI end K1 of the first inclined surface S1 facing the inner circumferential surface 2C of the pulley body 2, has an endless convex rib A1 that continues in the circumferential direction C (Figures 1 and 2).

[0039] The double-flanged pulley 1 has a solidified portion D of molten resin formed by ultrasonic welding, which will be described later, and extends over the range shown in Figure 4, for example, and a joint E made of molten resin is located in the area including the annular range between the first inclined surface S1 and the second inclined surface S2.

[0040] <Modification> As shown in the enlarged longitudinal cross-sectional view of the essential part in FIG. 5, the radial outer peripheral surface 6A of the inward extending portion 6 of the flange body 3 may be provided with an endless recessed groove B1 that continues in the circumferential direction C, instead of a protruding ridge A1.

[0041] As shown in the enlarged longitudinal cross-sectional view of a main part in Fig. 6, in addition to the ridge A1 in Fig. 4, an endless second ridge A2 continuing in the circumferential direction C may be provided on the inner peripheral surface 5B, which is the peripheral wall surface on the radially outer side RO of the fitting recess 5. Also, as shown in the enlarged longitudinal cross-sectional view of a main part in Fig. 7, in addition to the groove B1 in Fig. 5, an endless second groove B2 continuing in the circumferential direction C may be provided on the inner peripheral surface 5B.

[0042] As shown in the enlarged longitudinal cross-sectional view of the essential part in Figure 8, when the flange body 3 does not have an inward extending portion 6, a convex rib A1 may be provided on the outer peripheral surface 5A, i.e., the outer peripheral surface of the flange body 3 that connects to the end K1 on the radially inner side RI of the first inclined surface S1 facing the inner peripheral surface 2C of the pulley body 2, or a concave groove B1 may be provided on the outer peripheral surface 5A.

[0043] A convex rib A1 may be provided on the outer peripheral surface 6A or the outer peripheral surface 5A, and a second concave groove B2 may be provided on the inner peripheral surface 5B, or a concave groove B1 may be provided on the outer peripheral surface 6A or the outer peripheral surface 5A, and a second convex rib A2 may be provided on the inner peripheral surface 5B.

[0044] By providing the ridges A1 or grooves B1, the ridges A1 or grooves B1 are present in the path along which the molten resin generated when ultrasonically welding the pulley body 2 and the flange body 3 mainly flows, thereby preventing the molten resin from moving beyond the ridges A1 or grooves B1. Therefore, even when the pulley body 2 and the flange body 3 are joined using an ultrasonic welding machine, no welding burrs are generated.

[0045] By providing the second convex ridge A2 or the second concave groove B2, when the volume of molten resin is large during ultrasonic welding, the second convex ridge A2 or the second concave groove B2 is present in the path of the molten resin that flows from the tip surface 4A of the fitting convex portion 4 along the outer peripheral surface 4D, making it possible to prevent the molten resin from moving beyond the second convex ridge A2 or the second concave groove B2. Therefore, even when the volume of molten resin is large when joining the pulley body 2 and the flange body 3 using an ultrasonic welding machine, no welding burrs are generated.

[0046] <Size and shape of the convex stripe and second convex stripe, and the concave groove and second concave groove> The height of the ridges A1 and A2 and the depth of the grooves B1 and B2 may also serve as undercuts during injection molding. In this case, the heights of the ridges A1 and A2 and the depths of the grooves B1 and B2 are adjusted to prevent deformation, cracking, or tearing when removed from the injection molding die, depending on the specifications of the resin material used. The heights of the ridges A1 and A2 and the depths of the grooves B1 and B2 are, for example, 0.05 mm to 0.2 mm. The widths (lengths in the axial direction J) of the ridges A1 and A2 and the grooves B1 and B2 are, for example, 0.5 mm to 3.0 mm.

[0047] The shapes of the ridge A1 and second ridge A2 and the groove B1 and second groove B2 provided on the flange body 3 are smooth so as to reduce stress when the flange body 3 is forcibly removed from the injection molding die. For example, as in this embodiment, it is preferable that the cross section cut on a plane including the rotation axis O has an arc shape. Alternatively, the cross section may be trapezoidal.

