JPH0656216A - Motor-driven traveling rack device - Google Patents

Abstract

PURPOSE:To provide a motor-driven traveling rack device which prevents a traveling rack device from falling down and stored articles from being dropped off by minimizing the oscillation of the traveling rack device by starting traveling rack device driving motors at a low speed in starting the driving motors. CONSTITUTION:This motor-driven rack device is provided with plural racks which travel in an orthogonal direction to a frontage surface and arranged so that they may converge and separate from each other, rack driving motors 7 installed on the respective rack devices, and a traveling rack device control circuit 14 which forms a passage for taking in and out articles between a desired rack corresponding to a passage forming command signal and the frontage surface to the rack by controlling normal and reverse rotation, and stopping of the motors 7 at the respective rack devices from the passage forming command signal and the positional relation of the respective racks. A motor speed switching part 15 is also provided, which starts the motors 7 whose normal and reverse rotation and stopping are controlled by the traveling rack device control circuit 14 at a low speed, and then drives them at a stationary speed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric movable rack, and more particularly to an electric movable rack that is set to a steady speed after being slowly started.

[0002]

2. Description of the Related Art A plurality of shelves movable in a direction perpendicular to a front surface are arranged so as to be converged by a driving force of a motor, and the shelves are moved to move articles into and out of a desired front surface of the shelves. There is an electric mobile shelf that can form a working path. In such a conventional electric mobile shelf,
The rotation speed of the moving rack drive motor is a single speed.

[0003]

According to the conventional electric type movable rack, since the rotation speed of the motor for driving the movable rack is a single speed, when the motor is started, it reaches a steady rotation speed immediately. The moving shelves were shaking a lot at startup. In particular, a moving rack having a large height relative to the ratio of the depth has large shaking at the time of starting, and it is necessary to equip the falling preventive means of the moving rack. In addition, the stored articles may fall due to the shaking of the moving shelf.

An object of the present invention is to reduce the shaking of the moving rack by starting the moving rack drive motor at a slow speed, and to prevent the moving rack from falling and the stored articles falling. The purpose is to provide a mobile shelf.

[0005]

SUMMARY OF THE INVENTION In the electric movable rack of the present invention, the forward / reverse rotation and the stop of the motor of each shelf are controlled based on the positional relation between the passage formation command signal and each rack, and the desired movement according to the passage formation command signal is achieved. In a motorized moving rack having a moving rack control circuit for forming a passage for loading and unloading articles between the shelves and the front surface of the shelf, forward / reverse rotation and stop are controlled by the moving rack control circuit. The motor is characterized in that it has a motor speed conversion unit that starts the motor at a slow speed when the movable shelf is started and then drives it at a steady speed. The motor speed converter may be composed of an inverter.

[0006]

When the aisle formation command signal is input, the moving shelf control circuit controls the motor of each shelf based on the positional relationship between the aisle formation command signal and each shelf so that the space between the shelves corresponds to the aisle formation command signal. Form a working passage. The motor speed conversion unit starts the motor at a slow speed when the mobile shelf is started, and then drives the motor at a steady speed.

[0007]

1 and 2, reference numeral 1 is a fixed shelf, and a plurality of laterally-movable fixed shelves 1 are movable along a guide rail 4 in a direction perpendicular to the front surface by a driving force of a motor. The shelves 2 and 3 are arranged together with the fixed shelf 1 so as to be able to converge. A main operation plate 5 is provided on the side plate of the fixed shelf 1, and each shelf 1, 2,
The side plate 3 is provided with an operation plate 6 for performing a passage forming operation and the like. The movable shelves 2 and 3 are driven by respective motors 7. Each of the movable shelves 2 and 3 also has a circuit board 8. As is well known, the movable shelf control circuit incorporated in the circuit board 8 provides a passage formation command signal based on the operation of the operation plate 6 and the movable shelf control circuit. By controlling the forward / reverse rotation and stopping of the motor 7 based on the positional relationship, a path for taking in and out articles is formed between desired shelves and the front surface of the shelves. A swing arm 9 is pivotally mounted on the top plate of each shelf so as to be rotatable in a horizontal plane. The tip ends of the swing arms 9 of the adjacent shelves are pivotally attached to each other, and the rotation angle of the swing arms 9 changes according to the passage width between the adjacent shelves.

