JP3646188B2 - Work lifting device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a workpiece lifting apparatus, and more particularly to a workpiece lifting apparatus capable of improving the productivity by shortening the operation time of a lifting unit.
[0002]
[Prior art]
An apparatus for moving a workpiece up and down is known from Japanese Patent Application Laid-Open No. 62-83993. According to the publication, when lifting and lowering a workpiece carrier by a lifting rope linked to a driving source, a piston rod of an air cylinder provided in the vertical direction is connected to the carrier, and the air cylinder is used as a driving source for the lifting measure. It is supposed to operate in the same direction synchronously. Therefore, a part of the load applied to the elevating part is borne by the piston rod of the air cylinder, and a sudden change in the load is alleviated by the cushion function of the air cylinder.
[0003]
[Problems to be solved by the invention]
However, in the above-described invention, since the workpiece is lifted and lowered by the lifting rope and the sprocket that winds the lifting rope, it is not suitable for high-speed operation, and there is a limit to the improvement of productivity, and the lifting portion in a state where the workpiece is not particularly placed. It was unsuitable for speeding up when descent. SUMMARY OF THE INVENTION An object of the present invention is to provide a workpiece lifting / lowering device that enables high-speed operation of the lifting / lowering section, and in particular, can improve the productivity of conveyance by lifting / lowering the workpiece by increasing the speed at the time of lowering.
[0004]
[Means for Solving the Problems]
The invention of claim 1 made for the purpose of solving the above-mentioned problems is a motor for rotationally driving, an elevating part for raising a workpiece placed by the rotational driving of the motor, a workpiece detecting sensor for detecting the presence or absence of the workpiece, An electromagnetic clutch provided between the motor and the lifting unit, a rising end sensor for detecting a rising end position of the lifting unit, a brake sensor for detecting a predetermined intermediate position of the lifting unit, A descent end sensor for detecting a descent end position of the elevating unit; a braking means for applying a braking force to the elevating unit in response to a detection signal of the brake sensor; and a descent end position of the elevating unit at the descent end position. An elevating device comprising a buffering portion in contact with the elevating device, wherein the elevating end sensor detects that the elevating portion is in the elevating end position, and the work detecting sensor detects that there is no workpiece. The electromagnetic clutch is disengaged and the lifting unit is dropped by its own weight.When the brake sensor detects that the lifting unit is at a predetermined intermediate position, a braking force is applied to the lifting unit, The elevating part is configured to come into contact with the buffer part at the lowered position.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan sectional view and a front sectional view of a workpiece lifting / lowering device according to an embodiment of the present invention, and FIG. 2 is a plan view and a front view showing the relationship between the workpiece lifting / lowering device and a workpiece transfer device according to the present embodiment. FIG. A main body 3 of an elevating device 2 is fixed on a base 1a of a work transfer device 1 (see FIG. 2). Two guide holes 3a and 3b are formed in the vertical direction substantially at the center of the main body 3, and the rack gear 4 is fitted to the rack guides 4 and 4 fitted to the opening of one guide hole 3a, and the other guide is fitted. A guide shaft 7 is loosely fitted and assembled to the linear bushes 6 and 6 fitted in the openings of the holes 3b to prevent the rack gear 5 from rotating.
[0006]
The upper ends of the rack gear 5 and the guide shaft 7 are fixed to a Y-shaped workpiece push-up plate 8 and the lower ends are fixed to a fixed plate 9 to form a rectangular frame-shaped lift 10. The rack gear 5 is configured such that a pinion gear 11 pivotally supported by the main body 3 is engaged with the rack gear 5, and the lifting unit 10 is moved up and down by the rotation of the pinion gear 11. A motor 12 whose rotational speed can be adjusted by an electronic control device (not shown) is fixed to the mounting plate 14, an output shaft 12a of the motor 12 is fixed to a first gear 15, and an electromagnetic clutch is connected to the drive shaft 11a of the pinion gear 11. 17, the second gear 16 is fixed. The first and second gears 15 and 16 mesh with each other.
[0007]
A rising end light shielding plate 7a is fixed to the lower portion of the guide shaft 7 of the elevating unit 10, a lower end light shielding plate 7b is fixed to the upper portion, and the rising end light shielding plate 7a or the lower end light shielding plate 7b is fixed to the main body 3, and the projector The position of the workpiece push-up plate 8 of the elevating unit 10 is detected by shielding the light source of the brake sensor 18a, the rising end sensor 18b, or the falling end sensor 18c. A brake cylinder 19 that applies a braking force to the guide shaft 7 by pressing the guide shaft 7 in a direction perpendicular to the axis of the guide shaft 7 is provided in the main body 3. When the elevating part 10 is lowered most, that is, the buffer part 20 is provided at a position where the work push-up plate 8 is lowered and abuts by its own weight and is buffered and softly stopped. It has been. If the buffer part 20 is comprised with a commercially available shock absorber, it will be economical.
[0008]
