JPH0650469Y2 - Lift device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Field of the Invention The present invention is a lift used in an automobile assembly line or the like to lift heavy articles sequentially conveyed to a predetermined height and perform various assembling operations. Regarding the device.

Problems to be Solved by Conventional Techniques and Inventions For example, in an automobile engine assembly line, a mounting plate on which an engine is mounted is vertically movable along an elevating guide installed upright on the base, and the base is also installed. A screw rod that is driven to rotate by a motor is installed on the mounting plate, and the screw rod is screwed into the female screw part provided on the mounting plate. When the engine is transported and it is mounted on the mounting plate, the mounting plate is rotated by the screw rod. In addition, there is a lift device that lifts the engine to a predetermined height and receives a mounting plate with a balancing fluid pressure cylinder installed on the base so that the load due to the weight of the engine is not applied to the screw rod and the like. Although it is used, in the past, only a constant fluid pressure corresponding to the weight of the engine was supplied to the fluid pressure cylinder via a pilot-type regu- lator, so the type of engine being transported changed. If the weight fluctuates,
It is extremely troublesome to adjust the fluid pressure supplied to the fluid pressure cylinder each time, and in order to avoid such complicated adjustment of the fluid pressure, the size and strength of the screw rod, motor, etc. Although it may be possible to prepare a large size in advance so that it can withstand the increase in the weight of the mounted engine, this has a drawback that the size of the entire apparatus becomes large.

As a means for solving the above problems, as a means for solving the above problems, the lift device of the present invention lifts a placing plate on which an article is placed by an actuator along an elevating guide installed upright on a base. At the same time, in a lift device in which a balance fluid pressure cylinder installed on the base receives the placing plate, a sensor for detecting the weight of the article is provided on the placing plate, and a detection signal from the sensor is received. A control device for controlling the fluid supply pressure to the fluid pressure cylinder according to the weight of the article is provided.

Advantageous Effects and Advantages of the Invention The present invention has the above-mentioned configuration, and when the article is placed on the placing plate, the weight of the article is detected by the sensor, and the control device receives the detection signal and applies the fluid pressure corresponding to the signal to the fluid pressure cylinder. The fluid pressure cylinder pushes up the placing plate with a force balanced with the weight of the article, and the article and the placing plate are lifted by its driving without applying a load to the actuator. Since it is performed for each item, the supply pressure to the fluid pressure cylinder is automatically adjusted and balanced when the weight of the item changes, so that it is not necessary to set the fluid pressure one by one. Work efficiency can be improved, and because the fluid pressure cylinder is always balanced against fluctuations in the weight of the article as described above, no load is applied to the actuator. ,
It is only necessary to use the minimum necessary actuator, and it is possible to reduce the size of the entire device.

Embodiment An embodiment of the present invention will be described below with reference to FIG.

In the figure, 1 is a mounting plate on which the article a is mounted,
A female rod mounted on the mounting plate 1 is a screw rod 6 mounted on the mounting plate 1 so as to be vertically movable along a guide 3 standing on the base 2 and driven by a servo motor 5 mounted on the base 2. Body 7
The mounting plate 1 is moved up and down by screwing the screw rod 6 in the forward or reverse direction and the base 2
An air cylinder 8 for balancing is erected on the upper side, and its piston rod 9 is applied to the lower surface of the mounting plate 1.

