JPH0688091B2 - Crankshaft forging device - Google Patents

Description

TECHNICAL FIELD The present invention relates to a crankshaft forging device.

(Prior Art) As a crankshaft forging device, the left and right molding dies, each of which is composed of a pair of split dies, press the molding dies against each other while sandwiching and fixing the molding shaft material. Then, the shaft material is compressed in the axial direction, and a part of the shaft material is deformed in the orthogonal direction by the punch and the anvil inserted between the molding dies, so that A crank throw portion having a pair of arm portions is formed, and a crank throw portion, which is made up of a pair of split dies, is formed on one side of the molding die opposite to the other molding die, and which is already formed. There is one in which a sandwiching die which is sandwiched and fixed and is pressed against the other molding die is arranged together with the one molding die.

By the way, in a crankshaft having several crank throw portions, the phases of the crank throw portions are generally different from each other.

(Problems to be Solved by the Invention) However, in the above-mentioned prior art, the single clamping die is not sandwiched so as to be able to cope with the above-mentioned phase difference of the crank throw portion. When molding the crank throw part in the middle of the crank shaft and molding the next crank throw part, it is necessary to replace it with another clamping die. It was necessary to prepare a clamping die and the work was troublesome.

It is an object of the present invention to provide a crankshaft forging device that can solve the above problems.

(Means for Solving Problems) The features of the present invention taken to achieve the above object will be described based on FIG. 19 and FIG. 20 of the claim correspondence diagram.

That is, the feature of the present invention is that a pair of clamp members 4 are disposed on both sides of the molding shaft blank 10 in a direction orthogonal to the axial center direction, and a pair of molding dies 26 is provided on each clamp member 4. , 27 corresponding split molds 28, 29 are provided, and the shaft material 10 is sandwiched and fixed by the both molds 26, 27, and the two molds 26, 2 are formed.
While pressing 7 to the other side, both molds 26, 27
Are pressed to the other side to compress the shaft material 10 in the axial direction, and the punch 9 inserted between the molding dies 26 and 27 is pressed.
By deforming a part of the shaft material 10 in the orthogonal direction by the 1 and the anvil 92, the pin portion 64 of the crankshaft 59 is formed.
And a pair of arm portions 62, a crank throw portion 104 is formed, and a pair of split molds 54 is formed on the opposite side of the one molding die 26 or 27 from the other molding die 27 or 26. In the one in which the already-formed crank throw portion 104 is sandwiched and fixed, and the sandwiching die 53 which is pressed against the other molding die 27 or 26 is arranged together with the one of the above molding die 26 or 27. , A pair of floating members 37 in which the split dies 54 of the sandwiching dies 53 are provided on both clamp members 4 so as to be rotatable around their axes.
Is disposed between the clamp member 4 and the floating member 37,
By moving both floating members 37 forward and backward relative to the other side, an advancing and retracting device 42 for substantially integrating the split mold 54 of the sandwiching mold 53 in a state in which the split mold 54 is allowed to rotate about its axis. The point is that a rotating device 68 for rotating the sandwiching die 53, which is interposed and substantially integrated, about the axis is provided.

(Operation) As shown in FIG. 19 of the claim correspondence diagram, at the time of work, the molding shaft material 10 is clamped and fixed by both molding dies 26 and 27, and the shaft material is clamped by the punch 91 and the anvil 92. Fix it.

After that, the molding dies 26 and 27 are pressed against each other to compress the shaft blank 10 in the axial direction.

At the same time, the punch 91 is moved forward in a state where the shaft material 10 is sandwiched and fixed by the punch 91 and the anvil 92, and the crank throw portion 104 having the pin portion 64 and the pair of arm portions 62 of the crankshaft 59 is formed. Mold.

As shown in FIG. 20 of the claim correspondence diagram, when sandwiching and fixing the already formed crank throw portion 104 by the sandwiching die 53, both the floating members 37 are relatively moved by the advance / retract device 42. The other split side 54 of the sandwiching die 53 is substantially integrated.

