JP2023056221A - Forging apparatus and manufacturing method for forged product - Google Patents

Abstract

To provide a forging apparatus that can properly form a work-piece into a shape protruding in an oblique direction even in cold forging, and a manufacturing method for a forged product.SOLUTION: A forging apparatus 1 is equipped with an upper die 11 and a lower die 14 which form a cavity 1C subjected to closed forging, and an upper punch 13 and a lower punch 16 which are pushed into the cavity 1C, which pushes out a work-piece W in the cavity 1C using the upper punch 13 and the lower punch 16 and subjects a work-piece to cold forging. The lower die 14 has a concave surface 15 in a concave shape that can push out the work-piece W along a circumference of the upper punch 13. The upper die 11 has a concave surface 12 in a concave shape comprising a guide surface 12a that inclines obliquely upward to the outside in a radial direction in which a pushed-out piece w2 pushed out to a rear side of the work-piece W is slid to the outside in the radial direction. When slid along the guide surface 12a, the pushed-out piece w2 is formed into a shape protruding obliquely to the outside in the radial direction with respect to a base part w1 of the work-piece W.SELECTED DRAWING: Figure 2

Description

The present invention relates to a forging apparatus and a method for manufacturing forged products. More specifically, it has an upper die and a lower die that form a cavity for closed forging by clamping, and has an upper punch that is pushed into the cavity through the upper die and a lower punch that is pushed into the cavity through the lower die. The present invention relates to a forging apparatus for cold forging by extruding a workpiece in a cavity, and a method for manufacturing a forged product using this forging apparatus.

Patent Literature 1 discloses a bracket for fixing hydraulic pipes mounted on an automobile to a vehicle body. The bracket is made of a pressed metal plate and is fixed to the vehicle body by bolting.

JP-A-3-56785

When forming the bracket by cold forging to ensure structural strength, there is a problem that it is difficult to form the bracket into a complicated shape that protrudes in an oblique direction. Accordingly, the present invention provides a forging apparatus and a method for manufacturing a forged product, which can appropriately form a workpiece into a shape protruding in an oblique direction even by cold forging.

In order to solve the above problems, the forging apparatus and method for manufacturing a forged product of the present invention employ the following means.

That is, the forging apparatus of the present invention includes an upper die and a lower die that form a cavity for closed forging by clamping, an upper punch that passes through the upper die and is pushed into the cavity, and a punch that passes through the lower die and enters the cavity. and a lower punch to be pushed in, wherein the upper punch and the lower punch push out the work in the cavity for cold forging. A lower die has a concave forming surface capable of receiving the upper punch and pushing the workpiece backward around the upper punch.

The upper die receives the extruded piece that is pushed out backward of the work, and as the backward extruding progresses, the tip of the extruded piece comes into contact with the work and slides radially outward of the work. It has a concave receiving surface with guide surfaces. The forging device slides along the guide surface to shape the extruded piece into a shape that rises diagonally outward in the radial direction with respect to the base portion that is pressed between the upper and lower punches of the workpiece.

According to the above configuration, the extruded piece that is pushed out backward of the workpiece can be formed into a shape that is obliquely raised radially outward by contact with the guide surface of the upper die. Therefore, even with cold forging, the workpiece can be appropriately formed into a shape that protrudes in an oblique direction with an angle with respect to the vertical direction or the radial direction.

Moreover, the forging apparatus of the present invention may be further configured as follows. The molding surface of the lower mold is a rectangular container-shaped concave surface. The upper punch consists of a prismatic body fitted with a gap for pushing out the workpiece backward only between the two inner side surfaces of the forming surface facing each other with respect to the forming surface. A pair of guide surfaces of the upper die slide two extruded pieces pushed out from the gaps between the two inner surfaces of the molding surface and the upper punch in opposite radial directions.

According to the above configuration, the work can be appropriately formed in a shape having two extruded pieces obliquely rising from the base portion in opposite radial directions.

Moreover, the forging apparatus of the present invention may be further configured as follows. The receiving surface of the upper die is a concave surface that drops downward from the slanted edge of the guide surface.

According to the above configuration, the receiving surface of the upper die can be formed into a shape that does not have an undercut, and can be formed into a shape that does not hinder the sliding of the push-out piece to the outside in the radial direction.

