JPH0644500Y2 - Pre-dead center position adjusting device of forging punch in forging machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention comprises a forging die arranged on a machine base and a forging punch mounted on the front surface of a ram reciprocating toward the forging die. The present invention relates to a device for adjusting the front dead center position of the forging punch in a forging machine for forging a material into a product having a predetermined shape.

(Prior Art) Generally, in a forging machine, a material supplied from one side of the machine stand among a plurality of forging dies arranged in parallel at predetermined intervals on a machine stand at a predetermined position is referred to as a transfer chuck. While being sequentially moved by the material transfer device, the forging die and a plurality of forging punches mounted on the front surface of the ram so as to face the forging die and reciprocally moved toward the forging die by the ram, The raw material is gradually and finely stepwise pressed to continuously form parts of various shapes such as bolts and nuts.

(Problems to be Solved by the Invention) By the way, when a material is forged by a forging machine having the above-described structure, particularly, as shown in FIG. 11 (I), the material a is forged by a forging punch b. By punching into the die c and further advancing the forging punch b to press the tip of the forging punch b into the axial center of the material a, as shown in FIG. 11 (II), the material a When the peripheral portion of the material a is extruded rearward to form a concave portion in the axial center portion of the material a, in the case of so-called rearward extrusion by the material forming punch b, the peripheral portion of the material a is It is extremely important to keep the extrusion amount of 1 within the target prescribed dimensional accuracy. However, as the forging progresses, the forging punch b and the forging die c are heated due to the impact of the punch on the material, whereas the forging punch b and the forging die c reach a predetermined temperature immediately after the forging is started. Therefore, the temperature of the material a itself processed by the forging punch b and the forging die c is relatively low. For this reason, the malleability of the material a is low, and the peripheral portion of the material a cannot be satisfactorily extruded rearward, and as shown in FIG. 11 (II) until a predetermined time elapses after the start of forging. However, the backward extrusion amount 1 of the material a becomes insufficient, and therefore, the forging punch b, the forging die c, and the material a have a predetermined temperature or higher at least after a certain time has elapsed immediately after the start of the forging. Up to the point, there was a problem that defective products were continuously molded.

The above-mentioned problem is not limited to the case where the peripheral portion of the material a is extruded rearward toward the forging punch b side by press-fitting the tip of the forging punch b into the axial center of the material a. For example, the material a is driven into the forging die c by the forging punch b, and the tip of the knockout pin d (see FIGS. 11 (I) and (II)) inserted in the forging die c is attached to the material a. The material a by pressing into the shaft center of
This is also a concern when pushing out the peripheral portion of the above toward the knockout pin d side.

Therefore, when the peripheral part is extruded with respect to the axial center part of the material by the forging machine as described above, when the temperature of the forging punch or the like is low immediately after the forging is started, and when the forging proceeds to a temperature of the forging punch or the like. It is necessary to have some mechanism that can variably adjust the front dead center position of the forging punch depending on when the forging rises.In that case, if the variable adjustment is performed while the forging machine is operating, the forging punch will forge the material. Adjustment may occur when the die is driven into the die (that is, when the forging punch is under load), in which case the adjustment cannot be performed accurately.

Therefore, the present invention is capable of adjusting the position of the front dead center of the forging punch and adjusting the position of the front dead center of the forging punch in the forging machine, which is capable of performing this adjustment when the forging punch is in the unloaded state. The object is to provide a device.

(Means for Solving the Problems) In order to solve the above problems, the present invention is configured as follows.

That is, it has a forging die arranged on a machine base and a forging punch mounted on the front surface of a ram that is reciprocally moved toward the forging die by a crank mechanism. A front dead center position adjusting device for a forging punch in a forging machine for forging, a bearing for adjusting the front dead center position of the forging punch by changing the bearing portions at both ends of the crankshaft in the crank mechanism in the stroke direction of the ram. Position changing means, load detecting means for detecting an unloaded state in which the forging punch is not hitting a material, cooling oil temperature detecting means for detecting the temperature of cooling oil for cooling the forging die and the forging punch, and the cooling oil When the temperature detected by the temperature detecting means is equal to or lower than a predetermined temperature and the forging punch is in an unloaded state, the forging punch is moved by the bearing position varying means. Control for moving the front dead center position forward and moving the front dead center position of the forging punch backward by the bearing position changing means when the cooling temperature reaches a predetermined temperature and when the forging punch is in an unloaded state. And means are provided.

