JP4804292B2 - Forging device for molded product having undercut part - Google Patents

Description

  In the present invention, a first upsetting part and a second upsetting part are formed at both ends along the axial direction by forging the intermediate formed body, and the first upsetting part The present invention relates to a forged molding apparatus for a molded product having an undercut portion capable of obtaining a molded product in which an undercut portion is provided between the second upset molding portion and the second upset molding portion.

  Conventionally, it is known to manufacture a member having an undercut portion by forging.

  For example, Patent Document 1 discloses an annular projecting portion that is divided into a plurality of portions in the circumferential direction and projects inward in the radial direction corresponding to the shape of the contact surface and the undercut portion formed at one end portion in the axial direction. A lower mold that supports the member to be molded from the outside in the radial direction, and a seat surface that can come into contact with the abutment surface, and the axial direction from the abutment surface side to the radially outer side of the lower mold And an upper die that can be tightened from the radially outer side to the inner side.

  Further, Patent Document 2 includes a movable plate having a split-type knockout pin and a knockout pin, and guide means for guiding each split mold at a predetermined angle with respect to the movable direction of the split mold. A mold apparatus has been disclosed in which the time required for mold release is shortened to improve work efficiency by simultaneously performing the protrusion in one operation.

  Furthermore, Patent Document 3 is formed in a cylindrical shape having a through hole in the center, and annular flange portions protruding outward are formed at both end portions along the axial direction, respectively, on the outer periphery of one or the other annular flange portion. A toothed molded product having a tooth portion formed therein is disclosed.

JP 2002-346683 A Japanese Patent Laid-Open No. 9-239740 JP-A-6-114486

  However, in the technical idea disclosed in Patent Documents 1 to 3, it is only possible to bulge and form a single upset part by, for example, one forging (upset forming) process, The first upsetting part and the second upsetting part are formed almost simultaneously at both ends along the axial direction by one upsetting process, and the first upsetting part and the second upsetting part are formed. It is difficult to obtain a molded product in which an undercut part is provided between the parts.

  Further, the first movable punch and the second movable punch arranged coaxially are used, and the objects to be molded sandwiched between the first movable punch and the second movable punch are brought close to each other. It is conceivable to pressurize in the axial direction to bulge and form the first upsetting part and the second upsetting part at both ends along the axial direction.

  However, in this case, two driving mechanisms for driving the first movable punch and the second movable punch are required, and each of the first movable punch and the second movable punch is added. There is a problem that the amount of meat flow distributed to the first upsetting portion and the second upsetting portion must be adjusted by controlling the pressure.

  The present invention has been made in view of the above-mentioned problems and the like, and the first upsetting at both end portions along the axial direction is achieved by a simple single forging process that does not require adjustment of the amount of flow of meat to be distributed. An undercut portion in which a molded portion and a second upset molding portion are formed and a molded product having an undercut portion between the first upset molding portion and the second upset molding portion can be obtained. An object of the present invention is to provide a forging device for a molded product having

In order to achieve the above-mentioned object, the present invention is directed to a molded body comprising a cylindrical annular side wall portion extending by a predetermined length parallel to the axial direction and a solid portion continuous to the annular side wall portion . A forging molding apparatus that performs forging molding and obtains a molded product having an undercut portion ,
A plurality of split molds that are divided into a plurality along the circumferential direction to surround the molded body, and that are provided so as to be separated from the molded body when the mold is opened,
A lower mold that is provided at the center of the split mold and on which the molded body is placed;
A biasing means for supporting the plurality of split molds in a floating manner;
Disposed on the lower die coaxially, a single punch is provided vertically movably,
With
The punch is formed with a first molding portion that plastically deforms the annular side wall portion of the molded body in a radially outward direction and pressurizes the solid portion toward the lower mold,
The inner wall of the split mold includes an undercut molding portion formed of an annular projection that engages with a boundary portion between the annular side wall portion and the solid portion of the molded body, and a lower side continuous from the undercut molding portion. A second molded part formed of an annular recess formed ,
The lowered punch is formed by plastically deforming the annular side wall portion in the radially outward direction at the first molding portion, and further plastically deforming the solid portion in the radially outward direction. It is fluidized in the second mold portion and said Rukoto.

  In this case, the biasing means may be formed of a spring member, and the spring member may be provided so as to displaceably support a guide type member that guides the plurality of split dies upward in the radial direction.

