JP4734267B2 - Gear forming equipment - Google Patents

Description

  The present invention relates to a gear forming apparatus having a gear tooth portion and a boss portion, and a plurality of reverse taper spline teeth formed on the boss portion.

  2. Description of the Related Art Conventionally, for example, a manual transmission gear for an automobile is known, and a reverse-tapered spline tooth is formed on a boss portion of the manual transmission gear to prevent the gear from coming off.

  With regard to this type of gear, for example, in Patent Document 1, a spline tooth groove is formed in parallel to the gear axis with respect to a boss of a gear material, and then radially around the gear material so as to face the tooth groove. And a plurality of dies whose tips are formed in a shape corresponding to the inversely tapered spline teeth are pushed inward in the radial direction into the tooth grooves, and further, the plurality of dies are spring-backed by the spline teeth. It is disclosed that a splined gear is manufactured by reversing the position of the gear.

  In this case, in Patent Document 1, a holding groove in which the plurality of dies are arranged at equal intervals around the work, and the plurality of dies formed on the outer peripheral surface of the holding groove are slid in a slanting vertical direction. The provision of a die guide having a guide surface is described.

  Patent Document 2 discloses a gear member forging and forming apparatus for forging a spline tooth with a chamfer formed on the outer periphery of a boss portion of a gear member to form a spline tooth with a chamfer having a reverse taper shape, It is disclosed to provide a plurality of segment dies for forming reverse-tapered spline teeth on the outer periphery of the boss portion.

  In this case, Patent Document 2 relates to a ring member in which a guide surface that surrounds a plurality of segment dies and contacts the outer peripheral surface of the segment die is formed on the inner peripheral portion, and an inner end portion of the plurality of segment dies. And providing a segment guide in which a plurality of guide grooves are formed.

Japanese Patent Laid-Open No. 2001-1101 JP 2000-140983 A

  However, the die guide, ring member, segment guide, and the like provided in Patent Document 1 and Patent Document 2, respectively, have a plurality of reverse-tapered spline teeth that are substantially the same along the outer peripheral surface of the boss portion. In order to manufacture a gear member formed uniformly at an angular separation, it is intended to guide the operation of a single type of die or segment die having the same shape, for example, a plurality of spline teeth having a reverse taper shape. However, it is difficult to apply to a gear member having a missing tooth composed of a partial peripheral surface in which a particular spline tooth is notched.

  That is, different types of segment dies are required, each of which includes one or more first segment dies for forming missing teeth and a plurality of second segment dies for forming spline teeth. In order to form a spline tooth profile in which the tooth surface shape is straight and the tooth surface shape on the other side is a back taper (reverse taper), it is necessary to form both tooth surfaces of the spline teeth substantially simultaneously.

  For this reason, the first segment die that forms the missing teeth and the second segment die that forms the spline teeth are actuated, respectively, and the respective tooth portions of the first segment die and the second segment die are arranged on the outer peripheral surface of the molding material. It is necessary to parallelly move toward the radial inward direction of the molding material and press it to form both tooth surfaces of the spline teeth.

  In this case, the first segment die that forms one side tooth surface of the spline tooth and forms the missing tooth moves in parallel with a delay relative to the second segment die that forms the other side tooth surface of the spline tooth. In order to press the outer peripheral surface of the molding material, it is difficult to form spline teeth having a desired tooth profile shape in which one side tooth surface is straight and the other side tooth surface is a back taper (reverse taper). It was. Therefore, conventionally, one side surface of the spline tooth of the forged molded product has been formed into a desired shape by machining.

  The present invention has been made in view of the above points, and is provided with a guide function for preventing a delay operation of the first segment die forming the missing teeth with respect to the second segment die forming the spline teeth. An object of the present invention is to provide a gear forming apparatus.

