JP2011045915A - Die for roll forming, method of manufacturing tubular metal fitting using it and method of manufacturing vibration proof rubber bush using tubular metal fitting - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die for roll forming with which projections having new pattern are formed on an end face in the axial direction of a tubular metal fitting, a method of manufacturing the tubular metal fittings using it and a method of manufacturing vibration proof rubber bushes using the tubular metal fittings. <P>SOLUTION: This die includes a taper-shaped outer peripheral surface 30 which is pressed against the end face in the axial direction of a tubular metal fitting 14 and a serration working part where a plurality of inclined direction forming grooves 32 are provided on the taper-shaped outer peripheral surface 30. A starting pressing part 40 having a larger diameter than that of the serration working part is provided on the side of a large diameter in the axial direction of the serration working part and a peripheral direction forming groove 44, which is opened on the outer peripheral surface and extended in the peripheral direction is formed between the serration working part and the starting pressing part 40 in the end part on the side of the large diameter of the serration working part. The inclined direction forming groove 32 is connected to the peripheral direction forming groove 44 and also an outer peripheral pressing surface 42 which is pressed against an outer peripheral corner part from the outer peripheral side of the end face in the axial direction of the tubular metal fitting 14 by the end face in the axial direction of the starting pressing part 40 is formed. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a rolling mold used for rolling a non-slip projection on an axial end face of a cylindrical metal fitting, a method for manufacturing a cylindrical metal fitting using the same, and a manufacturing method based on the method of the present invention. The present invention relates to a method for manufacturing an anti-vibration rubber bush using the formed cylindrical fitting.

  Conventionally, cylindrical fittings have been widely used not only as a single structural member, but also as parts such as an inner cylindrical fitting of an anti-vibration bush.

  By the way, in this cylindrical metal fitting, a plurality of non-slip protrusions extending in the radial direction are radially provided in the circumferential direction as a whole for the purpose of positioning and prevention of rotation of the attachment surface to other members with respect to the axial end face. There is something formed. For example, as described in JP-A-5-237582 (Patent Document 1) and JP-A-2004-230740 (Patent Document 2).

  However, when the non-slip protrusion is formed on the axial end surface of the cylindrical metal fitting, the inner cylindrical metal fitting is located between the adjacent anti-skid projections even when the axial end face of the cylindrical metal fitting is pressed against the mounting surface of another member. A gap is likely to occur between opposing surfaces of the axial end surface and one of the members that are vibration-proof connected. For this reason, there is a possibility that rainwater or the like enters the inner peripheral surface of the inner cylinder fitting through the gap and causes problems such as rusting and corrosion.

JP-A-5-237582 JP 2004-230740 A

  The problem to be solved by the present invention is to provide a projection with a novel pattern that can prevent the intrusion of rainwater and the like through the gap caused by the non-slip projection without impairing the rotation prevention function by the non-slip projection. An object of the present invention is to provide a novel rolling mold that can be formed in the following manner.

  In addition, the present invention provides a new method for manufacturing a cylindrical metal fitting using the rolling mold having the structure according to the present invention, and a new vibration isolating bush using the cylindrical metal fitting manufactured according to the method of the present invention. It is also an object to provide a manufacturing method.

  A first aspect of the present invention is a rolling mold for manufacturing a cylindrical metal fitting having a non-slip projection formed on an axial end face, and a molding surface pressed against the axial end face of the cylindrical metal fitting. The molding surface is provided with a serration processing portion in which a plurality of inclined molding grooves extending in the taper tilt direction are formed in the circumferential direction, while the serration processing portion has a large axial direction. On the diameter side, a rising presser portion having a diameter larger than that of the serration processing portion is provided, and an opening is formed in the outer peripheral surface between the rising presser portion at the large diameter side end portion of the serration processing portion. A circumferential molding groove extending in the direction is formed, and the large-diameter side end portions of the plurality of inclined molding grooves are connected to the circumferential molding groove, respectively, and the serration processing in the rising presser portion By the axial end face Wherein the outer peripheral pressing surface which is pressed against the outer peripheral side of the outer peripheral corner portion of the shaft direction end surface of the cylindrical metal fitting is formed.

  By using the rolling mold described in the first aspect, plastic processing (rolling) is performed on the axial end surface of the cylindrical metal fitting, so that the axial end surface of the cylindrical metal fitting is prevented from slipping by the serration processing portion. A protrusion is formed, and an annular water stop protrusion that continuously extends in the circumferential direction is simultaneously formed on the outer peripheral side of the protrusion. By forming the annular water stop protrusion on the outer peripheral side of the anti-slip protrusion, a gap is generated between the adjacent anti-slip protrusions in a state where the axial end surface of the cylindrical fitting is pressed against the mounting surface of the other member. The opening to the outer peripheral side is closed. Therefore, the entry of rainwater or the like into the gap is prevented, and problems such as corrosion of the cylindrical fitting caused by the entry of rainwater or the like are avoided.

  In the process of completing the present invention, at the stage of trying to form an annular water stop protrusion by rolling on the outer peripheral edge of the cylindrical metal fitting, burrs are likely to occur on the outer peripheral side due to the pressure during rolling. At the same time, there is a big problem that the protrusion height of the annular water blocking protrusion is unstable and it is difficult to obtain sufficient dimensional accuracy. The present invention has been completed by finding a solution to such a problem.

  In other words, the rolling mold according to the present invention is provided with an outer peripheral pressing surface, and this outer peripheral pressing surface is pressed against the outer peripheral corner of the axial end of the cylindrical metal fitting during the rolling process. Yes. The outer periphery pressing surface prevents the end of the cylindrical fitting from being deformed to the outer peripheral side, thereby preventing the burr from projecting to the outer peripheral side, and that portion of the meat enters the circumferential molding groove to form an annular shape. An outer peripheral portion of the water stop protrusion is formed. In addition, in the rolling mold according to the present invention, each inclined molding groove is connected to the circumferential molding groove, and the non-slip projection and the annular water blocking projection are integrally plastic on the axial end surface of the cylindrical metal fitting. It is formed by processing. As a result, the protrusion height at the outer peripheral portion and the inner peripheral portion of the annular water stop protrusion is sufficiently secured, and the annular water stop protrusion having a shape corresponding to the circumferentially formed groove is formed with high accuracy over the entire circumference. Therefore, the desired water stop effect by the annular water stop protrusion can be obtained effectively.

  According to a second aspect of the present invention, in the rolling mold described in the first aspect, the first rolling mold having the serration portion on an outer peripheral surface and the rising presser portion are provided. The second rolling mold is separated from each other, and the first rolling mold and the second rolling mold are supported on the same central axis integrally or independently. It is what.