In the air supply passage 12 for supplying air from the air supply source 11 to the rear surface of the piston 10 of the balancing air cylinder 8, a pilot type reguulator 13 for obtaining a constant secondary pressure according to the pilot pressure is provided. , A pneumatic air path 15 which branches from the air supply path 12 and supplies the pilot pressure to the pilot type regurator 13 mentioned above, an electropneumatic reguulator 17 for obtaining a constant secondary pressure according to an input electric signal, and for a power failure correspondence The auxiliary reguulator 18 is connected in parallel and interposed, and the electromagnetic switching valve 19 is connected to each secondary side, and when the electromagnetic switching valve 19 is in the ON state, the secondary pressure of the electropneumatic regulator 17 is When it is turned off, the secondary pressure of the spare regu- lator 18 is supplied to the pilot type regu- lator 13 as the pilot pressure, and the weight of the article a placed on the placing plate 1 is detected. That the load sensor 21 of the piezoelectric type is installed, the detection signal from the load sensor 21 is input to the operational amplifier 22, the operational amplifier circuit 22, an article a
An electric signal corresponding to the total weight of the weight and the previously stored weight of the mounting plate 1 is amplified and output, and the electric signal is input to the electropneumatic regulator 17 described above, which is an input signal to the electropneumatic reguulator 17. The secondary pressure, that is, the pilot pressure of the pilot-type regurator 13 is controlled according to the magnitude of the, and the secondary pressure of the pilot-type regurator 13, that is, the air supply pressure to the air cylinder 8 is controlled by the pilot pressure. , Piston rod 9 of air cylinder 8
In addition, a pushing force comparable to the weight of the article a and the mounting plate 1 is applied.

The present embodiment has such a structure, the electromagnetic switching valve 19 is turned on when the apparatus is in operation, and the mounting plate 14 on which the article a conveyed by the not-shown conveying line is descending to the lower position.
Then, the load sensor 21 detects the load of the article a, an electric signal corresponding to the total weight of the article a and the placing plate 1 is input to the electropneumatic reguulator 17, and the pilot pressure corresponding to the electric signal value is input. Is supplied to the pilot type regu- lator 13, air having a constant pressure corresponding to the pilot pressure is supplied to the air cylinder 1, and the piston rod 9 balances the weight of the article a and the placing plate 1 with force. By pushing up the mounting plate 1 and rotating the screw rod 6, the article a and the mounting plate 1 are lifted to a predetermined height without applying a load to the screw rod 6 and the servomotor 5, and the work is completed. When the placing plate 1 is lowered by the reverse rotation of the screw rod 6 and a new article a is placed, the weight of the article a is detected again by the load sensor 21, and the type of the article a is changed and the weight is changed. Change, new An electrical signal corresponding to the total weight of the article a and the mounting plate 1 is input to the electro-pneumatic Regiyureta 17,
The pilot pressure increased or decreased from the previous time is supplied to the pilot type regu- lator 13, and the air pressure supplied to the air cylinder 8 is increased or decreased, and the piston rod 9
However, the placement plate 1 is pushed up by a force balanced with the weight of the new article a and the placement plate 1.

In the present embodiment, the air pressure supplied to the air cylinder 8 is automatically adjusted so as to always keep a balance when the weight of the article a changes, so that it is not necessary to adjust the air pressure one by one. As described above, since the air cylinder 8 is always balanced and the load is not applied to the screw rod 6 and the servomotor 5 regardless of the change in the weight of the article a, their size and strength can be kept to the necessary minimum.

Further, in the above-mentioned spare regu- lator 18, the secondary pressure applied as the pilot pressure to the pilot type regu- lator 13 is applied to the air cylinder 8 with respect to the screw rod 6 and the servo motor 5.
It is preset to supply the minimum air pressure that exerts a lifting force to the extent that no overload is applied, and in the event of a power outage during operation, the electromagnetic switching valve 19 switches and the backup regu By supplying the pilot pressure,
The above-mentioned minimum air pressure is supplied to the air cylinder 8 to receive the mounting plate 1 and to prevent the screw rod 6 and the servomotor 5 from being overloaded.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view and block diagram of an embodiment of the present invention. a: article, 1: mounting plate, 2: base, 3: guide, 5: servo motor, 6: screw rod, 8: air cylinder, 11: air supply source, 13: pilot type reguulator, 17: electropneumatic Regulator, 21: load sensor, 22: operational amplifier circuit

Claims (1)

[Scope of utility model registration request] 1. A placing plate on which an article is placed is lifted by an actuator along an elevating guide installed upright on a base, and a placing fluid plate is received by a balancing fluid pressure cylinder installed on the base. In the lift device,
The mounting plate is provided with a sensor that detects the weight of the article, and a control device that receives the detection signal of the sensor and controls the fluid supply pressure to the fluid pressure cylinder according to the weight of the article is provided. Lift device characterized by