JPH0318435A - Transfer device - Google Patents

Abstract

PURPOSE:To precisely transfer a work by driving a pair of parallel feed bars in the backward/forward direction with a ball screw as a driving force transmitting part, driving it in the clamping/loosening direction and driving the feed bars in the downward/upward direction with a rack and pinion as a driving force transmitting part. CONSTITUTION:The pair of parallel feed bars 10 is provided in the direction for transferring the work. In a feed mechanism, the feed bars 10 are driven backward and forward with a feed motor as a driving source and with a ball screw (feed screw) 32 as a driving force transmitting part. In a clamp mechanism, the feed bars 10 are clamped and loosened with a clamp motor 36 as a driving source and with the ball screw (feed screw) 32 as the driving force transmitting part. In a lift mechanism, the feed bars 10 are driven up and down with a motor 44 for elevating/lowering the feed bars as a driving motor and with a rack and pinion 26 as the driving force transmitting part. Thus, the feed motor and the clamp motor can be kept under easy control.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a transfer device that uses a servo motor as a power source. [Prior art] Conventional transfer equipment transports workpieces to be press-formed. Two long feed bars are placed on both sides of the press mold, for example the lower mold and the upper mold, and these bars clamp and transport the workpiece from both sides. For example, as shown in Japanese Patent Laid-Open No. 59-33042, the transfer device is capable of moving a pair of parallel feed bars in the front-rear, lateral, and up-down directions, and clamps the workpiece → raises → moves forward → lowers → unclamps the workpiece. The series of operations of →retreat →clamping is repeated to transport the workpieces to the presses for successive processes. [Problems to be Solved by the Invention] However, the power transmission section to the feed bar in the prior art described above converts the rotational driving force of the DC servo motor into linear motion using a rack and pinion. However, the rack and pinion has a large backlash due to pack lash, which limits the ability to improve the accuracy of the workpiece transfer position.

The present invention was made in view of the problems of the prior art, and
The purpose is to provide a transfer device that can accurately transport a workpiece to a predetermined position.

[Means to solve the problem]

In order to achieve the above object, in the transfer device according to claim (1), a pair of feed bars are provided parallel to each other along the conveyance direction of the workpiece, and a feed motor consisting of a servo motor is used as a drive source. , a feed mechanism that uses a ball screw as a driving force transmission part to drive the feed bar in forward and backward directions, and a clamp motor consisting of a servo motor as a driving source, and a ball screw as a driving force transmission part to clamp and clamp the feed bar. A clamp mechanism that moves in the unclamping direction and a lift mechanism that uses an up-down motor consisting of a servo motor as a drive source and a rack and pinion as a rotary power transmission part to move the feed bar in the up and down directions are independent of each other. It was designed to be set up as follows.

Further, in the transfer device according to claim (2), the feed motor, the clamp motor, and the up-down motor, which are the drive sources of the feed bar, are arranged so that their rotational output shafts are in the vertical direction. It is something.

[Effect]

The rotational power of the feed motor and clamp motor is converted into the sliding motion of the feed bar by a ball screw.
The teeth of the pinion track of a conventional rack and pinion have a one-to-one correspondence, but with this ball screw, the distance that the feed screw shaft moves in the axial direction when the feed screw shaft is rotated l and the pitch of the thread of the feed screw shaft are different. handle. Therefore, during the conversion, according to the conventional rack and pinion, the rack gear side moves by the length of the entire circumference of the pinion gear side due to one revolution of the pinion gear, but according to the present invention, the ball screw feed One rotation of the screw shaft causes the nut to move by the distance of the screw.

Therefore, the stroke amount can be adjusted more precisely than with a rack and pinion. Also, compared to a rack and pinion, the bolt 1 screw has no backlash, so there is less play. Therefore, control of the servo motor becomes easier.

In claim (2), each servomotor serving as a drive source is arranged so that its output shaft is oriented in the vertical direction, so that the space occupied by each heel motion source in the horizontal direction may be small.

〔Example〕

Next, one embodiment of the present invention will be explained with reference to FIGS. 1 to 7. FIG. 2 is a plan view showing the entire transfer device according to the embodiment of the present invention, FIG. 3 is a front view of FIG. 2, FIG. 4 is a side view of FIG. 2, and FIG. -1 sectional view, FIG. 5 is a sectional view taken along ■--■ in FIG. 1, FIG. 6 is an enlarged view of section ■ in FIG. 2, and FIG. 7 is a front view of FIG.