(Operation) According to the above configuration, when the peripheral part of the raw material is extruded rearward toward the forging punch side by the forging machine, when the forging machine is immediately cooled with the cooling oil When the temperature is low, both ends of the crankshaft in the crank mechanism that reciprocates the ram toward the forging die are moved forward in the stroke direction of the ram by the bearing position varying means, and the front die of the forging punch is dead. The point position moves forward. For this reason, the amount of press-fitting of the tip of the forging punch into the axial center of the material is increased, and the shortage of the amount of backward extrusion of the peripheral portion of the material immediately after the start of forging is corrected. When the cooling oil temperature rises to a predetermined temperature after a certain time has passed from the start of forging, the bearing position varying means returns the bearing portions at both ends of the crankshaft to the normal positions, and The amount of press fit into the material shaft center portion is reduced.

As a result, even if the temperature of the forging punch or the like is low immediately after the start of the forging, or when the temperature of the forging punch or the like rises due to the forging, it is possible to form a semi-molded product or product with specified dimensional accuracy. .

In that case, in the present invention, since the variable operation by the bearing position changing means is performed by the control means when the load detecting means detects the unloaded state of the forging punch, the forging punch strikes the material. It will not be done under the load condition.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic plan view of a multi-stage forging machine equipped with a pre-dead-center position adjusting device for a forging punch according to this embodiment. At a predetermined position of a machine base 2 of the forging machine 1,
The die block 3 is fixedly installed, and a plurality of forging dies 4 ... 4 (4 in the illustrated example are provided on the front surface of the die block 3.
Individual pieces) are arranged at regular intervals. Further, on the front surface of the ram 5 which moves back and forth toward each of the forging dies 4, the same number of forging punches 6 ... 6 as the forging dies 4 are arranged so as to face the forging dies 4, respectively. . Further, a gear 9 is fixedly provided on one shaft end of a rotary drive shaft 8 rotated by a drive motor 7 of the press molding machine 1, and a gear 10 meshing with the gear 9 is attached to a machine base. Two end portions of the crankshafts 11 are rotatably supported at predetermined positions on the rear portion of the crankshaft 2, and are fixed to one end portion of one of the crankshafts 11. The rear end portion of the connecting rod 14 is rotatably mounted on the crank pin portion 13 integrally formed between the pair of crank arms 12, 12 at the central portion of the crankshafts 11, 11 in the axial direction. While being fitted, the tip end of the connecting rod 14 is fixedly connected to a support pin 15 rotatably laterally installed in the rear end of the ram 5 via mounting bolts 16, 16. As a result, the crankshafts 11, 11 rotate in a predetermined direction in accordance with the operation of the drive motor 7, so that the ram 5 is inserted through the connecting rod 14 fitted on the crankpin portion 13 of the crankshaft 11. 6 are reciprocally driven with a predetermined stroke, so that the forging punches 6 ... 6 arranged on the front surface of the ram 5 have rear dead center positions as shown in the drawing, and the tips thereof are the forging dies 4. 4 is reciprocated between the front position of the die 4 and the position of the front dead center of the die 4 which plunges into each of the die dies 4. As a result, between each forging die 4 and each forging punch 6, the material (not shown) supplied from one side of the machine base 2 is subjected to the forging process step by step from coarse to fine. It is designed to mold products.

Although not shown, the die block 3 is provided on its upper surface with a material transfer device for sequentially transferring the material to the front position of the axial center of each forging die 4.