  According to the present invention, first, a cylindrical billet is pressed and subjected to backward extrusion to form a cylindrical annular side wall extending in a predetermined length parallel to the axial direction and a circle continuous to the annular side wall. An intermediate formed body composed of a columnar solid part is formed.

  Next, the intermediate molded body is used as a molded body, and the molded body is loaded into a cavity formed by a plurality of split molds and lower molds urged so as to be displaced by the urging means.

  Subsequently, the punch is lowered, and the first upsetting that plastically deforms the annular side wall portion of the molded body radially outward by the first molding portion of the punch while the split mold surrounding the molded body is lowered. By performing the molding, a first upset molding portion is formed on one end side in the axial direction of the molding target.

  Subsequently, the punch is further lowered, the solid portion is pressed while the punch is in contact with the solid portion of the workpiece and the solid portion is pressurized and the split mold surrounding the workpiece is lowered. A second upsetting that is plastically deformed radially outward is performed. By the second upset molding, the plastically deformed meat flows into the second molding part of the split mold and is filled, so that the second upset molding part is formed on the other end side in the axial direction of the molded body. And an undercut part is formed between the first upset part and the second upset part by the undercut part of the split mold.

  As described above, according to the present invention, the split mold urged by the urging means is disposed in a displaceable state, and the workpiece is pressed in the axial direction by a single punch, so that the first and first The first upsetting part and the second upsetting part are formed substantially simultaneously at both end portions along the axial direction by a single upsetting process of performing the upsetting process of 2; A molded body in which an undercut portion is formed between the first upset molding portion and the second upset molding portion is obtained.

  The distribution of the meat flow between the first upsetting part and the second upsetting part is a split undercut forming part that abuts on the boundary portion between the annular side wall part and the solid part of the molded body. Made by.

  By pressing the workpiece in the axial direction with a single punch, the first upsetting portion and the second upsetting portion are formed at both ends along the axial direction, and the first upsetting portion is formed. A molded body having an undercut portion between the molded portion and the second upset molded portion can be obtained.

  A preferred embodiment of a forging apparatus for a molded product having an undercut portion according to the present invention will be described in detail below with reference to the accompanying drawings.

  The manufacturing process of the transmission gear 10 manufactured using the forging apparatus according to the embodiment of the present invention is shown in FIGS. 1A to 1E.

  The transmission gear 10 is manufactured through a plurality of forging processes described below. 1A to 1D are preferably performed by warm or hot forging.

  First, after a preliminary process of forming a preform 16 (see FIG. 1B) in which a positioning recess 14 is formed on the bottom surface of the billet made of the cylindrical body 12 shown in FIG. 1A, a first forging device (not shown) is formed. The first molded body (molded body) 18 is obtained by performing backward extrusion molding on the preformed body 16 using (see FIG. 1C).

  On one end side along the axial direction of the primary molded body 18, a thin cylindrical annular side wall portion 20 is formed which is extended by a predetermined length parallel to the axial direction by backward extrusion, and the other end in the axial direction is formed. On the side, a cylindrical solid portion 22 that is continuous with the annular side wall portion 20 and is similar to the preform 16 is formed.

  Subsequently, by performing upset molding on the primary molded body 18 using the second forged molding apparatus according to the present embodiment, which will be described later, with the primary molded body 18 as a molded body, FIG. A secondary molded body (molded product) 24 as shown in 1D is obtained.

  The secondary molded body 24 includes a first upset molding portion 26a and a second upset molding portion 26b that are expanded in diameter by a predetermined length toward both ends along the axial direction. An undercut portion 28 is formed between the first upsetting portion 26a and the second upsetting portion 26b. The undercut portion 28 is annularly recessed by a predetermined length in the radial inward direction. In this case, the outer diameter of the side peripheral wall 30 of the first upset molding portion 26a on one end side is formed larger than the outer diameter of the side peripheral wall 32 of the second upset molding portion 26b on the other end side.

  The undercut portion 28 is substantially flat and extends along a horizontal direction substantially orthogonal to the axial direction through a corner R portion 34 having a curved cross section that is continuous with the side peripheral wall 30 of the first upsetting portion 26a. A first annular wall surface 36, a tapered portion 38 that is inclined by a predetermined angle with respect to the first annular wall surface 36 and gradually decreases in diameter toward the second upset molding portion 26b, and an axial direction continuous to the tapered portion 38 And a second annular wall surface 40 extending substantially parallel to the second annular wall surface 40 and a substantially flat third annular wall surface 42 extending along a horizontal direction that is continuous with the second annular wall surface 40 and substantially orthogonal to the axial direction. .