[0048] <Manufacturing method for double flanged pulley> The double flanged pulley 1 in the first embodiment is manufactured as follows: An example of manufacturing the double flanged pulley 1 shown in Figs.

[0049] (1) A process for forming the pulley body 2 The pulley body 2 before the flange body 3 is joined has a different shape of the fitting convex portion 4 from the pulley body 2 in Figures 1 to 4. That is, as shown in the upper cross-sectional view of Figure 9, the end portion on the radially inner side RI of the tip end surface 4A of the fitting convex portion 4 has a circular corner portion 4B.

[0050] An injection mold for molding the pulley body 2 having the shape of the pulley body 2 before joining the flange body 3 is opened, the metal core 2B is set as an insert work, and the mold is closed and clamped, and molten synthetic resin material is injected into the mold. After the material is cooled and solidified, the mold is opened and ejected with an ejector pin, thereby forming the pulley body 2 in which the resin portion 2A and the metal core 2B are integrated, which has the shape of the fitting protrusion 4 in the upper cross-sectional view of Figure 9.

[0051] (2) Step of forming flange body 3 A molten synthetic resin material is injected into an injection molding die that is used to form the flange body 3 having the shape shown in Figures 1 to 3 while the die is closed and clamped. After the material has cooled and solidified, the die is opened and ejected with an ejector pin, thereby forming the flange body 3 having the shape shown in Figures 1 to 3.

[0052] (3) Step of joining the pulley body 2 and the flange body 3 The process of joining the flange body 3 to the pulley body 2 by the ultrasonic welding machine G will be described with reference to the explanatory diagram of FIG.

[0053] The molded pulley body 2 in the shape before the flange body 3 is joined is placed with the first flange F1 facing downward, the fitting protrusion 4 facing upward, and the axial direction J aligned vertically.

[0054] Next, the molded flange body 3 is placed on the pulley body 2 so that the mating recess 5 is fitted into the mating protrusion 4 of the pulley body 2. The circular corner 4B of the mating protrusion 4 of the pulley body 2 comes into contact with the first inclined surface S1, which is a side surface of a truncated cone, of the mating recess 5 of the flange body 3.

[0055] Next, the horn H of the ultrasonic welding machine G presses the flange body 3 downward as indicated by the arrow P, while transmitting ultrasonic vibrations from the horn H to the inside of the flange body 3 and the inside of the pulley body 2 to generate frictional heat, which mainly melts the circular corner 4B of the pulley body 2 (Figure 9 (a) to (b)).

[0056] Because the corners 4B of the radially inner RI of the pulley body 2 mainly melt, the molten resin tends to flow downward from the end K1 of the radially inner RI of the side-shaped first inclined surface S1 of a truncated cone, as shown in Figure 9(b).The outer peripheral surface of the flange body 3 (the outer peripheral surface 6A of the inward extending portion 6) connected to the end K1 of the radially inner RI of the first inclined surface S1 has an endless ridge A1 that continues in the circumferential direction C, which prevents the molten resin from flowing downward beyond the ridge A1.

[0057] In addition, if there is a groove B1 as shown in Figure 5 instead of a protrusion A1, the molten resin will enter the groove B1, and the endless groove B1 that continues in the circumferential direction C will become a resin reservoir, making it difficult for the molten resin to flow downward beyond the groove B1.

[0058] When the ultrasonic vibration of the horn H is stopped, the temperature of the molten resin drops and it solidifies. As a result, as shown in Figure 9(b), a second inclined surface S2 facing the first inclined surface S1 is formed in the radially inward portion RI of the tip surface 4A of the fitting convex portion 4, and a solidified portion D of the molten resin is formed. The area including the annular range between the first inclined surface S1 and the second inclined surface S2 is joined, and a joint E made of the molten resin is present.

[0059] In the double-flanged pulley 1 manufactured by this method for manufacturing the double-flanged pulley 1, the ridges A1 or grooves B1 are present in the path along which the molten resin mainly flows when the flange body 3 is joined to the pulley body 2 by the ultrasonic welding machine G, so it is possible to prevent the molten resin from moving beyond the ridges A1 or grooves B1. Therefore, even when the pulley body 2 and the flange body 3 are joined using the ultrasonic welding machine G, no welding burrs are generated.

