JP2006102819A - Die apparatus for full enclosed die forging - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a die apparatus with which machine parts etc., having good quality without producing underfill are easily obtained by raising the enclosed force of dies. <P>SOLUTION: In the die apparatus for enclosed-forging a work 7 by pressure-splitting the work 7 in cavities 1a, 2a with an upper counter punch 8 and a lower counter punch 22 arranged in an upper die 1 and a lower die 2, respectively, while closing the cavities 1a, 2a between the upper die 1 fitted at a slide 6 side and the lower die 2 set at a bolster 17 side, at the upper side of the upper die 1 and at lower side of the lower die 2, pressurizing means 11, 19 for closing both sides of cavities 1a, 2a by pressurizing the upper die 1 and the lower die 2 from the vertical direction, are arranged. Furthermore, at the upper side of the upper counter punch 8 and at the lower side of the lower counter punch 22, a back-pressure giving means 12, 20, with which the work 7 is split to both sides by giving the back-pressure to the upper and the lower counter punches 8, 22 at the forming time, and at the time of filling up the work 7 into the cavities 1a, 2a, the back-pressure is removed, are arranged. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a forging die apparatus used for shunt blockage forging.

  Conventionally, as a method of manufacturing mechanical parts such as gears by forging, for example, those described in Patent Document 1 and Patent Document 2 are known.

The spur gear forging method of Patent Document 1 described above is a first machining step in which a primary working gear is formed by upsetting into a primary gear having a gear shape set smaller than the gear-shaped tooth profile of the spur gear from which a material is to be obtained. Each of these steps comprises a second processing step in which a material is freely flowed in a portion other than the tooth profile and compression-molded into a secondary processing gear, and a third processing step in which the secondary processing gear is cast into a final product. Is performed by cold forging, and the ironing allowance at the time of ironing is formed stably, so that there is an effect that a highly accurate product can be obtained with a low load.
Moreover, the extrusion method of the above-mentioned patent document 2 is formed by extruding with a punch having a hole, forming a convex part from the hole part of the punch, and pressurizing the convex part release end of this part with a predetermined pressure. This is a method of extruding and reducing or removing the pressure before the end of processing, and has the effect of greatly reducing the maximum load acting on the mold near the bottom dead center.

JP-A-5-154598 Japanese Patent No. 2534899

  However, in the forging method of Patent Document 1, since the material is formed smaller than the gear-shaped tooth profile of the spur gear to be obtained in advance, one or two steps are required to form the material into a gear shape. Since the number of processes is large, for example, the forging of the material requires 3 processes, forging takes time and the productivity is poor.

  In addition, since the forging is performed by exchanging the punches for each process, the replacement work becomes complicated, and it is necessary to prepare a plurality of types of punches and mandrels in advance.

On the other hand, in the extrusion method of Patent Document 2, the pressing member provided on the upper punch performs backward extrusion while partially restricting the flow of the material, and reduces or eliminates the pressing force of the pressing member before the end of processing. As a result, a high surface pressure acts on the mold from the start of molding, thereby causing problems such as seizing the mold and shortening the life of the mold early.
In the extrusion method of the above publication, since the pressure member is provided only on the upper punch side, the pressurizing force of the upper punch and the lower punch is non-uniform and the material flows only in one direction. The product has a non-uniform fiber flow, resulting in a decrease in strength of the product and defects such as cracks and sink marks in the product.

  The present invention was made to remedy such problems, and provides a closed forging die device that can obtain a high closing force by means of a pressurizing means. The purpose is to make it easy to obtain.

