JPH0248325A - Conveying device - Google Patents

Abstract

PURPOSE:To improve saving of energy of a conveying device by a method wherein a title device has structure in which a motor and a control circuit, located independently from each other, are mounted to each rotary roller, through decision of the presence of a load, each roller is controlled and driven. CONSTITUTION:During load running of a motor 1 for a rotary roller, a rotation detector 8 is rotated at a low speed, and during low torque running, the detector is rotated at a low speed being below a set value. By means of an output from a comparator 6, an output Q from a first flip flop circuit 10 is generated. Further, the current of the motor 1 is increased to a value higher than a low speed load current, and an output is transmitted from a comparator 4. An output from a first AND-circuit 11 is inputted to a second flip flop circuit 13, and this input causes transmission of an output Q from the circuit 13, and the motor is run at a high speed and high torque through the working of a driver circuit 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a conveying device used in an assembly conveyor.

[Conventional technology]

In general, in an assembly conveyor that consists of a plurality of assembly processes, there is a difference in the time required for assembly in each process, which poses a problem when performing a series of assembly operations. Therefore, free flow conveyors are used. This free flow conveyor allows the pallet loaded with workpieces to be freely engaged with the endless chain that is constantly driven, and when conveyance is required, the pallet is engaged with the endless chain and integrated. When moving and stopping, the pallet is disengaged.

Furthermore, a conveyor consisting of a large number of rollers is used in steel plate rolling equipment, etc., in which the position of the load is detected by a central control device and the necessary rollers are rotated.

[Problem to be solved by the invention]

Conventional free-flow converters drive the endless chain continuously under the same conditions as when loaded, regardless of whether there is a load on the chain, resulting in energy loss.

In addition, rolling equipment used in rolling equipment has a
There is energy loss due to rotation, and
Load detection sensors must be installed along the entire length.
It is expensive and needs to be rotated at high speed downstream.
In addition, the speed ratio of each roller is set depending on the plate thickness, and each roller is centrally controlled while detecting the position of the material, that is, the load.
When attempting to perform random feed control, it is difficult to change the system configuration.

[Means to solve the problem]

One of the present inventions was proposed in view of the above-mentioned problems of conventional devices.A motor is provided for each axis, and the presence or absence of a load is estimated from the current and rotational speed of the motor.
The motor is driven with high torque, and the motor is driven at low speed when no load is applied.
The motor is equipped with a large number of rotating rollers, each of which is provided with a control circuit that drives the motor with low torque. However, the presence or absence of a load is transmitted and received between the control circuits of each rotating roller, and the next rotating roller in the conveying direction is controlled by the presence or absence of a load on the previous rotating roller.

[Effect]

By estimating the presence or absence of a load from the current and rotation speed of the motor provided for each rotating roller, the motor is driven at high speed and quotient torque when loaded, and at low speed and low torque when no load is applied. , reducing energy loss during no-load conditions.

Furthermore, by controlling the next rotating roller in the conveying direction depending on the presence or absence of a load output from each rotating roller, the load can be moved smoothly without providing individual sensors.

〔Example〕

FIG. 1 is a block diagram of a control circuit provided for each rotating roller of the device of the present invention. fi2fffl is the first page showing an example of the discrimination circuit in FIG.

In Figure 1, (1) is the motor that drives the rotating roller, (2) is its driver circuit, (3) is the discrimination circuit, and (4) is the motor that drives the rotating roller.
)(5)(6)<7) are comparison circuits, (8) is a rotation speed detector such as a tacho generator, and (9) is a motor current detector.

The motor (1) has the relationship between current and rotation speed as shown in Figure 3 by keeping the voltage constant for one period, and the relationship between current and rotation speed during control is shown in Figure 4. That's right.

The comparator (4) sets the low-speed loaded current and compares it with the current feedbank value from the motor current detector (9), and the ratio/calibrator (5) sets the high-speed no-load current. This is used to compare the current feedback value from the motor current detector (9), and the comparator (6)
is to set the low speed rotation speed and compare this with the rotation speed feedback value from the rotation speed detector (8).
The comparator (7) sets a high rotation speed and compares this with the rotation speed feedback value from the rotation speed detector (8).