As shown in FIG. 2, a pair of feed bars 10.10 are
They are provided parallel to each other along the conveyance direction of a workpiece (not shown) to be pressed. The feed bars 10 are generally located on both sides of a workpiece to be pressed by a die consisting of an upper die and a lower die, and serve to sequentially convey the workpiece to the press for the next process. That is, feed bar 10
A jig called a finger (not shown) is attached to the inside or upper side of the workpiece, and the finger presses the workpiece from both sides to clamp and transport the workpiece.

Then, clamp → rise → advance → descend → unclamp →
Conveying is performed by repeating a series of movements: retreat → clamp. A pair of feed bars as shown in Figures 2 and 3.
Reference numeral 10 indicates two front and rear guides 2 provided in the front and rear directions.
is supported on top.

At the same time as this front and rear guide 12 moves in the vertical and lateral directions, the feed bar 10 slides on this front and rear guide 12 in the front and rear directions, so that the feed bar can move in three dimensions, that is, in the lateral, vertical, and front and rear directions. Allows for directional movement. Feed bar 10 front and rear guide 12
To slide along the slide gib 14 on the
As shown in FIG. 3, this is a feed pin 16 that vertically passes through a round hole at the end of the feed bar 10, and the feed bar 10 can move up and down along the vertical direction of this feed pin 16. ing.

Next, referring to FIG. 1, the clamp up/down unit 18 for moving the feed bar 10 laterally and vertically via the front and rear guide 12 will be explained.

The front and rear guide 12 is fixed to the upper end of an up-down rod 20 provided in the vertical direction. This up-down iron 20 is held movably in the vertical direction with respect to a slide frame 22 existing inside the housing of the clamp up-down unit 18, and has a rack gear 24 (see FIG. 5) formed on its surface. A pinion gear 26 is engaged with this rack gear 24. The pinion gear 26 is held by the slide frame 22. The slide frame 22 has a unit housing 28
Two slide guides 30 are provided in the horizontal direction inside.
30 so as to be slidable laterally.

A ball screw nut 31 is fixed to the slide frame 22 via a bracket. A feed screw 32 passes through this nut 31. The feed screw 32 has a male thread formed on its outer peripheral surface and is supported by a bearing fixed to the unit housing 28.
8 and is rotatably supported.

A pair of bevel gears 34 are provided at the ends of the feed screw 32, and are connected to the shaft of a clamp motor 36 provided in a direction perpendicular to the feed screw 32, that is, in the vertical direction.

Further, a spline rod 38 coaxially passes through the pinion gear 26. This spline rod 38
has spline 4o on the surface and pinion gear 26
It is possible to slide in the lateral direction and to transmit rotational force. The spline rod 38 is rotatably supported by a bearing fixed to the unit housing 28, and can be rotated in the vertical direction via a pair of bevel gears 42 provided at the ends. It is connected to the shaft of an up-down motor 44 provided. The slide guides 30, 30, feed screw 3
2 and spline rond 38 are provided horizontally and parallel to each other. The feed screw 32 and the spline iron 38 are covered with an elastic coil force bar 45 to protect the surface from dust.

Also, bevel gears 34, 42 and both rods 32 provided at the ends of the feed screw 32 or the spline iron 38
, 38 supported by the unit housing 28 are collectively housed inside a gear case 46, 48, and the inside is filled with lubricating oil. These gas cases 4G and 48 serve as an oil bath to prevent the lubricating oil 50 from leaking out of the unit housing 28 (
Figure 1). The lubricating oil 50 accumulated at the bottom of the gear cases 46, 48 is pumped up by an oil pump (not shown) and is supplied from above the gear cases 46, 48 again.