In order to achieve the above object, the invention according to claim 1 closes the cavity 1a of the upper mold 1 attached to the slide 6 side and the cavity 2a of the lower mold 2 installed on the bolster 17 side, and And a closed forging die apparatus for closing and forging the work 7 by pressurizing and diverting the work 7 in the cavities 1a and 2a with the upper counter punch 8 and the lower counter punch 22 provided in the lower mold 2,
Pressure means 11 and 19 are provided above the upper mold 1 and below the lower mold 2 to pressurize the upper mold 1 and the lower mold 2 from above and below to close the cavities 1a and 2a on both sides,
Back pressure is applied to the upper and lower counter punches 8 and 22 during molding through the pistons 12a and 20a by filling the hydraulic chambers 12b and 20b with pressure oil above the upper counter punch 8 and below the lower counter punch 22, respectively. Then, back pressure applying means by cylinders 12 and 20 for diverting the work 7 on both sides is provided
The closed forging is characterized in that when the work 7 is filled in the cavities 1a and 2a, the pressure oil in the hydraulic chambers 12b and 20b of the cylinders 12 and 20 is drained to the tank 35 to remove the back pressure. Mold equipment.

In order to achieve the above object, the invention according to claim 2 closes the cavity 1a of the upper mold 1 attached to the slide 6 side and the cavity 2a of the lower mold 2 installed on the bolster 17 side, and And a closed forging die apparatus for closing and forging the work 7 by pressurizing and diverting the work 7 in the cavities 1a and 2a with the upper counter punch 8 and the lower counter punch 22 provided in the lower mold 2,
Provided below the lower mold 2 is a pressurizing means 19 that pressurizes the lower mold 2 from below and closes the cavities 1a and 2a on one side,
Back pressure is applied to the upper and lower counter punches 8 and 22 during molding through the pistons 12a and 20a by filling the hydraulic chambers 12b and 20b with pressure oil above the upper counter punch 8 and below the lower counter punch 22, respectively. Then, back pressure applying means by cylinders 12 and 20 for diverting the work 7 on both sides is provided,
The closed forging is characterized in that when the work 7 is filled in the cavities 1a and 2a, the pressure oil in the hydraulic chambers 12b and 20b of the cylinders 12 and 20 is drained to the tank 35 to remove the back pressure. Mold equipment.

In order to achieve the above object, the invention according to claim 3 closes the cavity 1a of the upper mold 1 attached to the slide 6 side and the cavity 2a of the lower mold 2 installed on the bolster 17 side, and And a closed forging die apparatus for closing and forging the work 7 by pressurizing and diverting the work 7 in the cavities 1a and 2a with the upper counter punch 8 and the lower counter punch 22 provided in the lower mold 2,
Pressure means 11 and 19 are provided above the upper mold 1 and below the lower mold 2 to pressurize the upper mold 1 and the lower mold 2 from above and below to close the cavities 1a and 2a on both sides,
Applying back pressure to the upper counter punch 8 at the time of molding through the piston 12a by filling the hydraulic chamber 12b with pressure oil above the counter punch 8, and applying the back pressure by the cylinder 12 for dividing the work 7 on one side. Providing means,
A closed forging die apparatus characterized in that when the work 7 is filled in the cavities 1a and 2a, the pressure oil in the hydraulic chamber 12b of the cylinder 12 is drained to the tank 35 to remove the back pressure. It is.

In order to achieve the above object, the invention according to claim 4 closes the cavity 1a of the upper mold 1 attached to the slide 6 side and the cavity 2a of the lower mold 2 installed on the bolster 17 side. And a closed forging die apparatus for closing and forging the work 7 by pressurizing and diverting the work 7 in the cavities 1a and 2a with the upper counter punch 8 and the lower counter punch 22 provided in the lower mold 2,
Above the upper mold 1 is provided pressurizing means 11 that pressurizes the upper mold 1 from above and closes the cavities 1a, 2a on one side,
Above the upper counter punch 8, the hydraulic pressure is filled in the hydraulic chamber 12 b so that back pressure is applied to the upper counter punch 8 at the time of molding via the piston 12 a to cause the work 7 to flow on one side. Providing means,
A closed forging die apparatus characterized in that when the work 7 is filled in the cavities 1a and 2a, the pressure oil in the hydraulic chamber 12b of the cylinder 12 is drained to the tank 35, and the back pressure is removed. It is.

