JPH11123492A - Robot hand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hand capable of holding an intermediate forged body by a forging die in a preceding stage, and carrying it to a forging die in a succeeding process and charging it with high positional accuracy. SOLUTION: This hand 3 holds an intermediate forged body 104a (a stock of a bevel gear) which is roughly forged by a first forging die and has a plurality of teeth 106, and carries and charges it into a forging die in a succeeding process, and comprises a hand body 4 having a fitting part 5 to be fitted to an arm of a robot, a gripper comprising a pair of grip members 9a which are provided on the hand body 4 and hold an outer circumferential part of the intermediate forged body 104a and an opening/closing mechanism 6 to open/close a pair of grip members 9a, and a holding member 12 which is provided between a pair of grip members 9a in an urged manner in the direction opposite to the projecting of the intermediate forged body 104a by the first forging die.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for forging mechanical parts such as gears and clutch parts, and more particularly, to a forging station at a former stage in a forging facility in which a raw material finally becomes a product after passing through a plurality of forging stations. The present invention relates to a robot hand for transferring a forging intermediate from a forging station to a subsequent forging station.

[0002]

2. Description of the Related Art Hot forging is generally employed for mass production of mechanical parts such as gears and clutch parts. For forging bevel gears as products, forging steps as shown in FIG. Pass. That is, first, in the first forging station, by the upper die 101a and the lower die 101b,
The billet 100 heated at a high temperature equal to or higher than the recrystallization temperature is roughly forged to form a first forging intermediate 104a that approximates the outer shape of the bevel gear, and then the upper die (tooth) is formed at a second forging station. The first forged intermediate body 104a is forged by the mold 102a and the lower mold 102b to form a second forged intermediate body 104b whose teeth are roughly formed. Finally, the second forged intermediate body 104b is It is conveyed to the third forging station while being turned over, where the second forging intermediate 104b is forged by the upper die 103a and the lower die (finished tooth mold) 103b, and the teeth are finish-molded to form a product. Bevel gear 10
4c is manufactured. The forging process is not limited to the one shown in FIG. 6, but may be of the type shown in FIGS. 7 to 9 described later.

That is, as shown in FIG. 7, up to a second forging station, the same as in FIG. 6, but a second forging intermediate 104b molded at the second forging station is
It is conveyed to the third forging station without inversion, where the second forging intermediate 104b is forged by the upper die (finished tooth mold) 103a and the lower die 103b, and the teeth are finish-molded as a product. Is manufactured. As shown in FIG. 8, in a first forging station, an upper die (coarse tooth die) 101a and a lower die 101b roughly forge a billet 100 heated at a high temperature equal to or higher than a recrystallization temperature, so that the teeth are roughened. Molding the molded forged intermediate 104a,
At the second forging station, the upper mold (finished tooth mold) 1
02a and a lower mold 102b to forge an intermediate body 104a, finish-mold teeth, and bevel gear 104 as a product.
to produce c. As shown in FIG. 9, up to the first forging station, the same as FIG. 8, but the forging intermediate 104a formed at the first forging station is transported to the third forging station while being inverted. Then, the upper mold 102a
And a lower mold (finished tooth mold) 102b and a forging intermediate 104
a is forged and the teeth are finish-molded to produce a bevel gear 104c as a product.

[0004] Generally, a forging intermediate whose teeth have been coarsely forged in a former forging station is conveyed to a latter forging station by a robot operating according to a predetermined program. The details of the process at this time will be described. After the rough forging at the former forging station is completed, first, the forging intermediate is protruded by the knockout for taking out the forging die, and then is taken out from the forging die. The removed forging intermediate is gripped by the hand of the robot and transported to the subsequent forging station, where the forging intermediate is positioned so that the phase of its teeth matches the phase of the forging die side, Load (set) in the mold. As described above, the reason why the phase of the teeth of the forging intermediate is accurately matched with the phase of the mold side is that if the phase of the teeth does not exactly match the phase of the mold side, some of the teeth of the forging intermediate may not be aligned. This is because a large gap is generated between the mold and the inner surface of the mold, so that the finished product is not formed into a regular product shape in the final molding step.