  According to the 2nd aspect, by setting it as the structure which combined two shaping | molding dies, manufacture of the rolling shaping | molding die provided with the serration process part and the raising presser part becomes easy. In addition, the first and second rolling molds are supported on the same central axis, and the rolling process can be performed without problems by rotating the rolling molds around the central axis.

  According to a third aspect of the present invention, in the rolling mold described in the second aspect, the first rolling mold and the second rolling mold are different from each other. is there.

  According to the third aspect, the first rolling mold and the second rolling mold having different required characteristics are made of materials suitable for realizing the required characteristics, and the durability is improved. It is possible to advantageously realize reduction of frictional resistance and cost reduction.

  According to a fourth aspect of the present invention, in the rolling mold described in any one of the first to third aspects, at least one of the first rolling mold and the second rolling mold. On the other hand, the molding surface is coated.

  According to the fourth aspect, by reducing the friction coefficient on the molding surface or increasing the hardness, it is possible to suppress deformation due to wear or hitting of the molding surface, and to perform high-precision processing of the cylindrical metal fitting and rolling molding. Improved mold durability is advantageously realized.

  According to a fifth aspect of the present invention, in the rolling mold described in any one of the first to fourth aspects, wall inner surfaces on both sides in the width direction in the circumferential molding groove are molding surfaces. An inclined surface is formed in a direction that gradually widens on both sides in the width direction toward the end surface in the axial direction of the cylindrical metal fitting.

  According to the fifth aspect, the meat of the portion pressed against the rolling mold on the axial end face of the cylindrical metal fitting can easily enter the circumferential molding groove side from the outside in the width direction across the circumferential molding groove. An annular water stop protrusion is formed more efficiently. Furthermore, since the cross-sectional shape of the annular water blocking protrusion becomes narrower toward the distal end side, the annular water blocking protrusion can be formed with higher accuracy up to the distal end.

  According to a sixth aspect of the present invention, in the rolling mold described in the fifth aspect, the serrated portion is provided at an opening edge of the inner surface of the wall on the serrated portion side in the circumferential direction forming groove. A rounded chamfered curved surface is formed with respect to a connecting corner portion with the tapered outer peripheral surface.

  According to the sixth aspect, the target annular water stop projection is obtained by effectively guiding the wall of the cylindrical metal fitting in the circumferential molding groove from the region outside the circumferential molding groove on the end surface of the cylindrical metal fitting. Can be formed with high accuracy and efficiency.

  According to a seventh aspect of the present invention, in the rolling mold described in any one of the first to sixth aspects, a bottom surface of the circumferential molding groove is a flat surface.

  According to the seventh aspect, the annular water stop protrusion can be formed with a more accurate protrusion height, and the strength of the tip of the annular water stop protrusion can be improved. In particular, in this embodiment, the bottom surface of the circumferentially shaped groove is preferably smoothly continuous with the bottom surface of the inclined direction shaped groove, and more preferably a flat surface that is flush with the same plane. In such a preferable configuration, the front end surface of the non-slip projection and the front end surface of the annular water stop projection are made flat on the same plane, so that both the anti-slip effect and the water stop effect can be achieved more effectively. Is done. In addition, both the anti-slip protrusion and the annular water-stop protrusion have a flat surface with a predetermined width at the tip, so that the strength is improved and the occurrence of problems such as damage due to contact with other members is further effectively prevented.

  An eighth aspect of the present invention is a method for manufacturing a cylindrical metal fitting, wherein the serration processing in the rolling mold is performed using the rolling mold described in any one of the first to seventh aspects. While pressing the molding surface of the rolling mold against the axial end surface of the cylindrical metal fitting with the small diameter side of the portion facing the inner peripheral side of the cylindrical metal fitting and the large diameter side facing the outer peripheral side of the cylindrical metal fitting By rolling the rising presser portion of the rolling mold against the outer peripheral corner portion of the axial end surface of the cylindrical metal member in the circumferential direction, the rolling presser is rolled against the axial end surface of the cylindrical metal member. A plurality of non-slip protrusions are formed in a radial direction on the axial end face of the cylindrical metal fitting and are radially formed on the axial end face of the cylindrical metal fitting, and an axial direction at the outer peripheral edge portion. An annular water blocking protrusion that protrudes outward and extends in the circumferential direction is formed at the same time.

  According to the eighth aspect, by using the rolling mold having the structure according to the present invention, a plurality of radial anti-slip protrusions and an annular water-stop protrusion extending in the circumferential direction on the outer peripheral edge portion are provided. The cylindrical fitting provided in is manufactured with high accuracy. In addition, since the protrusions are efficiently projected by the upright holding portion, the contact force with the cylindrical metal fitting of the rolling mold can be suppressed. In addition, it is possible to avoid the burr from projecting to the outer peripheral side by pressing the upright holding part against the outer peripheral corner of the axial end face of the cylindrical metal fitting.

  According to a ninth aspect of the present invention, in the method for manufacturing a cylindrical fitting described in the eighth aspect, prior to or simultaneously with the processing by the rolling mold, the axial end of the cylindrical fitting is provided. Chamfering is performed on at least one of the outer peripheral side corner and the inner peripheral side corner.

  According to the ninth aspect, it is possible to avoid damage to the corners due to contact of the manufactured cylindrical fitting with other members, and to prevent burrs and to stabilize the shape of the cylindrical fitting. . In addition, by chamfering the outer peripheral corner, the upright holding portion can be stably brought into contact with the outer peripheral corner of the axial end of the cylindrical metal fitting. The formation of burrs is effectively prevented. In addition, even if there are burrs at the axial end of the cylindrical metal fittings before rolling, the burrs are removed by chamfering, so that the burr meat that exists partially on the circumference is annular It is possible to stabilize the cross-sectional shape of the annular water blocking protrusion while preventing the cross-sectional shape of the protrusion from being affected. On the other hand, by chamfering the corner on the inner peripheral side, it is possible to avoid the bolts and rods inserted through the cylindrical fitting from being caught by the burr, and the mounting work to the other member of the cylindrical fitting becomes easy.

  According to a tenth aspect of the present invention, there is provided a vibration-proof rubber bushing manufacturing method according to the cylindrical metal fitting manufacturing method described in the eighth or ninth aspect. After the plastic working by the rolling mold, respectively, the main rubber elastic body is vulcanized and bonded to the outer peripheral surface of the cylindrical fitting.

  In the anti-vibration rubber bush having the cylindrical metal fitting formed with the non-slip protrusion and the annular water-proof protrusion on the axial end face, the axial end face of the cylindrical metal fitting is connected to one member of the anti-vibration rubber bush for anti-vibration connection. By being pressed and attached, rotation of the anti-vibration rubber bush with respect to one of the anti-vibration connected members is prevented, and intrusion of rainwater between the cylindrical bracket and one of the anti-vibration connected members is prevented. Is done. According to the manufacturing method of this aspect, the anti-vibration rubber bush having such excellent effects can be reduced by forming the non-slip protrusion and the annular water-stop protrusion at the same time by rolling using a rolling mold. Easy to form with numbers.