In order to achieve the above object, the present invention is a gear molding apparatus having a gear tooth portion and a boss portion, wherein a plurality of reverse tapered spline teeth are formed on the boss portion,
An annular holder provided in the lower mold,
In the circular opening of the holder, it is divided and arranged radially in plan view, and a receiving seat is formed on which the molded body is placed when the mold is opened, and is displaced along the radial direction of the holder. A first segment die that is provided freely and has a tooth portion that forms a missing tooth with respect to the outer peripheral surface of the molded body, and a second that has a tooth portion for forming spline teeth with respect to the outer peripheral surface of the molded body. Segment die,
A die support for floatingly supporting the first segment die and the second segment die via an urging means;
A pressing member that is provided on an up and down movable upper mold and pressurizes the first segment die and the second segment die downward;
An upper mold main body provided with a recess that engages with an upper part of the molded body, and is provided so as to be displaced along the inner wall surface of the pressing member;
Guide means provided on the inner wall surface of the holder so as to be detachable and replaceable, and formed with a guide surface that comes into contact with the inclined surface of the first segment die;
It is characterized by providing.

  According to the present invention, first, the holders of the plurality of first segment dies and second segment dies that are arranged in a radial shape in plan view in the circular opening of the holder and that are in the mold open state are covered. After placing the molded body, the upper mold is lowered and the molded body is held by the upper mold main body, and the first segment die and the second segment die are moved by a pressing member fitted on the upper mold main body. Pressurize downward.

  The first segment die and the second segment die that are divided into a plurality of parts are pressed at substantially the same time, whereby the first inclined surface formed on the outer diameter portion of the first segment die and the outside of the second segment die. The first segment die and the second segment die move horizontally in the radial inward direction when the second inclined surface formed in the diameter portion slides along the inner wall of the holder.

  After the outer peripheral surface of the molded body is pressed by the teeth of the first segment die and the second segment die that move horizontally, the missing teeth and the spline teeth are respectively molded on the outer peripheral surface of the molded body. The one-segment die and the second segment die are respectively displaced in the radially outward direction away from the molded body, and the molded body is taken out.

  In this case, in the present invention, by providing a guide means having a guide surface that is in sliding contact with the first inclined surface of the first segment die, the delay operation of the first segment die with respect to the second segment die can be prevented, The tooth portions of the first segment die and the tooth portions of the second segment die press the outer peripheral surface of the molded body substantially simultaneously, and the missing teeth and the spline teeth are formed substantially simultaneously.

  The guide means is constituted by, for example, a guide plate attached to the inner wall surface of the holder and having a predetermined plate thickness, and the guide surface of the guide plate has the same inclination angle as the inclined surface of the first segment die. It is preferable to provide a plurality of guide plates that differ only in the thickness. By appropriately selecting a guide plate having a desired plate thickness from among a plurality of guide plates, the amount of movement when the first segment die moves horizontally can be appropriately set or adjusted.

  In the present invention, by providing guide means formed with a guide surface that contacts the inclined surface of the first segment die, the first segment die is prevented from being delayed with respect to the second segment die, and the first segment die is The tooth portion and the tooth portion of the second segment die press the outer peripheral surface of the molded body substantially simultaneously, and the missing teeth and the spline teeth can be formed substantially simultaneously.

  As a result, in the present invention, machining as post-processing which has been conventionally performed is unnecessary, and the tooth profile shape of the desired both side tooth surfaces of the spline teeth can be formed by a single forging process.

  Preferred embodiments of the gear forming apparatus according to the present invention will be described below and described in detail with reference to the accompanying drawings.

  First, a process for forming a mission gear as a product will be briefly described.

  A primary molded body 16 in which the outer peripheral surface 14 of the intermediate portion swells radially outward is formed by performing upsetting on the billet 12 including the cylindrical body shown in FIG. 10A (see FIG. 10B). Subsequently, roughing is performed to form recesses 18a and 18b at one end and the other end along the axial direction of the primary molded body 16 to form the secondary molded body 20 (see FIG. 10C). . After forming the secondary molded body 20, by performing upset molding on the secondary molded body 20, preliminary spline teeth 24 are formed on the outer peripheral surface of the boss portion 22, and at the intermediate portion. A third molded body 28 having an annular convex portion 26 projecting outward in the radial direction is formed (see FIG. 10D).