[0005]

As described above, conventionally, at the former forging station, the forging intermediate is once protruded from the forging die and taken out, then the forged intermediate is gripped by the robot hand, and Was transferred to the forging station and charged into the forging die. By the way, when the forging intermediate is protruded from the forging die, the forging intermediate rotates in the circumferential direction and is likely to be displaced. Will be grasped. Therefore, when inserting the forging intermediate gripped by the robot hand into the forging die in the subsequent stage, the forging intermediate is precisely positioned with respect to the forging die so that the above-described gap does not occur. Positioning must be performed, which consumes a lot of time and lowers productivity.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and grasps a forging intermediate without shifting its position in a former forging station and transfers it to a subsequent forging station in this state. It is another object of the present invention to provide a robot hand which can be easily inserted into the forging die with high positional accuracy.

[0007]

In order to achieve the above object, a first aspect of the present invention is to hold a forged intermediate which is roughly forged by a first forging die, and to carry out a second forging in a subsequent stage. A hand body having a mounting portion for attaching to a robot arm, the hand body having a mounting portion for being attached to a robot arm, and being provided on the hand body and gripping an outer peripheral portion of the forging intermediate. A gripper including a pair of grip members for opening and closing the pair of grip members, and a first gripper between the pair of grip members.
And a pressing member for pressing the protruding forging intermediate, which is provided so as to be urged in a direction opposite to a direction in which the forging intermediate protrudes by the forging die. It is a feature.

In the present invention, after the rough forging by the first forging die, the die is opened, and the robot hand of the present invention in which the pair of grip members is open is
Positioning is performed so that the forging intermediate is located immediately above the forging intermediate held by the lower mold, that is, between the pair of grip members. Here, the forging intermediate is protruded by the operation of the knockout for removal of the lower die, and hits the pressing member urged downward, and the pair of grip members close to grip the forging intermediate. As described above, the forging intermediate projecting from the first forging die is immediately pressed from above by the pressing member, and is not displaced in the circumferential direction due to the frictional force between the forging intermediate and the pressing member. In addition, the forged intermediate body is gripped by the pair of grip members without displacement. Thereafter, the robot operating according to the predetermined program transfers the robot hand to the second forging die at the subsequent stage, and inserts the forging intermediate into an appropriate position of the second forging die.

Here, for example, when the forged intermediate is large or heavy, the positional displacement of the forged intermediate may not be prevented only by the frictional force with the pressing member. The second problem has been solved by claim 2.
That is, in the invention of claim 2, the forging intermediate has a plurality of irregularities formed in a circumferential direction thereof, and the pressing member has
An engagement member capable of engaging with at least a part of the irregularities of the forging intermediate is provided. Based on such a configuration, when positioning the robot hand on the forging intermediate, the engaging member of the holding member is engaged with a part of the unevenness of the forging intermediate, and in this state, the knockout for removing the lower mold is taken out. The forging intermediate is pushed out by operation. Therefore, the position of the forged intermediate body in the circumferential direction is restricted by the engagement with the engaging member in addition to the frictional force with the pressing member, and the positional deviation can be reliably prevented.

Incidentally, in the case of hot forging, the pair of gripping members may become high in temperature due to the effect of heat conduction from the forging intermediate, and may be thermally expanded. can do. That is, the invention according to claim 3 is provided with cooling means for cooling each of the pair of grip members. Based on such a configuration, the pair of grip members are prevented from being heated, and thus the thermal expansion is prevented, so that the pair of grip members can be smoothly opened and closed and wear is reduced.

Here, as in the invention of claim 4, the cooling means includes a cooling passage formed in the pair of grip members so as to extend in the respective longitudinal directions and open at the respective tips. Cooling air supply means for supplying cooling air to the cooling passage from the proximal end side of the grip member, respectively, so that the pair of grip members can be efficiently cooled by the simple cooling means, No cooling air hits the forging intermediate, and no oxide film is formed on the surface of the forging intermediate.

According to a fifth aspect of the present invention, there is provided a retracting mechanism for retracting the pressing member from between the pair of grip members. According to the present invention, as described above, when it is necessary to load a second forging die after inverting a forging intermediate forged with a first forging die, By
The robot hand of the present invention holding the forging intermediate is turned over, and the holding member is retracted from between the pair of grip members by the retracting mechanism. Thus, when the pair of grip members are opened and the forging intermediate is loaded into the second forging die, the pressing member does not become an obstacle, and the loading can be performed smoothly.

[0013]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of one embodiment of the robot hand of the present invention, FIG. 2 is a front view of FIG.
1 is a schematic plan view of an example of a forging facility.