Next, the rotating device 68 rotates the clamping die 53 by a predetermined angle to clamp the clamping die 53 with the clamping die 53.
The phase of 104 is shifted by a predetermined angle with respect to the crank throw portion 104 to be molded next.

After that, the molded crank throw part 104 is clamped and fixed by the clamping die 53, and the shaft material 10 is clamped and fixed by both the molding dies 26 and 27, and the next crank The throw portion 104 is molded.

(Embodiment) Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a crankshaft forging device. In FIGS. 1 to 5, 1 is a C-shaped main frame, and a cradle. 2 is equipped on. On the upper and lower surfaces of the front and rear parts of the main frame 1, slide keys 3 are arranged in the front-rear direction for the left and right pairs.

Reference numeral 4 denotes a pair of front and rear L-shaped clamp members, which are respectively disposed on the front and rear upper surfaces of the main frame 1 and correspond to the corresponding slide keys 3
By being engaged with, it is slidable in the front-back direction.

The front and rear wall portions of the main frame 1 are respectively provided with a pair of left and right clamping hydraulic cylinders 5 that expand and contract in the front-rear direction, and each cylinder 5 is connected to each side portion of each clamp member 4. Has been done. Reference numeral 6 shown in FIG. 4 is a load cell.

Shifting members 7 and 8 are arranged on both left and right sides of each clamp member 4, respectively. As shown in FIG. 10, each shift member 7 and 8 is a slide integrally formed on each clamp member 4. By being engaged with the key portion 9, it is slidable in the left-right direction. Shaft material for molding of each shifting member 7,8 1
On the 0-side end surface, receiving portions 11 and 12 having a curved concave shape are formed.

13 shown in FIGS. 1 and 2 is a hydraulic cylinder for shifting.
As shown in FIG. 6, the shifting members 7 and 8 are interposed between the left and right end portions of the clamp members 4, and the cylinder tubular portion 14 formed integrally with the shifting members 7 and 8 is provided. , A piston 15 and a piston rod 16, and the piston rod 16 is a receiving member 17 fixed to each end face of the clamp member 4.
It is fixed to.

As shown in FIG. 2, reference numeral 18 denotes a pair of front and rear positioning devices for the systemizing members 7 and 8, which determine the positions of the shifting members 7 and 8 at the start of work, and are configured as follows. .

That is, as shown in FIGS. 2 and 10, a pair of left and right catches are provided on the left and right sides of the upper and lower walls of each clamp member 4.
19 are fixedly mounted, and the receiving metal 19 is rotatably provided with a rotation 20 and is rotated by a rotary type hydraulic cylinder 21 for rotation which is fixedly mounted on the upper surfaces of the front and rear walls. Rotation axis
Receptacles 22 are fixed to the support portions of the respective catches 19 in 20, and adjusting screw shafts 23 are respectively screwed in the reciprocating rods 22 so as to be able to move forward and backward, and lock nuts 24 It is fixed by. On the other hand, the upper surface of each shifting member 7, 8 has L
The shape-regulating member 25 is fixed. By the rotation of the rotating shaft 20, each of the receiving members 22 and the adjusting screw shaft 23 can be freely moved to a position corresponding to the restricting member 25 in the left-right direction and a position not corresponding to the restricting member 25.

As shown in FIGS. 3, 5 and 11 to 14, 26,2
7 is a left-side and right-side molding die, which is composed of a pair of front and rear split dies 28 and 29 each having a stepped outer peripheral surface.
As shown in FIGS. 3 and 4, in the stepped receiving portion 11 of each of the left side shifting members 7, and as shown in FIGS. 1 and 7, the split mold 29 is provided for each of the right side shifting members 8. The stepped inner part of the receiving part 12 is axially immovably engaged with the inner part of each of the split dies 28 and 29, and the inner end part of each split mold 28, 29 is a shifting member.
It is detachably fixed to the inner ends of 7, 8 with bolts 30 (see No. 3). A pair of upper and lower guide grooves 31, 32 are formed in the front-rear direction on the inner end surfaces of the molding dies 26, 27, and the arm forming part 3 is provided between the guide grooves 31, 32, respectively.
3,34 are recessed. In addition, holes 35 and 36 through which the shaft material 10 passes are formed through the shaft center portions of the respective molding dies 26 and 27. The left molding die 26 is considerably longer than the right molding die 27.