In addition, the method for manufacturing a forged product of the present invention includes an upper die and a lower die that form a cavity for closed forging by clamping, an upper punch that passes through the upper die and is pushed into the cavity, and and a lower punch to be pushed into the cavity. This forged product manufacturing method includes a backward extrusion process and a sliding deformation process.

In the backward pushing step, the upper punch is pushed toward the concave forming surface formed on the lower die, thereby pushing the workpiece backward along the space between the upper punch and the forming surface. In the sliding deformation step, the extruded piece of the work extruded backward is brought into contact with a guide surface inclined upward in the radial direction forming the top plate surface of the concave receiving surface formed in the upper die, and is extruded backward. advances to slide radially outward of the workpiece along the guide surface. In this method of manufacturing a forged product, the extruded piece is molded by a sliding deformation process into a shape that rises obliquely outward in the radial direction with respect to a base that is pressed between the upper and lower punches of the workpiece.

According to the above configuration, the extruded piece that is pushed out backward of the workpiece can be formed into a shape that is obliquely raised radially outward by contact with the guide surface of the upper die. Therefore, even with cold forging, the workpiece can be appropriately formed into a shape that protrudes in an oblique direction with an angle with respect to the vertical direction or the radial direction.

Further, the method for manufacturing a forged product of the present invention may be further configured as follows. The molding surface of the lower mold is a rectangular container-shaped concave surface. The upper punch is composed of a prismatic body fitted with a gap for pushing the workpiece backward against the forming surface. The workpiece consists of a cylindrical body with a circular cross-section that fits within the cross-section of the rectangular container on the molding surface.

According to the above configuration, as the upper punch is pressed, the work made of a cylindrical body is appropriately plastically flowed in the gap formed between the rectangular container-shaped molding surface in the lower mold and along the molding surface. can be formed into any shape.

Further, the method for manufacturing a forged product of the present invention may be further configured as follows. In the backward extrusion step, the workpiece is extruded backward only from two locations between the two opposing inner surfaces of the forming surface and the respective opposing surfaces of the upper punch, and the two extruded pieces are formed into a symmetrical shape inclined in the radial direction opposite to each other. molded into

According to the above configuration, the work can be appropriately formed in a shape having two extruded pieces obliquely rising from the base portion in opposite radial directions.

Further, in the method for manufacturing a forged product of the present invention, the extruded piece of the work cold-forged using the forging device is processed into a shape that can be bent at right angles to the outside in the radial direction with respect to the base portion using the pressing device. It has a bending process that

According to the above configuration, the extruded piece of the work is formed into a shape in the middle of rising obliquely from the base portion by the forging device, so that the extruded piece can be easily bent into a shape that opens perpendicularly from the base portion by the pressing device. Therefore, it is possible to appropriately form a workpiece having a right-angled open shape as described above into a shape having high structural strength from a cold-forged forged product.

Further, the method for manufacturing a forged product of the present invention may be further configured as follows. The workpiece is a bracket with a hat-shaped cross section having a pair of extruded pieces on both sides of the base.

According to the above configuration, the bracket having a hat-shaped cross section can be appropriately formed from a cold-forged forged product having high structural strength.

1 is a cross-sectional view of a forging device; FIG. FIG. 4 is an enlarged view of a main part showing a state before and after the forging machine processes a workpiece; FIG. 2 is a front view of a workpiece formed by forging; FIG. 4 is a plan view of a workpiece formed by forging; FIG. 2 is a front view of a work molded by press working; FIG. 2 is a plan view of a work formed by pressing; FIG. 4 is a front view of a workpiece formed by drilling; FIG. 4 is a plan view of a workpiece formed by boring; FIG. 4 is a side view of a workpiece formed by boring; FIG. 4 is a cross-sectional view showing states before and after a press device processes a work; FIG. 11 is a front view of a work according to another embodiment;

Embodiments for carrying out the present invention will be described below with reference to FIGS. 1-11. In the following description, when directions such as front, back, up, down, left, and right are indicated, they refer to the respective directions shown in the respective drawings.