[0060] [Embodiment 2] The double-flanged pulley 1 according to the second embodiment of the present invention, shown in the longitudinal cross-sectional view of Figure 10 and the enlarged longitudinal cross-sectional view of a main part of Figure 11, differs from the double-flanged pulley 1 according to the first embodiment, shown in the longitudinal cross-sectional view of Figure 3 and the enlarged longitudinal cross-sectional view of a main part of Figure 4, in that the first inclined surface S1 and the second inclined surface S2 are different, and the position of the ridge A1 is different.

[0061] In the second embodiment, the radially outward RO portion of the annular inner surface 5C of the fitting recess 5 of the flange body 3 is formed as a first inclined surface S1 shaped like a side surface of a truncated cone, which inclines toward one end J1 in the axial direction J as it moves toward the radially outward RO. The radially outward RO portion of the tip end surface 4A of the fitting protrusion 4 of the pulley body 2 has a second inclined surface S2 facing the first inclined surface S1. Furthermore, the inner peripheral surface 5B of the flange body 3, which faces the outer peripheral surface 4D of the fitting protrusion 4 of the pulley body 2 and is connected to the radially outward RO end K2 of the first inclined surface S1, has an endless ridge A1 that continues in the circumferential direction C.

[0062] The double-flanged pulley 1 has a solidified portion D of molten resin formed by ultrasonic welding, which will be described later, and extends over the range shown in Figure 11, for example, and a joint E made of molten resin is present in the area including the annular range between the first inclined surface S1 and the second inclined surface S2.

[0063] <Modification> As shown in the enlarged longitudinal cross-sectional view of a main part in FIG. 12, the inner peripheral surface 5B of the flange body 3 may be provided with an endless recessed groove B1 that continues in the circumferential direction C, instead of the ridge A1.

[0064] In the second embodiment, similarly to the first embodiment, a second ridge A2 or a second groove B2 may be provided in addition to the ridge A1 in Fig. 11 or the groove B1 in Fig. 12. That is, an endless second ridge A2 or groove B2 continuing in the circumferential direction C may be provided on the outer peripheral surface 6A, 5A of the flange body 3 facing the inner peripheral surface 2C of the pulley body 2.

[0065] By providing the ridges A1 or grooves B1, the ridges A1 or grooves B1 are present in the path along which the molten resin generated when ultrasonically welding the pulley body 2 and the flange body 3 mainly flows, thereby preventing the molten resin from moving beyond the ridges A1 or grooves B1. Therefore, even when the pulley body 2 and the flange body 3 are joined using an ultrasonic welding machine, no welding burrs are generated.

[0066] By providing the second convex ridge A2 or the second concave groove B2, when the volume of molten resin is large during ultrasonic welding, the second convex ridge A2 or the second concave groove B2 is present in the path of the molten resin that flows from the tip surface 4A of the fitting convex portion 4 along the inner peripheral surface 2C, making it possible to prevent the molten resin from moving beyond the second convex ridge A2 or the second concave groove B2. Therefore, even when the volume of molten resin is large when joining the pulley body 2 and the flange body 3 using an ultrasonic welding machine, no welding burrs are generated.

[0067] <Manufacturing method for double flanged pulley> The double flanged pulley 1 in the second embodiment is manufactured as follows: An example of manufacturing the double flanged pulley 1 shown in FIG. 11 will be described.

[0068] (1) A process for forming the pulley body 2 The pulley body 2 before the flange body 3 is joined has a different shape of the fitting convex portion 4 from the pulley body 2 in Fig. 11. That is, as shown in the upper cross-sectional view of Fig. 13, the end of the tip surface 4A of the fitting convex portion 4 on the radially outer side RO has a circular corner 4C.

[0069] An injection mold for molding the pulley body 2 having the shape of the pulley body 2 before joining the flange body 3 is opened, the metal core 2B is set as an insert work, and the mold is closed and clamped, and molten synthetic resin material is injected into the mold. After the material is cooled and solidified, the mold is opened and ejected with an ejector pin, thereby molding the pulley body 2 in which the resin portion 2A and the metal core 2B are integrated, which has the shape of the fitting protrusion 4 in the upper cross-sectional view of Figure 13.

