JPH06127660A - Controlling method for transfer equipment - Google Patents

Abstract

PURPOSE:To provide a controlling method for transfer equipment for exactly retaining the distance between transferring items. CONSTITUTION:The distance between transferring items is set by a difference in speed between low-speed sending-in conveyor parts 5a, 5b and high-speed sending-in conveyor parts 6a, 6b. When the transferring item shades a first photoelectric sensor 7a for the high-speed sending-in conveyor part 6a and the transferring item shades a first photoelectric sensor 7b for the high-speed sending-in conveyor part 6b, a sending-in conveyor 2b suspends its operation. When the transferring item from the sending-in conveyor 2a shades a second photoelectric sensor 8 and then passes light, the sending-in conveyor 2b restarts transferring operation to transfer the transferring item to a combined conveyor 3. In accelerating or decelerating the sending-in conveyors 2a, 2b, normal acceleration and deceleration are made when the sending-in conveyors 2a, 2b are decelerated for suspending their operation and are again accelerated. When the sending-in conveyors 2a, 2b are accelerated again during deceleration before suspending their operation, speed at the time of receiving instructions for acceleration during deceleration is retained for a period expected to be suspended in deceleration. Then, normal acceleration is made.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conveying device which is driven at a constant speed during conveyance and stopped during standby to convey an object at a constant interval.

[0002]

2. Description of the Related Art A conventional conveying device of this type for maintaining a predetermined distance from a preceding conveyed object is driven at a constant speed when it is separated from the preceding conveyed object by a predetermined distance or more, and the preceding conveyed object is conveyed. When not separated by a predetermined distance or more, the vehicle is stopped to keep the distance to the preceding conveyed object constant.

[0003]

When the transport device travels at a constant speed or stops, it is linearly accelerated due to the inertia of the motor and the mechanism after the constant speed start or stop signal. Or it slows down and does not immediately enter the constant speed or stop state.

Therefore, when the constant speed is re-established immediately after the stop instruction, the transport device is not reliably stopped, and the vehicle is accelerated again from the low-speed traveling state. In some cases, the distance becomes short and it becomes impossible to maintain a predetermined distance from the preceding conveyed product, which causes a problem that the distance between conveyed products cannot be accurately maintained.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a control method of a transfer device capable of accurately maintaining a distance between transferred objects.

[0006]

SUMMARY OF THE INVENTION According to the present invention, when a preceding object is separated by a predetermined distance or more, it is driven at a constant speed,
In the control method of the carrier device, which stops when the object is not separated from the preceding conveyed object by a predetermined distance or more, accelerates / decelerates between the constant speed and the stop, and conveys the conveyed object at constant intervals. When returning to the constant speed again during the stop from 0 to 1, the speed during the deceleration until the stop at the time of returning to the constant speed is maintained for a predetermined time and then accelerated again.

[0007]

The present invention operates at a constant speed when the object to be conveyed is separated from the preceding object by a predetermined distance or more, and stops when the object is not separated from the preceding object by a predetermined distance or more. When returning to a constant speed while stopping from a constant speed when conveying at intervals, the speed during deceleration until the stop at the time of returning to a constant speed is maintained for a predetermined time and then accelerated again. By doing so, the time to start acceleration can be made equal to that in the normal case, so it is possible to maintain the distance between conveyed items as in the case of accelerating after stopping. You can

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A conveying apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1 and FIG. 2, reference numeral 1 denotes a transfer device, which is a device for transferring two parallel carry-in conveyors 2a,
2b, a merging conveyor 3 is provided downstream of the carry-in conveyors 2a, 2b for merging the conveyed products from the carry-in conveyors 2a, 2b in a row, and a transport conveyor is provided downstream of the merging conveyor 3. 4 are provided.

The carry-in conveyors 2a and 2b are low-speed carry-in conveyors 5a and 5b driven by, for example, a servo motor (not shown), and the low-speed carry-in conveyors 5a and 5b are provided downstream of the low-speed carry-in conveyors 5a and 5b. High-speed carry-in conveyors 6a and 6b driven by, for example, servomotors are also provided, which are faster than 5a and 5b and set the interval between the conveyed objects by the speed difference between the low-speed carry-in conveyors 5a and 5b.