The output of each comparator (4) (5) (6) (7) is the discriminator circuit (
As shown in FIG. (4)
(5) is input to the first AND circuit (11) and the second AND circuit (12) together with the output of the first flip-flop (10), and the outputs of both AND circuits (11) and (12) are input to the second AND circuit (11) and the second AND circuit (12). The output of the second flip-flop circuit (13) is input to the driver circuit (2), and the motor (1) is controlled and driven.

In the above configuration, when the rotary roller motor (1) is rotating at low speed and low torque under load, the rotation speed detector (8) rotates at a low speed below the setting, and the output from comparison 3 (6) According to the first flip-flop circuit (10)
As the Q output is output, the current of the motor (1) becomes larger than the low-speed loaded current as shown in Fig. 3, and an output is output from the comparator (4) and the first The output is output to the flip-flop circuit (13), which causes the Q output of the circuit (13) to be output to the driver circuit (2).
The motor (1) is driven at high speed and high torque through.

When the motor (1) is rotating at high speed and high torque with no load, the first rotation detection a (8) rotates at a high speed higher than the set value, and the output from comparison 3 (7) indicates that
As the Q output of the first flip-flop circuit (lO) is output, the current of the motor (1) becomes smaller than the set high-speed no-load current as shown in Figure 3, and the output is output from the comparator (5). Q
The output of the motor (1) passes through the driver circuit (2).
) is driven at low speed and low torque.

Of course, if the driving conditions of the motor (1) match the presence or absence of a load, it goes without saying that this state will be maintained.

The control circuit (A) is connected to a bus type signal line (B) as shown in FIG.
), the presence or absence of a load can be sent and received between the control circuits (A) of each rotating roller, and the next rotating roller in the conveying direction can be controlled by the presence or absence of a load on the previous rotating roller.

In this case, for example, the circuit shown in Fig. 1 is provided on the rotating roller at the starting end of each process or the rotating roller at the starting end of each conveyance group, and only the driver circuit (2) is provided on the subsequent rotating rollers. Discrimination circuit (before driver circuit 2)
3) Or the output of the driver circuit (2) is sent via a bus type signal line.

With the above configuration, when a load arrives, the next rotating roller is started up to a preset rotation speed in response to a signal from the previous rotating roller, and the load can be moved smoothly.

[Effects of the Invention] One of the features of the present invention is that each rotating roller has an independent motor and a control circuit, and is controlled and driven by determining the presence or absence of a load, thereby improving the energy saving of the conveying device. obtain.

Another aspect of the present invention is that, in addition to the above, the load of the conveying device can be smoothly moved, and the entire conveying device can be made inexpensive.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of a control circuit provided for each rotating roller of the device of the present invention, Fig. 2 is a circuit diagram showing an example of the discrimination circuit shown in Fig. 1, and Fig. 3 shows the motor when the voltage is constant. FIG. 4 is a control graph showing the relationship between current and rotational speed during motor control, and FIG. 5 shows an example of the connection of the control circuit of the device of the present invention. (1) - Motor, (2) - Driver circuit,
-Discrimination circuit, (5) (6) (7L-1 comparator, rotation speed detector, motor current detector.

Claims (2)

[Claims] (1) A motor is provided for each axis, and the presence or absence of a load is estimated from the current and rotation speed of the motor, and when there is a load, the motor is driven at high speed and high torque, and when there is no load, the motor is driven at low speed and low torque. 1. A conveyance device comprising a large number of rotating rollers each having a control circuit for each motor. (2) A motor is provided for each axis, and the presence or absence of a load is estimated from the current and rotation speed of the motor, and when there is a load, the motor is driven at high speed and high torque, and when there is no load, the motor is driven at low speed and low torque. A large number of rotating rollers are equipped with a control circuit for each motor, and the control circuits of each rotating roller are connected by a bus-type signal line, and the presence or absence of load is transmitted and received between the control circuits of each rotating roller. A conveying device characterized in that the next rotating roller in the conveying direction is controlled depending on the presence or absence of a load on the preceding rotating roller.