  According to the first aspect of the present invention, when the upper mold 1 is lowered together with the slide 6 and the upper mold 1 and the lower mold 2 are brought into close contact with each other, the upper mold 1 and the lower mold 2 are pressurized by the pressurizing means. Then, the cavities 1a and 2a are closed on both sides, and at the same time, the work in the cavities 1a and 2a is pressurized in the vertical direction by the upper counter punch 8 and the lower counter punch 22 by the back pressure applying means, so When the workpieces are filled in the cavities 1a and 2a, the back pressure of the upper and lower counter punches 8 and 22 is removed so that no abnormally high pressure is generated in the cavities 1a and 2a. Since high-pressure closing force can be easily obtained, large machine parts can be easily forged, and when the work is filled in the cavity, the back pressure of the back pressure applying means is removed. Since was Unishi, or mold damage abnormally high pressure occurs, die life is not reduced at an early stage.

  In addition, since a large closing force can be secured until the slide reaches the bottom dead center, the filling of the material in the cavity is improved, and a molded product having a good quality with no lack of wall is obtained. Therefore, it is not necessary to remove burrs after molding.

  Furthermore, since the upper and lower molds can be closed simultaneously by supplying hydraulic pressure to the upper and lower pressurizing means, it is possible to supply pressure oil with a single hydraulic generator, which can reduce equipment costs and block Since the hydraulic pressure only needs to be generated during forging, it is possible to reduce the size of the mold mounting parts and the like, thereby reducing the cost of the mold apparatus.

  According to the second aspect of the present invention, when the upper mold 1 is moved down together with the slide 6 and the upper mold 1 and the lower mold 2 are brought into close contact with each other, the lower mold 2 is pressurized by the pressurizing means so that the cavities 1a and 2a are formed. One side is closed, and at the same time, the work in the cavities 1a and 2a is pressurized in the vertical direction by the upper counter punch 8 and the lower counter punch 22 with the back pressure applying means, and the work is made to flow into the cavities 1a and 2a while being divided into both sides. When the work is filled in 1a and 2a, the back pressure of the upper and lower counter punches 8 and 22 is removed so that no abnormally high pressure is generated in the cavities 1a and 2a. Since it can be easily obtained, large machine parts can be easily forged, and when the work is filled in the cavity, the back pressure applied by the back pressure application means is reduced. From or mold damage abnormally high pressure occurs, die life is not reduced at an early stage.

  In addition, since a large closing force can be secured until the slide reaches the bottom dead center, the filling of the material in the cavity is improved, and a molded product having a good quality with no lack of wall is obtained. Therefore, it is not necessary to remove burrs after molding.

  Furthermore, since it is sufficient to generate hydraulic pressure only during closed forging, it is possible to reduce the size of mold mounting parts and the like, thereby reducing the cost of the mold apparatus.

  According to the third aspect of the present invention, when the upper die 1 is lowered together with the slide 6 and the upper die 1 and the lower die 2 are brought into close contact with each other, the upper die 1 and the lower die 2 are pressurized by the pressurizing means. The cavities 1a and 2a are closed on both sides, and simultaneously the workpieces in the cavities 1a and 2a are pressurized from above and below by the upper counter punch 8 and the lower counter punch 22 to flow into the cavities 1a and 2a while being divided into one side, When the work is filled in the cavities 1a and 2a, the back pressure of the upper counter punch 8 is removed so that no abnormally high pressure is generated in the cavities 1a and 2a. Therefore, large machine parts can be easily forged, and when the work is filled in the cavity, the back pressure applied by the back pressure application means is removed. An abnormally high pressure does not occur and the mold is not damaged, and the mold life is not shortened early.

  In addition, since a large closing force can be secured until the slide reaches the bottom dead center, the filling of the material in the cavity is improved, and a molded product having a good quality with no lack of wall is obtained. Therefore, it is not necessary to remove burrs after molding.

  Furthermore, since the upper and lower molds can be closed simultaneously by supplying hydraulic pressure to the upper and lower pressurizing means, it is possible to supply pressure oil with a single hydraulic generator, which can reduce equipment costs and block Since the hydraulic pressure only needs to be generated during forging, it is possible to reduce the size of the mold mounting parts and the like, thereby reducing the cost of the mold apparatus.