  Further, the hole of the third molded body 28 is pierced to form a fourth molded body 30 having a through hole 29 (see FIG. 10E), and then the fourth molded body 30 is formed. Sizing is performed to form a fifth molded body (not shown), and then one side tooth surface with respect to the preliminary spline teeth 24 formed on the outer peripheral surface of the boss portion 22 of the fifth molded body. A sixth formed body 38 is formed having a plurality of spline teeth 36 and missing teeth 37 in which 32 is straight and the other one-side tooth surface 34 is formed into a back taper (reverse taper) (FIGS. 10F and 11). reference). By forming helical gear teeth on the outer peripheral surface of the annular convex portion 40 of the sixth molded body 38, a mission gear that is a product is finally obtained.

  1 to 4, reference numeral 100 functions as a gear forming device according to an embodiment of the present invention, and forms a back taper or the like with respect to the fifth formed body to form a sixth formed body 38. Consists of a forging machine for forging.

  The forging apparatus 100 includes a lower mold 102 and an upper mold 104 that is attached to a ram of a crank press machine (not shown) and is provided so as to be movable up and down.

  The lower mold 102 is formed of a substantially rectangular parallelepiped block body, and a die base 106 in which a space portion penetrating in the vertical direction is formed. The lower mold 102 is fixed to the upper surface of the die base 106 with a plurality of bolts 108. A plate-like support die 110 and a plurality of bolts 112 arranged along the circumferential direction are fixed to the upper surface of the support die 110, and an inner wall surface 114 that gradually decreases in diameter toward the lower side is formed at the center. And an annular cover member 122 that is fixed to the upper surface of the holder 116 and restricts upper limit positions of a first segment die 118 and a second segment die 120, which will be described later.

  Further, the lower die 102 is stacked in the vertical direction in the space of the die base 106 and is held by the support die 110, and a support 128 is provided at the center of the die block 126. A substantially disc-shaped segment guide 134 formed with first guide grooves 132 that are fixed to each other and engage with an inner diameter portion 150 of the first segment die 118 and an inner diameter portion 152 of the second segment die 120, which will be described later, respectively. The first support member 136a and the second support member 136b that are disposed on the lower side of the guide 134 and support the segment guide 134, and an annular body that surrounds the outer periphery of the segment guide 134, are formed on the die block 126. Die support phosphorus provided so as to be displaceable along the annular recess 138 formed Body (die support) and a 140.

  Furthermore, the lower mold 102 is continuous with the annular recess 138 of the die block 126, and a plurality (six in FIG. 4) are formed at equal angular intervals along the circumferential direction of the die block 126. ) And a plurality of springs that support the die support ring body 140 in a floating manner under the action of the spring force. A plurality of first segment dies 118 and second segment dies supported on the member 144 and the die support ring body 140 and radially divided in a circular opening of the holder 116 in plan view. 120.

  As shown in FIGS. 5 and 6A to C, the first segment die 118 is formed of a substantially L-shaped body formed with a thick wall and has four separation angles of 90 degrees along the circumferential direction. A tooth portion 146 is provided (see FIG. 4) and protrudes inward in the radial direction by a predetermined length to form a missing tooth on the inner diameter portion at the upper end. On the other hand, as shown in FIG. 7, each of the second segment dies 120 is formed of a substantially L-shaped body formed thin, and four each of the second segment dies 120 are arranged between the adjacent first segment dies 118, for a total of 16 pieces. A tooth portion 148 for forming spline teeth on the outer peripheral surface of the boss portion of the molded body is formed so as to protrude inward in the radial direction by a predetermined length.