  In addition, it is provided so as to continue from the third annular wall surface 42 to the side peripheral wall 32 of the second upset molding portion 26b through the corner R portion 44.

  Subsequently, after a piercing process for punching out the solid part 46 of the secondary molded body 24 by a third forging apparatus (not shown), the first upsetting part 26a and the second upsetting part are machined. The first gear portion 48 and the second gear portion 50 are respectively formed on the side peripheral walls 30 and 32 of 26b to obtain the transmission gear 10 (see FIG. 1E) as a product.

  Next, the 2nd forge forming apparatus 60 which concerns on embodiment of this invention is shown in FIGS.

  The second forging apparatus 60 performs upset molding using the primary molded body 18 shown in FIG. 1C as a molded body.

  The second forging apparatus 60 includes a die base 62, a knockout pin 64 provided so as to be vertically displaceable through a through-hole penetrating the center of the die base 62 under the driving action of an actuator (not shown), and the die base A lower mold 66 held on 62 and connected to the tip of the knockout pin 64 so as to be able to move up and down together with the knockout pin 64; And a split mold 68 (see FIG. 4 and FIG. 5) that surrounds the molding target and is provided so as to be separated from the molding when the mold is opened.

  Further, in the second forging apparatus 60, the tapered first annular guide surface 70a and the second annular guide surface 70b for guiding each of the split dies 68 divided upward in the radial direction when the die is opened are provided on the inner wall. The guide mold member 72 formed on the guide mold member 72, the support base 74 for supporting the guide mold member 72, and the split molds provided on the lower side of the guide mold member 72 and divided into four through the guide mold member 72. A spring member 76 that functions as an urging means for supporting 68 in a floating manner, and a cylindrical shape that surrounds the outer peripheral surface of the guide mold member 72, abuts against the annular convex portion 72 a of the guide mold member 72, and the guide An annular step 78a that prevents the mold member 72 from rising is provided with a side mold member 78 formed on the inner wall.

  In this case, the split mold 68 is provided to be displaceable in the vertical direction by an urging means such as a spring member 76 provided on the lower side of the guide mold member 72. As shown in FIG. 2A, the split mold 68 is provided. In a state where no load is applied to 68, the position where the upper surface of the split mold 68 coincides with the alternate long and short dash line H is set as the initial position. The biasing means is not limited to a spring member such as a coil spring or a leaf spring that exerts an elastic force. For example, a buffer mechanism such as a gas spring or a pressure fluid (oil, air) is used. Also good.

  Further, the inner wall adjacent to the lower mold 66 of the split mold 68 protrudes radially inward (substantially in the horizontal direction) and abuts against the boundary portion between the annular side wall portion 20 and the solid portion 22 of the primary molded body 18. An undercut forming portion 80 formed of an annular projecting portion and an annular concave portion formed on the lower side continuous from the undercut forming portion 80, the solid portion 22 of the primary molded body 18 is directed radially outward. And a second molding portion 82 for plastic deformation to form the second upset molding portion 26b.

  As shown in FIG. 10, the undercut forming portion 80 includes a curved portion 81a having a circular arc cross section, a contact portion 81b that is continuous with the curved portion 81a and contacts the object to be molded, and the contact portion 81b. And a horizontal portion 81c extending substantially along the horizontal direction. Between the curved part 81a and the contact part 81b, there is provided a distribution point A for distributing the meat flow to the first upsetting part 26a and the second upsetting part 26b, as will be described later. As shown in the modification of FIG. 11, an undercut forming portion 80a in which the upper surface is a flat surface 81d and the distribution point A is provided at the chamfered portion may be configured.

  As shown in FIG. 10, the second molding portion 82 is provided on the lower side of the undercut molding portion 80, and the second molding portion 82 includes a horizontal plane formed by the horizontal portion 81 c and a vertical plane perpendicular to the horizontal plane. The surface 83a and the inclined surface 83b inclined by a predetermined angle with respect to the vertical surface 83a.

  Further, as shown in FIG. 3, the outer diameter side wall of the split mold 68 includes tapered surfaces corresponding to the first annular guide surface 70a and the second annular guide surface 70b of the guide mold member 72, respectively. A first annular inclined surface 84a and a second annular inclined surface 84b are formed to engage with the first annular guide surface 70a and the second annular guide surface 70b, respectively.