First, as shown in FIG. 5, the forging equipment is provided with a first forging die 1 and a forging intermediate 104.
a, the forged intermediate body 104a is gripped by the hand 3 of the present invention mounted on the arm A of the robot R, and further conveyed to the second forging die 2, where the hand 3 is The forged intermediate body 104a that has been inverted is loaded into the second forging die 2, where the forged intermediate body 104a is finish-forged. That is, the forging equipment performs the forging process shown in FIG. 9 described above, but the forged product gripping robot hand 3 of the present invention performs not only the forging process shown in FIG. In the forging process shown in FIG. 1, the forging intermediate can be transferred from the former forging die to the latter forging die.

Next, as for the configuration of the forged product gripping robot hand 3 of the present embodiment, as shown in FIGS. 1 and 2, this hand 3 has a large-diameter hollow portion 4a and a small-diameter hollow portion 4b coaxial with each other. With an integrated hand body 4,
The distal end (right end in FIG. 1) of the small-diameter hollow portion 4b of the hand main body 4 is a flange portion (mounting portion) 5 mounted on the arm A (see FIG. 5) of the robot R. Large diameter hollow part 4
A pair of grip members 9a and 9b protrude from an opening / closing mechanism 6 provided at one end (the left end in FIG. 1) of the pair a, and the middle portions of the pair of grip members 9a and 9b are bent, and the tip ends of the pair of grip members 9a and 9b are bent. The spacing is wider than the spacing on the proximal side.

A well-known chuck (opening / closing mechanism) 6 for opening and closing the pair of grip members 9a and 9b in a direction away from and close to each other is provided in the large-diameter hollow portion 4a of the hand body 4. The chuck 6 has bases 9 of a pair of grip members 9a and 9b.
c and 9d are connected. A pair of grip members 9a,
At the tip of 9b, grip portions 10a and 10b for gripping portions of the forged intermediate body 104a that differ by 180 degrees in the circumferential direction are mounted, respectively. Also, a pair of grip members 9
A tension coil spring 11 is stretched over the base end sides of the grip members 9a and 9b, and the pair of grip members 9a and 9b are urged toward each other to close. Note that a gripper is constituted by the pair of grip members 9a and 9b and the chuck 6.

A plate-like pressing member 12 for pressing the upper end of the forged intermediate body 104a is disposed between the pair of grip members 9a and 9b, and the pressing member 12 moves in the opening and closing direction of the pair of grip members 9a and 9b. It is attached to one end of an arm 13 extending in a direction perpendicular to the direction. A base end portion 14 of the arm portion 13 is attached to a front end portion of a later-described rack member 17 extending in the same direction as the arm portion 13 so as to be vertically movable in FIG.
Are biased downward by compression coil springs 16 (biasing members). The state where the base end 14 is in the upper position is indicated by reference numeral 14a in FIG.

The holding member 12 includes the holding member 12
One end of an engagement arm 15 provided so as to be orthogonal to and extending toward the hand body 4 is fixed.
5 has an engaging projection 16 as an engaging member on the lower surface of the free end.
Are attached integrally. This engaging projection 16 is
Plurality of teeth 1 of forged intermediate 104a (intermediate product of bevel gear)
06 (a plurality of irregularities) between two adjacent teeth, that is, into the tooth space 105, and engages with the forging intermediate 104a in the circumferential direction.

A rack member 17 is provided on the hand body 4 side.
Are provided so as to be movable in a direction parallel to the hand body 4 (the left-right direction in FIG. 2).
It is supported by a plurality of rollers 18 for smoothing the movement. On the other hand, a torque actuator 7 is provided in the large-diameter hollow portion 4a, and the rotation of the torque actuator 7 is transmitted to a pinion gear 8 meshing with the rack member 17, so that the rack member 17 is moved on both sides thereof. It moves smoothly while being guided by the rollers 18.

According to the robot R equipped with the hand 3 of this embodiment, the hand 3 holding the forging intermediate 104a
Is reversed, and in this state, the grip is released and the forged intermediate body 104a can be released. That is, with the holding member 12 advanced, the pair of grip members 9
a, 9b, the forged intermediate body 104a is gripped, and in this state, the entire hand 3 is turned over and the rack member 17
Is retracted (moved in the direction of the hand body 4), the pressing member 12 is retracted from between the pair of grip members 9a and 9b (the base end portion 14b in FIG. 1 and the rack member 17a in FIG. 2).
reference). When the pair of grip members 9a and 9b are opened, the forged intermediate body 104a is separated from the pair of grip members 9a and 9b without being interfered by the pressing member 12. As is apparent from the above description, the rack member 17, the torque actuator 7, the pinion gear 8, and the like constitute a retracting mechanism for the pressing member 12.