<First embodiment>
First, a forging apparatus 1 according to a first embodiment of the present invention will be described. A forging apparatus 1 according to the present embodiment, as shown in FIG. 1-2, is an apparatus for cold forging a columnar metal work W into a bracket with a hat-shaped cross section. The workpiece W is formed into a hat-shaped cross section having extruded pieces w2 that are extruded backward, as shown in FIG. 3-4. The workpiece W is press-worked by a further press device 2 (see FIG. 10) after the molding described above. As a result, the workpiece W is shaped such that each extruded piece w2 is bent at right angles as shown in FIG. 5-6. Further, the workpiece W is punched or cut, so as to have through-holes such as mounting holes w3 and insertion holes w4 in places, as shown in FIGS. 7-9. Through these processes, the workpiece W is formed as a bracket into which a hydraulic hose of a hydraulic suspension of an automobile is inserted and fixed to the vehicle body.

As shown in FIG. 1 , the forging apparatus 1 has an upper mold 11 arranged above and a lower mold 14 arranged below to face the upper mold 11 . The upper die 11 is configured to be vertically movable. The lower die 14 is set in a state of being pushed up to a predetermined height by each lift pin 17 . The upper mold 11 has a concave surface 12 in the center of its lower surface. The lower mold 14 has a concave surface 15 in the center of its upper surface. By clamping the upper mold 11 and the lower mold 14 together, a cavity 1C composed of the concave surface 12 and the concave surface 15 is formed.

The forging apparatus 1 has an upper punch 13 integrally attached to the central portion of the upper die 11 and a lower punch 16 provided to the central portion of the lower die 14 so as to be slidable with respect to the lower die 14 . . The upper punch 13 protrudes below the lower surface of the upper die 11 . As a result, the upper punch 13 protrudes into the cavity 1C and extends further downward than the upper surface of the lower die 14 when the upper die 11 and the lower die 14 are clamped. The lower punch 16 is arranged such that its upper surface is located below the cavity 1C when the lower die 14 is pushed up. The lower punch 16 is relatively raised toward the cavity 1C by the upper die 11 pressing the lower die 14 downward.

As shown in FIG. 2, the forging apparatus 1 forges the workpiece W as follows. First, the work W is placed on the lower punch 16 . Thereby, the upper part of the work W is arranged so as to protrude from below into the concave surface 15 of the lower mold 14 . Next, the upper mold 11 is lowered so as to push down the lower mold 14 . As a result, the upper punch 13 presses the workpiece W supported by the lower punch 16 from above. By this pressing, the upper punch 13 laterally spreads the upper portion of the work W along the shape of the concave surface 15 . Then, the upper punch 13 pushes the laterally expanded work W further upward along the periphery of the upper punch 13 from each gap 1G between the upper punch 13 and the concave surface 15 (rearward push-out). process).

Next, the forging device 1 deforms each extruded piece w2 of the work W extruded upward into a shape that opens left and right along the shape of the cavity 1C. Specifically, each extruded piece w2 extruded into the concave surface 12 of the upper mold 11 as the backward extrusion progresses is slid along each inclined top plate surface (guide surface 12a) of the concave surface 12 (sliding deformation step ). By this sliding deformation, each extruded piece w2 of the work W is formed into a shape that rises obliquely outward in the left-right direction.

Then, the forging device 1 lowers the upper die 11 until the lower die 14 is pushed down to the lowest position. As a result, the upper surface of the lower punch 16 becomes substantially flush with the lower surface of the concave surface 15 of the lower die 14 . Thereby, the forging device 1 pushes the lower part of the work W into a shape along the concave surface 15 . The forging device 1 forms the base w1 of the workpiece W by this pressing.

A specific configuration of each part of the forging apparatus 1 will be described below with reference to FIGS. 1-2. The forging apparatus 1 is used by being attached to a press machine (not shown). The forging apparatus 1 includes an upper die holder 18 attached to a slide (not shown) that forms a vertical movable part on the upper side of the press machine, and a hydraulic cylinder 19 that is attached to a bolster (not shown) that forms a fixed part on the lower side of the press machine. and have The upper die holder 18 reciprocates vertically in accordance with the operation of a slide (not shown).

<Upper die 11>
The upper mold 11 is integrally attached to the lower part of the upper mold holder 18, as shown in FIG. The upper die 11 has a prism-shaped through hole 11a vertically penetrating the central portion thereof, and a concave surface 12 that opens downward from the lower end of the through hole 11a and spreads in the horizontal direction. The concave surface 12 has guide surfaces 12a forming its top plate surface, and hanging surfaces 12b forming side surfaces in the left-right direction. Each guide surface 12a has an inclined surface shape extending linearly and obliquely upward from the through hole 11a toward the outside in the left-right direction. The width of the concave surface 12 in the front-rear direction is substantially the same as the width in the front-rear direction of the through hole 11a.

