JP3544312B2 - Press forming machine for crankshaft - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a press machine for a crankshaft.
The integral crankshaft is machined in the order of stamping, twisting and shaping of a billet. Of these, the stamping is performed by one forging press because the pressing direction is only the up and down direction although there are processes of rough land forming, rough stamping, finish stamping, and blanking. However, the twisting process and the shaping process are performed separately by separate forging presses because of different pressing methods. However, the use of two forging presses is disadvantageous in terms of equipment costs and man-hours. In recent years, forming presses capable of performing a twisting process and a shaping process with one device have been developed. The present invention relates to a crankshaft press forming machine that performs such twisting and shaping by one unit.
[0002]
[Prior art]
As a conventional crankshaft press forming machine, there is one described in Japanese Patent Publication No. 7-4640.
This conventional example will be described with reference to FIG.
A slide 106 is hung on the tip of a piston rod of a ram cylinder 108 attached to a crown, and an upper die holder 151 is attached to the lower surface of the slide 106. It has 102 upper molds. On the other hand, the lower die of the torsion die 101 and the lower die of the shaping die 102 are attached to the lower die holder 152 fixed on the base. When the slide 106 descends and the upper mold and the lower mold of the torsion mold 101 and the shaping mold 102 are combined, the upper and lower molds are assembled so that the pass lines of the two are at the same height. When the slide 106 is lowered, the workpiece in the torsion mold 101 is held by the mold, and at the same time, the workpiece of the shaping mold 102 is pressed to undergo shaping. Then, as shown in FIG. 7, while the slide 106 is lowered, the torsion cylinder 109 provided in the slide 106 and the pushing rod 171 penetrating through the slide 106 are further lowered to perform torsion processing. As shown in FIG. 8, the mold is opened.
Therefore, at the same time as the shaping process for correcting the shape of the crankshaft is performed by the shaping mold 102, the workpiece is held by the torsion mold 101, and the torsion cylinder 109 is subsequently operated to push the pushing rod 171 downward to move. One of the torsion dies 101 can be turned counterclockwise and the other can be turned clockwise to form a twist.
[0003]
In the above-mentioned conventional example, as shown in FIG. 8, the movable type holding structure of the torsion type 101 has upper and lower retainers 111 each having a semi-circular rotating surface in order to enable twisting. The lower die is fitted, and the retainer 111 is rotatably supported by the rollers of the vertical rotation guide 112, so that the rigidity is poor and it is necessary to prevent overload. Therefore, in order to prevent an abnormal load due to the inclination of the slide 106 from acting on the rotary guide 112, a kiss plate for restricting the operation of the slide 106 at the molding end position of the shaping mold 102 or slightly short of the former is placed on the left and right sides of the upper and lower bolsters. A gap is provided between the upper and lower molds of the torsion mold 101 so that no load acts on the movable mold holding structure such as the torsion mold 101 and the vertical rotation guide 112 at that time. The crankshaft is formed by being twisted by the cylinder 109.
[0004]
[Problems to be solved by the invention]
However, at this time, as shown in FIG. 9, there is a gap δ of about several mm between the upper mold 11 and the lower mold 12 and no mold clamping force is applied, so that the movable holding structure is twisted in a state where play is not killed. As a result, the torsion accuracy is varied.
Therefore, in order to secure the torsional accuracy, it is very important to adjust the vertical twist type gap δ and the vertical shaping type gap when the upper and lower kiss plates are in a kiss state.
However, the crankshaft material W is given that a hot forged material, is impossible to precisely set by adjusting the vertical torsion type clearance for its forging accuracy variations at the expense of torsional accuracy is the current situation.
[0005]
SUMMARY OF THE INVENTION In view of the above circumstances, it is an object of the present invention to provide a crankshaft press forming machine which enables torsional molding while eliminating backlash which causes variations in torsional accuracy and improves torsional accuracy.
[0006]
[Means for Solving the Problems]
The press forming machine for a crankshaft according to claim 1 is a press forming machine for a crankshaft in which a torsion forging section and a shaping forging section are provided in one press , wherein a vertical die is provided between a slide and a head heart plate. and upper and lower kiss plate mounted between the holder and the upper die of the torsion type, a retainer on which accommodates the upper mold, and the upper rotary guide for rotatably holding the upper retainer, the lower mold of the torsion type When a lower retainer for accommodating a lower die, and a cushion cylinder and a torsion forging unit, for supporting the upper rotation guide or the lower rotation guide including the lower rotation guide for rotatably holding the lower retainer, said the high-pressure oil cushion force exerted cushion cylinder provided with an accumulator for supplying, from after the torsion type sandwiching a crankshaft material, the upper and lower Kisu plates to each other Through the contact state, further until the torsional forming, characterized in that against the bending force the cushion cylinder torsional and adapted to support the torsion forging unit.