In this embodiment, by changing the bearing positions of the crankshafts 11 and 11 with respect to the machine base 2 in the stroke direction of the ram 5, the front deadening of each forging punch 6 arranged on the front surface of the ram 5 is performed. Bearing position changing means 17 for variably adjusting the point position back and forth is provided. As shown in FIGS. 1 to 3, the bearing position changing means 17 has outer peripheral surfaces on both sides of the machine base 2. The crankshaft 1 is rotatably supported via the bushes 18 and 18, and the crankshaft 1 is provided on the inner peripheral surface via the bushes 19 and 19.
A pair of left and right bearing sleeves 20 and 20 rotatably supporting the bearings 1 and 11 respectively, and a drive means 21 for simultaneously rotating the bearing sleeves 20 and 20 in the same direction and at the same angle, respectively. The rotation centers (axial centers) of the crankshafts 11, 11 are supported eccentrically with respect to the rotation centers (axial centers) of the sleeves 20, 20. That is, as shown in an enlarged manner in FIGS. 3 and 4, the crankshaft 1 is arranged with respect to the shaft center 20a of the bearing sleeve 20 on the vertical centerline X of each bearing sleeve 20.
The shaft center 11a of 1 is rotatably supported in a state of being eccentric downward.

As shown in FIGS. 1 and 2, the drive means 21 is rotatably supported above the rear part of the machine base 2 and a drive motor 22 mounted at a predetermined position on the upper surface of the rear part of the machine base 2. Is driven to rotate by the drive motor 22 via the gear mechanism 23, and the rotary shaft 25 having the bevel gears 24 and 24 fixed to both ends thereof, and the pair of bevel gears meshing with the bevel gears 24 and 24, respectively. 26 and 26 are fixed to the upper end, respectively, and worms 27 and 27 (see FIG. 2, only one is shown)
And a pair of left and right drive shafts 28, 28 that are integrally formed and are rotatably supported in the up and down direction on the both sides of the rear part of the machine base 2, respectively.
And worm gears 29, 29 (see FIG. 2, only one shown) that mesh with the worms 27, 27, respectively,
A pair of rotating members 3 fixed to the end faces of the pair of bearing sleeves 20, 20 via a plurality of mounting bolts 30 ... 30 so as to rotate integrally with the pair of bearing sleeves 20, 20.
It is composed of 1 and 31. Therefore, with the rotation of the rotary shaft 25 by the drive motor 22, a pair of drive shafts 28,
As the worms 27, 27 integrally formed with the 28 rotate, the pair of bearing sleeves 20, 20 are simultaneously rotated via the rotating members 31, 31 respectively.

On the other hand, in this embodiment, as shown in FIG. 1, a control unit 32 for controlling the operation of the drive means 21 is provided, and the control unit 32 has a load detection means 33 and a cooling oil temperature sensor 35. And the input means 34 are connected, and the control unit 32 controls the drive means 21 by the control signal D by the signals input from these means 33 to 35.

In that case, the load detecting means 33 is a means such as a strain gauge provided on one side surface of the machine base 2 in the vicinity of the sliding portion of the ram 5, and measures the strain of the machine base 2 during the forging. The load state of the forging punch 6 is detected based on this, and when the forging punch 6 and the ram 5 are retracted from the forging die 4, the control unit 32 is in the no-load state of the forging punch 6. Is input. In addition, the cooling oil temperature sensor 35
Measures the temperature of the cooling oil for cooling the forging die 4 and the forging punch 6, and inputs an output signal C indicating the temperature of the cooling oil to the control unit 32. Further, the input means 34 inputs the correction signal B to the control unit 32. That is, when adding the forming shown in FIG. 11 (II) to the raw material by the forging forming machine 1 shown in FIG. According to the present embodiment, trial striking is performed with the pre-dead center position (the front dead center position set when the cooling oil temperature reaches a predetermined temperature, as will be apparent from the description given later). Then, measure how much the material size is different from the specified size immediately after the start of forging, and store the correction amount as data for each product type, and when manufacturing a product of a certain size type, Then, the correction amount corresponding to the product is input to the control unit 32 by the input means 34.

On the other hand, in the control unit 32, when the output signal C input from the cooling oil temperature sensor 35 is equal to or lower than a predetermined temperature of the cooling oil, the punching punch is pressed by the correction amount input by the input means 34. The drive means 21 is moved so that the front dead center position of 6 is moved forward, and when the cooling oil temperature reaches a predetermined temperature, the front dead center position is moved back to the normal position.
The control signal D is output to the drive motor 22 in the above, and in such control, the detection signal A indicating the no-load state of the forging punch 6 is input from the load detection means 33 to the control unit 32. It is supposed to be done when.