  According to the fourth aspect of the present invention, when the upper mold 1 is moved down together with the slide 6 and the upper mold 1 and the lower mold 2 are brought into close contact with each other, the upper mold 1 is pressurized by the pressurizing means so that the cavities 1a and 2a are formed. One side is closed, and simultaneously the upper counter punch 8 and the lower counter punch 22 pressurize the work in the cavities 1a and 2a from above and below to flow into the cavities 1a and 2a while diverting the work on one side, and into the cavities 1a and 2a. When the workpiece is full, the back pressure of the upper counter punch 8 is removed so that no abnormally high pressure is generated in the cavities 1a and 2a. Machine parts can be easily forged, and when the work is filled in the cavity, the back pressure applied by the back pressure application means is removed, resulting in abnormal high pressure. Or mold damage, mold life is not reduced at an early stage.

  In addition, since a large closing force can be secured until the slide reaches the bottom dead center, the filling of the material in the cavity is improved, and a molded product having a good quality with no lack of wall is obtained. Therefore, it is not necessary to remove burrs after molding.

  Furthermore, since it is sufficient to generate hydraulic pressure only during closed forging, it is possible to reduce the size of mold mounting parts and the like, thereby reducing the cost of the mold apparatus.

A first embodiment of the present invention will be described in detail with reference to the drawings shown in FIGS.
Fig. 1 is a cross-sectional view of a mold device for closed forging for forging machine parts (hereinafter referred to as workpieces) such as inner races of constant velocity joints, bevel gears, flange parts, etc. The circuit diagram of an apparatus is shown.

In these drawings, 1 is an upper mold, 2 is a lower mold, and the upper mold 1 is detachably attached to the lower surface of the upper support member 4 via an upper mold holder 3. The upper support member 4 is an upper cylinder block 5. Is attached to the lower surface of the slide 6 of the forging press.
A cavity 1a for forming the workpiece 7 is formed at the center of the lower surface of the upper mold 1. Inside the cavity 1a, an upper counter punch 8 supported at the center of the upper mold 1 is slidable in the vertical direction. The tapered tip portion 8a protrudes from the upper side so as to be able to protrude and retract.

  An elevating member 4a for elevating and lowering the upper mold 1 is accommodated in the upper support member 4, and the upper mold 1 is attached to the lower surface of the elevating member 4a by a holder 3, and the elevating member 4a A step portion 4b is formed on the outer peripheral surface, and the step portion 4b is locked to the locking ring 4c, so that the elevating member 4a is prevented from falling out of the upper support member 4 and is moved up and down. The lower ends of the plurality of operating pins 10 are in contact with the upper surface of the member 4a.

Each operating pin 10 is provided so as to penetrate the end plate 11a of the outer cylinder 11 provided in the cylinder block 5 in the vertical direction, and the upper end surface is accommodated in the outer cylinder 11 so as to be slidable in the vertical direction. It is in contact with the lower surface of the piston 11b.
The upper side of the piston 11 b is a hydraulic chamber 11 c and is connected to a hydraulic pressure generator 25 shown in FIG. 2 through an oil passage 5 a and a pipe 29 formed in the cylinder block 5.

An inner cylinder 12 is provided at the center of the outer cylinder 11, and the lower surface of the piston 12 a accommodated in the inner cylinder 12 so as to be slidable in the vertical direction is connected to the upper counter punch 8 via a presser 13. While being in contact with the upper surface, a knockout pin 14 of a slide knockout (not shown) provided in the slide 6 is penetrated through the central portion of the piston 12a so as to be slidable in the vertical direction.
The upper side of the piston 12a is a hydraulic chamber 12b, which is filled with oil in advance, and an oil passage 5b formed in the cylinder block 5 and the first electromagnetic valve 32 and the relief valve 33 are connected in parallel. 2 is connected to the oil tank 35 of the hydraulic pressure generator 25 shown in FIG.