  Each of the first segment die 118 and the second segment die 120 has an inclined surface continuous downward from the tooth portions 146 and 148 and engages with the first guide groove 132 of the segment guide 134. Inner diameter portions 150 and 152 are formed.

  Further, the first segment die 118 is provided with a first inclined surface 156 that comes into contact with a guide plate 160, which will be described later, on the side opposite to the tooth portion 146, and the first inclined surface 156 is in relation to the vertical surface (V). It is set to tilt about 7 degrees. The second segment die 120 is provided with a second inclined surface 158 that contacts a second guide groove of a holder 116, which will be described later, on the side opposite to the tooth portion 148, and the second inclined surface 158 is a vertical surface (V). It is set to be inclined about 10 degrees with respect to the angle.

  Thus, the inclination angle (θ1) of the first inclined surface 156 formed on the outer diameter portion of the first segment die 118 and the inclination angle of the second inclined surface 158 formed on the outer diameter portion of the second segment die 120 ( By setting θ2) to be different from each other (θ1 <θ2), the tooth portion 146 of the first segment die 118 and the tooth portion 148 of the second segment die 120 substantially extend the outer peripheral surface of the boss portion of the molded body. By pressing simultaneously, the missing teeth and the spline teeth are formed almost simultaneously.

  Furthermore, between the plurality of first segment dies 118 and the holder 116, there is a guide surface 159 that is in sliding contact with the first inclined surface 156 of the first segment die 118, and functions as a guide means. 160 are provided.

  Each guide plate 160 is detachably and replaceably attached to the inner wall surface 114 of the holder 116 by a bolt 162. The guide surface 159 of the guide plate 160 is formed at the same angle as the inclination angle (θ1) of the first inclined surface 156 of the first segment die 118.

  That is, a plurality of types of guide plates (not shown) that differ only in the thickness of the guide plate 160 are prepared, and a guide plate having a predetermined thickness is appropriately selected from the prepared types of guide plates. Thus, the amount of movement along the radial direction of the first segment die 118 can be set to a predetermined amount. Further, the movement amount of the first segment die 118 along the radial direction is finely adjusted by replacing the guide plate 160 mounted on the inner wall surface of the holder 116 with a guide plate (not shown) having a predetermined plate pressure. It becomes possible.

  A second inclined surface 158 formed on the outer diameter side of the second segment die 120 is slidably contacted with the inner wall of the holder 116 to thereby guide the second segment die 120 along the radial direction. A groove 163 is formed. The second guide grooves 163 are arranged at a predetermined angle along the circumferential direction corresponding to the arrangement of the second segment die 120, and the first guide of the segment guide 134 described above when forging the workpiece. It has a function of preventing the second segment die 120 from swinging in the circumferential direction under the cooperative action with the groove 132 and accurately displacing the tooth portion 148 of the second segment die 120 toward the center of the holder 116. .

  For example, if the tooth surface shapes on both sides of the spline teeth are both back-tapered (reverse taper), the tooth surface shapes on both sides are symmetrical, so that a symmetrical force is applied to each segment die. On the other hand, when the tooth surface shape on one side is straight and only the tooth surface shape on the other side forms a spline tooth shape having a back taper (reverse taper), the tooth surface shape on both sides is Because of the asymmetry, the segment collapses due to an asymmetric force (the force applied to the segment taper on the back taper side is larger than the straight side) between the segment die on the straight side and the segment die on the back taper side. May occur. However, in the present embodiment, the first segment die is under the cooperative action of the first guide groove 132 of the segment guide 134 and the plurality of second guide grooves 163 that guide the second segment die 120 along the radial direction. 118 and the second segment die 120 can be prevented from swinging in the circumferential direction, and the segment collapse can be suitably prevented.