Further, on the carry-in conveyors 2a and 2b, the first
Photoelectric sensors 7a and 7b are provided, and a second photoelectric sensor 8 is provided on the merging conveyor 3. The distance P between the first photoelectric sensors 7a and 7b and the second photoelectric sensor 8 is set to a predetermined distance between the conveyed objects.
Further, this interval P is the first of the high-speed carry-in conveyor sections 6a and 6b.
Of the photoelectric sensors 7a, 7b and the high-speed carry-in conveyor sections 6a, 6b, and the distance b between the transport ends of the high-speed carry-in conveyor sections 6a, 6b and the transport end of the merge conveyor 3. And the distance c between the conveyance end of the merging conveyor 3 and the second photoelectric sensor 8 of the merging conveyor 3.

The distance a [mm] is a distance Pmi generated by the speed difference between the low-speed carry-in conveyor units 5a and 5b and the high-speed carry-in conveyor units 6a and 6b when the minimum conveyed product is conveyed.
It must be smaller than n [mm].

Here, if the length of the minimum transported object is Lmin, the transport speed of the low-speed carry-in conveyor sections 5a and 5b is VL, and the transport speed of the high-speed carry-in conveyor sections 6a and 6b is VH, then Pmin = (VH / VL) .times.Lmin-Lmin.

Therefore, a> Pmin, and the distance a may be set longer than the interval Pmin in the case of the minimum conveyed object.

Assuming that the transport speeds of the high-speed carry-in conveyor sections 6a and 6b are equal to the transport speed of the merging conveyor 3, the distance obtained by adding the distances a and b is equal to the first photoelectric sensors 7a and 7b. When it is turned on and stopped, and then restarted, acceleration is completed within the distance of distance a plus distance b,
You need to return to a constant speed.

As shown in FIG. 3, the overrun distance when the vehicle is stopped is Lx [mm] and the delay distance when the vehicle is started is Ly [m].
m], the acceleration speed amount every 10 ms is VG [m / min], the acceleration / deceleration time is TG [ms], and the acceleration / deceleration distance is KG, then KG = VH / VG, and the acceleration / deceleration time TG is TG = KG X10. Therefore, the overrun distance Lx at the time of stop is Lx = [VH * {TG / (1000 * 60)} * 1000] / 2 = (VH * TG) / 120.

The delay distance Ly of the high-speed carry-in conveyors 6a and 6b is the overrun distance L when the acceleration / deceleration amounts are equal.
It is equal to x and Lx = Ly.

Since LX = Ly, a + b> {(VH * TG) / 120} * 2, and therefore a + b> (VH * TG) / 60.

Next, the operation of the above embodiment will be described.

First, the conveyed goods are conveyed by the carry-in conveyors 2a and 2b, respectively, and the distance between the conveyed goods is set by the speed difference between the low-speed carry-in conveyor sections 5a and 5b and the high-speed carry-in conveyor sections 6a and 6b. Then, the conveyed object shields the first photoelectric sensor 7a of the high-speed carry-in conveyor section 6a of either one of the carry-in conveyors 2a, and the high-speed carry-in conveyor section 6b of the other carry-in conveyor 2b.
When the first photoelectric sensor 7b of 1 is shielded from light by the conveyed object, the other carry-in conveyor 2b is stopped. When the other carry-in conveyor 2b is stopped, a servo motor (not shown) is servo-locked to prevent drift.

When the conveyed product from one of the carry-in conveyors 2a passes through the second photoelectric sensor 8 after being shielded from light, the other carry-in conveyor 2b starts the conveying operation again and conveys the conveyed product to the merging conveyor 3. To do.

When the carry-in conveyors 2a and 2b are accelerated / decelerated, if they are decelerated, stopped, and then accelerated again, they are decelerated as usual, as shown in FIG. Accelerate.

On the other hand, in the case of accelerating again during deceleration before the stop, as shown in FIG. 4, the speed at the time of the acceleration instruction during the deceleration is stopped for a predetermined time, for example, when the speed is decelerated as it is. Hold for some time, then accelerate normally.