Next, the operation of the hand 3 of this embodiment will be described together with a series of forging steps. First, as shown in FIGS. 5 and 9, the heated billet 100 is transferred to the first forging die 1, roughly forged, and the mold is opened. The teeth of the obtained forged intermediate body 104a face upward.

Here, the hand 3 of the present embodiment is attached to the arm A.
Is operated, and as shown in FIGS. 1 and 2, the forged product gripping robot hand 3 in a state where the pair of grip members 9a and 9b are open is held by the lower die. Immediately above the forged intermediate 104a, that is, between the pair of grip members 9a and 9b, the forged intermediate 104a
Is positioned so as to be positioned, and is further lowered to engage the engagement convex portion 16 of the holding member 12 with the tooth groove 105 of the forged intermediate body 104a. In this state, the forging intermediate 104a is protruded by the operation of the knockout for taking out the lower mold, and immediately hits the lower surface of the pressing member 12 urged downward, and the arm portion 13 and the pressing member 12 etc. Both move upwardly against the elastic force of the compression coil spring 16a (the arm portion 13a and the base end portion 1 in FIG. 2).
4a), the pair of gripping materials 9a, 9b are closed to grip the forged intermediate 104a.

As described above, the forging intermediate 104a protruding from the first forging die 1 is immediately pressed by the pressing member 12 from above, and is circumferentially moved by the frictional force with the pressing member 12. As a result, the forged intermediate body 104a is gripped by the pair of grip members 9a and 9b without being displaced. Moreover, since the engaging projections 16 are engaged in the circumferential direction of the forging intermediate body 104a, for example, even in the case where the forging intermediate body 104a is large or its weight is large, the forging intermediate body 104a particularly in the circumferential direction. Displacement can be reliably prevented.

Next, the hand 3 is transported by the robot R to the second forging die 2 and is turned over. Here, the forging intermediate 10 is placed just above the lower die of the second forging die 2.
The positioning member 4a is positioned, and the rack member 17 is retracted so that the holding member 12 is retracted from between the pair of grip members 9a and 9b. Then, a pair of grip members 9a, 9
When b is opened, the forged intermediate body 104a is released from the pair of grip members 9a and 9b and is charged into the lower mold.

As described above, the forged intermediate body 104a roughly forged by the first forging die 1 is provided with a pair of grip members 9a.
Since the forging intermediate body 104a is gripped without being displaced by the a and 9b, the forging intermediate body 104a is loaded into the lower die of the second forging die 2 with a high degree of positional accuracy without performing complicated positioning. can do. As a result, the productivity is improved, and the forging intermediate 104 is added to the second forging die.
a is inserted with the plurality of teeth and the inner surface of the second forging die in phase with each other, so that the plurality of teeth of the forging intermediate body 104a and the inner surface of the second forging die are Since a large gap is not generated between the forged intermediate body 104a and the conventional forged intermediate body 104a, the forged intermediate body 104a is formed into a regular product shape by the finishing tooth mold, and the quality is stabilized. When the forging intermediate 104a is small and lightweight, the forging intermediate 104a can be reliably prevented from being displaced only by the frictional force with the pressing member 12, so that the engaging projection 16 of the pressing member 12 is unnecessary. is there.

FIG. 3 is a plan view of another embodiment of the robot hand of the present invention, and FIG. 4 is a front view of FIG. The forged product gripping robot hand 40 of the present embodiment includes a holding member 36.
And a pair of grip members 30
The hand shown in FIGS. 1 and 2 is significantly different from the hand shown in FIGS.

The right end flange 34b of the hand body 34
Is a mounting portion for mounting on the arm of the robot.
Is equipped with a known grip opening / closing mechanism 33. The grip opening / closing mechanism 33 allows the pair of grip members 30
The a and 30b are pivoted about the respective base ends 38a and 38b in the directions of moving away from and approaching each other. A pair of grip members 3
Holders 31a and 31b are attached to the distal ends of 0a and 30b, respectively. A base 32 of an arm member 37 is fixed to the grip opening / closing mechanism 33. A free end of the arm member 37 has a plate-shaped pressing member 36 at its lower end.
Is provided so as to be vertically movable in FIG.