  The upper mold 104 has a lifting member 164 provided so as to be movable up and down along a vertical vertical direction under the driving action of a ram (not shown), and is fixed to the lifting member 164 and is integrally displaced with the lifting member 164. A pressing member 166 that abuts on the upper surfaces of the first segment die 118 and the second segment die 120 and pressurizes the first segment die 118 and the second segment die 120 toward the lower side, respectively, and a molding member at the center. A concave portion 168 that engages with the upper portion is formed, and an upper mold main body portion 172 that is displaceable along the vertical direction of the inner wall surface of the pressing member 166 by the spring force of the spring member 170 is provided.

  The upper die main body 172 is formed with a sliding portion 174 that engages with the inner wall surface of the cylindrical pressing member 166, and the pressing member 166 is used for the first segment die 118 and the second segment die 120. When the upper mold main body 172 is pressed against the upper surface and pressed downward, a recess 168 formed at the tip of the upper mold main body 172 engages with the molded body, and the upper mold main body is maintained while maintaining the engaged state. The portion 172 overcomes the spring force of the spring member 170 and is displaced upward.

  The forging and forming apparatus 100 that functions as the gear forming apparatus according to the present embodiment is basically configured as described above. Next, the operation, operation, and effect thereof will be described in detail.

  First, the 5th molded object shape | molded through the shaping | molding process as shown to FIG. 10A-E is made into a to-be-molded body, The said 1st segment die | dye 118 and the 2nd segment die 120 which are the mold open states It is mounted on a seat formed on the upper end of the. Therefore, an elevating means (not shown) is energized to lower the upper mold main body 172 and the pressing member 166 integrally with the elevating member 164, and a plurality of first segment dies 118 and second segments are formed by the distal end of the pressing member 166. All the segment dies composed of the dies 120 are pressed toward the lower side substantially simultaneously.

  Each of the first segment dies 118 and the second segment dies 120 is pressed downward by the annular pressing member 166 so that all the segment dies including the plurality of first segment dies 118 and the second segment dies 120 are simultaneously pressed downward. The outer diameter surface (inclined surface) is guided by the guide surface 159 of the guide plate 160 and the second guide groove 163 of the holder 116, and the inner diameter surface is guided by the first guide groove 132 of the segment guide 134. It is displaced toward the inside in the direction (center of holder 116).

  Therefore, for the spline teeth with the chamfer formed on the outer periphery of the boss portion of the molded body, the missing teeth 37 are forged by the tooth portions 146 of the first segment die 118 and the teeth of the second segment die 120 are formed. The back taper spline teeth 36 are forged by the portion 148 (see FIG. 11).

  Subsequently, the first segment die 118 and the second segment die 120 are moved from the center along the first guide groove 132 and the second guide groove 163 by raising a knockout pin (not shown) under the driving action of an actuator (not shown). The sixth molded body 38 that has been displaced and moved upward in the direction of separation is gripped by gripping means (not shown), so that it is transferred to the next step.

  In this case, in the present embodiment, the first inclined surface 156 of the first segment die 118 that slides along the guide surface 159 of the guide plate 160 is set to be inclined about 7 degrees with respect to the vertical surface (V). The second inclined surface 158 of the second segment die 120 that slides along the second guide groove 163 of the holder 116 is set so as to be inclined about 10 degrees with respect to the vertical surface (V). The first inclination angle (θ1) of the first segment die 118 forming the teeth 37 is set to be smaller than the second inclination angle (θ2) of the second segment die 120 (θ1 <θ2).

  Therefore, in the present embodiment, the inclination angle between the first inclined surface 156 formed on the outer diameter portion of the first segment die 118 and the second inclined surface 158 formed on the outer diameter portion of the second segment die 120 ( θ1 and θ2) are set to be different from each other, and by providing the guide plate 160 with which the guide surface 159 comes into contact with the outer diameter surface (first inclined surface 156) of the first segment die 118, the first segment The amount of horizontal movement in the radial inward direction between the die 118 and the second segment die 120 is set to be different. Note that the first segment die 118 and the second segment die 120 are displaced in the vertically downward direction by the pressing of the pressing member 166.