[0070] (2) Step of forming flange body 3 A molten synthetic resin material is injected into an injection molding die that is closed and clamped to form the flange body 3 having the shape shown in Fig. 10. After the material has cooled and solidified, the die is opened and ejected with an ejector pin to form the flange body 3 having the shape shown in Fig. 10.

[0071] (3) Step of joining the pulley body 2 and the flange body 3 The process of joining the flange body 3 to the pulley body 2 by the ultrasonic welding machine G will be described with reference to the explanatory diagram of FIG.

[0072] The molded pulley body 2 in the shape before the flange body 3 is joined is placed with the first flange F1 facing downward, the fitting protrusion 4 facing upward, and the axial direction J aligned vertically.

[0073] Next, the molded flange body 3 is placed on the pulley body 2 so that the mating recess 5 is fitted into the mating protrusion 4 of the pulley body 2. The circular corner 4C of the mating protrusion 4 of the pulley body 2 comes into contact with the first inclined surface S1, which is a side surface of a truncated cone, of the mating recess 5 of the flange body 3.

[0074] Next, the horn H of the ultrasonic welding machine G presses the flange body 3 downward as indicated by the arrow Q, while transmitting ultrasonic vibrations from the horn H to the inside of the flange body 3 and the inside of the pulley body 2 to generate frictional heat, which mainly melts the circular corner 4C of the pulley body 2 (Figure 13 (a) to (b)).

[0075] Because the corners 4C of the radially outer RO of the pulley body 2 mainly melt, the molten resin tends to flow downward from the end K2 of the radially outer RO of the first inclined surface S1 shaped like a side surface of a truncated cone, as shown in Figure 13(b).The inner peripheral surface 5B of the flange body 3, which is connected to the end K2 of the radially outer RO of the first inclined surface S1, has an endless ridge A1 that continues in the circumferential direction C, which prevents the molten resin from flowing downward beyond the ridge A1.

[0076] In addition, if there is a groove B1 as shown in Figure 12 instead of a protrusion A1, the molten resin will enter the groove B1, and the endless groove B1 that continues in the circumferential direction C will become a resin reservoir, making it difficult for the molten resin to flow downward beyond the groove B1.

[0077] When the ultrasonic vibration of the horn H is stopped, the temperature of the molten resin drops and it solidifies. As a result, as shown in Figure 13(b), a second inclined surface S2 facing the first inclined surface S1 is formed in the radially outward RO portion of the tip surface 4A of the fitting convex portion 4, and a solidified portion D of the molten resin is formed. The area including the annular range between the first inclined surface S1 and the second inclined surface S2 is joined, and a joint E made of the molten resin is present.

[0078] In the double-flanged pulley 1 manufactured by this method for manufacturing the double-flanged pulley 1, the ridges A1 or grooves B1 are present in the path along which the molten resin mainly flows when the flange body 3 is joined to the pulley body 2 by the ultrasonic welding machine G, so it is possible to prevent the molten resin from moving beyond the ridges A1 or grooves B1. Therefore, even when the pulley body 2 and the flange body 3 are joined using the ultrasonic welding machine G, no welding burrs are generated.

[0079] In the above description, in the first embodiment, an example has been shown in which the first inclined surface S1 is located on the radially inner side RI of the annular rear surface 5C of the fitting recess 5, and in the second embodiment, an example has been shown in which the first inclined surface S1 is located on the radially outer side RO of the annular rear surface 5C of the fitting recess 5. The first inclined surface S1 may be located on both the radially inner side RI and the radially outer side RO of the annular rear surface 5C of the fitting recess 5. In this case, in the double-flanged pulley 1, the second inclined surface S2 on the tip end surface 4A of the fitting protrusion 4 is also located on both the radially inner side RI and the radially outer side RO so as to face the first inclined surface S1 located on both the radially inner side RI and the radially outer side RO.