As shown in FIG. 1, 37 is a pair of front and rear floating members. As shown in FIG. 5, FIG. 7, and FIG. 8, the front and rear sides of the right shifting member 8 are located outside the right molding die 27. And a pair of slide keys 38 (see FIG. 5) fixedly mounted on each right side shifting member 8 are engaged with the lower portion of each floating member 37 and The upper part of the floating member 37 is the receiving portion 12 of each shifting member 8 on the right side.
Is fitted to the outer side portion of. A stepped receiving portion 39 is provided in a curved concave shape on the end surface of each floating member 37 on the shaft material 10 side.

As shown in FIG. 9, the falling prevention hydraulic cylinders 40 are vertically provided on the outer sides of the lower portions of the respective floating members 37, and the piston rods 41 of the cylinders 40 are attached to the respective floating valves. It is freely retractable in the receiving portion 39 of the member 37.

As shown in FIG. 8, 42 is an advancing / retreating device.
Reference numeral 42 denotes a pair of front and rear hydraulic cylinders for floating, which are interposed between each floating member 37 and each right shifting member 8, and a cylinder tubular portion 43 integrally formed at the bottom of each floating member 37. , A piston 44, and a piston rod 45, and each piston rod 45 is fixed to a receiving member 46 fixed to each of the right shifting members 8.

A square hole-shaped equipment hole 7 is formed in the rear end surface of the lower portion of the front side floating member 37, and a mounting square tube 48 is inserted into the equipment 7. The pressing body 9 is inserted into the mounting rectangular tube 48 so as to be movable in the axial direction and not ejectable, and the adjusting shaft 50 is screwed into the bottom of the mounting rectangular tube 48 so as to be movable back and forth in the axial direction. There is.
The tip of the adjusting shaft 50 is inserted into the base side cylinder of the pressing body 49, and between the tip of the adjusting shaft 50 and the bottom surface of the base side cylinder, the pressing body 49 is biased rearward. The Belleville spring 51 is inserted in a resilient manner.

As shown in FIG. 4, FIG. 8 and FIG. 10, 52 is a center guide member, which is arranged in the left-right direction at the center in the front-rear direction on the right side of the upper surface of the bottom wall of the main frame 1, and is provided with both flow paths. The tongue member 37 is prevented from moving from one side to the other side more than a predetermined amount.

As shown in FIGS. 5, 7 and 10, 53 is a clamping die,
As shown in FIG. 17 to FIG. 17, it is composed of a pair of front and rear split dies 54 each having a stepped outer peripheral portion, and each of these split dies 5 is arranged in the receiving portion 39 of each floating member 37 in the axial direction. It is immovably and rotatably fitted in. As shown in FIG.
Each split mold 54 is divided into two in the axial direction and is composed of inner and outer constituent members 55, 56.
56 (see FIG. 17) is fastened and integrated by bolts and nuts 57.

As shown in FIG. 16, in the clamping die 53, the first clamping part for clamping the shaft blank 10 or the journal part 60 of the crankshaft 59.
61 and a second arm for sandwiching the pair of arm portions 62 of the crankshaft 59.
A holding portion 63 and a third holding portion 65 that holds the pin portion 64 of the crankshaft 59 are formed.

In addition, a spur gear portion 66 is formed on the outer peripheral surface of the inner portion of each outer structure 56, and the piston rod 41 of the drop prevention hydraulic cylinder 40 is detachably engaged with the outer peripheral surface of the outer portion. An engagement groove 67 having a crescent-shaped cross section is formed over the entire length in the circumferential direction.