Due to the inclination of each guide surface 12a, each push-out piece w2 pushed backward and abutted against each guide surface 12a slides along the inclination as the pushing progresses. By this sliding, each push-out piece w2 is guided so as to protrude outward in the left-right direction at an oblique angle. Here, the concave surface 12 corresponds to the "receiving surface" of the present invention.

Each drooping surface 12b of the concave surface 12, as shown in FIG. 2, is shaped to vertically drop downward from each extended edge of each guide surface 12a. As a result, the concave surface 12 has a concave shape that drops from each inclined guide surface 12a. Thereby, the concave surface 12 can be formed into a shape without an undercut so that the workpiece W can be easily released from the mold after forging. Moreover, each hanging surface 12b is arranged at a position where the tip of each push-out piece w2 pushed backward does not abut. As a result, each hanging surface 12b does not hinder the lateral sliding of each pushing piece w2.

<Lower mold 14>
As shown in FIG. 1, the lower die 14 is assembled to the upper portion of the hydraulic cylinder 19 so as to be vertically slidable. The lower die 14 is supported from below by each lift pin 17 arranged below the hydraulic cylinder 19 . The lower mold 14 is vertically movable or held by each lift pin 17 . The lower die 14 has a columnar through hole 14a vertically penetrating its central portion, and a concave surface 15 opening upward from the upper end of the through hole 14a in the shape of a rectangular container. The through hole 14a of the lower mold 14 and the through hole 11a of the upper mold 11 are formed so that their central axes are on the same axis. The diameter of the through-hole 14a is approximately the same length as the diameter of the workpiece W before processing, as shown in FIG.

The concave surface 15 is configured to open wider in the horizontal direction than the through hole 14a. The forged work W is deformed along the concave surface 15 of the lower mold 14, thereby forming a rectangular base w1 as shown in FIG. 3-4. Here, the concave surface 15 corresponds to the "molding surface" of the present invention.

<Upper punch 13>
As shown in FIG. 1, the upper punch 13 is a prismatic metal member that is integrally assembled so as to fit into the through hole 11a of the upper die 11. As shown in FIG. The upper punch 13 moves integrally with the vertical movement of the upper die 11 . The upper punch 13 is configured to be fitted to the front and rear surfaces of the concave surface 12 with substantially no gap. The upper punch 13 is configured such that its lower portion extends beyond the concave surface 12 and protrudes further downward than the lower surface of the upper die 11 . Therefore, when the upper die 11 and the lower die 14 are superimposed one on the other, the upper punch 13 protrudes into the concave surface 15 of the lower die 14 .

The upper punch 13 protruding into the concave surface 15 forms a gap 1G between each inner side surface 15a of the concave surface 15 in the horizontal direction. Further, the upper punch 13 is configured to be fitted to the inner surface of the concave surface 15 in the front-rear direction (the front-rear direction of the paper surface) so as not to form a gap. As a result, each extruded piece w2 of the work W is extruded along each gap 1G from two locations facing each other in the left-right direction on the upper side of the base w1. Here, the upper punch 13 corresponds to the "prism body" of the present invention.

<Lower Punch 16>
The forging apparatus 1 also has a columnar lower punch 16 fitted in the through hole 14a of the lower die 14 and slidably assembled to the lower die 14, as shown in FIG. The lower punch 16 is fixed so as not to move vertically with respect to the hydraulic cylinder 19 . As a result, the lower punch 16 slides up and down relative to the lower die 14 as the lower die 14 moves in the vertical direction.

As shown in FIG. 1, the lower punch 16 has its upper surface located below the concave surface 15 when the lower die 14 is pushed up to the highest position. Further, as shown in FIG. 2, when the lower die 14 is pushed down to the lowest position, the upper surface of the lower punch 16 is substantially flush with the upper end of the through hole 14a, that is, the lower surface of the concave surface 15. . As a result, the workpiece W is pressed between the upper punch 13 and the lower punch 16, so that the rectangular container-shaped base w1 along the shape of the concave surface 15 is appropriately formed.