  According to the present invention, a non-slip projection that exhibits a rotation prevention function and an annular water stop projection that closes a gap between adjacent anti-slip projections to prevent intrusion of rainwater or the like on the axial end surface of the cylindrical metal fitting. On the other hand, a rolling mold that can be molded simultaneously and with high accuracy is realized. In addition, by following the method of the present invention, a cylindrical metal fitting that exhibits an excellent anti-rotation effect and water-stopping effect by the non-slip protrusion and the annular water-stop protrusion can be easily manufactured in a stable shape. Furthermore, by using a cylindrical metal fitting formed with a non-slip projection and an annular water-stop projection, it is possible to advantageously manufacture a vibration-proof bush used for, for example, a suspension bush for an automobile.

The longitudinal cross-sectional view of the cylindrical metal fitting as one Embodiment of this invention. The side view of the cylindrical metal fitting shown by FIG. The perspective view which expands and shows the principal part of the cylindrical metal fitting shown by FIG. Explanatory drawing which shows the plastic working as one manufacturing process of the cylindrical metal fitting shown by FIG. It is a longitudinal cross-sectional view which shows the rolling mold used by the plastic working shown by FIG. 4, Comprising: VV sectional drawing in FIG. FIG. 6 is a right side view of the rolling mold shown in FIG. 5. The side view which shows the mounting state to the holder of the rolling mold shown by FIG. The principal part enlarged view which extracts and shows the attachment part to the holder of the rolling mold shown by FIG. The side view which shows the internal peripheral cutting blade with which the holder shown by FIG. 7 is mounted | worn. The side view which shows the outer periphery cutting blade with which the holder shown by FIG. 7 is mounted | worn. It is a longitudinal cross-sectional view which shows one Embodiment of the vibration isolating bush manufactured according to this invention method using the cylindrical metal fitting shown in FIG. 1, Comprising: XI-XI sectional drawing in FIG. FIG. 12 is a left side view of the vibration isolating bush shown in FIG. 11. Explanatory drawing which shows the mounting state of the anti-vibration bush shown by FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  1-3, the cylindrical metal fitting 10 manufactured according to the method of this invention is shown. This cylindrical metal fitting 10 has a cylindrical shape, and projections having a specific shape are formed on both end surfaces in the axial direction. In addition, a bulging large-diameter portion 12 is formed by bulging or the like in the axial central portion of the cylindrical metal fitting 10, but this large-diameter portion 12 is an object when applied to a vibration-proof bushing described later. It is for realizing the spring characteristics, and is not essential in the present invention.

  When manufacturing the cylindrical metal fitting 10 according to the method of the present invention, first, a cylindrical shell 14 is prepared as a processing material. The cylindrical base tube 14 is shown in FIG. 4, and is manufactured by cutting a cylindrical metal tube obtained by a known pipe material manufacturing method such as extrusion or drawing, to an appropriate length. I can do it. As the material of the cylindrical base tube 14, an appropriate material such as stainless steel is selected according to the characteristics required for the target cylindrical fitting 10. Further, the cylindrical base tube 14 may be subjected to appropriate shape processing such as the formation of the large diameter portion 12 described above.

  Next, the cylindrical element tube 14 is subjected to plastic working on its axial end surface, and as shown in FIG. 3, a plurality of non-slip protrusions 16 extending radially and circumferentially are formed. An extending annular water blocking protrusion 18 is formed. That is, each of the non-slip protrusion 16 and the annular water stop protrusion 18 is formed integrally with the cylindrical metal fitting 10, and has a protrusion shape protruding outward in the axial direction from the axial end surface 20 of the cylindrical metal fitting 10. It is doing.

  When forming these protrusions 16 and 18, as shown in FIG. 4, a rolling forming die 22 as a specific forming piece is used and plastic working is performed on the axial end face 20 of the cylindrical tube 14. Apply. As shown in FIGS. 5 and 6, the rolling mold 22 has a substantially annular shape as a whole. The first rolling mold 24 and the second rolling mold are separated from each other. The mold 26 is formed in combination.

  The first rolling mold 24 has a generally frustoconical shape as a whole, is formed of high speed (high speed tool steel), and the surface is coated with titanium or the like to improve durability. The frictional resistance is reduced. The material of the first rolling mold 24 is, for example, carbon tool steel, cemented carbide in consideration of the material of the cylindrical element tube 14 to be processed, the shape and size of the projection to be formed, the processing speed, and the like. An alloy or the like can be appropriately employed.

  The first rolling mold 24 has a first support hole 28 penetrating on the central axis, and a tapered side surface (outer peripheral surface) that forms a part of the molding surface. The outer peripheral surface 30 is formed. The tapered outer peripheral surface 30 is provided with a plurality of inclined direction forming grooves 32. The inclined direction forming groove 32 extends continuously from the small-diameter end of the tapered outer peripheral surface 30 to the large-diameter end thereof in parallel with the generatrix in the taper inclined direction of the tapered outer peripheral surface 30. And it is located at equal intervals in the circumferential direction. The inclined direction forming groove 32 is formed over the entire length of the tapered outer peripheral surface 30 in the generatrix direction, and the entire tapered outer peripheral surface 30 is a serrated portion.

  The inclined direction forming groove 32 formed on the tapered outer peripheral surface 30 of the rolling mold 22 has a shape corresponding to a plurality of protrusion shapes provided on the axial end surface 20 of the target cylindrical metal fitting 10. The specific shape is designed according to the target protrusion shape of the cylindrical fitting 10.

  Specifically, the inclined direction forming groove 32 extends linearly in the radial direction without being inclined in the circumferential direction from near the inner peripheral edge to the outer peripheral edge. Each inclined direction forming groove 32 has a trapezoidal groove cross-sectional shape and extends in the radial direction, and has an expanded cross-sectional shape in which the width dimension of the cross-section increases toward the opening side. Furthermore, a plurality of inclined direction forming grooves 32 are formed in the circumferential direction close to each other, and as a whole, a large number of inclined direction forming grooves extending radially about the central axis of the first rolling forming die 24. 32 is formed. In other words, the circumferential section of the first rolling mold 24 has a continuous sawtooth shape formed by a large number of inclined molding grooves 32.

  Furthermore, the shape and size of all the inclined direction forming grooves 32 are the same, and the bottom surface of all the inclined direction forming grooves 32 is one cone corresponding to the forming surface of the first rolling mold 24. It is positioned on the surface.