[0080] The above description of the embodiments is given by way of example only and is not intended to be limiting, and various improvements and modifications can be made without departing from the scope of the present invention. [Explanation of symbols]

[0081] 1. Pulley with double flanges 2. Pulley body 2A Resin part 2B Core metal 2C Inner surface 3 Flange body 4. Fitting protrusion 4A. Tip surface 4B,4C Corner 4D Outer surface 5 Fitting recess 5A Outer periphery 5B Inner surface 5C Annular back surface 6 Inward extension 6A Outer surface A1 Convex B1 Concave groove A2 2nd convex line B2 2nd concave groove C Circumferential direction D Solidified part of molten resin E Joint made of molten resin F1 First flange F2 Second flange G Ultrasonic welding machine H Horn I Inner surface J Axis direction J1 One end J2 Other end K1 Radial inner end K2 Radial outer end O Rotation axis R Radial direction RI Radial direction inward RO Radial outward S1 1st inclined surface S2 2nd inclined surface T tooth

Claims

1. A pulley body, a flange body joined to the pulley body in a concave-convex fit state; Equipped with The pulley body is The core metal and the resin part integrated with the core metal are included. The resin portion is The outer surface is formed with teeth that mesh with the teeth of the toothed belt. a first flange at one end in an axial direction parallel to a rotation axis, the first flange protruding radially outward in a direction perpendicular to the rotation axis; a ring-shaped fitting protrusion protruding in the axial direction at the other end in the axial direction, The flange body is Located at the other end of the pulley body in the axial direction, a second flange protruding outward in the radial direction; a ring-shaped fitting recess recessed in the axial direction and fitted to the fitting protrusion, a first inclined surface having a side surface shape of a truncated cone, the first inclined surface being inclined toward one end in the axial direction as it extends radially inward, a radially inner portion of the tip end surface of the fitting protrusion has a second inclined surface facing the first inclined surface, an outer peripheral surface of the flange body, which faces the inner peripheral surface of the pulley body and is connected to an inner end of the first inclined surface in the radial direction, has an endless convex strip or concave groove that is continuous in the circumferential direction, a cross section of the ridge taken along a plane including the rotation axis and a cross section of the groove taken along a plane including the rotation axis are arc-shaped or trapezoidal-shaped, a joining portion formed by molten resin when the pulley body and the flange body are ultrasonically welded together is present in a region including an annular range between the first inclined surface and the second inclined surface; Double flanged pulley.

2. A pulley body, a flange body joined to the pulley body in a concave-convex fit state; Equipped with The pulley body is The core metal and the resin part integrated with the core metal are included. The resin portion is The outer surface is formed with teeth that mesh with the teeth of the toothed belt. a first flange at one end in an axial direction parallel to a rotation axis, the first flange protruding radially outward in a direction perpendicular to the rotation axis; a ring-shaped fitting protrusion protruding in the axial direction at the other end in the axial direction, The flange body is Located at the other end of the pulley body in the axial direction, a second flange protruding outward in the radial direction; a ring-shaped fitting recess recessed in the axial direction and fitted to the fitting protrusion, a first inclined surface having a side surface shape of a truncated cone, the first inclined surface being inclined toward one end in the axial direction as it goes radially outward, a radially outer portion of the tip surface of the fitting protrusion has a second inclined surface facing the first inclined surface, an inner peripheral surface of the flange body, which is connected to an outer end of the first inclined surface in the radial direction and faces an outer peripheral surface of the fitting convex portion of the pulley body, has an endless convex strip or concave groove that is continuous in the circumferential direction; a cross section of the ridge taken along a plane including the rotation axis and a cross section of the groove taken along a plane including the rotation axis are arc-shaped or trapezoidal-shaped, a joining portion formed by molten resin when the pulley body and the flange body are ultrasonically welded together is present in a region including an annular range between the first inclined surface and the second inclined surface; Double flanged pulley.

3. an endless second convex strip or second concave groove is provided on an inner peripheral surface of the flange body facing an outer peripheral surface of the fitting convex portion of the pulley body, the second convex strip or second concave groove being continuous in a circumferential direction; a cross section of the second convex ridge cut along a plane including the rotation axis and a cross section of the second concave groove cut along a plane including the rotation axis each have an arc shape or a trapezoid shape; 2. The double flanged pulley according to claim 1.