<Forging>
A series of operations of the forging apparatus 1 for cold forging the workpiece W will be described below based on the configuration of the forging apparatus 1 described above. As an initial state, the lower die 14 is assumed to be in a state of being lifted to the maximum height and held by the lift pins 17, as shown in FIG. Also, the upper mold 11 is in a state of being lifted further upward from the position shown in FIG. 1 so as to be kept away from the lower mold 14 . It is also assumed that the workpiece W is inserted into the through hole 14 a of the lower mold 14 and placed on the lower punch 16 . The inserted work W is fitted in the through hole 14 a and its upper portion protrudes into the concave surface 15 of the lower die 14 .

In the forging apparatus 1, the press machine (not shown) is operated from the initial state described above, so that the upper die holder 18 attached to the slide first descends. As a result, the upper die 11 and the upper punch 13 assembled to the upper die holder 18 are integrally moved downward. Due to this descent, the upper die 11 comes into contact with the lower die 14 from above, as shown in the left half of FIG. A closed cavity 1C is formed between the upper mold 11 and the lower mold 14 by this contact. Also, the upper punch 13 protrudes into the concave surface 15 of the cavity 1C. In this state, the upper punch 13 does not come into contact with the workpiece W. As shown in FIG.

The upper mold 11 in contact with the lower mold 14 is moved further downward so as to push down the lower mold 14 as it is. As a result, the upper die 11, the lower die 14 and the upper punch 13 are integrally moved downward while the cavity 1C is formed. Each lift pin 17 that supports the lower mold 14 is provided with an arbitrary pressure on the lower mold 14 so that the contact surface with the upper mold 11 does not open when the lower mold 14 abuts against the upper mold 11 and descends. is hanging The lower punch 16 slides in the through hole 14a so as to escape the downward movement of the lower die 14. As shown in FIG. That is, the lower punch 16 and the work W are held in place without moving up and down. As a result, the upper punch 13 that has descended contacts the work W supported by the lower punch 16 and presses the work W from above. Further, the lower punch 16 presses the work W from below by the reaction force of the force pressed by the upper punch 13 through the work W. As shown in FIG. As a result, the work W is pressed between the upper punch 13 and the lower punch 16 so as to be sandwiched from above and below.

By being pressed and sandwiched between the upper punch 13 and the lower punch 16, the upper portion of the work W protruding from the concave surface 15 of the lower die 14 is laterally spread. The upper punch 13 and the concave surface 15 further push the laterally expanded work W upward along the periphery of the upper punch 13 as the upper die 11 descends. More specifically, as shown in FIG. 2, the upper punch 13 pushes the work W upward along each gap 1G between the upper punch 13 and each inner side surface 15a of the concave surface 15 facing in the left-right direction. By this extrusion, the forging device 1 forms each extrusion piece w2 extending upward from two locations facing each other in the left-right direction of the work W (rearward extrusion step). By fitting the lower part of the work W into the through-hole 14a with substantially no gap, the lower part of the work W inserted into the through-hole 14a is prevented from expanding in the horizontal direction. As a result, the upper portion of the work W protruding into the concave surface 15 is easily pushed upward. The thickness of each extruded piece w2 is determined based on each width of each gap 1G.

Each push-out piece w2 pushed out backward is formed in a shape extending into the concave surface 12 through each gap 1G. Each extruded piece w2 thus formed is further extruded upward as the upper die 11 and the lower die 14 are lowered. At this time, the inner peripheral surfaces of the push-out pieces w2 receive a large amount of force that is pushed upward as the upper punch 13 descends, while the outer peripheral surfaces of the push-out pieces w2 come into contact with the inner surfaces 15a of the concave surface 15. , and is not supported from the outside in the radial direction, i. For the above reason, each pushing piece w2 has a peripheral length difference between the inner peripheral surface and the outer peripheral surface as the rearward pushing progresses, and extends upward while curving slightly outward in the radial direction. molded.

Each extruded tip of each extruded piece w2 abuts on the inner side in the left-right direction of each guide surface 12a of the concave surface 12 from below. Then, each push-out piece w2 in contact with each guide surface 12a slides along the inclination of each guide surface 12a as the backward push-out progresses further. Each pushing piece w2 contacts each guide surface 12a while curving outward in the left-right direction, so that it can appropriately slide outward in the left-right direction along the inclination of each guide surface 12a. In this way, the extruded pieces w2 are molded into a symmetrical shape that rises obliquely outward in the left-right direction so as to oppose each other (sliding deformation step).