Next, the effect | action which removes the workpiece | work on a workpiece conveyance apparatus using the raising / lowering apparatus which concerns on this embodiment is demonstrated with reference to FIG. 1 and FIG. This apparatus is controlled by an electronic control unit (not shown). When the power is turned on, the elevating unit 10 of the elevating device 2 is lowered to a position where it comes into contact with the buffer unit 20. When the descending end sensor 18c detects the presence of the descending end light shielding plate 7b, an output signal is output corresponding to the detection signal. By this output signal, the rotary table 1b of the workpiece transfer device 1 is rotated by a predetermined angle, and the workpiece 21 stacked on the magazine 1c fixed to the rotary table 1b and provided with the guide 1d is placed on the workpiece push-up plate of the elevating unit 10 It stops just above the middle position of the 8 notches 8a. When it is detected that the turntable 1b has stopped, the motor 12 of the elevating device 2 rotates to raise the elevating unit 10 via the first gear 15, the second gear 16, and the electromagnetic clutch 17, and the workpiece push-up plate 8 is stacked. Only the received workpiece 21 is pushed up.
[0009]
When the transmitted light between the sensors 22a and 22b attached to the sensor mounting posts 22 and 22 installed upright on the base 1a of the workpiece transfer device 1 is blocked by the uppermost workpiece 21, the detection of the sensors 22a and 22b is performed. Upon receiving the signal, the motor 12 stops. Therefore, when one workpiece 21 is grasped and removed by a robot arm (not shown), the blocking of transmitted light by the workpiece 21 existing between the sensors 22a and 22b is released, the motor 12 rotates again, and the elevating unit 10 is raised. As a result, the workpiece 21 rises. Since the uppermost workpiece 21 blocks the transmitted light between the sensors 22a and 22b, the motor 12 stops again, and the workpiece 21 is removed by repeating this process sequentially. Note that the configuration and operation for removing the workpiece 21 are not directly related to the present invention, and thus the description thereof is omitted here.
[0010]
When all the workpieces 21 are removed and the elevating unit 10 reaches the uppermost stage, the rising end light shielding plate 7a shields the rising end sensor 18b from light. At this time, the electromagnetic clutch 17 is disengaged in response to the detection signal of the ascending end sensor 18b, the elevating unit 10 is disconnected from the motor 12, and the elevating unit 10 starts to fall due to its own weight. When the rising end light-shielding plate 7a blocks the transmitted light from the brake sensor 18a in the middle of dropping, compressed air is sent to the brake cylinder 19 by the sensor detection signal to press the guide shaft 7 from the side and drop by its own weight. A braking force is applied to the elevating unit 10 to decelerate. The magnitude of the braking force of the brake cylinder 19 is adjusted to such an extent that the falling speed can be reduced to about 1/2 to 1/3. In addition, about this braking means, you may apply braking force with the structure by the combination of electromagnetic force and a spring. The workpiece push-up plate 8 of the lifting / lowering part 10 whose release speed has been loosened by the pressure from the side of the guide shaft 7 is then brought into contact with the buffer part 20 and the lifting / lowering part 10 is softly stopped gently by the action of the shock absorber.
[0011]
【The invention's effect】
Since this invention is comprised as mentioned above, there exist the following effects. That is, the work placed on the lifting part is lifted by the rotational drive of the motor, the removal of all the works is detected, and the electromagnetic clutch provided in the middle of the motor output shaft and the lifting part is disconnected to lift the lifting part. After dropping by its own weight, detecting a predetermined position in the middle of dropping and applying a braking force, the elevating part is brought into contact with the buffer part to make a soft stop, so that the speed of the elevating part when descending can be increased, Productivity during workpiece supply can be improved. In addition, even if the workpiece is left under its own weight, the workpiece will not be damaged.
[Brief description of the drawings]
FIG. 1 (a) is a plan sectional view of a lifting apparatus according to an embodiment of the present invention.
FIG.1 (b) is front sectional drawing of the raising / lowering apparatus based on one Embodiment of this invention.
FIG. 2 (a) is a plan view showing the relationship between a lifting device and a workpiece transfer device according to an embodiment of the present invention.
FIG.2 (b) is a front view which shows the relationship between the raising / lowering apparatus which concerns on one Embodiment of this invention, and a workpiece conveyance apparatus.
[Explanation of symbols]
2 Lifting device 5 Rack gear 7 Guide shaft 8 Work lifting plate 10 Lifting portion 11 Pinion gear 12 Motor 17 Electromagnetic clutch 18a Brake sensor 18b Lifting end sensor 18c Lowering end sensor 19 Brake cylinder 20 Buffering portion 21 Work 22a Sensor 22b Sensor

Claims (1)

A motor that rotates, a lifting unit that lifts a workpiece placed by the rotation driving of the motor, a workpiece detection sensor that detects the presence or absence of a workpiece, and an electromagnetic clutch provided between the motor and the lifting unit A rising end sensor for detecting a rising end position of the lifting unit, a brake sensor for detecting a predetermined intermediate position of the lifting unit, a falling end sensor for detecting a falling end position of the lifting unit, and the brake An elevating device comprising: a braking means for applying a braking force to the elevating unit in response to a detection signal of the sensor for use; and a buffer unit abutting on the elevating unit at a descending end position of the elevating unit, When the end sensor detects that the elevating part is at the ascending end position and the work detection sensor detects that there is no work, the electromagnetic clutch is disengaged and the elevating part is self-weighted. When the brake sensor detects that the lifting part is at a predetermined intermediate position, a braking force is applied to the lifting part, and the lifting part comes into contact with the buffer part at the lower end position. An apparatus for lifting and lowering a workpiece characterized by being configured as described above.

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