JPH11209038A - Elevator for construction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To facilitate smooth start and stop and stable, continuous and horizontal elevation of an elevator at a high speed and with reduced weight. SOLUTION: An elevator for construction includes a working board 3 elevatably mounted between columns 2a, 2b planted in a basement 1 at a mutually specified space and sprockets 6a, 6b connected to motors 5a, 5b mounted at both mounting ends of the working board 3 and engaged with racks 4a, 4b annexed to the columns 2a, 2b respectively, providing elevatable drive. Inverters 8a, 8b are connected to at least one sides of the motors 2a, 2b and an inclination correcting device 7 is installed on the working board 3 to send a correction signal to at least one of the inverter 8a, 8b in accordance with an inclination angle.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a construction elevator used at a construction site.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG. 7, a worktable 3 having, for example, a cage 3a is installed between pillars 2a, 2b planted on a base 1 at a predetermined interval so as to be able to move up and down. And a sprocket 6 connected to motors 5a, 5b provided at both ends of the work table 3 on racks 4a, 4b attached to the pillars 2a, 2b, respectively.
2. Description of the Related Art There is known a construction elevator in which a.

[0003] Such a construction elevator is a motor 5
a, 5b, the motor 5
The work table 3 may be tilted during the ascent and descent because the rotation speeds of the a and 5b are not always the same or the engagement states of the sprockets 6a and 6b and the racks 4a and 4b are not the same. There is a concern that you will be unable to move up and down.

Therefore, for example, the work table 3 is provided with a tilt correction device 7 having a tilt sensor and a control device for the motors 5a and 5b, and when the work table 3 is tilted to a certain value (for example, 2 °) or more, the control device is controlled. The motor 5a (or 5b) on the preceding side is stopped by a stop signal issued from the controller and when the work table 3 becomes horizontal, the motor 5a (or 5b) is operated again to move up and down.

It is also conceivable that the two sprockets 6a and 6b are connected by one shaft and driven by one motor to synchronize the rotations of the two sprockets 6a and 6b (not shown).

[0006]

However, when the motor 5a (or 5b) on the preceding side is stopped and moved up and down, the moving up and down speed must be set to, for example, about 10 m / min or less, and it is difficult to move up and down at a high speed. It is.

In addition, since the motor 5a (or 5b) is intermittently driven, it cannot be operated in a stable state in which the elevation is discontinuous.

Further, when the two sprockets 6a and 6b are connected by one shaft to synchronize the rotation, there is a problem that the structure becomes complicated and the equipment weight increases.

[0009]

SUMMARY OF THE INVENTION The present invention has been made in order to solve these problems, and it is possible to smoothly start and stop the motor, and to stably and continuously move up and down at a high speed. Another object of the present invention is to provide a construction elevator that does not increase in weight.

[0010]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. According to the present invention, a worktable is erected between pillars planted on a base plate at a predetermined interval so as to be able to move up and down. And, in a construction elevator in which a sprocket connected to a motor provided at each of the two erection ends of the worktable is respectively meshed with a rack attached to each of the pillars and driven up and down, each motor has at least An inverter is connected to one of the inverters, and a tilt correction device that sends a correction signal to at least one of the inverters according to a tilt angle is installed on the workbench.

When the work table tilts, a correction signal corresponding to the correction angle is sent from the tilt correction device to the inverter to control the rotation speed of each motor.

In the above means, when the inclination correcting device is provided with an operation control device for controlling the operation of each of the motors when the worktable has an abnormal inclination angle, the inclination is caused by the abnormal inclination. It is possible to avoid danger such as falling.

[0013]

1 to 4 show one of the preferred embodiments of the present invention. The whole structure is almost the same as that of the conventional example, and the base 1 is spaced apart from each other by a predetermined distance. A worktable 3 having, for example, a cage 3a is erected between the pillars 2a and 2b planted in the rack, and racks 4a and 4 attached to the pillars 2a and 2b, respectively.
b, motors 5 provided at both ends of the work table 3
The sprockets 6a and 6b connected to the a and 5b are respectively engaged with each other to drive up and down.

An inverter 8 is connected to one motor 5a.
a, an inverter 8b is connected to the other motor 5b, and an inclination correction device 7 is connected to the inverter 8a connected to the motor 5a.

The tilt correcting device 7 includes a level 71 for checking the horizontal state of the work table 3 and a tilt sensor 7 for detecting the tilt angle of the work table 3 and transmitting a tilt angle signal 91.
2. Amplify the tilt angle signal 91 from the tilt sensor 72, and correct the angle correction signal 92 and the abnormal angle detection signal 9
And a sequence circuit 74 for providing a rising signal 95 or a falling signal 96 for transmitting an angle correction voltage signal 94 corresponding to the correction angle to the inverter 8a based on the angle correction signal 92. Provided.

In this embodiment constructed as described above, as shown in FIG. 1, a constant frequency is applied to one of the inverters 8b to which the inclination correcting device 7 is not connected to rotate the motor 5b at a constant output. The other of the inverters 8a to which the inclination correcting device 7 is connected is provided with a frequency corresponding to the constant frequency given to the one inverter 8b, and the motor 5a is rotated at the same output as the motor 5b, thereby making the work table 3 Is raised and lowered while keeping the horizontal state.