  On the other hand, the second rolling mold 26 has a substantially annular shape extending in the circumferential direction with a substantially constant rounded rectangular cross section, and is formed of cemented carbide. The material of the second rolling mold 26 is the same as that of the first rolling mold 24, the material of the cylindrical tube 14 to be processed, the shape and size of the projection to be formed, the processing speed, etc. For example, high speed steel or carbon tool steel may be appropriately employed. Further, the material of the first rolling mold 24 and the material of the second rolling mold 26 may be the same, and the second rolling mold 24 is the same as the first rolling mold 24. The molding surface of the mold 26 may be coated.

  Further, the outer diameter dimension of the second rolling mold 26 is larger than the outer diameter dimension at the large-diameter side end of the first rolling mold 24. Further, in the radial center of the second rolling mold 26, a second support hole 34 penetrating in the axial direction is formed with substantially the same diameter as the first support hole 28 of the first rolling mold 24. Has been. Further, a tapered step 36 is provided on the outer peripheral portion of the second rolling mold 26, and the outer peripheral portion sandwiching the step 36 is thinner than the inner peripheral portion. The inclination of the step 36 corresponds to the inclination of the tapered outer peripheral surface 30 in the first rolling mold 24.

  The large-diameter side end faces of the first rolling mold 24 are overlapped with one end face in the axial direction of the second rolling mold 26 so that the first rolling mold 24 and the second rolling mold are overlapped. A mold 26 is disposed on the same central axis. Further, the support shaft 38 is inserted into the first support hole 28 of the first rolling mold 24 and the second support hole 34 of the second rolling mold 26, thereby the first rolling mold. The mold 24 and the second rolling mold 26 are combined with each other to form the rolling mold 22. The first and second rolling molds 24 and 26 may be combined so as to rotate independently of each other, or are combined so as to rotate integrally with a fitting portion. Also good.

  Thus, in the rolling mold 22 in which the first rolling mold 24 and the second rolling mold 26 are combined, the outer peripheral portion of the second rolling mold 26 is the first over the entire circumference. It protrudes to the outer peripheral side from the large-diameter side end of the rolling mold 24. And the protrusion part of the outer periphery of this 2nd rolling shaping | molding die 26 is made into the raising presser part 40. FIG. In addition, the surface on the side where the first rolling mold 24 is overlaid on the end surface in the axial direction of the rising presser portion 40 is an outer peripheral presser surface 42.

  Further, the rolling mold 22 is formed with a circumferential molding groove 44. The circumferential forming groove 44 is formed between the large diameter side end portion of the first rolling forming die 24 and the upright holding portion 40, and the wall inner surfaces 45 on both sides in the width direction are both inclined surfaces. Then, it extends over the entire circumference in a substantially constant trapezoidal groove cross-sectional shape that gradually widens toward the opening side. The circumferential direction shaping grooves 44 are connected to the end portions on the large diameter side of the plurality of inclined direction shaping grooves 32. In addition, the opening edge of the wall inner surface 45 on the first rolling mold 24 side in the circumferential molding groove 44 is connected to the connecting corner portion with the tapered outer peripheral surface 30 of the first rolling mold 24. Then, a rounded chamfering process is performed to form a curved surface 46. Further, the bottom wall surface of the circumferential forming groove 44 is formed by a step 36 provided in the second rolling mold 26, and the pair of wall inner surfaces 45, 45 are separated in the width direction at the bottom wall side end. is doing. Further, the bottom wall surface of the circumferentially formed groove 44 is a flat curved surface having no irregularities, extends substantially parallel to the tapered outer peripheral surface 30, and smoothly continues to the bottom wall surface of the inclined direction molded groove 32. is doing.

  The rolling mold 22 is supported by a holder 48 as shown in FIG. The holder 48 has a circular block shape as a whole, and includes a tool mounting portion 50 having a substantially frustoconical shape in the opposite direction, and a connecting portion 52 protruding from the large-diameter side end surface of the tool mounting portion 50. Three independent flat portions are provided on the outer peripheral surface of the tool mounting portion 50, and a support metal fitting 54, an inner peripheral chamfering bit 56, and an outer peripheral chamfering bit 58 are overlapped with each flat portion. Has been fixed. The connecting portion 52 has a substantially cylindrical shape and has a plurality of regulating planes 60 on the outer peripheral surface, and is inserted into a machine tool (not shown) and fixed.

  As shown in FIG. 8, the support fitting 54 is a metal plate, and two bolt holes are formed through the upper portion thereof in the thickness direction. Further, the tip of the support shaft 38 inserted through the rolling mold 22 is fixed to the lower end of the support metal 54, and the roll forming mold 22 is rotated around the support shaft 38 by the support metal 54. It comes to be supported as possible.

  As shown in FIG. 9, the inner peripheral chamfering tool 56 is a peeling tool in which a blade portion and a shank are integrally formed, and a tip portion (lower end portion in FIG. 9) is tapered. In addition, a linear cutting edge is provided at one end in the width direction of the tip portion. Further, two bolt holes penetrating in the thickness direction are formed in the shank portion. The material of the inner peripheral chamfering bit 56 is set in accordance with the material and processing speed of the cylindrical tube 14 to be processed, and is not particularly limited. For example, high speed steel, cemented carbide, carbon Tool steel etc. are adopted. Further, the inner peripheral chamfering tool 56 may be a brazing tool or a clamp tool in which the blade portion and the shank are separated.

  As shown in FIG. 10, the outer peripheral chamfering tool 58 has a structure in which a tip 64 as a blade portion is attached to the tip portion of the shank 62 by brazing or mechanical fixing. As with the cutting tool 56, the tip end portion (lower end portion in FIG. 10) is tapered, and a linear cutting edge is provided at one end in the width direction. The shank 62 has two bolt holes penetrating in the thickness direction. The outer peripheral chamfering tool 58 is not limited to the same material as the inner peripheral chamfering tool 56, but high speed steel, cemented carbide, carbon tool steel, etc. are preferably employed. Further, as the outer peripheral chamfering tool 58, a peeling tool can be used.

  Then, the support fitting 54 to which the rolling mold 22 is attached, the inner peripheral chamfering bit 56, and the outer peripheral chamfering bit 58 are set in the holder 48. That is, the support metal 54 and the cutting tools 56 and 58 are overlapped with each other and fixed to the plurality of flat portions formed on the tool mounting portion 50 of the holder 48 by bolting, respectively. 58 is mounted such that the rolling mold 22 and the blades of the cutting tools 56 and 58 protrude toward the tip side of the holder 48 (the small diameter side of the tool mounting part 50). In such an attached state, the rolling mold 22, the inner peripheral chamfering bit 56 and the outer peripheral chamfering bit 58 are spaced apart from each other in the circumferential direction and arranged at substantially equal intervals. The small-diameter side end of the rolling mold 22 faces the inner peripheral side, the cutting edge of the inner peripheral chamfering bit 56 is on the outer peripheral side, and the cutting edge of the outer peripheral chamfering bit 58 is on the inner peripheral side, respectively. The support fitting 54 and the cutting tools 56 and 58 are set in the holder 48 so that they face each other.