Next, the operation of the present embodiment will be described. In the forging and molding machine 1 of the present embodiment, a correction amount B corresponding to the product to be manufactured by the forging and molding machine 1 is corrected by the input means 34.
It is operated in the state of being input to the control unit 32 as. Immediately after starting the forging, the temperature of the forging punch 6 and the like is low, and therefore the temperature of the cooling oil temperature detected by the cooling oil temperature sensor 35 is low.
When the load detection means 33 detects the unloaded state of the forging punch 6, it sends a control signal D to the drive means 21, drives the drive motor 22, and rotates the drive shafts 28, 28. As a result, a worm gear 29 that meshes with the worms 27, 27 formed integrally with the drive shafts 28, 28,
The rotary members 31, 31 on which the 29 are formed rotate simultaneously, and accordingly, the pair of bearing sleeves 20, 20 on which the rotary members 31, 31 are fixedly installed are simultaneously in the same direction and at the same angle. As shown in FIG. 4, the crankshaft 11 is rotated about the shaft center 20a of each bearing sleeve 20.
Is swung forward, and the entire crankshaft 11 moves forward in the stroke direction of the ram 5, as shown by the chain line. As a result, the front dead center position of the forging punch 6 mounted on the front surface of the ram 5 which is reciprocally moved toward the forging tie 4 is moved forward, and the front end of the forging punch 6 is made of the above-mentioned material. The amount of plunge into the shaft center will increase, and the shortage of the amount of extrusion to the rear of the material peripheral part immediately after the start of forging is corrected,
It can be satisfactorily extruded to the target prescribed dimensional accuracy. Then, when it is detected that the temperature of the cooling oil has risen with the lapse of time from the start of the forging and the forging die 4 and the forging punch 6 have reached a predetermined temperature, the control unit 32 causes the load detecting means 33 to operate. When the unloaded state of the press punch 6 is detected, the control signal D is sent to the drive means 21 to control the rotation of the drive motor 22. Therefore, the crankshaft
11 and 11 are returned to the regular position, and the front dead center position of the forging punch 6 is also returned to the regular position, so that the peripheral portion of the material is not pushed unnecessarily and the target prescribed dimension is reached. It is possible to mold a semi-molded product or a product with high precision. As described above, according to this embodiment, the forging is started regardless of whether the temperature of the forging punch 6 or the like is low immediately after the forging is started or when the temperature of the forging punch 6 or the like is increased after a lapse of time from the forging. Immediately after that, it is possible to continuously mold a good semi-molded product or a product in which the peripheral portion of the material is extruded rearward with a prescribed dimensional accuracy.

Moreover, in the present embodiment, the bearing position changing means 17
However, the outer peripheral surface is rotatably supported at a predetermined position of the machine base 2,
Moreover, since the crankshafts 11 and 11 are constituted by a pair of bearing sleeves 20 and 20 which eccentrically support the outer peripheral rotation center in an eccentric state, and a driving means 21 which simultaneously rotates them in the same direction and at the same angle, Even during operation of the forging machine 1,
Drive means for driving the pair of bearing sleeves 20, 20 as required
By rotating it through 21, it is possible to adjust the position of the front dead center of the forging punch 6 very easily, and this adjustment is performed by the load detecting means 33.
This adjustment is performed in the non-loaded state, so that this adjustment can be accurately and easily performed.

Next, another embodiment of the driving means will be described.

The same components as those in the first embodiment will be described with the same reference numerals as in the first embodiment.