  Furthermore, the second forging apparatus 60 includes an elevating member 86 provided so as to be able to move up and down along the vertical vertical direction under the driving action of a ram (not shown), the punch holder 88 fixed to the elevating member 86, And a punch 90 provided so as to be movable up and down integrally with the lifting member 86 via a punch holder 88. A first molding portion 92 for forming the first upset molding portion 26a by plastically deforming the annular side wall portion 20 of the primary molded body 18 is provided at the tip portion of the punch 90.

  A cylindrical sleeve member 94 that abuts the upper surface of the split mold 68 and regulates the outer diameter of the first upset molding portion 26a when forging is formed on the punch 90, and the sleeve member 94 is The holding member 96 fixed to the elevating member 86 is provided so as to be displaceable along the axial direction of the punch 90.

  In this case, the annular protrusion 94 a formed on the outer diameter surface of the upper end portion of the sleeve member 94 comes into contact with the annular protrusion portion 96 a formed on the inner diameter surface of the lower end portion of the holding member 96, so Is prevented from coming off. An annular recess 98 is formed in the inner wall of the sleeve member 94, and the lower end portion 88a of the punch holder 88 abuts against the bottom surface 99 of the annular recess 98 (see FIG. 6), so that the punch 90 is lowered. Is regulated and reaches bottom dead center.

  The second forging apparatus 60 according to the present embodiment is basically configured as described above. Next, its operation and effects will be described in detail based on FIGS. 2A to 2F. To do.

  First, the primary molded body 18 shown in FIG. 1C is loaded into the cavity formed by the lower mold 66 and the split mold 68 divided into four parts. Therefore, an elevating means (not shown) is energized to lower the punch 90 integrally with the elevating member 86, and as shown in FIG. 2A, the first forming portion 92 formed on the front end surface of the punch 90 is the primary. It engages with the annular side wall 20 of the molded body 18 (see FIG. 3).

  In this case, the undercut molding part 80 of the split mold 68 is in contact with the boundary portion between the annular side wall part 20 and the solid part 22 which are the outer surfaces of the primary molded body 18, and the split mold 68 is It is biased to the initial position by biasing means such as the spring member 76 without being displaced downward.

  Subsequently, as shown in FIGS. 2B and 2C, when the punch 90 further descends toward the lower die 66, the annular side wall portion 20 of the primary molded body 18 is undercut by the first molding portion 92 of the punch 90. The first upsetting molding starting from the forming portion 80 and starting to increase the diameter in an oblique direction is started, and the first upsetting forming portion 26a and the second upsetting portion 26a are set as starting points (distribution points A). The meat flow with the upsetting part 26b is distributed.

  In this case, a first upset molding in which the annular side wall portion 20 of the primary molded body 18 is plastically deformed corresponding to the shape of the first molded portion 92 of the punch 90 is performed, so that One upsetting part 26a is formed. 2B and 2C, the split mold 68 is slightly changed by the deformation amount (deformation degree) of the first upsetting portion 26a due to the pressing force of the punch 90 and the pressing force of the punch 90. In accordance with the balance of the forming force with the solid portion 22 where the diameter expansion has started toward the second forming portion 82, the state is gradually lowered.

  Subsequently, as shown in FIGS. 2D and 2E, the punch 90 further descends toward the lower mold 66, and the tip of the punch 90 abuts against and presses the solid portion 22 of the primary molded body 18. As a result, the solid portion 22 is pressurized, and second upsetting is performed in which the solid portion 22 is plastically deformed radially outward.

  That is, the tip portion of the punch 90 presses the solid portion 22 of the primary molded body 18 downward, so that the solid portion 22 of the primary molded body 18 held by the lower mold 66 is A reaction force that tries to press toward the upper side opposite to the pressurizing direction is generated, and plastic deformation toward the second molding portion 82 side composed of the annular recess of the adjacent split mold 68 under the action of the reaction force. The bulging of the meat is promoted (see FIGS. 2D and 2E).

