JPH0457596B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hanging device that suspends articles from a lifting section that moves up and down relative to a frame by driving a motor.

[Prior Art] In general, this type of device lifts and lowers the lifting section and the article by energizing the motor, and then turns off the power to the motor and uses the servo lock of the motor itself to lift the lifting section and the article to a predetermined hanging height. The article is held in this position, and the article is conveyed to the unloading position while maintaining this holding state.

[Problems to be Solved by the Invention] However, if the entire weight of the lifting section and the article is loaded onto the motor, a large-capacity motor is indispensable, and especially if the speed and frequency of lifting is high, it may not be sufficient. In order to ensure sufficient margin, a larger capacity motor is required. Also, if the weight of the lifting section is balanced using air pressure from an air cylinder, for example, the load on the motor will be only the goods, so a relatively small-capacity motor can be used.
If the weight of the items being handled varies widely from light to heavy, the motor capacity must be adjusted to the weight of the item that is the largest. There were problems such as unavoidable waste of some of the material.

The purpose of this invention is to solve the problems of the above-mentioned conventional devices and provide a suspension device that requires a small motor capacity and can automatically change the balance load depending on the weight of the article being handled. That is.

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an apparatus for suspending an article from an elevating part that moves up and down relative to a frame by driving a motor, in which at least the weight of the elevating part is suspended by air pressure. an air cylinder that maintains a balance with the object, a member that detects the weight of the article, and a member that automatically switches the air pressure of the air cylinder according to the weight of the article detected by the detection member. It is.

[Function] This invention adopts the above means, so that the air pressure of the air cylinder is equal to the weight of the elevating section, as well as
Depending on the weight of the article to be hung, the air pressure is automatically set to balance at least a portion of the article.

[Example] Hereinafter, an example of the present invention shown in the drawings will be described.

1 to 6 show an embodiment of the present invention, and 1 is a table supported so as to be able to run along rails 2, 2, as shown in FIGS. 2 and 5. A ball nut 4 screwed into a ball screw 3 fixed in parallel is rotatably attached to the lower surface of the table 1, and a servo motor 5 attached to the upper surface of the table 1 is driven to rotate the rotation shaft 6 of the motor 5.
A pulley 7 fixed to the table 1 and a pulley 8 fixed to the ball nut 4 are interlocked via a belt 9 to rotate the ball nut 4, so that the table 1 moves back and forth along the rails 2, 2. There is. Reference numeral 10 denotes a ball nut that is rotatably attached through the table 1, and when a servo motor 11 attached to the top surface of the table 1 is driven, a pulley 13 fixed to the rotating shaft 12 of the motor 11 and the ball nut 10 are rotated. Fixed pulley 14
is interlocked with the ball nut 1 via the belt 15.
0 is set to rotate. ball nut 1
0 is screwed with a vertically extending ball screw 16, and an elevating plate 17 is fixed to the lower end of the ball screw 16.
The lifting plate 17 has columns 18, 18 and a mounting plate 19.
The rotating unit 20 is suspended so as to be vertically displaceable, and appropriate articles can be suspended from the rotating shaft 21 protruding from the lower end of the rotating unit 20 via the hanging frame 22 as necessary. ing. As shown in FIG. 4, an air cylinder 23 is also vertically attached to the table 1, and guide shafts 24, 24 extending parallel to the air cylinder 23 are attached so as to be movable up and down. The protruding piston rod 25 and the lower ends of the guide shafts 24, 24 are fixed to the elevating plate 17, so that the ball screw 16 and the air cylinder 23 are parallel to each other, and the ball screw 16 and the piston rod 25 are connected via the elevating plate 17. combined into one,
As a result, the ball screw 16 is held unrotatable and is moved up and down by the rotation of the ball nut 10. At the lower end of the piston rod 25, a load cell 26 is installed which detects the weight of the article and generates an output while the rotary shaft 21 or the hanging frame 22 holds the article. As shown in FIG. 6, the air cylinder 23 is connected to an output port of a pilot type relief regulator 29 whose input port is connected to a compressed air source 27 via a pressure adjustment unit 28. A low pressure pilot regulator 31, an intermediate pressure pilot regulator 32, and a high pressure pilot regulator 33 are connected to the pilot pressure port 30 of 29, to which compressed air is applied from the compressed air source 27 via the pressure adjustment unit 28. The electromagnetic valves 34 and 35 are connected via a solenoid valve 34 for switching between low and medium pressures and a solenoid valve 35 for switching between medium and high pressures.
is connected to the controller 36 together with the load cell 26. The controller 36 connects the output of the load cell 26 to the lifting section (i.e., the ball screw 16,
From only the weight applied to the load cell 26 out of the dead weight of the lifting plate 17, columns 18, 18, mounting plate 19, rotating unit 20, guide shafts 24, 24, etc.), the predetermined weight of relatively light items is added to this weight. If the length of the range up to the weight is detected, set the solenoid valves 34 and 35 to the positions shown in the figure to reduce the air pressure in the air cylinder 23 to the low pressure pilot regulator 3.
1, the air cylinder 23 and only the self-weight of the elevating section are balanced, and the output of the load cell 26 is set to the predetermined weight of the article which is relatively light compared to the weight of the elevating section's own weight that is applied to the load cell 26. If a weight in the range from 100% plus the predetermined weight of a relatively heavy item is detected, the electromagnetic valve 34 is automatically switched to the opposite position from the one shown in the figure to close the air cylinder. The air pressure of the air cylinder 23 is set to an intermediate pressure controlled by the intermediate pressure pilot regulator 32 to balance the weight of the air cylinder 23 and the elevating section plus the predetermined weight of the relatively light article. If the output of the electromagnetic valve 34 is determined by adding the predetermined weight of the relatively heavy article to the weight applied to the load cell 26 out of the self-weight of the lifting section, the electromagnetic valve 34, 35 is automatically switched to the opposite position from the one shown in the figure, and the air cylinder 23
The air pressure is set to a high pressure controlled by the high-pressure pilot regulator 33 to balance the weight of the air cylinder 23 and the lifting section plus the predetermined weight of the relatively heavy article. There is.