The lower part of the workpiece W inserted into the through hole 14a is pushed out into the concave surface 15 of the lower die 14 as the upper die 11 and the lower die 14 descend. By pushing down the upper mold 11 and the lower mold 14 to the lowest position, the workpiece W is pushed out to the lower surface of the workpiece W into the concave surface 15 . As a result, the lower portion of the work W is formed into a rectangular base portion w1 along the shape of the concave surface 15. As shown in FIG. Since the work W before processing is cylindrical, a uniform pressure is applied to the work W in the radial direction. Therefore, the workpiece W is appropriately plastically flowed within the concave surface 15 .

<Press processing>
Next, the forged workpiece W is pressed using the press device 2 . As a result of this press working, the work W is bent in such a manner that each extruded piece w2 extends upward from the base portion w1 and then opens at right angles to the outside in the left-right direction, as shown in FIG. 5-6. As shown in FIG. 10, the press device 2 includes an upper die 21 attached to a slide (not shown), an upper punch 23 integrally assembled with the upper die 21, and a lower punch fixed to a bolster (not shown). a mold 24; The upper mold 21 has a concave molding surface 22 on its lower surface. The lower mold 24 has a concave support surface 25 on its upper surface. The molding surface 22 and the support surface 25 form a closed cavity 2C by superimposing the upper mold 21 and the lower mold 24 vertically. As shown in FIG. 10 , the press device 2 moves the upper die 21 downward while the base w1 of the work W is fitted and set on the support surface 25 . Then, the press device 2 presses the workpiece W so as to fit it into the cavity 2C. As a result, each extruded piece w2 sandwiched between the molding surface 22 and the lower die 24 is bent into a shape that opens perpendicularly outward in the left-right direction (bending step). Further, the upper surface of the base w1 is pressed from above by the upper punch 23 and shaped horizontally.

<Drilling process>
Next, punching or cutting is performed on the pressed workpiece W by another pressing device (not shown). As a result, as shown in FIGS. 7-9, the workpiece W is provided with circular mounting holes w3 penetrating vertically through the central portion of each push-out piece w2, and cylindrical insertion holes w4 penetrating through the base portion w1. and a trimming surface w5 obtained by obliquely cutting the corner of the base w1. The insertion hole w4 opens downward from the upper surface of the base w1, is bent at right angles inside, and opens toward the trimming surface w5. Each attachment hole w3 functions as each attachment hole w3 for attachment to the vehicle body of an automobile. A hydraulic hose is passed through the insertion hole w4. The trimming surface w5 allows the hydraulic hose to be properly assembled without interfering with the corners of the base w1.

<Summary>
In summary, the forging apparatus 1 according to the first embodiment has the following configuration. In the following description, the symbols shown in parentheses are the symbols corresponding to the configurations shown in the above embodiments.

That is, the forging apparatus (1) includes an upper die (11) and a lower die (14) that form a closed forging cavity (1C) by clamping, and a An upper punch (13) to be pushed and a lower punch (16) to be pushed into the cavity (1C) through the inside of the lower die (14), and the cavity (13) and the lower punch (16) 1C) is a forging device (1) for extruding and cold forging a work (W) in the inside. A lower die (14) has a concave forming surface (15) capable of receiving the upper punch (13) and pushing the workpiece (W) backward along the periphery of the upper punch (13). The upper die (11) receives the extruding piece (w2) pushed backward from the work (W), and as the backward extruding progresses, the tip of the extruding piece (w2) is brought into contact with the work (W) radially outwardly of the work (W). It has a concave receiving surface (12) with a guide surface (12a) sloping radially outwardly and upwardly for sliding into. The forging device (1) has a base ( It is formed into a shape that rises obliquely outward in the radial direction with respect to w1).

With such a configuration, the extruding piece (w2) pushed out backward of the work (W) is slanted radially outward due to contact with the guide surface (12a) of the upper die (11). It can be molded into a stand-up shape. Therefore, even in cold forging, the workpiece (W) can be appropriately formed in a shape that protrudes in an oblique direction with an angle with respect to the vertical direction and the radial direction.

Further, the molding surface (15) of the lower mold (14) is a rectangular container-shaped concave surface (15). The upper punch (13) has a gap (1G) for pushing out the work (W) backward only between the two inner side surfaces (15a) of the forming surface (15) opposed to the forming surface (15). It consists of a prismatic body (13) fitted with a space. Two extruding pieces that the guide surface (12a) of the upper die (11) is extruded backward from each gap (1G) between the two inner surfaces (15a) of the molding surface (15) and the upper punch (13). (w2) are configured to slide in opposite radial directions.

