JPH07164082A - Work transfer device in press machine - Google Patents

Abstract

PURPOSE:To produce a upper die in compact and at low cost by making a holding fitting descend/retreat to the position not interfere with a lower die and at the approximate same height as the lower die at press bottom dead center. CONSTITUTION:Plural lower dies 2a-2b are mounted on a bolster 1a of a press machine main body 1 through a die set 1b, plural works W is simultaneously subjected to press working. The work placed on lower dies 2a-2b is clamped/ released by a holding fitting 9 (suction fitting). The holding fitting 9 is approached/transferred to the prescribed upper face of lower die by a transfer mechanism consisting of a feed bar 3, load 4, etc. The transfer mechanism is driven by a drive mechanism consisting of a worm gear reducer, large pulley 17a, etc. The transfer mechanism is constituted so that at the press lower dead point, the holding fitting 9 is descended/ retreated to the position not to interfere the lower die 2 and at the approximate same height as the lower die 2. By this method, high speed operation of a press machine becomes possible, further improving productivity.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work transfer device in a press machine.

[0002]

2. Description of the Related Art Conventionally, it is known that a plurality of dies are attached to a press machine and a work is sequentially transferred to a lower die to perform multi-step press working simultaneously. In this case, as shown schematically in FIG. 5, for example, the suction tool 9 (also referred to as a gripping tool) is generally moved along the route of R11 to R13 to transfer the work W. In the figure, the retracted state in which the suction tool 9 is located above the adjacent lower molds 2a and 2b is shown by a solid line. This transfer procedure will be described below. First, the suction tool 9 in the retracted position moves laterally up to the lower mold 2a and descends from that position until it comes into contact with the work W on the lower mold 2a (R11). The suction tool 9 sucked onto the work W moves up and lifts up the work W, then moves laterally and moves down onto the lower mold 2b in the next step to release the work W (R12). When the work W is set on the lower mold 2b, the suction tool 9 moves backward and stops at the initial (retracted) position between the lower molds 2a and 2b (R13). Then, in this state, the upper die (not shown) is lowered to perform the press working. Further, the transfer device for transferring the work W as described above is generally constituted by a robot or the like having a drive source independent of the press machine.

[0003]

However, in the work transfer device described above, since the gripping tool is located considerably above the lower die at the bottom dead center of the press, the height dimension of the upper die should be kept sufficiently large. Otherwise, the interference between the gripping tool and the upper die holder cannot be avoided. In other words, the upper die is made larger than necessary, which has been an obstacle to making the upper die compact. Further, since the movement of the robot or the like is synchronized with the press, the structure of the transfer device is complicated, and further, the influence of the load variation spreads to the drive mechanism, and the smooth movement of the gripping tool is likely to be disturbed.

Therefore, according to the present invention, the upper mold can be made compact by retracting the gripping tool to an appropriate position, and the gripping tool can be smoothly moved through a drive mechanism connected to the press machine. This is a technical issue to be solved.

[0005]

To this end, the following work transfer device for a press was created. That is, in the invention according to claim 1, in a press machine in which a plurality of lower molds are attached to a bolster to perform multi-step press working at the same time, a gripping tool capable of grasping and releasing a work placed on the lower mold is provided. A moving mechanism for moving the gripping tool closer to the upper surface of a predetermined lower mold, and a driving mechanism for driving the moving mechanism, wherein the moving mechanism moves the gripping tool to the lower mold at the bottom dead center of the press. It is characterized in that it is configured to be lowered to the same height as the lower mold and retracted at a position where it does not interfere. Further, in the invention according to claim 2, the drive mechanism drives the moving mechanism via a worm gear reducer that is connected to an auxiliary output shaft of the press machine and locks without transmitting torque in the speed increasing direction. It is characterized in that it is configured to enable interlocked operation with a press machine.

[0006]

In the work transfer device described above, the work is transferred onto a predetermined lower mold, and then lowered at a position where the gripping tool does not interfere with the lower mold until the height is almost the same as that of the lower mold. Therefore, even when the height of the upper die is smaller than that of the conventional one, the upper die holder, the upper die holding rail, and the like of the press do not interfere with the gripping tool at the bottom dead center of the press. In addition, since the worm gear reducer cannot transmit torque from the output shaft to the input shaft, even if a relatively large load change occurs in the moving mechanism, it does not affect the drive side of the reducer, and the reduction speed is reduced. The machine does not rotate backwards. Therefore, the moving mechanism moves smoothly in conjunction with the press machine, and the work transfer device operates stably.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view of a main part of the press machine, and FIG. 2 is a side view. The press machine shown in both figures has four types of lower molds 2 (2a to 2d) on the bolster 1a of the main body 1 through the die set 1b.
However, for example, blanking, bending, bending, and punching are attached in the order of the processing steps so that four workpieces W can be simultaneously pressed. These lower molds 2a
The moving mechanism and the drive mechanism of the work transfer device for sequentially transferring the work W between 2d will be described in order.