The swing arm 9 constitutes a part of the passage width detecting device. FIG. 3 shows an example of a passage width detecting device having a swing arm 9. In FIG. 3, a semicircular plate 10 is fixed to the base of the swing arm 9, and a magnet 11 is fixed to the plate 10. Reed switches 12 and 13 are arranged so as to face the passage of the magnet 11 accompanying the rotation of the swing arm 9, and the magnet 11 faces the reed switch 12 or the reed switch 13 as the swing arm 9 rotates. When it reaches, the reed switch 12 or the reed switch 13 is turned on or off. Since the rotation angle of the swing arm 9 corresponds to the passage width between the shelves, the passage width signal between the shelves can be obtained by taking the on / off signals of the reed switches 12 and 13.

A passage width signal from the passage width detecting device as shown in FIG. 3 is provided as a speed control signal for the moving rack drive motor 7. In FIG. 5, the moving rack control circuit 14 is a circuit similar to a conventional moving rack control circuit, and controls forward / reverse rotation and stop of the motor 7 from the positional relationship between the passage formation command signal and each rack at that time. Thus, the movable rack is caused to travel to form a work passage at a designated place. The motor 7 is, for example, a three-phase AC motor, and the moving rack control circuit 14 switches the respective phases of the three-phase AC, or cuts off the supply of the three-phase AC power to the motor 7, so that the motor 7 is rotated in the normal and reverse directions. It is designed to be controlled.

An inverter 15 as a motor speed conversion unit, which is a feature of the present invention, is interposed between the movable rack control circuit 14 and the motor 7. The inverter 15 itself is well known, and the AC-DC converter 16 once converts AC into DC and stabilizes it with the constant voltage circuit 17, and then D
When converting to AC in the C-AC converter 18,
Based on the voltage-frequency control by the speed command circuit 19, it is converted into an alternating current having a frequency according to the command signal from the speed command circuit 19, and this converted output is supplied to the motor 7 as the converted output of the inverter 15. .

Therefore, in the circuit example of FIG. 5, the inverter 15 outputs the passage width signal from the passage width detecting device as shown in FIG.
Is input to the speed command circuit 19 to convert the frequency of the AC power source applied to the motor 7 according to the passage width signal, and thus the rotation speed of the motor 7 is converted according to the passage width. The speed command circuit 19 uses the motor 7 when the moving shelf is activated.
DC-AC converter 1 so that it starts at a slow speed
The frequency of the AC output of 8 is controlled to be low. Then, when the movable rack travels for a certain distance, the swing arm 9 rotates by a certain angle and the reed switch 12 or the reed switch 13 is turned on and off. The speed command circuit 19 drives the DC-
The frequency of the AC output of the AC converter 18 is controlled to be high.

As described above, by combining the passage width detecting device as shown in FIG. 3 and the motor speed converting unit as shown in FIG. 5, the moving rack can be started at a slow speed. It is possible to reduce the shake of the moving shelf at the time of start-up, and it is possible to prevent the moving shelf from falling or the stored articles falling.

In the above embodiment, one of the reed switches 12 and 13 is actuated to convert the motor 7 to a steady speed, and then the movable shelf further travels a certain distance, so that the other of the reed switches 12 and 13 is activated. When activated, the speed command circuit 19 may control the frequency of the AC output of the DC-AC converter 18 to be low. With this configuration, the moving shelves can be slowly stopped even when the moving shelves are stopped, and it is possible to effectively prevent the shaking of the shelves and the fall of the stored articles due to the sudden stop. Further, when the movable rack is stopped, the drive motor may be deenergized and naturally stopped.

A passage width detecting device using a swing arm may be constructed as shown in FIG. In FIG. 4, a sliding contact piece 21 is integrally provided on a rotary shaft 20 that is integral with the swing arm 9, and the sliding contact piece 21 is in sliding contact with a sliding body to form a variable resistance. However, in the above sliding body, the resistors 22 and 23 are formed only in a certain range at both ends,
A good conductor 24 is formed in the middle of the resistors 22 and 23.
The lead-out terminal to the outside is taken from the sliding contact piece 21 and the good conductor 24. When the swing arm 9 rotates along with the traveling of the movable rack, the sliding contact position of the sliding contact piece 21 is set to the resistance 2
It moves from one of the resistors 2 and 23 to the good conductor 24 and further to the other of the resistors 22 and 23.