With such a configuration, the workpiece (W) can be appropriately formed in a shape having two extruded pieces (w2) obliquely rising in opposite radial directions from the base (w1).

Further, the receiving surface (12) of the upper die (11) is a concave surface (12) that drops downward from the inclined edge of the guide surface (12a).

With such a configuration, the receiving surface (12) of the upper die (11) can be formed into a shape free from undercuts, and the pushing piece (w2) slides outward in the radial direction. It can be a shape that does not hinder the

Further, the method for manufacturing a forged product of the present invention includes an upper die (11) and a lower die (14) that form a closed forging cavity (1C) by clamping, and a cavity (1C) that passes through the upper die (11). ) and a lower punch (16) pushed into the cavity (1C) through the lower die (14), the upper punch (13) and the lower punch (16) This is a method of manufacturing a forged product using a forging apparatus (1) for cold forging by extruding a work (W) in a cavity (1C). This forged product manufacturing method includes a backward extrusion process and a sliding deformation process. In the backward extrusion step, the upper punch (13) is pushed toward a concave forming surface (15) formed on the lower die (14), thereby pushing the workpiece (W) into the upper punch (13) and the forming surface (15). Extrude backward along between In the sliding deformation step, the extruded piece (w2) of the work (W) extruded backward is obliquely raised to the outside in the radial direction forming the top plate surface of the concave receiving surface (12) formed in the upper die (11). The workpiece (W) is slid outward in the radial direction along the guide surface (12a) as the backward extrusion progresses. In this forged product manufacturing method, the extruded piece (w2) is pressed against the base (w1) sandwiched between the upper punch (13) and the lower punch (16) of the work (W) by a sliding deformation process. It is formed into a shape that rises diagonally outward in the radial direction.

With such a configuration, the extruding piece (w2) pushed out backward of the work (W) is slanted radially outward due to contact with the guide surface (12a) of the upper die (11). It can be molded into a stand-up shape. Therefore, even in cold forging, the workpiece (W) can be appropriately formed in a shape that protrudes in an oblique direction with an angle with respect to the vertical direction and the radial direction.

Further, the molding surface (15) of the lower mold (14) is a rectangular container-shaped concave surface (15). The upper punch (13) consists of a prismatic body (13) fitted with a gap (1G) for pushing out the workpiece (W) backward against the forming surface (15). The workpiece (W) consists of a cylindrical body with a circular cross-section that fits within the cross-section of the rectangular container of the forming surface (15).

With such a configuration, as the upper punch (13) is pushed in, the cylindrical work (W) is placed between the rectangular container-shaped forming surface (15) in the lower die (14). It can be formed into a shape along the molding surface (15) by appropriate plastic flow in the formed gap (1G).

In addition, the backward pushing step pushes the workpiece (W) backward only from two locations between the two opposing inner side surfaces (15a) of the molding surface (15) and the opposing surfaces of the upper punch (13). The two extruded pieces (w2) are formed into symmetrical shapes inclined in the radial direction opposite to each other.

With such a configuration, the workpiece (W) can be appropriately formed in a shape having two extruded pieces (w2) obliquely rising in opposite radial directions from the base (w1).

Also, the extruded piece (w2) of the work (W) cold forged using the forging device (1) is processed into a shape that can be bent at right angles to the base (w1) in the radial direction using a press device. It has a bending process that

With such a configuration, the extruded piece (w2) of the work (W) is formed into a shape in the middle of rising obliquely from the base (w1) by the forging device (1), so that the extruded piece is formed by the pressing device. (w2) can be easily bent from the base (w1) into a shape that opens at right angles. Therefore, the workpiece (W) having a right-angled open shape as described above can be appropriately formed into a shape having high structural strength from a cold-forged forged product.

Also, the workpiece (W) is a bracket with a hat-shaped cross section having a pair of extruded pieces (w2) on both sides of the base (w1).

With such a configuration, the bracket having a hat-shaped cross section can be appropriately formed from a cold-forged forged product having high structural strength.

<Other embodiments>
As described above, the present invention has been described using one embodiment, but the present invention can be implemented in various forms other than the above-described embodiment.