In addition, as shown in FIGS. 2 and 3, there are two clamp up/down units l8 in the front and rear direction. Next, in Figs. 6 and 7, the feeder IQ
The feed unit 52 that moves the machine in the front-back direction will be explained.
Feed pin l6 that moves the feed bar 10 in the front-back direction
holds the feed bar 10 so as to be slidable in the vertical and longitudinal directions, and is fixed to the slider 54. The slider 54 is capable of sliding laterally along a slide guide 56. The slide guide 56 is fixed to the slide frame 58. The slide frame 58 is connected to the unit housing 6 of the feed unit 52.
Two slide guides 62 (
(see Figure 1), it is slidable in the front and back direction. A ball screw nut 64 is fixed to the center of the slide frame 58, and a feed screw 66 passes through the nut 64 horizontally in the front and back direction. This feed screw 66 has a male thread formed on its outer peripheral surface, and is rotatably supported by the unit housing 60. A pulley 68 is fixed to the rear end of the feed screw 66, and this pulley 68 is connected to a feed motor 72 via a belt 70.
It is designed to be rotated by Feed motor 7
The axis of No. 2 is parallel to the screw rond 66. Note that a proximity switch 74 is provided between the slide frame 58 and the unit housing 60 to detect movement of the slide frame 58 in the front-back direction.

A proximity switch 76 is also provided between the slide frame 58 and the slider 54, so that the lateral movement of the slider 54 can be detected. Next, the operation of this embodiment will be explained. First, the operation of clamping or unclamping a workpiece by lateral movement of the feed bar 10.10 will be explained.

Feed bars 10.10 positioned at a height for clamping the workpiece move toward the center in the lateral direction to perform a clamping operation. This clamping operation is performed by transmitting the rotation of the shaft of the clamp motor 36 to the feed screw 32 via the bevel gear 34. The male thread on the outer peripheral surface of the feed screw 32 meshes with a ball inside the nut 31 of the ball screw, and moves the nut 31 in the lateral direction by rotating. Since the nut 3J is physically fixed to the slide frame 22, the slide frame 22 moves laterally along the slide guide 30. This slide frame 22 holds an up-down rond 20, and a front and rear guide 12 supports the feed bar 10 at the upper end of the up-down rond 20, so that the feed bar 10 moves laterally. At this time, the male thread of the feed screw 32 or the ball groove inside the nut 31 is a reverse thread on the left and right slide frames 22 and 22,
When the feed screw 32 rotates in one direction, the pair of left and right feed bars 10 and 10 move symmetrically. The unclamping operation is performed in the same manner as described above by rotating the shaft of the clamp motor 36 in the opposite direction. Next, an explanation will be given of an up operation or a down operation performed by vertically moving the feed bar 10.

With the feed bar 10.10 clamping or unclamping the workpiece, the up-down motor 44 operates, and the rotation of the shaft is transmitted to the spline rond 38 via the bevel gear 42.
This is done by conveying the information to spline rondo 3
8 rotates the pinion gear 26 that is engaged with the spline 40, and since this pinion gear 26 is engaged with the rack gear 24 of the up-down rond 20, it moves the up-down rond 20 up and down. At this time,
Since the spline rod 38 can slide in the axial direction while being engaged with the pinion gear 26 by the spline 40, rotational force can be transmitted regardless of the position of the pinion gear 26, that is, the position of the slide frame 22. The bar 10 can be moved up and down. By rotating the up-down motor 44 forward or backward, the feed bar 10 can be moved up or down. Next, the forward motion or backward motion of the feed bar 10 in the front-rear direction will be explained. When the feed bar 10.10 is in a state where the workpiece is clamped (during forward motion) or in an unclamped state (during backward motion), the feed motor 72
When the motor shaft rotates, the rotation is transmitted to the pulley 68 via the belt 70, causing the screw rod 66 to rotate. Due to this rotation, the nut 64 of the ball screw moves back and forth, and the slide frame 58 to which this nut 64 is fixed also moves back and forth. The function of this ball screw is the same as in the clamping or unclamping operation described above. As the slide frame 58 moves back and forth, the slider 54 and feed pin 16 also move back and forth. At this time, the slider 54 to which the feed pin 16 is fixed can freely slide laterally along the slide guide 56 of the slide frame 58, and the feed bar 10 can slide vertically and in the direction along the feed pin 16. Since the feed bar 10 is free, no matter what lateral or vertical position the feed bar 10 is in, the feed bar 10
can be moved forward and backward.