The two guide columns 1c, 1c standing upright at the rear of the lower mold of the bolster 1a support a feed bar 3 extending horizontally in the horizontal direction so that the feed bar 3 can be moved up and down and slidable in the left and right directions. The tip of the rod 4 is connected to the connector 3a attached to the left end of the feed bar 3, and although the details will be described later, when the rod 4 is pushed and pulled, the feed bar 3 is moved to the left and right accordingly. It is designed to slide.

On the other hand, the main body 1 side is provided with two support shafts 5a, 5b extending in a direction perpendicular to the plane of the drawing.
Approximately L-shaped arms 6a and 6b are rotatably attached to 5b. 1 and 3, a roller 6c is attached to one end of each of the arms 6a and 6b, and the roller 6c contacts the lower side of the feed bar 3 to position the feed bar 3 in the vertical direction. ing. The lower ends of both arms 6a and 6b are connected to each other by a rod 7 so that both arms interlock. Arm 6a
Further, a rod 8 is connected to the arms, and as will be described later in detail, when the rod 8 is pushed and pulled, both arms 6a, 6a are
b is rotated, and the feed bar 3 is moved up and down accordingly.

A mounting arm 3b that overhangs on the lower mold 2 is mounted on the feed bar 3 at the same interval as the lower mold 2 is arranged. (Also called a tool) is attached. The suction tool 9 communicates with a suction pump (not shown), and the work W contacting the suction cup is evacuated through the operation of a solenoid valve (not shown), so that the suction tool 9 can be grasped or released at a predetermined timing. You can do it. It should be noted that the suction tool 9 may be replaced with another gripping means such as a magnet type or a mechanical type.

Next, a mechanism for pushing and pulling the rods 4 and 8 will be described. As shown in FIGS. 1 and 2, two swinging arms 11 and 12 are rotatably attached to a mounting base 10 provided on the left side of the main body 1 via support shafts 11a and 12a. Groove cams 13 and 14 for swinging the shafts at predetermined timings are attached to the output shaft end of a worm gear reducer 15 (see FIG. 2) described below. Note that FIG. 1 shows only the contour of the cam. And
The rods 4 and 8 are rotatably connected to the tip ends of the swing arms 11 and 12, and cam followers 12b and 11b that engage with the groove cams 13 and 14 are provided in the middle portions.
The grooved cam 13 shown in the drawing makes one rotation per stroke of the press to reciprocate the rod 4 in the substantially longitudinal direction to slide the feed bar 3 left and right, while the grooved cam 14 makes one rotation per stroke of the press to make the rod. The feed bar 3 is configured to move up and down 3 times in a substantially longitudinal direction, and the feed bar 3 is moved up and down 3 times. The suction tool 9 is set to move along a predetermined locus.

A drive mechanism for driving the moving mechanism configured as described above will be described below. The worm gear reducer 15 has a worm as a driving side and a worm wheel as a driven side, and has a general gear specification in which the worm cannot be rotated from the worm wheel. A timing belt 18a is hung between a pulley 16 attached to the input shaft end of the worm gear reducer 15 and a large pulley 17a provided on the left side of the main body 1, and is integrated with the large pulley 17a. A small pulley 17b provided on the main body 1 and the auxiliary output shaft 1 of the main body 1.
A timing belt 18b is hung between the pulley 19a attached to the gear 9 and the pulley 19a. That is, in the above drive mechanism, the rotation of the auxiliary output shaft 19 is once accelerated and then decelerated. In this embodiment, the speed increasing ratio between the auxiliary output shaft 19 and the worm is 1:10, and the speed reducing ratio of the worm gear reducer 15 is 10: 1.