The above hanging device has a rotating shaft 21 or a hanging frame 2.
2 may hold the item, the controller 36
In this case, the solenoid valves 34 and 35 are placed in the illustrated positions to balance the air cylinder 23 and the weight of the lifting section, so that no downward force is substantially applied to the ball screw 16, so that the motor 11 is servo-locked with a small amount of current. The ball screw 16 remains stationary at an arbitrary height. The motor 11 is driven, the ball nut 10 is rotated, the ball screw 16 is lowered to a predetermined height, and when the drive of the motor 11 is stopped and the rotating shaft 21 or the suspension frame 22 holds an article, the load cell 26 calculates the weight of the article. is detected, and if the article is relatively light and weighs less than the predetermined weight, the controller 36 activates the electromagnetic valve 3.
4 and 35 remain in the positions shown in the figure, and if the article is between the relatively light predetermined weight and the relatively heavy predetermined weight and below, the controller 36 automatically moves the electromagnetic valve 34 to the opposite position from the one shown in the figure. Furthermore, if the article is relatively heavy and within the permissible range above the predetermined weight, the controller 36 automatically switches the electromagnetic valves 34 and 35 to the opposite position from that shown. Subsequently, when the motor 11 is driven to rotate the ball nut 10 in the opposite direction, only the weight remaining after subtracting the weight balanced by the air cylinder 23 from the weight of the suspended article is loaded on the ball screw 16. 11 can raise the elevating part and the article with a small capacity, and when the ball screw 16 is raised to a predetermined height, the drive of the motor 11 is stopped. Then, the servo lock of the motor 11 itself reliably holds the lifting section including the article at a predetermined height. By driving the motor 5 in this state, the article can be conveyed along the table 1 to a desired position along the rails 2, 2. When the desired position is reached, the drive of the motor 5 is stopped, while the motor 11 is driven to rotate the ball nut 10 to lower the ball screw 16 to a predetermined height. When the article is unloaded from the lower frame 22, the load cell 26 detects this and the controller 36 automatically switches the electromagnetic valves 34, 35 to the illustrated positions. Next, when the motor 11 is driven to rotate the ball nut 10 in the opposite direction, the ball screw 16 rises without substantially applying any downward force, and when the ball nut 16 rises to a predetermined height, the drive of the motor 11 is stopped. Then, the elevating part is balanced by the air cylinder 23 and stands still at that height, and the motor 5 is driven in this state to transport it to the original position. By rotating the rotating unit 20 when the rotating shaft 21 or the hanging frame 22 is holding or lowering the article, the article can be held at a predetermined angle no matter what angle it is at. , can be lowered at a desired angle, and when the rotating unit 20 receives an upward force, it is displaced upwardly with respect to the lifting plate 17 together with the columns 18, 18, thereby giving an impact to the article (for example, a cathode ray tube). It can be held without any problems and can be taken down.