More specifically, a cylindrical bush 24 is fixed to a free end of the arm member 37, and the rod 25 is inserted through a hollow portion of the bush 24 so as to be movable vertically (upward). If it is in the position, see the rod 25a in FIG. 4). The lower surface of the holding member 36 is
Engagement projections 29a and 29b are integrally provided at positions different by 80 °. The bush 24 has a cooling passage (not shown) described later.

At the upper end of the rod 25 of the pressing member 36, a through hole 28 is formed in a form orthogonal to the axial direction, and one end of a spring wire 26 as an urging member passes through the through hole 28. doing. This spring wire 2
6 is provided so as to extend substantially in parallel with the arm member 37, and the other end of the spring wire 26 is supported by the base 32 of the arm member 37 by a plurality of spring support members 27a and 27b. Based on such a configuration, the rod 25 having the holding member 36 is urged downward by the spring wire 26.

The pair of grip members 30a, 30b have cooling passages 20a, 20b extending in the longitudinal direction thereof.
b are formed respectively. These cooling passages 20a, 2
Ob is formed on the end surface of the free end of the gripping members 30a, 30b and formed up to the vicinity of the base end. On the other hand, the cooling air pipe 22 is
One end (right side in FIG. 4) of the cooling air pipe 22 is connected to a cooling air source (not shown), and the other end is branched into three, and a pair of branch pipes 22a (one is not connected). Shown)
The cooling passage 20a of the pair of grip members 30a, 30b,
The remaining one branch pipe 23 which communicates with the base end side of 20b is connected to the cooling passage (not shown) of the bush 24.

Based on such a configuration, cooling air can be efficiently cooled by flowing cooling air from the cooling air pipe 22 into the cooling passages 20a and 20b of the pair of grip members 30a and 30b and the cooling passage of the bush 24. . As is apparent from the above description, a cooling air supply means is constituted by the cooling air source (not shown), the cooling air pipe 22, the bracket 21, and the like, and the cooling means is constituted by the cooling air supply means and the cooling passages 20a and 20b. It is configured.

Therefore, even in the case of hot forging as in the present embodiment, by appropriately supplying cooling air,
Preventing the temperature of the pair of grip members 30a, 30b and the like, and thereby preventing the thermal expansion, smoothly opens and closes the movable parts, particularly the pair of grip members 30a, 30b, and reduces wear. Further, since the cooling air is blown out from the end surfaces of the pair of grip members 30a, 30b, the cooling air does not hit the forged intermediate, and no oxide film is formed on the surface of the forged intermediate. The forged product gripping robot hand 40 of the present embodiment is used when it is not necessary to reverse the forging intermediate, and is provided with a cooling unit and without a retracting mechanism for a holding member. , FIG. 1 and FIG. 2, and other operations are the same as those shown in FIG. 1 and FIG.

In each of the embodiments described above, the forging intermediate of the bevel gear is described as the object to be grasped. However, the present invention is not limited to this. For example, a general forging intermediate or a plurality of irregularities formed in the circumferential direction, for example, Shaft members such as splines and serrations, clutch parts, and the like may be used.

[0034]

Since the present invention is configured as described above, it has the following effects. According to the first aspect of the present invention, the forging intermediate projecting from the first forging die is immediately pressed from above by the pressing member, and is displaced in the circumferential direction by a frictional force with the pressing member. As a result, the forged intermediate body is gripped by the pair of grip members without displacement. Therefore, the robot that operates according to the predetermined program moves the robot hand to the forging die at the subsequent stage, and
It is possible to insert the forging die at an appropriate position in the subsequent stage without complicated positioning. Therefore, while the productivity is improved, a large gap is not generated between the inner surface of the forging die and the forging intermediate in the subsequent forging die, and as a result, the final forging step is performed to form a product having a regular shape. Quality is stable.

According to the second aspect of the present invention, when positioning the robot hand on the forging intermediate, the engaging member of the pressing member is engaged with the uneven portion of the forging intermediate, and in this state, the lower mold is taken out. The forging intermediate is protruded by the knockout operation. Therefore, in addition to the above-mentioned effects, for example, even when the forged intermediate is large or its weight is large, the forged intermediate is not limited to the frictional force with the pressing member, but can also be engaged with the engaging member in the circumferential direction. The position is regulated, and the position shift can be reliably prevented.