  Further, the holder 48 is attached to the machine tool, and the cylindrical raw tube 14 as a work is supported by a work base or the like. As shown by a one-dot chain line in FIG. 4, the cylindrical base tube 14 is set so that its central axis 66 substantially coincides with the central axis of the holder 48 and is opposed to be separated in the axial direction. , And is supported so as to be rotatable around the central axis 66.

  Furthermore, the rolling forming is performed so that the intersection angle between the center axis 68 of the rolling mold 22 and the center axis 66 of the cylindrical base tube 14 becomes an angle corresponding to the inclination angle of the bus bar in the first rolling mold 24. The mold 22 is inclinedly supported by the holder 48 so that the tapered outer peripheral surface 30 of the tapered first rolling mold 24 faces the axial end surface 20 of the cylindrical tube 14 substantially in parallel. Further, each of the inner peripheral chamfering cutting tool 56 is positioned on the inner peripheral side of the cylindrical tube 14 and the outer peripheral chamfering cutting tool 58 is positioned on the outer peripheral side of the cylindrical tube 14. Bytes 56 and 58 are set.

  Then, the cylindrical base tube 14 fixed and supported in the direction perpendicular to the axis by the work base or the like is rotated by driving means such as a motor, and is moved in the axial direction toward the rolling mold 22 in the approaching direction. The axial end surface 20 of the tube 14 is pressed against the tapered outer peripheral surface 30 of the rolling mold 22 to perform molding. That is, as the cylindrical element tube 14 rotates about the central axis, the rolling mold 22 supported by the support shaft 38 so as to be fixed in position and rotatable is pressed against the axial end surface 20 of the cylindrical element tube 14. As a result, the axial end surface 20 of the cylindrical shell 14 serving as the machining surface is plastically deformed, and the cylindrical shell 14 is also rotated with the rotation of the cylindrical shell 14 around the central axis due to contact resistance with the cylindrical shell 14. Rotate around the central axis. By the rotation of the cylindrical base tube 14 and the rolling mold 22, the plasticity by the tapered outer peripheral surface 30 of the rolling mold 22 over the entire circumference with respect to the axial end surface 20 of the cylindrical base pipe 14. By being processed, the protrusions 16 and 18 corresponding to the circumferentially formed groove 44 and the inclined formed groove 32 formed on the tapered outer peripheral surface 30 are simultaneously formed.

  In this plastic working, the tapered outer peripheral surface 30 of the rolling mold 22 is pressed against the axial end surface 20 of the cylindrical element tube 14, and at the same time, the outer peripheral pressing surface 42 of the rising presser portion 40 is moved to the axial end surface of the cylindrical element tube 14. Press against the outer peripheral corner of 20 from the outer peripheral side. When the rolling mold 22 is mounted on the holder 48, the outer periphery pressing surface 42 is inclined and spreads with respect to the central axis 66 of the cylindrical tube 14, and the rolling mold 22 and the cylindrical tube 14 are axially moved. , The outer periphery pressing surface 42 is pressed against the outer peripheral corner of the axial end surface 20 of the cylindrical tube 14. In addition, the rolling that is pressed against the axial end surface 20 of the cylindrical tube 14 by the tapered outer peripheral surface 30, the groove inner surface of the inclined direction forming groove 32, the outer periphery holding surface 42, and the groove inner surface of the circumferential direction forming groove 44. A molding surface of the mold 22 is configured.

  Simultaneously with or prior to plastic working by the rolling mold 22, chamfering by the inner peripheral chamfering tool 56 and the outer peripheral chamfering tool 58 is provided at the edge of the axial end of the cylindrical tube 14. Apply processing. That is, when the cylindrical base tube 14 approaches the cutting tools 56 and 58 in the axial direction while rotating with respect to the cutting tools 56 and 58, the corners of the cylindrical base tube 14 become the cutting edges of the inner peripheral chamfering tool 56 and the outer peripheral chamfering tool 58. And a predetermined inclined surface is formed at both edges on the inner peripheral side and the outer peripheral side of the cylindrical shell 14. As a result, chamfering is performed on the inner and outer peripheral edge portions at the axial end portion of the cylindrical tube 14.

  The chamfering process can be realized by forming a tapered surface by plastic working with a rolling piece or the like in addition to the cutting process using the above-described chamfering tool. In addition, the rising presser 40 of the rolling mold 22 is used without specially using a rolling piece for chamfering processing, and protrudes on the outer peripheral surface at the small-diameter side end of the rolling mold 22 in the generatrix direction. In addition, by integrally forming an annular forming protrusion for taper processing extending in the circumferential direction, the rolling forming die 22 can also have a taper processing function, and the chamfering processing and the forming processing of the protrusions 16 and 18 can be performed simultaneously. However, it is desirable to provide a rolling piece for taper machining and a cutting tool for surface machining separately from the rolling mold 22.

  It is also possible to dispose the rolling mold 22 and the cutting tools 56 and 58 on both sides in the axial direction of the cylindrical tube 14 and simultaneously perform plastic working on both end surfaces in the axial direction of the cylindrical tube 14. A reduction in the number is realized. Further, in place of the above-described rotational driving around the central axis 66 of the cylindrical raw tube 14, the holder 48 is rotated around the central axis 66 while the cylindrical raw tube 14 is supported in a non-rotating state, whereby a rolling mold is formed. It is also possible to perform the desired plastic working by rolling and displacing 22 around the central axis 66 of the cylindrical tube 14 in addition to the rotation around the central axis 68.

  If the cylindrical metal fitting 10 provided with the non-slip projection 16 and the annular water-stop projection 18 is formed by plastic deformation using the rolling mold 22, a plurality of the non-slip projections 16 are formed by one rolling mold 22. And the annular water blocking protrusion 18 can be formed simultaneously. Therefore, the equipment for forming the protrusions 16 and 18 on the cylindrical tube 14 can be easily and reduced, and the number of processing steps for forming the protrusions 16 and 18 can be reduced, and the cylindrical fitting 10 can be easily manufactured. I can do it.

  Moreover, in the method of the present invention, when the axial end surface 20 of the cylindrical shell 14 is subjected to plastic working by the rolling mold 22, the rising presser 40 is placed on the outer peripheral corner of the axial end surface 20 of the cylindrical shell 14. It is designed to be pressed. As a result, the wall of the cylindrical tube 14 pushed out by the pressure at the time of rolling is raised to the outside in the axial direction on the inner peripheral side of the outer peripheral holding surface 42 without protruding to the outer peripheral side and forming a burr. The water stop projection 18 is efficiently projected.