As explained above, in the transfer device of this embodiment, the feed mechanism, that is, the mechanism built in the feed unit 52, employs a ball screw as a driving force transmission part, and the clamp mechanism, that is, the mechanism built in the feed unit 18, uses a ball screw as a driving force transmission part. The built-in mechanism that moves the slide frame 22 in the lateral direction uses a ball screw as the driving force transmission part, so compared to the conventional example that uses a rack and pinion for these driving force transmission parts, it has the following effects. has. (2) Since the ball screw has less play, that is, less backlash, it becomes easier to control the feed motor 72 or the clamp motor 36, which is a servo motor.

Furthermore, (2) the less backlash makes it possible to increase the accuracy of moving the feed bar 10, that is, the feeding accuracy.

■Furthermore, adjustment during assembly is easy, making assembly work easier.

■Also, fewer parts need to be supplied with lubricant, the amount of lubricant leaking from the transfer device can be reduced, and work surfaces can be prevented from becoming contaminated with lubricant. In other words, conventional rack and pinions require constant supply of lubricating oil, and conventional transfer devices with rack and pinions in multiple locations require lubricating oil to be supplied to multiple locations, resulting in leakage from the transfer device. It was easy to cause this and make the work floor dirty. On the other hand, in this embodiment, a ball screw is used instead of the rack and pinion, so the ball screw can be lubricated with grease, eliminating the need for large-scale lubrication means such as an oil bath. Further, the gear cases 46 and 48 are present only at both ends shown in the drawing, and since these gear cases also serve as an oil bath, oil leakage can be prevented.

In particular, in transfer equipment, as the amount of movement of the feed bar increases, the rack gear also becomes long, and housing the entire rack gear in the oil bath would increase the cost of the equipment, so this was not adopted. In contrast, in this embodiment, as described above, leakage of lubricating oil can be easily prevented and the work floor will not be soiled.

Furthermore, conventional clamp motors and up-down motors are of horizontal type, and protrude in the lateral direction of the clamp up-down unit, reducing the work floor area. In contrast, in this embodiment, the clamp up/down unit is of a vertical type and does not protrude in the lateral direction, so that the work floor area is not narrowed.

〔Effect of the invention〕

As explained above, according to the transfer device of the present invention, by employing a ball screw instead of the conventionally employed rack and pinion, the stroke amount, that is, the feed amount for moving the feed bar in the front and back direction, can be finely adjusted. Therefore, the workpiece can be transported to a predetermined position with high precision. In addition, since the ball screw has little backlash, it is possible to easily control the feed motor and clamp motor, which are servo motors. Furthermore, the number of locations to which lubricating oil is supplied can be reduced and made smaller, making it easier to prevent oil from leaking from the device.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a main part of a transfer device according to an embodiment of the present invention (cross-sectional view taken along line I-1 in FIG. 2), FIG. 2 is a plan view of the entire embodiment, and FIG. Fig. 4 is a side view of Fig. 2, Fig. 5 is a sectional view of Fig. 1, Fig. 6 is an enlarged view of the FIG. 10... Feed bar 12... Front and rear guide, l6... Feed bin, 18... Clamp up/down unit, 20...
Up/down rond, 22... Slide frame, 24... Rack gear, 26... Pinion gear, 28... Unit housing, 30... Slide guide, 3l... Ball screw nut, 32... Feed screw, 38...Spline rond, 52...Feed unit, 54...Slider 56...Slide guide, 58...Slide frame, 60...Unit housing, 64...Ball screw Nut, 66...Feed screw. Patent Applicant Co., Ltd.

Claims (2)

[Claims] (1) A pair of feed bars are provided parallel to each other along the workpiece conveyance direction, and a feed motor consisting of a servo motor is used as a drive source, and a ball screw is used as a driving force transmission part to drive the feed bars in the forward and backward directions. A clamp mechanism that uses a clamp motor made of a servo motor as a drive source, a clamp mechanism that uses a ball screw as a drive force transmission part to drive the feed bar in the clamping and unclamping directions, and an up-down motor made of a servo motor as a drive source. and a lift mechanism for driving the feed bar in the up and down directions using a rack and pinion as a driving force transmitting part, each of which is independently provided. (2) A transfer device characterized in that the feed motor, the clamp motor, and the up-down motor are arranged with their rotational output shafts oriented in the vertical direction.