On the other hand, the lower mold 2 is attached to the upper surface of an elevating member 14a accommodated in the lower support member 14 via a lower mold holder 15, and the lower support member 14 is forged via a lower cylinder block 16. It is attached to the upper surface of the bolster 17 of the press.
A step portion 14b is formed on the outer peripheral surface of the elevating member 14a, and the step portion 14b is locked to the locking ring 14c. Lower ends of a plurality of operating pins 18 are in contact with the upper surface of the elevating member 14a.

Each operating pin 18 is provided so as to penetrate the end plate 19a of the outer cylinder 19 provided in the cylinder block 16 in the vertical direction, and the lower end surface is accommodated in the outer cylinder 19 so as to be slidable in the vertical direction. In contact with the upper surface of the piston 19b.
The lower side of the piston 19 b is a hydraulic chamber 19 c and is connected to the hydraulic pressure generator 25 through an oil passage 16 a and a pipe 29 formed in the cylinder block 16.

Further, an inner cylinder 20 is provided at the center of the outer cylinder 19, and the upper surface of the piston 20 a accommodated in the inner cylinder 20 so as to be slidable in the vertical direction is disposed on the lower surface of the lower counter punch 22 via a presser 21. It is in contact with.
A tapered tip portion 22a formed at the upper end of the lower counter punch 22 protrudes from a lower portion into a cavity 2a formed on the upper surface of the lower die 2, and protrudes from the center of the piston 20a. A knockout pin 23 of a bed knockout (both not shown) provided in the bed is slidably penetrated.

  The lower side of the piston 20a is a hydraulic chamber 20b, which is prefilled with oil, and an oil passage 16b formed in the cylinder block 16 and a second electromagnetic valve 36 and a relief valve 37 in parallel. It is connected to the oil tank 35 of the hydraulic pressure generator 25 through the connected pipe line 38.

  As shown in FIG. 2, the hydraulic pressure generating device 25 includes intermediate pressure generating means 26 having cylinders 26a and 26b having different diameters, and high pressure generating means 27 having cylinders 27a and 27b having different diameters. By supplying the pressure oil to the cylinders 26b, 27b on the smaller diameter side than 28, medium pressure or high pressure oil is generated in the large diameter cylinders 26a, 27a. The pressure oil generated in 27 is supplied to the hydraulic chamber 11c of the outer cylinder 11 provided on the upper die 1 side and the hydraulic chamber 19c of the outer cylinder 19 provided on the lower die 2 side through the pipe 29. It has become so.

  In FIG. 2, reference numeral 40 denotes a residual pressure extracting valve for extracting the residual pressure in the medium and high pressure generating means 26 and 27 to the oil tank 35.

Next, the operation of the above-configured closed forging die apparatus will be described.
When the work 7 is loaded into the cavity 2a of the lower mold 2 by a work conveying means (not shown) while the slide 6 is stopped at the top dead center, the upper mold 1 is lowered together with the slide 6 so that the lower surface of the upper mold 1 is moved. When the upper mold 1 and the lower mold 2 are brought into close contact with each other, pressure oil is supplied simultaneously from the intermediate pressure generating means 26 or the high pressure generating means 27 to the hydraulic chambers 11c and 19c of the outer cylinders 11 and 19, respectively. The mold 2 is pressurized from above and below to close the cavities 1a and 2a (this is called double-side closing).

  At the same time, the work 7 in the cavities 1a and 2a is given back pressure in the vertical direction by the tip portions 8a and 22a of the upper counter punch 8 and the lower counter punch 22 projecting into the cavities 1a and 2a. The work 7 is forged in the closed cavities 1a and 2a by diverting into 2a (this is called bilateral diversion).

Then, the divided work 7 is filled in the cavities 1a and 2a, and the first and second electromagnetic valves 32 and 36 are opened immediately before the internal pressure rises, and the hydraulic chambers 12b and 20b of the inner cylinders 12 and 20 are opened. The pressure oil is drained to the oil tank 35.
As a result, the back pressure applied to the upper and lower counter punches 8 and 22 is removed, and the pressure distribution of the workpiece 7 is stopped, so that the increase in the internal pressure of the cavities 1a and 2a is suppressed, and the internal pressure rises abnormally. This prevents the mold from being damaged.