  In addition, since the curved surface 46 is formed at the opening edge portion of the circumferential forming groove 44 on the first rolling mold 24 side, the curved outer surface 30 moves by pressing the tapered outer peripheral surface 30 against the cylindrical tube 14. The meat of the cylindrical shell 14 is guided along the curved surface 46 to the circumferential forming groove 44 side. As a result, the annular water blocking protrusion 18 is more efficiently projected and formed, and the annular water blocking protrusion 18 having a target shape (projection height) can be accurately formed.

  The rolling mold 22 is a divided structure in which a first rolling mold 24 having a tapered outer peripheral surface 30 and a second rolling mold 26 having a rising presser 40 are combined. It is said that. Since both the first rolling mold 24 and the second rolling mold 26 have simple shapes that are easy to manufacture, compared to the case where the rolling mold 22 is integrally formed. And easy to manufacture. In addition, the material of the first rolling mold 24 and the material of the second rolling mold 26 can be easily changed, and the required characteristics of the tapered outer peripheral surface 30 and the required characteristics of the upright presser portion 40. Even if they are different, it is possible to cope with high altitude. Further, when only one of the first and second rolling molds 24 and 26 is damaged, the plastic working can be performed again by replacing only the damaged side.

  As shown in FIGS. 1 to 3, the axial end face 20 of the target cylindrical fitting 10 obtained by subjecting the cylindrical tube 14 to plastic working by the rolling mold 22 described above is shown. On the other hand, corresponding to the circumferential molding groove 44 and the inclined molding groove 32 of the rolling mold 22, there are a plurality of non-slip projections 16 extending radially and an annular water blocking projection 18 extending in the circumferential direction. Is formed. That is, each of the non-slip protrusion 16 and the annular water stop protrusion 18 is formed integrally with the cylindrical metal fitting 10, and has a protrusion shape protruding outward in the axial direction from the axial end surface 20 of the cylindrical metal fitting 10. is doing.

  In particular, the non-slip projection 16 extends linearly in the radial direction without being inclined in the circumferential direction from the vicinity of the inner peripheral edge to the vicinity of the outer peripheral edge on the axial end face 20 of the cylindrical metal fitting 10. . Both end surfaces of the anti-slip protrusion 16 in the length direction (the radial direction of the axial end surface 20 of the cylindrical metal fitting 10) are inclined surfaces that spread in a mountain skirt shape, so that they do not hit or interfere with other members. The loss and deformation | transformation of the longitudinal direction edge part of the accompanying anti-slip | projection protrusion 16 are aimed at.

  Further, the anti-slip protrusion 16 has a trapezoidal cross-sectional shape and extends in the radial direction, and has a tapered cross-sectional shape in which the width dimension of the cross-section decreases toward the protruding tip side. Further, a plurality of the non-slip protrusions 16 are formed close to each other in the circumferential direction, and as a whole, a large number of anti-slip protrusions 16 extending radially about the central axis of the cylindrical metal fitting 10 are formed. . That is, in the circumferential cross section of the cylindrical metal fitting 10, a continuous sawtooth-like shape is formed by a large number of non-slip protrusions 16.

  Furthermore, the shape and size of all the anti-slip protrusions 16 are the same, and the protruding front end surfaces of all the anti-slip protrusions 16 are positioned on one plane perpendicular to the central axis of the cylindrical metal fitting 10. It has been. Thereby, when the cylindrical metal fitting 10 is mounted on the other member and the axial end surface 20 thereof is superimposed on the flat mounting surface of the other member, all the non-slip protrusions 16 are formed on the mounting surface. The protruding tip is in contact. However, it is not essential that the entire projecting tip surface of the anti-slip projection 16 is on one plane. For example, the projecting tip surfaces of all the anti-slip projections 16 are tapered so as to incline outward in the axial direction toward the outer peripheral side. It may be positioned on the surface.

  On the other hand, the annular water blocking protrusion 18 has an annular shape that continuously extends in the circumferential direction on the outer peripheral edge portion in the radial direction on the axial end surface 20 of the cylindrical metal fitting 10. The annular water blocking protrusion 18 also has a trapezoidal cross-sectional shape and extends in the circumferential direction, like the anti-slip protrusion 16, and has a tapered cross-sectional shape that decreases in width as the width of the cross section increases toward the protruding tip side. .

  Further, the annular water blocking protrusion 18 extends with a constant cross-sectional shape over the entire length in the circumferential direction, and the protruding front end surface of the annular water blocking protrusion 18 is orthogonal to the central axis of the tubular metal fitting 10 over the entire length. It is positioned on one plane. Moreover, the projecting tip surface of the annular water blocking projection 18 is positioned on the same plane as the plane on which the projecting tip surface of the anti-slip projection 16 is located. In short, all the projecting tip surfaces of the plurality of non-slip projections 16 and the annular water stop projections 18 are set on the same plane. Thereby, when the cylindrical metal fitting 10 is mounted on the other member and the axial end face 20 is superimposed on the flat mounting surface of the other member, only the non-slip protrusions 16 are provided on the mounting surface. In addition, the protruding tip of the annular water blocking protrusion 18 is also pressed.

  Further, the annular water stop protrusion 18 is formed on the radially outer peripheral edge portion of the axial end surface 20 of the cylindrical metal fitting 10, and all the slip stopper protrusions 16 are connected to the annular water stop protrusion 18 at the outer peripheral edge portion. ing. At each of these intersections, the projecting front end surface of the annular water blocking protrusion 18 is continuous in the circumferential direction, so that an annular surface closed in the circumferential direction is superimposed on the axial end surface 20 of the cylindrical metal fitting 10. It is pressed against the mounting surface of the member. Each of the anti-slip protrusions 16 extends from the intersection with the annular water stop protrusion 18 to the inner peripheral side of the annular water stop protrusion 18, and is superimposed on the axial end surface 20 of the cylindrical metal fitting 10. It can be pressed against the mounting surface of the other member.

  Further, a groove-like recess 69 extending in the radial direction exists between the anti-slip protrusions 16, 16 adjacent in the circumferential direction on the axial end surface 20 of the cylindrical metal fitting 10. An annular water stop protrusion 18 is formed across the outer peripheral end in the length direction in the circumferential direction. Since this annular water blocking protrusion 18 is continuous over the entire circumference in the circumferential direction, all the groove-like recesses 69 are lost so as to be blocked by the annular water blocking protrusion 18 at the outer peripheral edge. ing.

  Therefore, the cylindrical metal fitting 10 having the axial end surface 20 having both the non-slip projection 16 and the annular water blocking projection 18 as described above presses the axial end surface 20 against the mounting surface of the other member when mounted on the other member. By mounting, the relative displacement around the central axis with respect to the other member of the cylindrical metal fitting 10 is effectively prevented, and the cylinder through the gap between the axial end surface 20 of the cylindrical metal fitting 10 and the mounting surface of the other member. Intrusion of rainwater or the like into the inner peripheral surface of the metal fitting 10 is also effectively prevented. In order to facilitate understanding of these technical effects, an anti-vibration rubber bush is shown as an example of a product using the above-described cylindrical metal fitting 10, and the function and effect of the present invention are specifically described for the anti-vibration rubber bush. Explained.