1. The workpiece may initially consist of a prismatic material rather than a cylindrical material.

2. The forging device may form the base of the work in a columnar shape instead of a prismatic shape. The forging device may be configured to push the workpiece backwards as well as forwards and/or sideways as shown in FIG. The forging device may extrude a pair of extruded pieces of the work from both sides of the base, or may extrude from one or three or more locations in the circumferential direction of the base.

3. The guide surface has an inclined surface shape that extends linearly upward obliquely outward in the left-right direction. It can be.

Reference Signs List 1 forging device 11 upper die 11a through hole 12 concave surface (receiving surface)
12a guide surface 12b hanging surface 13 upper punch (prism)
14 lower die 14a through hole 15 concave surface (molding surface)
15a Inner surface 16 Lower punch 17 Lift pin 18 Upper die holder 19 Hydraulic cylinder 1C Cavity 1G Gap 2 Press device 21 Upper die 22 Molding surface 23 Upper punch 24 Lower die 25 Support surface 2C Cavity W Work w1 Base w2 Extruding piece w3 Mounting hole w4 Insertion hole w5 Trimming surface

Claims (8)

An upper die and a lower die that form a closed forging cavity by clamping, an upper punch that is pushed into the cavity through the upper die, and a lower punch that is pushed into the cavity through the lower die. , wherein the upper punch and the lower punch push out and cold forge the workpiece in the cavity,
the lower die having a concave forming surface capable of receiving the upper punch and pushing the workpiece backward along the perimeter of the upper punch;
The upper die receives the extruded piece of the work that has been extruded backward, and causes the tip of the extruded piece to contact and slide radially outward of the work as the backward extrusion progresses. having a concave receiving surface with an upwardly sloping guide surface;
A forging device that slides along the guide surface to shape the extruded piece into a shape that rises diagonally outward in the radial direction with respect to a base portion of the work that is pressed between the upper and lower punches of the work. . A forging apparatus according to claim 1,
The molding surface of the lower mold is a rectangular container-shaped concave surface,
The upper punch is composed of a prismatic body that fits into the molding surface with a gap for pushing out the work backward only between two inner side surfaces of the molding surface facing each other,
A pair of guide surfaces of the upper mold for sliding the two extruded pieces pushed backward from the gaps between the two inner surfaces of the molding surface and the upper punch in opposite radial directions. A forging device with a configuration of A forging apparatus according to claim 1 or claim 2,
A forging apparatus in which the receiving surface of the upper mold is a concave surface that is recessed downward from the inclined edge of the guide surface. An upper die and a lower die that form a closed forging cavity by clamping, an upper punch that is pushed into the cavity through the upper die, and a lower punch that is pushed into the cavity through the lower die. A method for manufacturing a forged product using a forging device for cold forging by extruding the work in the cavity with the upper punch and the lower punch,
a backward pushing step of pushing the upper punch toward a concave forming surface formed on the lower mold to push the workpiece backward along between the upper punch and the forming surface;
The extruded piece of the work extruded backward is brought into contact with the guide surface inclined upward in the radial direction forming the top plate surface of the concave receiving surface formed in the upper die. a sliding deformation step of sliding the workpiece radially outward along the guide surface;
A method for manufacturing a forged product in which the extruded piece is shaped so as to rise diagonally outward in the radial direction with respect to a base portion of the work that is pressed between the upper and lower punches of the work by the sliding deformation step. . A method for manufacturing a forged product according to claim 4,
The molding surface of the lower mold is a rectangular container-shaped concave surface,
The upper punch is composed of a prismatic body fitted with a gap for pushing out the workpiece backward against the molding surface,
A method for manufacturing a forged product in which the workpiece is a cylindrical body with a circular cross section that fits within the cross section of the rectangular container on the forming surface. A method for manufacturing a forged product according to claim 5,
In the backward pushing step, the work is pushed backward only from two positions between two opposing inner surfaces of the forming surface and the respective facing surfaces of the upper punch, and the two extruded pieces are pushed out in opposite radial directions. A method of manufacturing a forged product that is formed into a symmetrical shape inclined to A method for manufacturing a forged product according to any one of claims 4 to 6,
Furthermore, a bending step of processing the extruded piece of the work cold-forged using the forging device into a shape that is bent radially outward at right angles to the base portion using a pressing device. Production method. A method for manufacturing a forged product according to claim 7,
A method of manufacturing a forged product, wherein the workpiece is a bracket with a hat-shaped cross section having the pair of extruded pieces on both sides of the base.

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