  In order to smoothly flow and fill the plastically deformed meat to every corner in the second molding portion 82 of the split mold 68, as shown in FIG. Whether the height H1 along the vertical direction of the surface formed at the boundary between the portion 20 and the solid portion 22 is set to be larger than the height H2 along the vertical direction of the horizontal portion 81c of the undercut molding portion 80. Alternatively, at least the same height is set as the molding condition (H1 ≧ H2). The heights H1 and H2 along the vertical direction refer to heights in the vertical direction with respect to the arbitrarily set common reference plane on the lower side. FIG. 12 shows a state immediately before the meat about to start plastic deformation flows into the second molding portion 82 of the split mold 68.

  Next, as shown in FIG. 2F, the punch 90 is further lowered toward the lower die 66, and the second plastic molding of the solid portion 22 of the primary molded body 18 breaks the plastically deformed meat. The second upsetting part 26b on the other end side is formed by flowing into the second forming part 82, which is an annular recess of the mold 68, and filling all the corners (see FIG. 6).

  As a result, as shown in FIG. 1D, the first upsetting part 26a and the second upsetting part 26b, whose diameters are increased by a predetermined length outward in the radial direction on both end sides along the axial direction, are obtained. Each of the secondary molded bodies 24 is formed and has an undercut portion 28 between the first upset molding portion 26a and the second upset molding portion 26b.

  In this case, the split mold 68 is held at a predetermined position where the first upsetting force and the second upsetting force are balanced. That is, the split mold 68 held in a floating state by the urging means such as the spring member 76 slightly changes the first upsetting portion 26a and the solid portion 22 that plastically deform the annular side wall portion 20 by the pressing force of the punch 90. The first upset forming force for plastically deforming the annular side wall portion 20 and the solid portion 22 are plastically deformed after gradually descending corresponding to the respective deformation amounts of the second upset formed portion 26b to be expanded in diameter. It balances with the 2nd upsetting force to make it hold | maintain at a predetermined position (refer FIG. 2F).

  The balance position of the split mold 68 is set in advance according to forging forming conditions such as the standby position of the punch 90 and the pressurizing force of the punch 90, and the lower end portion 88a of the punch holder 88 immediately before the completion of forming is the sleeve member 94. When the punch 90 reaches the bottom dead center by contacting the bottom surface 99 of the annular recess 98 formed on the inner wall of the mold, the material dimensions of the molded product are secured, so that the final balance position of the split mold 68 is set. Is done.

  Then, the first annular inclined surface 84a and the second annular surface 84a formed on the outer diameter side wall of the split mold 68 are pressed by pressing each split mold 68 divided upward through a pressing means (not shown) upward. The annular inclined surface 84 b is guided along the first annular guide surface 70 a and the second annular guide surface 70 b formed on the guide mold member 72. Therefore, when each split mold 68 moves upward on the radially outer side, the undercut molding portion 80 and the second molding portion 82 of the split mold 68 are separated from the molded product, and the mold opening is completed.

  In other words, at the time of upsetting, only the first annular guide surface 70a formed on the lower side of the inner wall of the guide mold member 72 and the second annular inclined surface 84b formed on the upper side wall of the split mold 68 were engaged. In this state, the split mold 68 is moved radially outward and upward, whereby the first annular guide surface 70a and the second annular guide surface 70b of the guide mold member 72 and the first annular inclination of the split mold 68 are obtained. The mold 84 is in an open state in which the surface 84a and the second annular inclined surface 84b are engaged with each other (see FIG. 7).

  Further, by raising the knockout pin 64 integrally with the lower mold 66 under the driving action of an actuator (not shown), the molded body raised from the center portion of the split mold 68 is held by a gripping means (not shown), whereby the next step It is transferred to.

  As described above, in the present embodiment, the split mold 68 urged by the urging means including the spring member 76 and the like is disposed so as to be displaceable, and the object to be molded (primary primary) is formed by the single punch 90. The first upsetting part 26a and the first upsetting part 26a are formed on both end sides along the axial direction by a single upsetting process in which the molded body 18) is pressed in the axial direction to perform the first and second upsetting processes. The second upsetting part 26b is formed substantially simultaneously, and a molded body (first body) in which an undercut part 28 is formed between the first upsetting part 26a and the second upsetting part 26b. A secondary compact 24) is obtained.

  In this case, the distribution of the meat flow between the first upsetting part 26a and the second upsetting part 26b is a split mold that abuts on the boundary portion between the annular side wall part 20 and the solid part 22 of the molded body. The distribution point A (see FIGS. 10 and 11) of the 68 undercut forming portions 80 is used.