As shown in FIG. 7, 68 is a rotating device for rotating the sandwiching die 53 about its axis. Hereinafter, with reference to FIG. 7, 69 is a motor with reduction gear, and the right side is shown. It is fixed to the outer side of the rear side shifting member 8.

The output shaft 70 on the side of the electric motor 69 is inserted into the shifting member 8, and a bevel gear 71 integrally formed at its tip portion is interlocked with a bevel gear 72.

The bevel gear 72 is supported by the shifting member 8 so as to be rotatable around the axis in the front-rear direction, and the sliding shaft 73 is provided in the bevel gear 72.
Are splined so that they can slide freely in the front-rear direction.

A bevel gear 74 is fixed to the front end portion of the sliding shaft 73, and the bevel gear 74 is supported by the shifting member 8 and is interlocked with the bevel gear 76 of the transmission gear 75.

A support shaft 77 that supports the transmission gear 75 is rotatably arranged in the left-right direction on the floating member 37, and a flat gear portion of the transmission gear 75.
78 is interlocked with the flat gear portion 66 of the clamping die 53.

As shown in FIG. 5, a pair of left and right mounting boards 79 are arranged on both left and right sides of the main frame 1. These mounting boards 79 are mounted on the main frame 1 by mounting bolts 80, and
79 are connected to each other by a tie rod 81.

Reference numeral 82 shown in FIGS. 1 and 5 denotes a pair of left and right main hydraulic cylinders.
Each mounting board 79 is arranged in the left-right direction, each piston rod 101 is connected to the pressure member 83, the inner end surface of each pressure member 83 is the outer end surface of the left molding die 26 or the clamping die 53. Is facing.

An adjusting screw shaft 85 having a rotating pin 84 is screwed into the shaft center of each pressurizing member 83 so as to be movable back and forth in the shaft center direction, and the end surface of the shaft blank 10 is attached to the tip end of the adjusting screw shaft 85. Spacing adjusting member 86
Is fixed. 87 is a load cell (see FIG. 5).

1 and 3, reference numeral 88 denotes a pair of front and rear forming hydraulic cylinders, which are disposed in the front-rear and rear-direction in the center portion of the front-rear wall portions of the main frame 1 in the left-right direction. A pressurizing member 90 is provided, and each pressurizing member 90 has a mold for both moldings.
A punch 91 or an anvil 92 inserted between 26 and 27 is detachably attached.

Reference numeral 93 shown in FIG. 3 is a load cell.

As also shown in FIG. 18, at the upper and lower edges of the punch 91 and the anvil 92, convex portions 94 that are movably engaged with the guide grooves 31 and 32 of the molding dies 26 and 27 are formed. Punch 91 and anvil
A pin molding portion 95 for forming the pin portion 64 of the crankshaft 59 is formed at the tip portion of 92.

As shown in FIG. 3, a pin 96 protruding upward from the shifting members 7 and 8 is fixed to the tip of the punch 91.

As shown in FIG. 1, potentiometers 97 exemplified as detectors arranged on the left and right sides of the pin 96 are provided.
Are connected via a wire 98, the values of these potentiometers 97 are compared by a comparator 99, and in accordance with the difference in the values of the potentiometers 97, the control device 100 causes both main hydraulic cylinders 82 to control the control valve 102. Controlled via
The pin 96 has a smaller diameter than the gap when the left and right molding dies 26, 27 and the left and right corresponding shifting members 7, 8 are closest to each other.

The length of the main hydraulic cylinder 82 may be detected by the magnescale 103 and the value may be input to the control device 100.

According to the embodiment configured as described above, at the start of work,
As shown in the lower part of FIG. 1, both clamp members 4 are in the retracted position spaced apart from each other in the front-rear direction, and the corresponding left and right shifting members 7 and 8 are in the retracted position separated from each other in the left-right direction. Is in a retracted position housed in each of the right shifting members 8, and both the pressurizing members 90 for each punch and anvil are also in a retracted position separated from each other in the front-rear direction.