According to a third aspect of the present invention, in addition to the above-described effects, by cooling the pair of grip members, the pair of grip members can be prevented from being thermally expanded and prevented from thermally expanding, so that the pair of grip members can be opened and closed. And reduce abrasion.

According to a fourth aspect of the present invention, the cooling means includes a cooling passage formed in the pair of grip members so as to extend in a longitudinal direction of each of the grip members and open at each of the distal ends thereof. And cooling air supply means for supplying cooling air from the base end side of the grip member. In addition to the above effects, the pair of grip members can be efficiently cooled by the simple cooling means. In addition, the cooling air does not hit the forged intermediate, and no oxide film is formed on the surface of the forged intermediate.

According to a fifth aspect of the present invention, there is provided a robot for reversing a forging intermediate forged by a first forging die and then loading the intermediate forging into a second forging die. With this arm, the robot hand of the present invention holding the forged intermediate body is inverted, and the retraction mechanism retracts the pressing member from between the pair of grip members. Accordingly, in addition to the above effects, when the pair of grip members are opened and the forging intermediate is inserted into the second forging die, the pressing member does not become an obstacle, and the charging can be performed smoothly.

[Brief description of the drawings]

FIG. 1 is a plan view of a first embodiment of a robot hand according to the present invention.

FIG. 2 is a front view of the first embodiment of the robot hand according to the present invention.

FIG. 3 is a plan view of a second embodiment of the robot hand according to the present invention.

FIG. 4 is a front view of a second embodiment of the robot hand according to the present invention.

FIG. 5 is a schematic configuration diagram of an example of a forging facility.

FIG. 6 is a schematic diagram for explaining an example of a forging process.

FIG. 7 is a schematic diagram for explaining another example of the forging process.

FIG. 8 is a schematic view for explaining still another example of the forging step.

FIG. 9 is a schematic view for explaining still another example of the forging step.

[Explanation of symbols]

 R Robot A arm 1 First forging die 2 Second forging die 3,40 Forged product gripping robot hand 4 34 Hand body 5,34a, 34b Flange part 6,33 Opening / closing mechanism (chuck) 7 Torque Actuator 8 Pinion gear 9a, 9b, 30a, 30b Grip member 10a, 10b, 31a, 31b Gripping portion 11 Tension spring 12, 36 Holding member 13 Arm 14 Base end 15 Engagement arm 16, 29a, 29b Engagement protrusion ( 16a Compression coil spring 17 Rack member 18 Roller 20a, 20b Cooling passage 21 Pipe bracket 22 Cooling air pipe 22a, 23 Branch pipe 24 Bush 25 Rod 26 Spring wire 27a, 27b Spring holding member 28 Through hole 100 Billet 101a, 102a, 103a Upper die 101b, 102b, 103b Lower die 104a First forged intermediate 104b Second forged intermediate 104c Product (bevel gear)

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Haruo Ikeda 1230 Kamideya, Okegawa-shi, Saitama Mitsubishi Mate Real Co., Ltd.Okegawa Works (72) Inventor Hitoshi 1230 Kamijiya, Okegawa-shi, Saitama Okegawa Manufacturing Co., Ltd.

Claims (5)

[Claims] 1. A hand for gripping a forging intermediate that has been roughly forged by a first forging die, transporting the intermediate forging to a second forging die, and loading the intermediate forging. A hand body having a mounting portion for attachment to an arm; a pair of grip members provided on the hand body for gripping an outer peripheral portion of the forged intermediate body; and an opening / closing mechanism for opening and closing the pair of grip members. And a gripper formed between the pair of grip members and provided in such a form as to be urged in a direction opposite to a direction in which the forging intermediate body projects by the first forging die, and wherein the forging is protruded. A robot hand, comprising: a holding member for holding an intermediate body. 2. The robot hand according to claim 1, wherein the forging intermediate has a plurality of irregularities in a circumferential direction thereof, and the pressing member has at least a part of the irregularities of the forging intermediate. A robot hand provided with an engageable engaging member. 3. The robot hand according to claim 1, further comprising cooling means for cooling the pair of grip members. 4. The robot hand according to claim 3, wherein the cooling means includes a cooling passage formed in the pair of grip members so as to extend in a longitudinal direction of each of the grip members and to open at a tip of each of the cooling members. A cooling air supply unit configured to supply cooling air to the cooling passage from a base end side of the grip member. 5. The robot hand according to claim 1, further comprising a retracting mechanism for retracting the pressing member from between the pair of grip members. Robot hand.