In the above embodiment, the ball nut 10 is rotated by the drive of the servo motor 11, and the ball screw 1 is rotated by the drive of the servo motor 11.
Although the ball screw 16 and ball nut 10 may be replaced with a rack and pinion, the ball screw 3 and ball nut 4 may be similarly replaced with a rack and pinion. In addition, in the above embodiment, the load cell 26 was used as a member for detecting the weight of the article, but for example, a strain gauge or other appropriate device may be used. Although the pressure applied to the pilot pressure port 30 is set to three levels: low pressure, medium pressure, and high pressure, the present invention is not limited thereto, and furthermore, as the controller 36, for example, a computer can be used, but the present invention is not limited to this. However, it goes without saying that the present invention can be modified in various ways to the above-described embodiments.

[Effects of the Invention] Since the present invention is configured as described above, the air pressure of the air cylinder is added to the own weight of the lifting section, and the air pressure is adjusted to maintain a balance with at least a part of the weight of the article to be suspended. It can be set automatically, so the motor capacity is small enough to lift and lower the weight of the suspended item minus the weight balanced by the air cylinder. done, therefore,
Since the capacity of the motor is small, the moment of inertia is reduced and high-speed response control can be realized, which has excellent effects.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is a longitudinal sectional front view taken along the line - in FIG. 1, FIG. 3 is a longitudinal sectional side view taken along the line - in FIG. 4 is a longitudinal sectional side view taken along the - line in FIG. 1, FIG. 5 is a longitudinal sectional side view taken along the - line in FIG. 1, and FIG. 6 is an air system diagram of the air cylinder. 1...Table, 2...Rail, 3...Ball screw,
4... Ball nut, 5... Servo motor, 6... Rotating shaft, 7, 8... Pulley, 9... Belt, 10... Ball nut, 11... Servo motor, 12... Rotating shaft, 1
3, 14... Pulley, 15... Belt, 16... Ball screw, 17... Elevating plate, 18... Support column, 19... Mounting plate, 20... Rotating unit, 21... Rotating shaft, 22...
Hanging frame, 23...air cylinder, 24...guide shaft,
25...Piston rod, 26...Load cell, 27
...Compressed air source, 28...Pressure adjustment unit, 29...
Pilot type relief regulator, 30... Pilot pressure port, 31... Pilot regulator for low pressure, 32... Pilot regulator for medium pressure,
33...High pressure pilot regulator, 34...Low,
Solenoid valve for medium pressure switching, 35... Solenoid valve for medium and high pressure switching, 36... Controller.

Claims (1)

[Scope of Claims] 1. A device for suspending an article from an elevating section that is moved up and down relative to a frame by driving a motor, comprising: an air cylinder that balances at least the weight of the elevating section with air pressure; A hanging device comprising: a detecting member; and a member automatically switching the air pressure of the air cylinder according to the weight of the article detected by the detecting member. 2. The hanging device according to claim 1, wherein the elevating part includes a ball screw that is screwed into a ball nut rotatably provided on the frame and is moved up and down by the rotation of the ball nut. 3. The suspension device according to claim 2, wherein the air cylinder is arranged parallel to the ball screw. 4. The suspension device according to claim 2, wherein the air cylinder is attached to the frame, and the piston rod is integrally connected to the ball screw. 5. The suspension device according to claim 4, wherein the detection member comprises a load cell assembled to the piston rod.