  As a result, in the present embodiment, the horizontal movement amount of the first segment die 118 in the radial inward direction is set to be smaller than the horizontal movement amount of the second segment die 120 in the radial inner direction. The delayed operation of the first segment die 118 with respect to the segment die 120 can be prevented, and the tooth portion 146 of the first segment die 118 and the tooth portion 148 of the second segment die 120 are the outer peripheral surface of the boss portion 22 of the molded body. Can be formed substantially simultaneously with the missing teeth 37 and the spline teeth 36.

  Thus, in the present embodiment, in order to form the tooth profile shape of the spline tooth 36 in which the shape of the one side tooth surface 32 is straight and the shape of the other one side tooth surface 34 is a back taper (reverse taper). It is necessary to form both side tooth surfaces 32 and 34 of the spline teeth 36 at substantially the same time. The guide surfaces 159 are detachably and replaceably attached to the inner wall surface of the holder 116 and slidably contact the first inclined surface 156 of the first segment die 118. By providing the guide plate 160 having a predetermined thickness, the delay operation of the first segment die 118 relative to the second segment die 120 can be prevented, and the tooth portion 146 and the first portion 146 of the first segment die 118 can be prevented. The tooth part 148 of the two-segment die 120 presses the outer peripheral surface of the boss part 22 of the fifth molded body substantially simultaneously, and the missing tooth 37 and the spline tooth 6 substantially to can be molded simultaneously.

  On the other hand, the first inclined surface 156 of the first segment die 118 for forming the missing teeth 37 and the second inclined surface 158 of the second segment die 120 for forming the spline teeth 36 have the same inclination angle. When the guide plate 160 is not provided (θ1 = θ2), the horizontal movement amount in the radial inward direction of the first segment die 118 and the second segment die 120 is the same, and one side of the spline teeth 36 is set. The first segment die 118 that forms the tooth surface 32 and the missing tooth 37 operates with a delay with respect to the second segment die 120 that forms the other one-side tooth surface 34 of the spline tooth 36, and the molded object In order to press the outer peripheral surface of the boss portion 22 with a time lag, one one-side tooth surface 32 is a straight and the other one-side tooth surface 34 is a back taper (reverse tape). The spline teeth 36 having a desired tooth profile shape composed of a super-type) cannot be formed.

  The reason why the first segment die 118 forming the missing teeth 37 is delayed with respect to the second segment die 120 forming the other one-side tooth surface 34 of the spline teeth 36 is as shown in FIG. The segment width of the first segment die 118 orthogonal to the axis is set larger than the segment width of the second segment die 120, and the left side portion of the spline teeth 36 in FIG. And the right portion of the spline teeth 36 are different in the pressing force by the tooth portion 146 of the first segment die 118 and the tooth portion 148 of the second segment die 120 (the pressing force of the second segment die 120 is different from the first segment die 120). The first segment die 118 having a large segment width is larger than the second segment die 120). This is because to operate with a delay.

  In other words, in FIG. 12, the tooth portion 146 of the first segment die 118 that engages the axis of the first segment die 118 passing through the center of the gear, the intersection of the lines orthogonal to the axis, and the right side portion of the spline teeth 36. A second right-angled triangle that engages with the axis of the second segment die 120 passing through the center of the gear, the intersection of the lines perpendicular to the axis, and the left portion of the spline teeth 36. Assume a second right triangle connecting the tooth portion 148 of the segment die 120. In this case, the length of the hypotenuse S1 of the first right triangle is set larger than the length of the hypotenuse S2 of the second right triangle (S1> S2), and the tooth portion 146 and the second segment of the first segment die 118 are set. Since the pressure applied by the teeth 148 of the die 120 is different, the first segment die 118 having a large segment width operates with a delay relative to the second segment die 120.