Next, the operation of the work transfer device will be described.
FIG. 1 shows a state in which the feed bar 3 retracts the suction tool 9 to each intermediate position of the lower die 2 and the upper die 20 is almost at the bottom dead center of the press. When the operation from this state is outlined, the auxiliary output shaft 19 rotates together with the crank of the press, the grooved cams 13 and 14 rotate once per stroke of the press in synchronization with this, and further, the feed bar that follows both cams. 3 slides left and right and moves up and down, and then returns to the retracted position. During this period, the suction tool 9 sucks each work W on the lower die 2 and transfers it to the adjacent lower die 2, and then the upper die 20 is lowered to perform the press working. Next, the movement of the suction tool 9 will be described in detail.

FIG. 4 is a diagram schematically showing the movement trajectory of the suction tool 9. As shown in the figure, the suction tool 9 in the retracted position
First, after ascending to a predetermined height, it moves to the left and further descends to grab the work W on the lower die 2a (in the figure,
R1 track). Next, after rising again, it moves to the right and descends onto the lower mold 2b to set the work W at a predetermined position (the locus of R2 in the figure). Then, after the work W is released, the work W is raised again, moved to the left, and lowered to a height substantially the same as that of the lower molds 2a and 2b at the intermediate position between the lower molds 2a and 2b (
R3 track). That is, this position is the retracted position of the suction tool 9, and when this state is reached, the upper die 20 is lowered and press working is performed at the same timing. 1 to 3, 21 is an upper die holder and 22 is a holding rail.

In the work transfer apparatus of this embodiment, as described above, the suction tool 9 and the mounting arm 3b are lowered to the same height as the lower mold 2 and retracted. Therefore, the positions of the upper die holder 21 and the holding rail 22 of the main body 1 at the bottom dead center of the press can be set sufficiently close to the lower die 2, and the height of the upper die 20 is higher than that of the conventional one. The size can be reduced.

Next, the operation of the drive mechanism will be described. As described above, the rotation of the auxiliary output shaft 19 of the main body 1 is once accelerated by the belt mechanism and then reduced by the worm gear reducer 15, and the output shaft of the worm gear reducer 15 includes the groove cams 13 and 14. The cams 13 and 14 are driven to rotate and push and pull the rods 4 and 8 to move and stop the feed bar 3. Therefore, the output shaft of the worm gear reducer 15 directly connected to the cams 13 and 14 has a large load variation, but the worm gear reducer 15 cannot rotate in the reverse direction in the speed increasing direction. The influence does not spread to the input shaft side, and both cams 13 and 14 rotate smoothly.

Although the worm gear speed reducer is used in this embodiment, the present invention is not limited to this, and it is also possible to use a transmission of a type that locks from the driven side to the driving side without transmitting torque.

[0018]

As described above, according to the present invention, since the height dimension of the upper mold can be set smaller than the conventional one, there is an effect that the upper mold can be manufactured compactly and inexpensively. Further, since the gripper moves smoothly in synchronization with the press machine and the operation of the work transfer device is stabilized, there is an effect that the press machine can be operated at high speed and the productivity can be improved.

[Brief description of drawings]

FIG. 1 is a front view of a main part of a press machine according to an embodiment, showing a press bottom dead center state.

FIG. 2 is a side view of the press machine according to the embodiment, showing almost the top dead center of the press.

FIG. 3 is a diagram schematically illustrating a main part of a moving mechanism according to the embodiment.

FIG. 4 is an explanatory diagram of a movement locus of the suction tool according to the embodiment.

FIG. 5 is an explanatory diagram of a movement locus of a suction tool of a conventional example.

[Explanation of symbols]

 1 Main body 1a Bolster 2, 2a-2d Lower mold 3 Feed bar 9 Adsorption tool (grasping tool) 15 Worm gear reducer 19 Auxiliary output shaft 20 Upper mold

Claims (2)

[Claims] 1. A pressing machine in which a plurality of lower molds are attached to a bolster to simultaneously perform multi-step press working, and a gripping tool capable of gripping and releasing a work placed on the lower mold, and the gripping tool. The moving mechanism includes a moving mechanism for moving the moving mechanism closer to a predetermined lower die upper surface, and the moving mechanism lowers the gripping tool at a position that does not interfere with the lower die at the bottom dead center of the press. A work transfer device in a press machine, characterized in that the work transfer device is configured to be lowered to approximately the same height as the mold and retracted. 2. The press mechanism is configured to drive the moving mechanism via a worm gear reducer that is connected to an auxiliary output shaft of the press machine and locks without transmitting torque in the speed increasing direction. The work transfer device in a press machine according to claim 1, wherein the work transfer device is capable of being interlocked with.