JPH0434179A - Lift device - Google Patents

Abstract

PURPOSE:To increase the availability factor of a lift device by providing a computing element and actuator equipped with a sensor for detecting the posture of a lift bed at one or more positions of a lift shaft, and computing vertical dislocation at each suspension member fitting position on the basis of a signal from the sensor. CONSTITUTION:Four corners of a lift bed 11 are suspended with wire ropes 12a, 12b, 12c and 12d, and stationary sheaves 13a, 13b, 13c and 13d are arranged at the upper portions of the aforesaid wires for changing the direction of the lift bed 11. Furthermore, the wire ropes 12a, 12b and 12c are wound about a drum 15 via adjustment devices 14a, 14b and 14c, while the remaining wire rope 12d is directly wound about the drum 15. Then, shading plates 21a, 21b, 21c and 21d are arranged at four corners of the lift bed 11, and sensors 22a, 22b, 22c and 22d comprising a projector and a light receiver are installed. Thereafter, the sensors 22 are connected to a computing element for calculating the amount of dislocation of the ropes 12 and the length of each rope is thereby corrected. According to the aforesaid construction, the posture of the lift bed 11 can be automatically corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is utilized in the technical field of lifting devices having a loading platform, and particularly relates to a device for maintaining the platform in a normal position.

[Conventional technology]

Conventionally, there is a type of platform in which a lifting platform is suspended at a plurality of locations by suspension members such as wire ropes or chains, and is lifted and lowered. For example, it is used as a lifting platform to bring cargo or automobiles to a predetermined position in a multi-story hangar.

In this conventional device, as shown in FIG. 6, wire ropes 2a, 2b, 2c, and 2d are attached to the lifting platform 1 at its four corners.
These wire ropes are suspended from the drums 3a, 3.
The lifting platform 1 is raised and lowered by winding or unwinding at b. The drums 3a, 3b are rotationally driven by a motor 5 via a speed reducer 4.

Each wire rope 2a, 2b, 2c, 2d has a lifting platform 1.
Manual tensioning mechanisms 6a, 6b, 6c, and 6d, such as turnbuckles, were attached to the mounting portions of the robots, respectively, and by adjusting these mechanisms, the normal horizontal posture was maintained.

There is also a device that suspends the lifting platform 1 using chains as shown in Fig. 7, but in this case too, each chain 7a, 7b, 7c, and 7d is equipped with a manual screwdriver similar to that shown in Fig. 6. Mechanisms 8a, 8b, 8c, and 8d were provided to similarly adjust the posture.

[Problem to be solved by the invention]

In the apparatus shown in FIGS. 6 and 7, since the lifting platform is suspended by a plurality of suspension members, the tension of each suspension member becomes uneven depending on the position of the load. That is, the amount of elongation of the suspension member due to the tension becomes uneven, and as a result, the lifting platform is tilted from its normal horizontal state. In addition, even if the load is in a symmetrical position, after long-term use, each suspension member will not stretch uniformly due to differences in its characteristics and other conditions such as torsion, and the lifting platform will Tilt (.

Therefore, the posture has been corrected by manually adjusting each of the screw mechanisms described above at appropriate times. However, with this method, the device must be stopped for a period of time, during which time the device cannot be used. Moreover, since the adjustment is done manually, there are problems in that the work is difficult and takes a long time.

The present invention solves the problems of such conventional devices,
It is an object of the present invention to provide a lifting device which can easily correct its posture during lifting and lowering operations without stopping the device.

[Means to solve the problem]

According to the present invention, the above-mentioned object is: In a lifting device in which a loading platform is suspended in a hoistway so that it can be raised and lowered by suspension members at a plurality of locations, the lifting platform is suspended at one or more positions in the hoistway. It is equipped with a sensor that detects the posture of the lifting platform, and has a computing unit that calculates the vertical deviation of each suspension member mounting position with respect to the normal attitude of the lifting platform based on the signal from the sensor. This is achieved by providing the suspension members with actuators that respectively modify the length of the suspension members by the amount.

[Effect]

In the apparatus of the present invention configured as described above, the attitude of the lifting platform is detected by the sensor. The signal from this sensor is sent to a calculator, which calculates the amount of vertical deviation from the normal posture at the suspension member attachment position of the lifting platform. The amount of this deviation is sent as a command signal to the actuators, and each actuator adjusts the length of the corresponding suspension member.
The lifting platform is maintained in a normal position, for example, in a horizontal position.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to FIGS. 1 to 5 of the accompanying drawings.