According to the passage width detecting device of FIG. 4, since the sliding contact piece 21 is in sliding contact with one of the resistors 22 and 23 at the start of the moving rack, a certain resistance value is present between the lead terminals. Yes, the resistance value becomes lower as the mobile shelf travels, and becomes substantially zero when the mobile shelf travels to some extent. When the movable rack further travels, the sliding contact piece 21 comes into sliding contact with the other one of the resistors 22 and 23, so that the resistance value between the terminals gradually increases. Therefore, if the resistance value between the terminals is introduced to the inverter 15 of FIG. 5 as a passage width detection signal, the moving rack is started at a slow speed when the moving rack is started, and the running speed is gradually increased as the moving rack travels, and eventually becomes steady. When the moving rack reaches the speed and travels to a certain extent, the traveling speed of the moving rack gradually decreases, and eventually the traveling width of the traveling rack is reduced, and the traveling rack is controlled to stop.

FIG. 6 shows how the speed of the movable rack changes when the passage width detecting device as shown in FIG. 4 is combined with the motor speed converter. Even with a conventional mobile shelf having no motor speed conversion unit, although strictly speaking, there is a speed change at the time of startup, the rise of the mobile speed is extremely rapid as compared with FIG. 6, and smooth startup is expected. I can't.

The passage width detecting device may be composed of an encoder which outputs the passage width signal as a pulse signal. 7 and 8 show an example thereof, in which a rotary encoder is attached to the moving rack driving motor 7. That is, the output shaft of the motor 7 has holes 26 at regular intervals in its peripheral portion.
A disc 27 having a disc is attached, and the optical sensor 28 arranged so that the disc 27 is sandwiched from the front and back sides optically detects the hole 26 to generate a pulse signal, thereby digitally counting the traveling distance and the passage width of the movable shelf. It is something that can be done. Although the holes 26 of the disk 27 are formed for two digits, the number of digits may be set arbitrarily.

If slippage occurs between the drive wheel to which the drive force of the motor 7 is transmitted and the guide rail, an error may occur between the count value obtained by the rotary encoder and the actual passage width. Therefore, for example, the rotary encoder may be provided integrally with the idler pressed against the guide rail. Further, the encoder is not limited to an optical encoder, and may be one using a magnetic sensor, for example.

As a passage width detecting device for outputting a passage width signal as a pulse signal, as shown in FIG. 9, reflecting members 30 as detectors are arranged on the side of the guide rail 4 at regular intervals. The light reflected from 30 may be detected by the optical sensor 31. The optical sensor 31 may have a light emitting unit. A magnet may be used as the detector, and this may be detected by a magnetic sensor.

When the passage width detecting device outputs a pulse signal as the passage width signal, a microcomputer can be used for speed control of the moving rack drive motor 7 as shown in FIG. In FIG. 10, a detection signal from an encoder 33 as a passage width detection device that outputs a passage width signal by a pulse signal is input to a microcomputer 34. Microcomputer 34
Calculates the current position of the shelf and the passage width between adjacent shelves based on the detection signal from the encoder 33, and controls the inverter 15 according to these calculated values. The inverter 15 is interposed between the moving rack control circuit 14 and the moving rack drive motor 7 as in the circuit example of FIG.

Next, the operation of the circuit of FIG. 10 will be described with reference to FIGS.
This will be described with reference to 2. Now, for example, as shown in FIG. 11, it is assumed that all the moving shelves 41, 42, 43, 44 have moved to the limit position to the right, and the shelves 41, 42, 43, 44 at that time The distances from the reference position are x1, x2, x3, and x4, respectively. These distance x
1, x2, x3, x4 can be obtained by adding or subtracting pulse signals from encoders provided as the passage width detection devices on the shelves. Further, in the above-mentioned state, the passage width formed on the left side of the shelf 41 at the left end is x. As described above, since the movable shelves 41, 42, 43, 44 are at the limit of movement to the right, the communication width x is the maximum passage width.