5 to 8 show a second embodiment of the driving means. The driving means 41 is a driving motor 42 installed at a predetermined position on the rear upper surface of the machine base 2 (see FIG. 5). Similarly, it is rotatably supported above the rear part of the machine base 2 and is rotationally driven by the drive motor 42 via the gear mechanism 43.
Rotating shaft with bevel gears 44, 44 fixed at both ends
45 and a pair of bevel gears 46, 46 meshing with the bevel gears 44, 44 are fixedly mounted on the upper end portions thereof, respectively, and nut members 47, 47 are screwed together so that the bevel gears 46, 46 are rotatably attached to the rear side surfaces of the machine base 2. A pair of left and right screw shafts 48 supported vertically
And an engagement pin 47 fixed to each of the nut members 47, 47.
a and 47a (see FIG. 5, only one shown) are formed with engaging portions 49, 49 (see FIG. 5, only one shown), and a pair of bearing sleeves 20, 20 (fifth, fifth, A plurality of mounting bolts 50 ... 50 are attached to the end surfaces of the pair of bearing sleeves 20, 20 so that they rotate integrally with each other (only one of which is shown in FIG. 7).
It is composed of a pair of engaging members 51, 51 that are respectively fixed via the. Therefore, with the rotation of the rotary shaft 45 by the drive motor 42, the pair of screw shafts 48, 48 rotate, whereby each nut member 47 screwed into the pair of screw shafts 48, 48, respectively. As the 47 reciprocates in the vertical direction in a straight line, the engaging portions 49, 49 that engage with the engaging pins 47a, 47a of the nut members 47, 47 are integrally formed. The pair of bearing sleeves 20 and 20 are simultaneously rotated in the same direction and at the same angle through the members 51 and 51, respectively.

Then, as shown in an enlarged view in FIGS. 7 and 8, the crankshafts 11 are supported in an eccentric state with respect to the bearing sleeves 20. That is, on the vertical center line X of the bearing sleeve 20, the shaft center 11a of the crankshaft 11 is eccentrically supported downward with respect to the shaft center 20a of the bearing sleeve 20.

Incidentally, below the respective nut members 47, 47, coil springs 52, 52 for constantly urging the nut members 47, 47 upward.
Are arranged respectively, and these coil springs are
The spring action of 52, 52 eliminates the backlash between the nut members 47, 47 and the screw shafts 48, 48 to ensure the nut members 47, 47 when the screw shafts 48, 48 rotate. The nut member 4 is adapted to be raised and lowered, and the nut members 4 and 47 are provided on both sides of the rear portion of the machine base 2 so as not to rotate when the screw shafts 48 and 48 rotate.
Rotation restricting members 53 and 53 (see FIG. 5, only one shown) engaged with 7 and 47 are fixed. Further, the driving means 41 may be configured to control its operation by a control unit having the same configuration as that of the first embodiment described above.

According to the above configuration, by pressing the tip of the forging punch 6 into the axial center of the material (not shown), when the peripheral portion of the material is pushed backward toward the forging punch 6, the forging is performed. Immediately after the start, when the amount of material extruded to the rear of the peripheral portion is insufficient, the drive motor 42 in the drive means 41 is used.
By rotating the screw shafts 48, 48 through the nut shafts 47, 47, the nut members 47, 47 linearly reciprocate in the vertical direction, whereby the pair of bearing sleeves 51, 51 are engaged with each other.
20 and 20 simultaneously rotate in the same direction and at the same angle, and as a result, as shown in FIG.
The shaft center 11a of each crankshaft 11 swings forward around 20a, and the entire crankshaft 11 moves forward in the stroke direction of the ram 5, as shown by the chain line. As a result, the front dead center position of the forging punch 6 mounted on the front surface of the ram 5 is moved forward, and the amount of protrusion of the tip of the forging punch 6 into the axial center portion of the material is increased. As a result, the shortage of the backward extrusion amount of the raw material peripheral portion immediately after the start of the forging is corrected, and the target dimensional accuracy can be favorably extruded. Then, when the temperature of the forging punch 6 or the like rises after a lapse of time from the start of forging, the crankshafts 11 and 11 are returned to the normal positions shown by the solid lines in FIG. It is possible to mold a semi-molded product or a product with the target prescribed dimensional accuracy without pushing out the peripheral portion more than necessary. As described above, according to this embodiment, the position of the front dead center of the forging punch can be adjusted very easily, and the straight lines of the nut members 47, 47 screwed to the screw shafts 48, 48 can be adjusted. Since the position of the front dead center of the forging punch is adjusted based on the reciprocating motion, the position of the front dead center of the forging punch 6 can be adjusted by appropriately setting the screw pitches of the screw shafts 48, 48. Can be easily and accurately fine-tuned. Further, even when the forging load during the forging process acts on the nut members 47, 47 via the crankshafts 11, 11, the pair of bearing sleeves 20, 20 and the engaging members 51, 51, The forging load is effectively dispersed by the screw shafts 48, 48, whereby the nut members 47, 47 are not unnecessarily displaced.