The device shown in FIG. 1 corresponds to the conventional device shown in FIG. 6, and the lifting platform 11 has wire lobes 12a, 12b,
It is suspended by 12c and 12d. Each wire lobe 12a, 12b, 12c, 12d has, in its upper part, a fixed position sheep 13a, 13b, 13c,
The direction is changed at 13d, and the former three wire lobes 12a, 12b, 12c are adjusted by adjusting devices 14a, 14.
b, 14c and the remaining wire lobe 12d is wound directly onto the drum 15.15. The drum 15
．． 15 is rotatably driven by a motor 17 via a speed reducer 16 to wind up and unwind each wire lobe by the same amount.

The adjustment devices 14a, 14b, and 14c are constructed in exactly the same way, and to explain one of them 14a, it includes two sheeps 18a in fixed positions, a movable sheep 19a, a fixed part, and an actuator 2 that connects the sheeps 19a.
0a.

On the other hand, the lifting platform 1 is provided with, for example, light shielding plates 21a, 21b, 21c, and 21d protruding from its four corners.

Further, in the hoistway of the hoisting platform 1, the light shielding plate 21a is provided.

Sensors 22a and 22 each consisting of a light emitter and a light receiver are placed at positions intersecting with the routes of the lights 21b, 21c, and 21d when moving up and down.
b, 22c, and 22d are provided. These sensors may be provided at appropriate positions along the path of the light shielding plate, and may be provided in an arbitrary number. Further, the sensor is not limited to the above-mentioned optical sensor, but may also be of a physical type such as a limit switch.

Such sensors 22a, 22b, 22c, 2
2d is connected to an arithmetic unit 23 as shown in FIG.
The amount of deviation of the hanging length of wire lobe 12c from wire lobe 12d is calculated. The calculation is performed as follows.

The sensors 22a, 22b, 22c, and 22d are connected to light shielding plates 21a and 22b.

When 22c and 22d pass, the sensor 21a is moved with reference to the sensor 22d located at the position corresponding to the wire lobe 12d which is not provided with an adjusting device as shown in FIG.

21b and 21C have time differences ta and tb in signal generation timing.
, tc occurs. The arithmetic unit 23 multiplies the vertical speed V when the signal is generated by the time differences ta, tb, and tc, and uses this as the amount of deviation for the actuators 20a,
20b and 20c, and each actuator raises and lowers the movable sheaves 19a, 19b, and 19c by that amount. Thus, any uneven length of each suspension member is corrected.

In addition, when it is desired to tilt the elevator platform not horizontally but by a predetermined angle, it is sufficient to add the length to the corresponding wire lobe in advance as an initial value in the arithmetic unit.

Furthermore, in the present invention, the suspension member does not have to be a wire lobe, but may be another member such as a chain, and various actuators in the adjustment device can be used.

Further, the structure of the sheave in the adjustment device is not limited to the form shown in FIG. 1, but may be as shown in FIG. 4, for example.

The position of the adjustment device may be installed in a part of the suspension member such as a wire lobe, and is not limited to the position shown in FIGS. 1 and 5. Therefore, the position and type of the applicable lifting platform drive device may also be The present invention is not limited to those shown in FIGS. 1 and 5.

Furthermore, the present invention can be applied to the suspension type of the conventional device shown in FIG. 7, as shown in FIG. 5 in the same manner as in FIG. In FIG. 5, parts common to those in FIG. 1 are given the same reference numerals.

〔Effect of the invention〕

As described above, the present invention detects the posture of the lifting platform using a sensor and corrects the length of the suspension member using the actuator based on the calculation result of the calculator, so every time the lifting platform passes the sensor position. The posture is automatically corrected at any time or at an appropriate time. Therefore, the operating rate is improved without stopping the device, and there is no need for manpower for corrections.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a schematic configuration of a device according to an embodiment of the present invention;
The figure is a configuration diagram of the sensor and adjustment device of the device shown in FIG. 1, FIG. 3 is a diagram showing the operation signal of the sensor of FIG. 2, and FIG. 4 is a modified form of the sheave applicable to the adjustment device of the device shown in FIG. FIG. 5 is a schematic perspective view of a device according to another embodiment of the present invention.
FIG. 6 is a perspective view of a schematic configuration of a conventional device, and FIG. 7 is a perspective view of a schematic configuration of another conventional device.

Claims (1)

[Scope of Claims] In a lifting device in which a loading platform is suspended in a hoistway so that it can be raised and lowered by suspension members at a plurality of locations, the attitude of the hoistway is detected at one or more positions in the hoistway. It is equipped with a sensor that calculates the vertical deviation of each suspension member attachment position with respect to the normal posture of the lifting platform based on the signal from the sensor, and the lifting platform is suspended by the amount of deviation mentioned above according to a command from the calculation unit. A lifting device characterized in that the suspension members are provided with actuators that adjust the lengths of the respective members.