[0007]
According to the crankshaft press forming machine of claim 1, the crankshaft material is torsion-formed by the torsion forging part in a state where the slide continues to descend and the upper and lower kiss plates are kissed. Since the torsion mold is clamped and the torsion is formed in a state in which "play" is killed, there is no play between the upper and lower molds of the torsion mold and the crankshaft material, and accurate torsion molding can be realized. Further, since the cut with holding the clamping force by the cushion cylinder at a constant accumulated pressure of the accumulator, a proper clamping force, can realize a torsion molding accuracy.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a sectional front view of a main part of a crankshaft press forming machine according to an embodiment of the present invention, FIG. 2 is an explanatory diagram of a state before die kiss in the crankshaft press forming machine, and FIG. FIG. 4 is an explanatory view of a die kiss state in the press forming machine, FIG. 4 is an explanatory view of a twist forming operation in the same crankshaft press forming machine, and FIG. 5 is a basic configuration diagram of the crankshaft press forming machine according to one embodiment of the present invention. is there.
[0009]
First, the basic configuration of the press molding machine will be described with reference to FIG.
1 is a bed hard plate, 2 is a crown, 3 is a column connecting them. Reference numeral 4 denotes a slide, and reference numerals 5A and 5B denote a slide cylinder mounted on the crown 2 and a lifting cylinder. The slide 4 is lowered by a large-diameter, large-output slide cylinder 5A, and the slide 4 is raised by a small-diameter, high-speed lifting cylinder 5B.
Reference numeral 20 denotes a torsion cylinder. A connecting block 23 is connected to a lower end of the piston rod 21 and push rods 31 are connected to four corners of the connecting block 23, respectively. As shown in FIG. 1, the four push rods 31 are disposed on the right and left sides of the torsion mold 10 before and after the slide 4, respectively. 32 and a torsion return beam 33.
[0010]
As shown in FIG. 5 again, an upper die holder 6 is attached to the lower surface of the slide 4. A lower die holder 7 is mounted on the upper surface of the base 1. An upper rotary guide 8 and an upper die 18 of a shaping die 17 are attached to the lower surface of the upper die holder 6. On the upper surface of the lower die holder 7, a lower rotary guide 9 and a lower die 19 of a shaping die 17 are attached.
The torsion mold 10 is composed of an upper mold 11 and a lower mold 12. The upper mold 11 is placed in an upper retainer 13 and held rotatably by an upper rotation guide 8. The lower mold is placed in a lower retainer 14. And is rotatably held by a lower rotation guide 9.
[0011]
A push-down arm 15 is attached to the upper retainer 13, and the push-down arm 15 is pushed down by a push rod 31 via the torsion beam 32, and the torsion mold 10 is moved together with the upper and lower retainers 13, 14 and the vertical rotation guide 8. , 9, the material sandwiched between the upper and lower dies 11, 12 can be twisted.
The shaping die 17 places a twisted material between the upper die 18 and the lower die 19 and presses the material in the vertical direction to perform a shaping process to correct the shape of the crankshaft.
[0012]
Next, features of the present invention will be described with reference to FIG.
A lower rotary guide 9 having a pair of guide rollers 9a is installed above the lower die holder 7 via a lower guide support 65, and an upper rotary guide 8 having a pair of guide rollers 8a is provided on the lower surface of the upper die holder 6. Is attached . An upper retainer 13 and a lower retainer 14 that rotate while holding the upper and lower dies 11 and 12 are supported by these vertical rotation guides 8 and 9. The upper retainer 13 and the lower retainer 14 are arranged in pairs in the upper and lower directions in the axial direction of the crankshaft material W.
Each of the upper retainers 13 has one arm 15 extending outward in the radial direction, and a roller is supported at the tip of the arm 15. The arms 15, 15 are arranged on the outer peripheral portion of the adjacent upper retainer 13 so as to be symmetrical with respect to the vertical center line when viewed from the front. In the illustrated state, one arm 15 is an arm of another upper retainer (not shown) axially adjacent to the upper retainer 13.
[0013]
On the lower surface of the upper die holder 6, upper kiss plates 35, 35 protruding downward are vertically provided on one side of the push rod 31 and on the side of the shaping mold 17. On the upper surface of the lower die holder 7, lower kiss plates 36, 36 are erected so as to face the upper kiss plates 35, 35. The upper and lower kiss plates 35 and 36 are set to have a length that limits the further downward pressurization by kissing each other immediately before or immediately after the molding by the shaping mold 17 is completed.
[0014]
Next, the cushion cylinder 60 will be described.
A concave portion 66 is formed in the lower die holder 7, and the lower guide support 65 is accommodated in a vertically movable manner. The bed hard plate 1 has a cylinder chamber 61 that forms the cushion cylinder 60. The cylinder chamber 61 accommodates a piston 62. Reference numeral 67 denotes a stopper that regulates a rising position of the guide support 65.
A hydraulic source 70, an accumulator 71, and a relief valve 72 are connected to the head-side oil chamber of the cylinder chamber 61 of the cushion cylinder 60, and hydraulic pressure can be supplied and discharged from the hydraulic source 70 via a direction control valve 73. It has been. Numeral 74 is a check valve for preventing discharge of the pressure oil when the direction control valve 73 is neutral. Reference numeral 75 denotes an overload detector that detects the hydraulic pressure in the cylinder chamber 61 and outputs a twister operation stop signal at a certain pressure (overload) or higher, for example, a hydraulic pressure detector such as a pressure switch.