The rotary shafts 25 and 45 of the drive means 21 and 41 in the first and second embodiments are rotationally driven by the drive motors 22 and 42 through the gear mechanisms 23 and 43, respectively. By providing a chain mechanism between the drive motors 22, 42 and the rotary shafts 25, 45, the rotary shafts 2
It is also possible to configure to rotate 5, 45.

9 and 10 show a third embodiment of the driving means. The driving means 61 is connected to the driving motor 62 installed at a predetermined position on the rear upper surface of the machine base 2. A nut member 64 integrally formed with a speed reducer 62a and a sprocket 64a rotatably supported at a predetermined position below the rear part of the machine base 2 and rotated by the drive motor 62 via a chain mechanism 63. A screw shaft 65 that is linearly reciprocated in the axial direction when the nut member 64 is screwed, and a pair of left and right bearing sleeves 20 that rotatably support the screw shaft 65 and the crankshafts 11, 11 in an eccentric state. , 20 and a link mechanism 66 provided therebetween. The link mechanism 66 includes a link member 66a that is rotatably connected to one end of the screw shaft 65, and swings in which upper ends of both side portions are fixed at predetermined positions of the bearing sleeves 20 and 2, respectively. Member 66
b, and a connecting member 66c that connects the swinging member 66b and the link member 66a. Therefore, by rotating the nut member 64 integrally formed with the sprocket 64a that is rotated by the driving motor 62 via the chain mechanism 63, the screw shaft 65 is moved in the axial direction thereof. The pair of bearing sleeves 20 and 20 are simultaneously rotated in the same direction and at the same angle via the link mechanism 66 by reciprocating linear movement.

Then, as shown in FIG. 10, the bearing sleeves 20, 20
On the other hand, the crankshafts 11, 11 are eccentrically supported. That is, the vertical center line X of each bearing sleeve 20.
Above, the shaft center 11a of the crankshaft 11 is axially supported in a downwardly eccentric manner with respect to the shaft center 20a of the bearing sleeve 20.

The operation of the drive means 61 is controlled by the control unit as in the first embodiment.

According to the above configuration, the drive motor 62 in the drive means 61 is operated, and the nut member is passed through the chain mechanism 63.
By rotating 64, the screw shaft 65 linearly reciprocates, whereby the pair of bearing sleeves 20, 20 simultaneously rotate in the same direction and at the same angle via the link mechanism 66. The shaft center 11a of the crankshaft 11 swings in a predetermined direction around the shaft center 20a, and the entire crankshaft 11 moves in the stroke direction of the ram 5. As a result, each crankshaft 11,
The position of the front dead center of the forging punch (not shown) mounted on the front surface of the ram 5 connected to 11 via the connecting rod 14 (see FIG. 9) is changed, and the position of the front dead center is changed. Can be adjusted very easily.

The pre-dead-center position adjusting device for a forging punch according to the present embodiment is provided with a plurality of forging dies 4 ... 4 and a plurality of forging punches 6 ... 6 facing the respective forging dies 4 ... 4 as described above. It is needless to say that the present invention is suitably applied not only to the multi-stage forging machine of the type described above, but also to a forging machine called a so-called header in which a material is forged by a pair of forging dies and a forging punch.

Further, for example, due to the influence of processing heat generated during the forging, the forging punch 6 extends in the axial direction of the forging and punches the material between the forging punch 6 and the forging die 4 facing the forging punch 6. Even when the upsetting amount changes, the front dead center position adjusting device for the forging punch according to the present embodiment variably adjusts the front dead center position of the forging punch 6 so that the upsetting amount becomes appropriate. It becomes possible.