4. an endless second convex strip or second concave groove is provided on an outer peripheral surface of the flange body facing the inner peripheral surface of the pulley body, the endless second convex strip or second concave groove being continuous in a circumferential direction; a cross section of the second convex ridge cut along a plane including the rotation axis and a cross section of the second concave groove cut along a plane including the rotation axis each have an arc shape or a trapezoid shape; 3. The double flanged pulley according to claim 2.

5. A method for manufacturing a double-flanged pulley comprising a pulley body made of synthetic resin and a flange body made of synthetic resin joined to the pulley body in a concave-convex fit state, comprising: The pulley body is The core metal and the resin part integrated with the core metal are included. The resin portion is The outer surface is formed with teeth that mesh with the teeth of the toothed belt. a first flange at one end in an axial direction parallel to a rotation axis, the first flange protruding radially outward in a direction perpendicular to the rotation axis; a ring-shaped fitting protrusion protruding in the axial direction at the other end in the axial direction, The flange body is Located at the other end of the pulley body in the axial direction, a second flange protruding outward in the radial direction; a ring-shaped fitting recess recessed in the axial direction and fitted to the fitting protrusion, a first inclined surface having a side surface shape of a truncated cone, the first inclined surface being inclined toward one end in the axial direction as it extends radially inward, the fitting protrusion of the pulley body has a circular corner portion facing the first inclined surface, an outer peripheral surface of the flange body connected to an inner end of the first inclined surface in the radial direction has an endless ridge or groove that is continuous in the circumferential direction, a cross section of the ridge taken along a plane including the rotation axis and a cross section of the groove taken along a plane including the rotation axis are arc-shaped or trapezoidal-shaped, a step of molding the resin portion by injection molding using the core metal as an insert work to form the pulley body in which the core metal and the resin portion are integrated; a step of molding the flange body by injection molding; a step of placing the molded pulley body with the first flange facing downward and the axial direction aligned vertically; placing the molded flange body on the pulley body so that the fitting recess fits into the fitting protrusion of the pulley body; a step of joining the flange body to the pulley body by propagating ultrasonic vibrations from a horn of an ultrasonic welding machine into the interior of the flange body and the interior of the pulley body while pressing the flange body downward with the horn of the ultrasonic welding machine, thereby melting mainly the corner portions of the pulley body; Including, A manufacturing method for a double flanged pulley.

6. A method for manufacturing a double-flanged pulley comprising a pulley body made of synthetic resin and a flange body made of synthetic resin joined to the pulley body in a concave-convex fit state, comprising: The pulley body is The core metal and the resin part integrated with the core metal are included. The resin portion is The outer surface is formed with teeth that mesh with the teeth of the toothed belt. a first flange at one end in an axial direction parallel to a rotation axis, the first flange protruding radially outward in a direction perpendicular to the rotation axis; a ring-shaped fitting protrusion protruding in the axial direction at the other end in the axial direction, The flange body is Located at the other end of the pulley body in the axial direction, a second flange protruding outward in the radial direction; a ring-shaped fitting recess recessed in the axial direction and fitted to the fitting protrusion, a first inclined surface having a side surface shape of a truncated cone, the first inclined surface being inclined toward one end in the axial direction as it goes radially outward, the fitting protrusion of the pulley body has a circular corner portion facing the first inclined surface, an inner circumferential surface of the flange body connected to an outer end of the first inclined surface in the radial direction has an endless convex strip or concave groove that is continuous in the circumferential direction, a cross section of the ridge taken along a plane including the rotation axis and a cross section of the groove taken along a plane including the rotation axis are arc-shaped or trapezoidal-shaped, a step of molding the resin portion by injection molding using the core metal as an insert work to form the pulley body in which the core metal and the resin portion are integrated; a step of molding the flange body by injection molding; a step of placing the molded pulley body with the first flange facing downward and the axial direction aligned vertically; placing the molded flange body on the pulley body so that the fitting recess fits into the fitting protrusion of the pulley body; a step of joining the flange body to the pulley body by propagating ultrasonic vibrations from a horn of an ultrasonic welding machine into the interior of the flange body and the interior of the pulley body while pressing the flange body downward with the horn of the ultrasonic welding machine, thereby melting mainly the corner portions of the pulley body; Including, A manufacturing method for a double flanged pulley.

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