In this state, a predetermined punch 91 and anvil 92 are attached to the punch and anvil pressurizing members 90, and the shift dies 7 and 8 are divided into mold halves 28 and 29, respectively. At the same time as mounting, each split mold 54 of the sandwiching mold 53 is fitted to each floating member 37, and the piston rod 41 of the drop-out prevention hydraulic cylinder 40 is projected into the receiving portion 93 as shown in FIG. And engages with the engaging groove 67 of each divided body 54.

Next, the forming shaft material 10 is put into a predetermined position in the crankshaft forging device, and the work is started in a state where it is supported by a supporting member (not shown). Set the work start position of 8, and set the shaft material 1
The amount of compression in the axial direction of 0, that is, the amount of molding is set as follows.

That is, first, in each positioning device 18 of the shifting members 7 and 8, the turning hydraulic cylinder 21 (see FIG. 2)
As shown by the solid line in FIG. 10 for the receiving plate 17 and the adjusting screw shaft 23,
The clamp member 4 is rotated to a position not corresponding to the regulating member 25.

In this state, the left and right shifting members 7 and 8 are once moved to the central position by the shifting hydraulic cylinder 13 as shown in the upper portion of FIG.

After that, the rotary hydraulic cylinder 21 is used to move the receiving plate 17 and the adjusting screw shaft 23 to the shifting members 7 and 8 as shown in FIG.
It is rotated upward to a position corresponding to each regulating member 25 in the left-right direction.

Next, after adjusting the adjustment screw shafts 23 forward and backward, the shifting hydraulic cylinders 13 are used to shift the left and right corresponding shifting members.
7 and 8 are separated left and right until they hit the head of each adjusting screw shaft 23.

As described above, the work is started after setting the work start positions of the shifting members 7 and 8. First, the clamp hydraulic cylinders 5 are operated to bring the clamp members 4 close to each other, With each split mold 28,29 of molding dies 26,27,
The shaft blank 10 is clamped and fixed by the first clamping portion 61 of each split mold 54 of the clamping mold 53.

After that, the left and right main hydraulic cylinders 82 are operated to bring the pressing members 83 into contact with the left side molding die 26 or the sandwiching die 53, but at this time, the adjusting screw shaft 85 Also, the distance regulating member 86 is in the retracted position. When the main hydraulic cylinder 82 is operated, is the shifting hydraulic cylinder 13 following the operation?
Alternatively, it is in a free state.

Then, after the contact, the adjusting screw shaft 85 is moved by the turning pin 84.
Is rotated to advance the interval regulating member 86 so that it comes into contact with the end surface of the shaft blank 10.

(The above operation corresponds to FIG. 19 (a) of the claim correspondence diagram.) Further, the front and rear forming hydraulic cylinders 8 are actuated, and the punch 91 is pressed.
Then, the anvil 92 is moved forward, and the pin blank 95 holds and fixes the shaft blank 10. Further, the support member is retracted to a position where it does not interfere with the next compression work. (The above operation corresponds to FIG. 19 (b) of the claim correspondence diagram.) Next, the left and right main hydraulic cylinders 82 are actuated to operate the left side molding die 26, the right side molding die 27, and The clamping die 53 and the clamping die 53 are pressed to the other side, and the end surface of the shaft blank 10 is pressed to compress the shaft blank 10 in the axial direction.

At the same time, while the shaft material 10 is clamped and fixed by the punch 91 and the pin forming portion 95 of the anvil 92, the forming hydraulic cylinder 88 is operated to move the punch 91 forward, and the pin forming portion 95 causes While forming the pin portion 64 of the crankshaft 59, a part of the shaft material 10 flows into the arm forming portions 33 and 34 of the respective molding dies 26 and 27, and the arm portion 6 of the crankshaft 59 is formed.
2 is formed, which allows the pin portion 64 and the pair of arm portions 6 to be formed.
A crank throw portion 104 having 2 and 2 is formed. (The above operation corresponds to FIG. 19 (c) of the claim correspondence diagram.) At this time, the punch 91 and the anvil 92 move to the left or right due to uneven hardness due to uneven temperature of the shaft material 10. The crank throw portion 104 may be swung in the direction, and if left as it is, the left and right arm portions 62 of the crank throw portion 104 have different wall thicknesses.