  In the present embodiment, when the split mold 68 is opened, the first annular guide surface 70a and the second annular guide surface 70b of the guide mold member 72, and the first annular inclined surface 84a and the second second of the split mold 68 are used. Although the split mold 68 is moved upward in the radial direction by engaging with the annular inclined surfaces 84b, the split mold may be provided so as to expand its diameter by other methods.

  For example, as shown in FIGS. 8 and 9, a ring member 100 that moves up and down integrally with the punch 90 via a connecting means (not shown) is used, and the split mold 102 that is divided during upsetting is used as the ring member 100. When the mold is opened, the ring member 100 is lifted integrally with the punch 90, and then the split mold 102 is pulled by the spring member 104 so that the split mold 102 has a radius. You may make it move to an outward direction.

FIG. 1A to FIG. 1E are longitudinal sectional views showing a manufacturing process of a transmission gear manufactured by the forging apparatus according to the embodiment of the present invention. 2A to 2F are vertical cross-sectional views showing a state of upsetting with respect to a workpiece using the forging apparatus. It is a longitudinal cross-section structure figure along the axial direction of the 2nd forge forming apparatus which concerns on embodiment of this invention. It is a top view which shows the state which comprises the said forge molding apparatus and the split mold | die divided into 4 along the circumferential direction closed. It is a top view which shows the state which the said split mold opened. It is a longitudinal cross-sectional view which shows the state by which the punch formed and the to-be-molded body plastically deformed, and the secondary molded object which has a 1st upsetting part and a 2nd upsetting part was formed. It is a longitudinal cross-sectional view which shows the state which the said split mold opened and the molded article rose. It is a longitudinal cross-sectional view which shows the split type | mold which concerns on a modification. It is a longitudinal cross-sectional view which shows the state which the split mold shown in FIG. 8 opened. FIG. 3 is a partially enlarged longitudinal sectional view of the undercut forming portion showing a distribution point of the meat flow between the first upset forming portion and the second upset forming portion in the split die constituting the forging forming apparatus shown in FIG. 3. It is. It is a partial expanded longitudinal cross-sectional view which shows the modification of the undercut shaping | molding part of FIG. It is a partial expanded longitudinal cross-sectional view which shows the filling conditions of the meat with respect to the 2nd shaping | molding part of a split mold.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Transmission gear 12 ... Cylindrical body 16 ... Preliminary molded object 18 ... Primary molded object 20 ... Annular side wall part 22 ... Solid part 24 ... Secondary molded object 26a ... First upset part 26b ... Second installation Molded portion 28 ... Undercut portion 60 ... Second forging device 64 ... Knockout pin 66 ... Lower die 68, 102 ... Split die 70a, 70b ... Annular guide surface 72 ... Guide die member 74 ... Support base 76, 104 ... Spring Member 78 ... Side mold member 80, 80a ... Undercut molding part 82 ... Second molding part 84a, 84b ... Round annular surface 90 ... Punch 92 ... First molding part

Claims (2)

A molded product having an undercut portion formed by forging a workpiece including a cylindrical annular side wall portion extending in parallel with the axial direction by a predetermined length and a solid portion continuous to the annular side wall portion. A forging device to obtain ,
A plurality of split molds that are divided into a plurality along the circumferential direction to surround the molded body, and that are provided so as to be separated from the molded body when the mold is opened,
A lower mold that is provided at the center of the split mold and on which the molded body is placed;
A biasing means for supporting the plurality of split molds in a floating manner;
Disposed on the lower die coaxially, a single punch is provided vertically movably,
With
The punch is formed with a first molding portion that plastically deforms the annular side wall portion of the molded body in a radially outward direction and pressurizes the solid portion toward the lower mold,
The inner wall of the split mold includes an undercut molding portion formed of an annular projection that engages with a boundary portion between the annular side wall portion and the solid portion of the molded body, and a lower side continuous from the undercut molding portion. A second molded part formed of an annular recess formed ,
The lowered punch is formed by plastically deforming the annular side wall portion in the radially outward direction at the first molding portion, and further plastically deforming the solid portion in the radially outward direction. moldings forging apparatus having an undercut portion, wherein Rukoto is fluidized in the second mold portion. The apparatus of claim 1.
The biasing means comprises a spring member, and the spring member is provided so as to support a guide-type member that guides the plurality of split dies radially outward and upward in a floating manner. A forging molding apparatus for molded products having

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