Therefore, for each moving rack, the microcomputer 34 determines where the current position is, and further, the state of the width of the passage that can be traveled is obtained, and the speed of the moving rack drive motor is converted according to the result. . FIG. 12 shows an example of speed conversion control by the microcomputer 34. In FIG. 12, the current position is obtained for each of the shelves 41, 42, 43 and 44, and it is determined whether or not they are located at x1, x2, x3 and x4, respectively. When the current position of each shelf is x1, x2, x3, x4, the traveling margin of each shelf is maximum, so slow start first on that shelf and make sure that it is a steady speed after traveling for a certain distance. After switching and running at a constant speed for a certain distance, slow down and stop at a predetermined position.

On the other hand, the current position of each shelf is x1, x
When it is not 2, x3 or x4, it means that the traveling margin of each shelf is limited. Even in that case, there may be a case where the traveling allowance of the movable rack is relatively sufficient and a case where the traveling allowance is not sufficient. Therefore, next, the state of the passage width is determined in order to obtain the traveling allowance of the movable shelf. Specifically, since the current position of each shelf is clarified by counting the pulse signals from the encoder of each shelf, the passage width is obtained from this current position, and the relationship between this passage width and the maximum passage width x. Seeking
It is determined whether the passage width is smaller or larger than x / 2. When the passage width is larger than x / 2, the traveling margin is still relatively large. Therefore, similarly to the case described above, the movable rack is slow-started, then brought to a steady speed, and further slowed down and stopped. On the other hand, when the passage width is smaller than x / 2, it means that the traveling margin is small. Therefore, the movable rack is slow-started and then slowed down and stopped.

When the speed of the moving rack drive motor is controlled by a microcomputer, a microcomputer may be provided for each rack and only that rack may be controlled, or one microcomputer may be used to control all racks. Centralized control may be performed.

An optical communication system using an optical fiber may be adopted for transmitting and receiving signals between the shelves.

[0026]

According to the present invention, a motor for converting a moving rack, which is provided with a motor speed converting unit and whose forward / reverse rotation and stop are controlled by a moving rack control circuit, is used by the motor speed converting unit when starting the moving rack. Is started at a slow speed and then driven at a constant speed, so when the mobile rack is started, the mobile rack starts to move slowly and does not start moving rapidly like the conventional electric mobile rack. Therefore, it is possible to reduce the shaking of the moving shelf, and to prevent the moving shelf from falling and the stored articles from falling.

[Brief description of drawings]

FIG. 1 is an external side view showing an embodiment of the present invention.

FIG. 2 is a plan view of the same.

FIG. 3 is a plan view showing an example of a passage width detection device used in the above embodiment.

FIG. 4 is a plan view showing another example of the passage width detection device.

FIG. 5 is a block diagram showing an example of an electric circuit used in the present invention.

FIG. 6 is a characteristic diagram showing an example of a traveling operation of the movable rack according to the present invention.

FIG. 7 is a perspective view showing another example of the passage width detection device used in the present invention.

FIG. 8 is an enlarged front view showing a portion of a detection body of the above passage width detection device.

FIG. 9 is a perspective view showing still another example of the passage width detection device used in the present invention.

FIG. 10 is a block diagram showing another example of an electric circuit used in the present invention.

FIG. 11 is a side view showing an arrangement relationship of movable shelves for explaining the operation of the above electric circuit.

12 is a flowchart showing an operation of the electric circuit of FIG.

[Explanation of symbols]

 2 Moving rack 3 Moving rack 7 Motor 13 Reed switch 14 Moving rack control circuit 15 Inverter as motor speed converter

Claims (2)

[Claims] 1. A plurality of shelves that move in a direction perpendicular to the front surface and are arranged so that they can be converged and separated from each other, a motor attached to each shelves for driving each shelves, and a passage formation command signal. Movement to form a passage for loading and unloading articles between desired shelves and the front surface of the shelves according to the passage formation command signal by controlling the forward / reverse rotation and stop of the motors of the shelves based on the positional relationship of the shelves. In an electric moving shelf having a shelf control circuit, the motor whose forward / reverse rotation and stop are controlled by the moving shelf control circuit is started at a slow speed when the moving shelf is started,
After that, an electric mobile shelf having a motor speed conversion unit driven at a constant speed. 2. The electric mobile shelf according to claim 1, wherein the motor speed conversion unit is an inverter that converts a power supply frequency of the motor.