However, in the embodiment, in the above case, the value of the potentiometer 97 is different, so that the control device 100 controls the control valve 1 of the main hydraulic cylinder 82 so as to eliminate this difference.
02 is controlled to control the extension amount of the main hydraulic cylinder 82, whereby the punch 91 and the anvil 92 are returned to the proper positions, and the left and right arm portions 62 of the crank throw portion 104 are controlled.
The thickness of each is almost the same.

That is, for example, when the punch 91 swings to the left, the extension of the right main hydraulic cylinder 82 is temporarily stopped and only the left main hydraulic cylinder 82 continues to be extended, whereby the punch 91 and the anvil 92 are properly positioned. After that, the expansion of the right main hydraulic cylinder 82 is restarted. (The above operation corresponds to FIG. 19 (d) of the claim correspondence diagram.) After the crank throw portion 104 is formed as described above, each main hydraulic cylinder 82 is contracted to press the pressure member 83. To the retracted position, and the hydraulic cylinders 5 for clamping are contracted to retract the clamp members 4, the shifting members 7, 8 and the floating members 37, and to clamp the left and right molding dies 26, 27. The pinch 91 and the anvil 92 are retracted while the clamping of the shaft blank 10 by the split molds 28, 29, 54 of the mold 53 is released and the molding hydraulic cylinder 88 is contracted.

In the above case, the shaft material 10 and the crank throw 104
Is supported by a support member.

Then, the left and right shifting members 7 and 8 are separated by the shifting hydraulic cylinder 13 until they come into contact with the head of the adjusting screw shaft 23.

This completes one cycle of forming work, and when forming the next crank throw portion 104, the forming work is repeated after moving the shaft blank 10 and the crank throw portion 104 to the right. However, the difference from the above-mentioned work will be described below.

That is, as shown in FIGS. 20 (a) and 20 (b), at the start of the work, the hydraulic cylinders 42 for floating are operated before the operation of the hydraulic cylinders 5 for clamping, so that both floating members 37 are mutually operated. In this case, the contact between the two floating members 37 is blocked by the pressing body 49 biased by the disc spring 51, and the two floating members 37 face each other with a small gap.

As a result, the sandwiching die 53 is substantially integrated with the already formed crank throw portion 104 inside, but the rotation around the axis thereof is allowed.

Next, the electric motor 69 of the rotating device 68 is driven, and the clamping die 53 is rotated around the shaft center via the transmission mechanism of the rotating device 68, so that the crank throw part 104 in the clamping die 53. Is rotated by a predetermined angle with respect to the arm forming portions 33, 34 of the forming dies 26, 27.

After that, as shown in the 20th (c), each clamp hydraulic cylinder 5 is operated to bring both clamp members 4 close to each other,
When the disc spring 51 is compressed, the pressing body 49 is retracted into the equipment hole 47, the floating members 37 are brought into contact with each other, and the clamping die is held.
The two split dies 54 of 53 are integrated, and the already-formed crank throw portion 104 is sandwiched and fixed by the sandwiching die 53. In this case, of course, the shaft blank 10 is clamped and fixed by the split dies 28 and 29 of the molding dies 26 and 27.

Then, next, the left and right main hydraulic cylinders 82 and the front and rear forming hydraulic cylinders 88 are operated to form the crank throw portion 104 in the same manner as described above. In this case, the crank throw portion 104 is formed. Is out of phase with the already formed crank throw portion 104 by a predetermined angle.

After forming the crank throw portion 104 as described above, in order not to return to the state before the molding operation, the main hydraulic cylinder 82,
The clamp hydraulic cylinder 5, the molding hydraulic cylinder 88 and the like are operated to retract the clamp member 4 and the like.