  That is, FIGS. 11 and 12 show an anti-vibration rubber bush 70 as an embodiment of a product using the above-described tubular metal fitting 10. The anti-vibration rubber bushing 70 is attached to a portion of the suspension arm constituting the suspension mechanism of the automobile that is attached to the vehicle body side or the wheel side to reduce transmission of road surface vibration to the vehicle body side.

  More specifically, the anti-vibration rubber bush 70 includes an inner cylinder fitting 72 constituted by the above-described cylindrical fitting 10, and the inner cylinder fitting 72 is axially on the central axis of the anti-vibration rubber bush 70. It is arranged through. Further, a main rubber elastic body 74 is fixed to the outer peripheral surface of the inner cylinder fitting 72. The main rubber elastic body 74 has a thick, generally cylindrical shape as a whole, and an inner peripheral surface thereof is fixed to an outer peripheral surface of the inner cylinder fitting 72. Further, a cylindrical outer cylinder fitting 76 is fixed to the outer peripheral surface of the main rubber elastic body 74. The outer cylinder fitting 76 is thinner than the inner cylinder fitting 72 and has a shorter axial length, and is spaced radially outward from the inner cylinder fitting 72 at the axial central portion of the inner cylinder fitting 72. 72 on the same central axis. Such an anti-vibration rubber bush 70 is manufactured as an integrally vulcanized molded product by molding and vulcanizing the main rubber elastic body 74 in the presence of the inner and outer cylindrical fittings 72 and 76, for example.

  In the present embodiment, a pair of straight portions 78 and 78 extending through the radial intermediate portion in the axial direction are formed on the main rubber elastic body 74. The pair of straight portions 78 and 78 are opposed to each other in one radial direction, and extend between the inner and outer cylindrical metal fittings 72 and 76 in a circular arc shape in the circumferential direction with a length of less than ¼ circumference, respectively. Tuning such as adjustment of the spring ratio between the facing direction of the straight portions 78 and 78 and the radial direction perpendicular thereto is performed.

  Then, as shown in FIG. 13, the anti-vibration rubber bush 70 is attached to a portion where the suspension arm 80 is attached to the vehicle body side member 82. For such mounting, first, the outer cylinder fitting 76 of the vibration-proof rubber bush 70 is press-fitted and fixed into the mounting hole 86 of the cylindrical arm eye 84 formed at one end of the suspension arm 80. Thereafter, the anti-vibration rubber bush 70 attached to the suspension arm 80 is fitted between the opposing surfaces of the pair of attachment portions 88 and 88 formed on the vehicle body side member 82 as the other member. Then, the inner hole 92 of the inner cylinder fitting 72 is aligned with the insertion holes 90, 90 formed in the pair of attachment parts 88, 88, and the attachment bolt 94 is moved from the insertion hole 90 of the one attachment part 88. It is inserted and inserted into the inner hole 92 of the inner cylindrical fitting 72 and protrudes outward from the insertion hole 90 of the other mounting portion 88. A tightening nut 98 is screwed onto the projecting end threaded portion 96 of the mounting bolt 94 and tightened so that both end surfaces in the axial direction of the inner cylinder fitting 72 are used as mounting surfaces for the pair of mounting portions 88, 88. Press against the opposite surface and fix.

  Under such a state in which the vibration isolating rubber bush 70 is mounted on the vehicle suspension mechanism, the pair of straight portions 78 and 78 in the main rubber elastic body 74 are provided to the vehicle so that the intended vibration isolating effect is stably exhibited. It is necessary to position in a specific direction such as the front-rear direction. This circumferential positioning is realized by the above-described anti-slip protrusion 16 projecting from both axial end surfaces 20, 20 of the inner cylinder fitting 72. That is, the anti-slip protrusion 16 is pressed against the mounting portion 88 based on the tightening force of the tightening nut 98 to the mounting bolt 94, so that it is inserted in the circumferential direction of the inner cylinder fitting 72 relative to the mounting portion 88. The relative rotational displacement is prevented.

  Moreover, since the annular water stop projection 18 is formed in addition to the anti-slip projection 16 on the axial end surface 20 of the inner cylinder fitting 72, the mounting portion 88 of the inner cylinder fitting 72 exhibited by the anti-slip projection 16. Therefore, it is possible to effectively prevent rainwater or the like from entering the inner hole 92 of the inner cylinder fitting 72 through the gap between the inner cylinder fitting 72 and the mounting portion 88 while ensuring a sufficient rotation preventing function against the above.

  That is, in the anti-vibration rubber bush 70 having the above-described structure, the mounting portion 88 of the vehicle body side member 82 and the axial end surface 20 of the inner cylinder fitting 72 are in the mounted state as shown in FIG. In the meantime, even if rainwater or the like enters from the outer peripheral side opening of the gap (groove-like recess 69) between the anti-slip protrusions 16 adjacent to each other in the circumferential direction, it is blocked by the annular water-stop protrusion 18. Therefore, rainwater or the like does not reach the inner peripheral edge of the axial end surface 20 of the inner cylinder fitting 72 and does not enter the inner hole 92 of the inner cylinder fitting 72.

  In addition, since the projecting tip of the annular water blocking protrusion 18 is formed into a flat surface extending in the circumferential direction by the bottom wall surface (step 36) of the circumferential forming groove 44 in the rolling mold 22, the mounting portion 88. The target water-stopping effect is stably exhibited by abutting (biting in) stably. In addition, the ring-shaped water stop protrusion 18 is formed with a substantially constant cross-sectional shape with high accuracy by the upright holding portion 40 of the rolling mold 22, and the water stop function is prevented from failing over the entire circumference.

  As mentioned above, although embodiment of this invention has been explained in full detail, this invention is not limited by the specific description of this embodiment. For example, the plastic working by the rolling mold 22 may be performed only on one end face in the axial direction of the cylindrical metal fitting 10. That is, the cylindrical metal fitting 10 is mounted with its axial direction oriented in the vertical direction, or a seal rubber is mounted on one side in the axial direction. When there is a function requirement only on one side in the axial direction, the annular water blocking protrusion 18 may be formed only on one side in the axial direction of the tubular metal fitting 10. Similarly, when the anti-slip protrusion 16 is mounted by pressing only one end face in the axial direction of the cylindrical metal fitting 10 against a mounting member or the like, a sufficient anti-rotation function is exhibited only by one end face in the axial direction. In such a case, it may be formed only on one end surface in the axial direction.