Further, as a mechanism for changing the position of the front dead center of the forging punch 6, a structure in which the length of the connecting rod 14 is variable is conceivable. However, this mechanism complicates the structure, and the forging punch 6 changes the material. Although the variable mechanism part may be damaged by the impact load when hitting, the crankshaft 11 of the present invention is eccentrically supported by the bearing sleeve 20, and the front dead center position is adjusted by the rotation of the bearing sleeve 20. By doing so, the bearing structure can be used as a part of the front dead center position adjusting device, the structure can be simplified, and the impact load can be stably received by the bearing part.
This eliminates the risk of the bearing position varying means 17 being damaged.

(Effect of the Invention) As described above, according to the present invention, by adjusting the front dead center position of the forging punch by the bearing position changing means, the forging punch and the like immediately after the forging start and after a certain time has elapsed from the forging start. Regardless of when the temperature rises, immediately after the start of forging, a good semi-molded product or product is continuously extruded backward with the specified dimensional accuracy from the periphery toward the forging punch side with respect to the axial center. Since the molding can be performed and the adjustment of the position of the front dead center is performed in the unloaded state of the forging punch, this adjustment can be performed accurately and easily.

[Brief description of drawings]

1 to 10 show an embodiment of the present invention, and FIG. 1 shows a part of a multistage forging machine equipped with a pre-dead center position adjusting device of a forging punch in the forging machine according to this embodiment. Fig. 2 is a schematic plan view showing a section of Fig. 2, and Fig. 2 is II-II in Fig. 1.
FIG. 3 is an enlarged sectional view of an essential part taken along the cutting line III-III in FIG. 1, and FIG.
FIG. 4 is an enlarged schematic view showing the relationship between the bearing sleeve and the crankshaft, FIG. 5 is a sectional view of an essential part showing the construction of the driving means of the second embodiment, and FIG. 6 is a VI- in FIG. FIG. 7 is an enlarged sectional view of an essential part of the second embodiment, and FIG. 8 is an enlarged schematic view showing the relationship between the bearing sleeve and the crankshaft in the second embodiment. FIG. 9 and FIG. 9 are front views of a driving means of a third embodiment, a part of which is shown in section,
The drawing is a cross-sectional view of essential parts taken along the line X-X in FIG. Further, FIGS. 11 (I) and (II) are schematic views for explaining the conventional problems during the forging process. 1 ... Multi-stage press forming machine (press forming machine) 2 ... Machine stand,
4 ... Forging die, 6 ... Forging punch, 11 ... Crank shaft, 17 ... Bearing position varying means, 20 ... Bearing sleeve, 2
1,41,61 …… Drive means, 22,42,62, …… Drive motor, 27
...... Worms, 29 ...... Worm gears, 32 ...... Control means (control unit), 33 ...... Load detection means, 35 ...
... Cooling oil temperature sensor, 47, 64 ... Nut member, 48, 65 ... Screw shaft, 51 ... Engaging member, 66 ... Link mechanism.

Claims (1)

[Scope of utility model registration request] 1. A forging die (4) disposed on a machine base (2).
And a forging punch (6) mounted on the front surface of a ram (5) reciprocally moved toward the forging die (4) by a crank mechanism, the forging die (4) and the forging punch (6). A front dead center position adjusting device for a forging punch (6) in a forging machine (1) for forging a raw material by using a stroke of a ram (5) for bearing portions at both ends of a crankshaft (11) in the crank mechanism. Bearing position varying means (17) for adjusting the front dead center position of the forging punch (6) by changing the direction, and load detecting means for detecting an unloaded state in which the forging punch (6) is not hitting the material. (3
3), cooling oil temperature detecting means (35) for detecting the temperature of the cooling oil for cooling the forging die (4) and the forging punch (6).
And when the temperature detected by the cooling oil temperature detecting means (35) is not higher than a predetermined temperature and when the forging punch (6) is in an unloaded state, the bearing position varying means (17) causes the forging punch (6). ) Is moved forward and the cooling oil temperature reaches a predetermined temperature, and when the forging punch (6) is in an unloaded state, the bearing position changing means (17) causes the forging punch (6). ) And a control means (32) for moving the position of the front dead center of (1) to the rear, the position adjusting device for the front dead center of the forging punch in the forging machine.