  When the forming of the work 7 is completed as described above, as the slide 6 starts to rise together with the upper mold 1, the knock pin 14 is first pushed down by the slide knockout, and the work 7 attached to the upper mold 1 is knocked out. Then, as the slide 6 further rises, the knockout pin 23 is pushed up by bed knockout and the workpiece 7 is knocked out from the lower mold 2, and then the workpiece 7 that has been molded is carried out by the workpiece transfer device.

  By repeating the above operation, the workpiece 7 is closed and forged, and the upper and lower molds 1 and 2 are closed on both sides, and at the same time, the workpiece 7 is forked by the upper and lower counter punches 14 and 22, and forging is performed. There will be no good quality molded products.

  In the first embodiment, the upper and lower molds 1 and 2 and the upper and lower counter punches 8 and 22 are simultaneously closed in the vertical direction. FIG. 4 shows an embodiment in the case of both-side occlusion and one-sided diversion, and FIG. 5 shows an embodiment in the case of one-side occlusion and one-sided diversion.

Next, these embodiments will be described.
The same parts as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.
In the second embodiment shown in FIG. 3, only the lower die 2 is pressurized from below by the piston 19a of the outer cylinder 19 and closed on one side, and at the same time back pressure is applied to the upper and lower counter punches 8 and 22 from the upper and lower directions. The work 7 is split on both sides, and immediately before the work 7 split on both sides is filled in the cavities 1a and 2a and the internal pressure rises, the first and second solenoid valves 32 and 36 are opened, The point that the back pressure of the upper and lower counter punches 8 and 22 is removed is the same as in the first embodiment.

  Further, in the third embodiment shown in FIG. 4, the upper die 1 and the lower die 2 are simultaneously pressurized by the pistons 11b and 19b of the outer cylinders 11 and 19 and closed on both sides, and at the same time, only the upper counter punch 8 is viewed from above. The back pressure is applied so that the work 7 is diverted to one side, and the back pressure of only the upper counter punch 8 is just before the work 7 divided in one side is filled in the cavities 1a and 2a and the internal pressure rises. To prevent the internal pressure of the cavities 1a and 2a from becoming abnormally high.

Further, in the fourth embodiment shown in FIG. 5, only the upper die 1 is pressurized by the piston 11b of the outer cylinder 11 and closed on one side, and simultaneously, the back pressure is applied only from the upper side to the upper counter punch 8 to The cavities 1a and 2a are filled with the work 7 divided on one side, and only the back pressure of the upper counter punch 8 is removed immediately before the internal pressure rises, and the internal pressure of the cavities 1a and 2a is reduced. Is designed to prevent abnormally high levels.
Even in the case of any one of the above embodiments, a molded product having a good quality without lacking in thickness can be obtained.

1 is a cross-sectional view of a closed forging die device according to a first embodiment of the present invention. 1 is a circuit diagram of a hydraulic pressure generator used in a closed forging die device according to a first embodiment of the present invention. FIG. It is sectional drawing of the metal mold | die apparatus for closure forging used as 2nd Embodiment of this invention. It is sectional drawing of the metal mold | die apparatus for closure forging used as the 3rd Embodiment of this invention. It is sectional drawing of the metal mold | die apparatus for closure forging used as the 4th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Upper mold | type, 1a ... Cavity, 2 ... Lower mold | type, 2a ... Cavity, 6 ... Slide, 7 ... Workpiece | work, 8 ... Upper counter punch, 11 ... Pressurization means (outer cylinder), 12 ... Back pressure provision means (inner side) Cylinder), 17 ... bolster, 19 ... pressure means (outer cylinder), 20 ... back pressure applying means (inner cylinder), 22 ... lower counter punch

Claims (4)