  Further, it is not necessary for any of the inclined direction forming grooves 32 to extend linearly in the radial direction. For example, it may be inclined with respect to the radial line, or may be in a spiral shape that is inclined and curved. If the inclined direction forming groove 32 is curved in a spiral shape toward one side in the circumferential direction, the anti-slip projection 16 formed thereby can also be expected to improve the rotation blocking force in a specific rotation direction.

  Furthermore, by forming a plurality of circumferentially formed grooves 44, a plurality of annular water stop protrusions 18 are formed in a radially separated manner in accordance with the required water stop ability and the properties of the other member to be pressed. May be.

  Furthermore, the depth dimension of the inclined direction forming groove 32 and the circumferential direction forming groove 44 does not necessarily have to be the same, and the non-slip protrusion 16 and the annular water stop protrusion 18 formed by using the grooves 32 and 44 are not necessarily the same. Each protruding tip surface does not have to be located on the same plane extending in the direction perpendicular to the axis of the cylindrical metal fitting 10. For example, by projecting the protruding tip end surface of the annular water stop protrusion 18 larger than the anti-slip protrusion 16 outward in the axial direction of the cylindrical metal fitting 10, the amount of biting into the other member is set to be less than the non-slip protrusion 16. It is possible to obtain a more advanced water stop effect more stably by increasing the size of the protrusion 18. On the other hand, the protruding tip surface of the non-slip projection 16 protrudes more outward in the axial direction of the cylindrical metal fitting 10 than the annular water-stop projection 18, so that the amount of biting into other members is less slipped than the annular water-stop projection 18. It is possible to set a larger rotation prevention force by increasing the protrusion 16. In consideration of the required rotation prevention force, the properties of other members, etc., the protrusion height and shape of some of the anti-slip protrusions 16 are different, or the protrusion height and shape of one anti-slip protrusion 16 are long. It is also possible to adjust by changing the direction.

  Further, the rolling mold 22 is not limited to a structure in which the first and second rolling molds 24 and 26 which are independent from each other are combined, and includes both a serration processing portion and a rising presser portion. It may be formed by an integrally molded product. On the other hand, the rolling mold may be formed by three or more parts.

  Further, it is not necessary that the entire tapered outer peripheral surface 30 is a serration processing portion provided with the inclined direction forming groove 32, and it is also possible to provide a serration processing portion partially in the generatrix direction of the tapered outer peripheral surface 30. is there. Specifically, for example, the inclined direction forming groove 32 is formed in a region that does not reach the small-diameter side end of the tapered outer peripheral surface 30, and the region that is out of the small-diameter side end is a serrated portion. good.

  Furthermore, the step 36 in the rolling mold 22 can be omitted, and the protruding tip of the annular water blocking protrusion may be left sharp, or the tip portion may be processed flat after rolling the annular water blocking protrusion. Also good.

10: cylindrical fitting, 16: non-slip projection, 18: annular water blocking projection, 22: rolling mold, 24: first rolling mold, 26: second rolling mold, 30: taper Outer peripheral surface, 32: Inclined direction forming groove, 40: Standing presser part, 42: Outer periphery pressing surface, 44: Circumferential direction forming groove, 70: Anti-vibration rubber bush, 74: Body rubber elastic body

Claims (10)

A rolling mold for producing a cylindrical metal fitting with a non-slip projection formed on an axial end face,
Serration processing comprising a tapered outer peripheral surface as a molding surface pressed against the axial end surface of the cylindrical metal fitting, and a plurality of inclined direction forming grooves extending in the tapered inclination direction formed in the tapered outer peripheral surface in the circumferential direction While the part is provided
On the large diameter side in the axial direction of the serration processing portion, a rising presser portion having a larger diameter than the serration processing portion is provided,
A circumferential molding groove that opens in the outer peripheral surface and extends in the circumferential direction is formed between the rising presser portion at the large-diameter side end of the serration processing portion, and a plurality of circumferential molding grooves are formed with respect to the circumferential molding groove. The end portions on the large diameter side of the inclined direction forming grooves are connected to each other,
An outer peripheral pressing surface that is pressed from an outer peripheral side against an outer peripheral corner portion of the axial end surface of the cylindrical metal fitting is formed by the axial end surface on the serration processing portion side of the rising presser portion. Rolling mold.   The first rolling mold having the serration portion on the outer peripheral surface and the second rolling mold having the rising presser portion are separated from each other. The rolling mold according to claim 1, wherein the dynamic mold and the second rolling mold are supported integrally or independently on the same central axis.   The rolling mold according to claim 2, wherein materials of the first rolling mold and the second rolling mold are different from each other.   The rolling mold according to any one of claims 1 to 3, wherein a coating treatment is applied to a molding surface of at least one of the first rolling mold and the second rolling mold. .   2. The inner wall surfaces on both sides in the circumferential direction in the circumferential molding groove are inclined surfaces in a direction of gradually widening on both sides in the width direction toward the axial end surface of the cylindrical metal fitting that is a molding surface. The rolling mold according to any one of -4.   A rounded chamfered curved surface is formed at the opening edge of the inner surface of the wall on the serration processing portion side in the circumferentially formed groove with respect to a connecting corner portion with the tapered outer peripheral surface of the serration processing portion. The rolling mold according to claim 5.   The rolling mold according to claim 1, wherein a bottom surface of the circumferential molding groove is a flat surface. Using the rolling mold described in any one of claims 1 to 7,
The tapered outer peripheral surface of the rolling mold is arranged with the small diameter side of the serration processing portion in the rolling mold facing the inner peripheral side of the cylindrical metal fitting and the large diameter side facing the outer peripheral side of the cylindrical metal fitting. The cylindrical fitting is pressed against the axial end face of the cylindrical fitting and rolled in the circumferential direction while pressing the outer peripheral pressing surface of the rolling mold against the outer peripheral corner of the axial end face of the cylindrical fitting. Applying plastic working with the rolling mold to the axial end face of
On the axial end surface of the cylindrical metal fitting, a plurality of non-slip protrusions are formed in a radially extending projecting shape in the radial direction, and project outward in the axial direction at the outer peripheral edge portion and extend in the circumferential direction. A method for manufacturing a cylindrical metal fitting, wherein an annular water blocking protrusion is formed simultaneously.   9. The chamfering process is performed on at least one of an outer peripheral side corner and an inner peripheral side corner of the axial end portion of the cylindrical metal fitting in the same process as the process by the rolling mold or an earlier process. Manufacturing method of cylindrical metal fittings.   In accordance with the method for manufacturing a cylindrical metal fitting according to claim 8 or 9, after plastic processing by the rolling mold is respectively performed on the end surfaces on both axial sides of the cylindrical metal fitting, the outer peripheral surface of the cylindrical metal fitting is applied. A method of manufacturing a vibration-proof rubber bush, characterized by vulcanizing and bonding a main rubber elastic body.

Images