By switching the direction control valve 73, high-pressure oil can be supplied to and discharged from the cylinder chamber 61 and the accumulator 71. When the direction control valve 73 is neutral, the piston 62 is held at the accumulated pressure of the accumulator 71. However, if the cylinder chamber 61 is overloaded due to a load during molding, the pressure escapes from the relief valve 72, so that the piston 62 can always exert an appropriate cushioning force.
[0015]
Next, the press forming operation of the present embodiment will be described.
(1) First, as shown in FIG. 2, the cushion cylinder 60 is raised before the slide descends. At this time, the cushion force for raising the lower mold 12 of the torsion mold 10 is held by the stopper 67. In the torsional forging part, the crankshaft material W is installed on the lower die 12, and the upper and lower kiss plates 35, 36 are not yet kissed.
(2) Next, as shown in FIG. 3, when the descending stroke is further reduced by several millimeters, the lower guide support 65 is pushed downward by a distance d from the stopper 67, and the upper and lower kiss plates 35 and 36 kiss at the same time. Therefore, the cushion force that pushes up the lower mold 12 acts as a mold clamping force. That is, the upper and lower dies 11, 12 come into contact with each other via the crankshaft material W from a position several millimeters from the upper end of the lower kiss plate 36, and a cushion force acts on the upper and lower dies 11, 12 to generate "play". You will be killed.
(3) Then, in a state where the slide continues to descend and the upper and lower kiss plates 35 and 36 kiss (coining molding is completed at this time), the torsion cylinder 20 lowers the push rod 31 as shown in FIG. The crankshaft material is torsion-molded. At this time, the mold is clamped by the cushioning force, and the torsion-molding is performed in a state where "play" is killed.
Therefore, according to the present embodiment, accurate torsion forming without play between the upper and lower molds and the crankshaft material can be realized.
[0016]
Next, another embodiment of the present invention will be described.
In the above embodiment, the cushion cylinder 60 is attached to the lower rotation guide 9, but may be attached to the upper rotation guide 8 instead. Even in this case, cushioning force can be applied so as to kill "play" between the upper mold 11 and the lower mold 12, and the same effect as in the above embodiment can be achieved.
[0017]
【The invention's effect】
According to claim 1 of the crank shaft for press molding machine, since the mold clamping by the cushion force of the click Tsu Deployment cylinder "play" is torsional molded in the state of being killed, there is no play between the upper and lower molds and the crankshaft material , And accurate twist forming can be realized. Further, since the cut with holding the clamping force by the cushion cylinder at a constant accumulated pressure of the accumulator, a proper clamping force, can realize a torsion molding accuracy.
[Brief description of the drawings]
FIG. 1 is a sectional front view of a main part of a crankshaft press forming machine according to an embodiment of the present invention.
FIG. 2 is an explanatory view of a state before die kiss in the crankshaft press forming machine.
FIG. 3 is an explanatory view of a die kissing state in the crankshaft press forming machine.
FIG. 4 is an explanatory view of a twist forming operation in the crankshaft press forming machine.
FIG. 5 is a basic configuration diagram of a crankshaft press forming machine according to an embodiment of the present invention.
FIG. 6 is a sectional front view of a main part of a conventional press molding machine.
FIG. 7 is an explanatory view of a twisting operation of a conventional press molding machine.
FIG. 8 is an explanatory view of a mold opening operation of a conventional press molding machine.
FIG. 9 is an explanatory view of a play between the upper and lower dies 11, 12 and the crankshaft material W.
[Explanation of symbols]
8 Upper rotation guide 9 Lower rotation guide 10 Torsion type 11 Upper type 12 Lower type 35 Upper and lower kiss plate 36 Lower kiss plate 60 Cushion cylinder 61 Cylinder chamber 62 Piston 71 Accumulator 72 Relief valve

Claims (1)

A press forming machine for a crankshaft in which a torsion forging part and a shaping forging part are provided in one press,
Between the slide and the head heart plate,
Upper and lower kiss plates attached between the upper and lower die holders,
A torsion-type upper die, an upper retainer that houses the upper die, an upper rotation guide that rotatably holds the upper retainer, the torsion-type lower die, and a lower retainer that stores the lower die; A torsion forged part consisting of a lower rotation guide that holds the lower retainer rotatably,
A cushion cylinder for supporting the upper rotation guide or the lower rotation guide,
An accumulator for supplying high-pressure oil for exerting the cushion force of the cushion cylinder is provided,
From after the torsion type sandwiching a crankshaft material, via the state in which the upper and lower kiss plate has contact with each other, further until the torsional forming, supporting the torsion forged part against the bending force the cushion cylinder torsional A press forming machine for a crankshaft, characterized in that the press forming machine is adapted to perform the following .

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