In this way, the delay distance Ly becomes equal to the overrun distance Lx by maintaining the constant speed for a predetermined time. Therefore, unlike the conventional example shown in FIG. 5, the delay distance Ly does not become smaller than the overrun distance Lx, and it is possible to prevent the distance between the conveyed object and the preceding conveyed object from becoming shorter than a predetermined distance.

Next, another embodiment will be described with reference to FIG.

In the embodiment shown in FIG. 6, in the carrying apparatus shown in FIG. 1, four parallel carry-in conveyors 2a, 2b, 2c,
Has 2d.

The carry-in conveyors 2a, 2b, 2c, 2d are low-speed carry-in conveyors 5a, 5b, 5c, 5d driven by low-speed servomotors 11a, 11b, 11c, 11d, and the low-speed carry-in conveyors. At the downstream side of the parts 5a, 5b, 5c, 5d, a servo motor 12 for higher speed and higher speed than the low-speed carry-in conveyor parts 5a, 5b is provided.
High-speed carry-in conveyor units 6a, 6b, 6c, 6d driven by a, 12b, 12c, 12d are provided.

The first photoelectric sensors 7a, 7b, 7c, 7d are arranged on the carry-in conveyors 2a, 2b, 2c, 2d.

Thus, the control is performed by the low speed servo motor 11
a, 11b, 11c, 11d and high speed servo motor 12a,
12b, 12c and 12d are independent, and pulse feedback is used for low speed servomotors 11a, 11b, 11c and 11d.
Only this is fed back to the high speed servomotors 12a, 12b, 12c and 12d.

Further, high speed servo motors 12a, 12b,
When 12c and 12d are stopped, proportional control prevents drift, and when the low speed servomotors 11a, 11b, 11c and 11d are stopped, servo lock prevents drift.

Then, the four parallel carry-in conveyors 2a,
2b, 2c and 2d are operated in the same manner as shown in FIG.

Another embodiment will be described with reference to FIG.

In the embodiment shown in FIG. 7, the low-speed carry-in conveyor sections 5a, 5b, 5c and 5d in the carrying apparatus shown in FIG.
The high-speed carry-in conveyor sections 6a, 6b, 6c, 6d are driven by one servo motor 15a, 15b, 15c, 15d, respectively, and the low-speed carry-in conveyor sections 5a, 5b, 5c, 5d and the high-speed carry-in conveyor section 6a. , 6b, 6c, 6d are linked by a chain.

Then, the same operation as that of the embodiment shown in FIG. 6 is performed, and the drift is prevented by the servo lock at the time of stop.

[0035]

According to the control method of the conveyor of the present invention,
When it is separated from the preceding conveyed object by a predetermined distance or more, it is driven at a constant speed, and when it is not separated from the preceding conveyed object by a predetermined distance or more, it is stopped. , When returning to constant speed while stopping from constant speed,
When the speed during deceleration until stopping again when maintaining the constant speed again is maintained for a predetermined time and then accelerating again, the time to start acceleration can be made equal to the normal case. As in the case of acceleration, the distance between the conveyed objects can be maintained, and the distance between the conveyed objects can be made exactly constant.

[Brief description of drawings]

FIG. 1 is an explanatory view of a carrying device according to an embodiment of the present invention as viewed from above.

FIG. 2 is an explanatory view seen from the side, showing the above-mentioned transfer device.

FIG. 3 is a graph showing an operation when the vehicle is decelerated, stopped, and then accelerated again.

FIG. 4 is a graph showing an operation when accelerating again during deceleration.

FIG. 5 is a graph showing an operation when accelerating again during deceleration in the conventional example.

FIG. 6 is an explanatory view seen from a plane showing a carrying device according to another embodiment.

FIG. 7 is an explanatory view seen from a plane showing a carrying device of another embodiment.

[Explanation of symbols]

 1 Conveyor

Claims (1)

[Claims] 1. A constant speed drive when a predetermined distance or more is separated from a preceding conveyed object, and a stop is performed when the preceding conveyed object is not separated from a preceding conveyed object by a predetermined distance or more. In a method of controlling a transporting device for accelerating and decelerating during a period of time and transporting a transported object at a constant interval, when returning to the constant speed again while stopping from the constant speed,
A control method for a transporting device, comprising: maintaining a speed in the middle of deceleration until stopping at a constant speed again for a predetermined time and then accelerating again.