As shown in FIG. 3, when the work table 3 is tilted so that, for example, the motor 5a side is upward during the ascent / descent, as shown in FIG.
And transmits an inclination angle signal 91 to the inclination correction control circuit 73.

The transmitted tilt angle signal 91 is amplified by the tilt correction control circuit 73 and is divided into an angle correction signal 92 and an abnormal angle detection signal 93.

The angle correction signal 92 is sent by a sequence circuit 74 to the inverter 8a as an angle correction voltage signal 94 corresponding to the correction angle to adjust the output of the motor 5a.

That is, in FIG. 3, the output of the motor 5a is reduced if the work table 3 is moving up, and the output of the motor 5a is increased if the work table 3 is moving down.
The inclination of the work table 3 is corrected during the lifting and lowering of the work table.

If the value of the abnormal angle detection signal 93 exceeds a value set in advance in the inclination correction control circuit 73, the operation control device in which the abnormal output signal 97 is disposed at another place such as the work table 3 or near the switchboard. Motor 5
The supply of power to a and 5b is cut off to stop the elevator.

Further, in this embodiment, by transmitting the frequency signal 97 of the inverter 8a to the inclination correction control circuit 73, the number of rotations of the motor 5a (5b) is detected, and if the set value is exceeded, the operation is started. The power is transmitted to the control circuit 75 and the supply of power to the motors 5a and 5b is cut off to stop the elevator.

FIG. 5 shows a different embodiment of the present invention. The whole structure is almost the same as that of the embodiment shown in FIGS. 1 to 4, but is connected to one motor 5a. In addition to the inverter 8a, the other motor 5b
Is also connected to the inclination correction device 7, and the inverters 8a and 8b are given a reference frequency to be moved up and down in a horizontal state. A predetermined angle correction voltage signal is transmitted to one or both of the inverters 8a (8b) to correct the inclination of the work table 3 while the work table 3 is moving up and down.

In this embodiment, each inverter 8
a, 8b can be variable frequency controlled, so that the inclination of the work table 3 can be quickly corrected,
Adjusting the lifting speed is also easy.

FIG. 6 shows still another embodiment of the present invention, which is different in that no inverter is connected to one motor 5b.

In this embodiment, the motor 5b to which no inverter is connected is rotated at the frequency of the commercial power supply,
When the work table 3 is tilted, a predetermined angle correction voltage signal is transmitted to the inverter 8a to correct the tilt of the work table 3 while the work table 3 is moving up and down.

According to the present embodiment, the number of parts such as inverters to be used may be smaller than those of the other embodiments, and the structure and the circuit of the inclination correcting device 7 are simple, which is very economically advantageous. is there.

[0028]

As described above, according to the present invention, each motor connected to a sprocket which meshes with a rack attached to a column disposed on a work table erected up and down between columns is provided with the motor. An inverter is connected to at least one of the inverters, and a tilt correction device that sends a correction signal to at least one of the inverters according to a tilt angle is installed on the workbench.

Therefore, when the work table tilts, a correction signal corresponding to the correction angle is sent from the tilt correction device to the inverter to control the rotation speed of each motor without stopping each motor, so that the elevator is not stopped. The inclination can be automatically corrected and constantly raised and lowered in a stable state within about 0.2 °. For example, a speed of about 20 to 30 m / min can be supported.

Also, starting from using an inverter,
Unlike the case where both stops are smooth and the rotation is synchronized by connecting both sprockets with one shaft, the structure is simple, the drive part can be arranged in a small space, the equipment weight is light, and maintenance and inspection are easy. Not only that, but a worktable having a divided structure can also be used.

If the inclination correcting device is provided with an operation control device for controlling the operation of the motors when the work table is at an abnormal inclination angle, there is a danger of falling down caused by abnormal inclination. Can be avoided.

[Brief description of the drawings]

FIG. 1 is a front view, partially in section, showing a preferred embodiment of the present invention.

FIG. 2 is a schematic diagram showing the inclination correcting device and the circuit in the embodiment shown in FIG. 1;

FIG. 3 is a front view of the embodiment shown in FIG. 1 in a different state.

FIG. 4 is a front view of the embodiment shown in FIG. 1 in a different state.

FIG. 5 is a partial front view showing a different embodiment of the present invention.

FIG. 6 is a partially sectional front view showing still another embodiment of the present invention.

FIG. 7 is a front view partially showing a cross section of a conventional example.

[Explanation of symbols]

1 base, 2a, 2b pillar, 3 workbench, 4a, 4b
Rack, 5a, 5b motor, 6a, 6b sprocket, 7 tilt correction device, 8a, 8b inverter, 75
Operation control device

Claims (2)

[Claims] 1. A work table is erected between pillars planted on a base plate at a predetermined interval from each other, and the work table is mounted on a rack attached to each of the columns. In a construction elevator for driving up and down by meshing sprockets respectively connected to motors provided at both erection ends, an inverter is connected to at least one of the motors, and at least one of these inverters is inclined. A construction elevator, wherein a tilt correction device for transmitting a correction signal according to an angle is installed on the workbench. 2. The construction elevator according to claim 1, wherein the inclination correcting device is provided with an operation control device that controls the operation of each of the motors when the worktable has an abnormal inclination angle.