  In addition, since the contact area between the first inclined surface 156 of the first segment die 118 and the guide surface 159 of the guide plate 160 can be set relatively large, the rotation of the first segment die 118 in the circumferential direction can be performed. There is an advantage that the horizontal movement in the radial inward direction can be smoothly performed.

It is a longitudinal section structure figure of a forge forming device which functions as a gear forming device concerning an embodiment of the invention. The upper die is lowered from the state shown in FIG. 1, the first segment die and the second segment die are pressurized, and the first segment die and the second segment die are horizontally moved inward in the radial direction, respectively. It is a longitudinal cross-sectional view. It is a perspective view of the lower mold | type which comprises the forge molding apparatus shown in FIG. It is a top view of the lower mold | type which removed the cover member from the lower mold | type shown in FIG. It is a perspective view of the 1st segment die which constitutes the forge forming device shown in FIG. 6A is a plan view of the first segment die, FIG. 6B is a side view of the first segment die, and FIG. 6C is a front view of the first segment die. It is a perspective view of the 2nd segment die which constitutes the forge forming device shown in FIG. 8A is a plan view of the second segment die, FIG. 8B is a side view of the second segment die, and FIG. 8C is a front view of the second segment die. It is a partially cutaway perspective view which shows the 2nd guide groove provided in the holder which comprises the forge molding apparatus shown in FIG. FIGS. 10A to 10F are explanatory views showing a mission gear forming process. FIG. 2 is a perspective view showing a state in which missing teeth and spline teeth are formed on the outer peripheral surface of a boss portion of the molded body, which is forged by the forging apparatus shown in FIG. 1. It is a figure with which the 1st segment die | dye which forms a missing tooth is used for description for a delay operation | movement with respect to the 2nd segment die | dye which forms the other one-side tooth surface of a spline tooth | gear.

Explanation of symbols

22 ... boss part 32, 34 ... tooth surface 36 ... spline tooth 37 ... missing tooth 38 ... molded body 40 ... annular convex part 100 ... forging molding device 102 ... lower mold 104 ... upper mold 116 ... holder 118 ... first segment die 120 ... 2nd segment die 132 ... 1st guide groove 134 ... Segment guide 140 ... Die support ring body 144, 170 ... Spring member 146, 148 ... Tooth part 150, 152 ... Inner diameter part 156 ... 1st inclined surface 158 ... 2nd inclination Surface 159 ... Guide surface 160 ... Guide plate 163 ... Second guide groove 166 ... Pressing member 168 ... Recess 172 ... Upper mold body 174 ... Sliding part

Claims (2)

A gear forming device having a gear tooth portion and a boss portion, wherein the boss portion is formed with a plurality of reverse tapered spline teeth,
An annular holder provided in the lower mold,
In the circular opening of the holder, it is divided and arranged radially in plan view, and a receiving seat is formed on which the molded body is placed when the mold is opened, and is displaced along the radial direction of the holder. A first segment die that is provided freely and has a tooth portion that forms a missing tooth with respect to the outer peripheral surface of the molded body, and a second that has a tooth portion for forming spline teeth with respect to the outer peripheral surface of the molded body. Segment die,
A die support for floatingly supporting the first segment die and the second segment die via an urging means;
A pressing member that is provided on an up and down movable upper mold and pressurizes the first segment die and the second segment die downward;
An upper mold main body provided with a recess that engages with an upper part of the molded body, and is provided so as to be displaced along the inner wall surface of the pressing member;
Guide means provided on the inner wall surface of the holder so as to be detachable and replaceable, and formed with a guide surface that comes into contact with the inclined surface of the first segment die;
Equipped with a,
Said guide means is mounted on the inner wall surface of the holder, the gear forming apparatus according to claim Rukoto such a guide plate having a predetermined plate thickness. The apparatus of claim 1 .
A gear forming apparatus, wherein the guide surface of the guide plate is provided with a plurality of guide plates having the same inclination angle as that of the inclined surface of the first segment die and differing only in thickness.

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