The upper mold (1) cavity (1a) mounted on the slide (6) side and the lower mold (2) cavity (2a) installed on the bolster (17) side are closed, and the upper mold (1) And the upper counter punch (8) and the lower counter punch (22) provided in the lower die (2), the work (7) in the cavities (1a) and (2a) is divided by pressurizing and the work (7) is closed. In the mold equipment for closed forging to forge,
Pressurizing the upper mold (1) and the lower mold (2) from above and below the upper mold (1) and below the lower mold (2) to block the cavities (1a) and (2a) on both sides. Providing means (11), (19);
The hydraulic chambers (12b) and (20b) are filled with pressure oil above the upper counter punch (8) and below the lower counter punch (22) to form through the pistons (12a) and (20a). Back pressure applying means is provided by cylinders (12) and (20) for applying back pressure to the upper and lower counter punches (8) and (22) and diverting the work (7) on both sides,
When the work (7) is filled in the cavities (1a) and (2a), the hydraulic oil in the hydraulic chambers (12b) and (20b) of the cylinders (12) and (20) is drained to the tank (35). A closed forging die apparatus characterized in that the back pressure is removed. The upper mold (1) cavity (1a) mounted on the slide (6) side and the lower mold (2) cavity (2a) installed on the bolster (17) side are closed, and the upper mold (1) And the upper counter punch (8) and the lower counter punch (22) provided in the lower die (2), the work (7) in the cavities (1a) and (2a) is divided by pressurizing and the work (7) is closed. In the mold equipment for closed forging to forge,
Provided below the lower mold (2) is a pressurizing means (19) for pressurizing the lower mold (2) from below and closing the cavities (1a) and (2a) on one side,
The hydraulic chambers (12b) and (20b) are filled with pressure oil above the upper counter punch (8) and below the lower counter punch (22) to form through the pistons (12a) and (20a). Back pressure applying means is provided by cylinders (12) and (20) for applying back pressure to the upper and lower counter punches (8) and (22) and diverting the work (7) on both sides,
When the work (7) is filled in the cavities (1a) and (2a), the hydraulic oil in the hydraulic chambers (12b) and (20b) of the cylinders (12) and (20) is drained to the tank (35). A closed forging die apparatus characterized in that the back pressure is removed. The upper mold (1) cavity (1a) mounted on the slide (6) side and the lower mold (2) cavity (2a) installed on the bolster (17) side are closed, and the upper mold (1) And the upper counter punch (8) and the lower counter punch (22) provided in the lower die (2), the work (7) in the cavities (1a) and (2a) is divided by pressurizing and the work (7) is closed. In the mold equipment for closed forging to forge,
Pressurizing the upper mold (1) and the lower mold (2) from above and below the upper mold (1) and below the lower mold (2) to block the cavities (1a) and (2a) on both sides. Providing means (11), (19);
Above the counter punch (8), the hydraulic chamber (12b) is filled with pressure oil, so that a back pressure is applied to the upper counter punch (8) during molding via the piston (12a). A back pressure applying means is provided by a cylinder (12) for diverting one side of
When the work (7) is filled in the cavities (1a) and (2a), the pressure oil in the hydraulic chamber (12b) of the cylinder (12) is drained to the tank (35), and the back pressure is removed. A mold apparatus for closed forging characterized by the above. The upper mold (1) cavity (1a) mounted on the slide (6) side and the lower mold (2) cavity (2a) installed on the bolster (17) side are closed, and the upper mold (1) And the upper counter punch (8) and the lower counter punch (22) provided in the lower die (2), the work (7) in the cavities (1a) and (2a) is divided by pressurizing and the work (7) is closed. In the mold equipment for closed forging to forge,
Above the upper mold (1) is provided a pressurizing means (11) for pressing the upper mold (1) from above and closing the cavities (1a) and (2a) on one side,
Above the upper counter punch (8), the hydraulic chamber (12b) is filled with pressurized oil, so that back pressure is applied to the upper counter punch (8) during molding via the piston (12a). ) Is provided with means for applying a back pressure by a cylinder (12) for diverting one side,
When the work (7) is filled in the cavities (1a) and (2a), the pressure oil in the hydraulic chamber (12b) of the cylinder (12) is drained to the tank (35), and the back pressure is removed. A mold apparatus for closed forging characterized by the above.

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