In this case, as the clamping hydraulic cylinder 5 is contracted, the floating hydraulic cylinder 42 is extended,
Both floating members (37) are maintained in a state of being opposed to each other through a small gap, and both split molds (54) of the sandwiching mold (53) are maintained in a substantially integrated state.

After that, the electric motor 69 of the rotating device 68 is operated to rotate and return the sandwiching die 53 to the original position, and each sandwiching die 53 is divided.
54 is positioned in the receiving portion 39 of each floating member 37.

Next, the hydraulic cylinder 42 for floating is reduced, each floating member 37 is retracted to the side of the shifting member 8 by the right side, and each split mold 54 of the sandwiching mold 53 is moved to the crank throw unit 104.
Back away from.

(Effects of the Invention) As described in detail above, according to the present invention, even when forging a crankshaft having several crank throw parts, a single clamping die may be used, and the work is different. You can do it. The present invention has the above advantages and is of great benefit.

[Brief description of drawings]

The drawings show an embodiment of the present invention, and FIG. 1 is an overall plan view,
FIG. 2 is a partially detailed plan view of FIG. 1, and FIGS. 3 to 6 are respective AA line, BB line, CC line, DD of FIG.
7 is a partial plan sectional view of FIG. 1, FIG. 8 is a sectional view taken along the line EE of FIG. 5, and FIG. 9 is a line FF of FIG. Sectional view taken in the direction of the arrow, FIG. 10 is a sectional view taken along the line GG in FIG. 5, FIG. 11 is a side view of the left side molding die, FIG. 12 is the same end view, and FIG. 13 is the right side molding. A side view of the die, FIG. 14 is an end view of the same, FIG. 15 is an end view of the holding die, FIG. 16 is a vertical cross-sectional view of the holding die having a crank throw portion inside, and FIG. Is a cross-sectional view showing the structure of the connecting portion of the clamping die, FIG. 18 is a bottom view of the punch, and FIGS. 19 and 20 are claims corresponding views. 4 ... Clamping member, 10 ... Shaft material for molding, 26, 27 ...
Molding dies, 28,29 ...... Split dies, 37 ...... Floating members, 42 ...... Advancing / retreating devices (hydraulic cylinders for floating),
53 …… Clamping mold, 54 …… Split mold, 59 …… Crank shaft,
62 ... Arm, 64 ... Pin, 68 ... Rotating device, 91 ...
... Punch, 92 ... Anvil, 104 ... Crank throw part.

Claims (1)

[Claims] 1. A pair of clamp members (4) are disposed on both sides of a molding shaft material (10) in a direction orthogonal to the axial center direction, and each clamp member (4) has a pair of molding dies ( Equipped with corresponding split molds (28) and (29) of 26) and (27), both molds (2
6) While holding the shaft material (10) by the (27), both molding dies (26) (27) are pressed to the other side, and both molding dies (26) ( 27) are pressed against each other to compress the shaft material (10) in the axial direction and
Punch (91) inserted between both molds (26) (27)
And a part of the shaft material (10) is deformed in the orthogonal direction by the anvil (92) to form a crank throw part having a pin part (64) and a pair of arm parts (62) in the crank shaft (59). (104) to form one mold (2
6) Or (27), on the side opposite to the other molding die (27) or (26), clamp and fix the already formed crank throw part (104) consisting of a pair of split molds (54). And a clamping die (53) pressed against the other molding die (27) or (26) is provided together with the one molding die (26) or (27) described above. The clamp member (4) is provided with a pair of floating members (37) in which the split molds (54) of the sandwiching mold (53) are rotatably provided around the axis, and the clamp member (4) is provided. And the floating member (37) between the floating member (37) and the other side by advancing forward and backward relative to the other side, the split mold (54) of the sandwiching mold (53) is rotated around the axis. With the advancing / retreating device (42) that is substantially integrated with the rotation allowed, the substantially integrated clamping die (53) is rotated around the axis. Crankshaft forging apparatus characterized by comprising a rotation device (68) to be.