JPH0337045Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that stops driving a rotating body when the torque of the rotating body exceeds a predetermined value.

In general, a power transmission device for a conveyor driven by an engine includes a transmission that reduces the rotational speed of the engine's rotating shaft to a predetermined rotational speed and transmits it to the output shaft of the conveyor, and a transmission that reduces the rotational speed of the engine's rotating shaft to a predetermined rotational speed and transmits it to the output shaft of the conveyor.
A clutch is installed to turn it off. When driving this conveyor, the clutch is first disengaged and then the engine is driven. After the engine reaches steady rotation, the clutch is engaged and the driving force of the engine is transmitted to the output shaft of the conveyor.

By the way, if the torque applied to the output shaft increases due to the conveyor getting caught in a foreign object during driving, or for other reasons, the engine load will increase, causing engine stall, or the clutch may slip, causing the clutch to seize. There were some inconveniences such as accidents or damage to the equipment. In such cases, the engine speed is detected, and when the speed drops below a preset value, an overload is detected, and the transmission is decelerated or the clutch is disengaged. Technologies with control systems are being developed. However, in the above technology, since the engine is connected to the rotating body through the clutch, even if the clutch slips, the engine speed will not drop to a speed that matches the load. Unable to detect overload. Further, since a complicated speed reduction mechanism is required to reduce the speed of the traveling transmission, the cost becomes excessive when applied to a simple device such as a belt conveyor. moreover,
When disengaging the clutch, if the set rotation speed is too low, there is an unavoidable risk of clutch slippage or engine stalling; if the set rotation speed is too high, the clutch will disengage frequently, which is troublesome, and the selection of the set value becomes difficult. It has the disadvantage of being difficult.

In view of the above circumstances, the present invention provides a pulse generator that generates pulses based on the rotation of a rotary body, and an alarm when the time interval between the pulses generated from this pulse generator exceeds a preset first setting value. The above problem can be solved by providing a mechanism that generates a pulse interval and a mechanism that disconnects the clutch when the pulse interval becomes larger than a second set value, which is set in advance to be larger than the first set value. be.

The present invention will be described in detail below with reference to the drawings.

1 and 2 show an embodiment of a control device according to the present invention, and reference numeral 1 in the figures indicates an engine. The driving force of the drive shaft of the engine 1 is transmitted to the input shaft 4a of the conveyor 4 via the transmission 2 and clutch 3. The conveyor 4 is driven by the driving force of the input shaft 4a.
A pulse generator 5 is provided on the input shaft 4a of the conveyor or on the rotating body 4b of the conveyor which is rotated in conjunction with the driving force of the input shaft 4a.
This pulse generator 5 is an input shaft 4a or a rotating body 4b.
Any type of device may be used as long as it generates pulses in response to the rotation of the device. This pulse generator 5 is provided with a discriminator 7 that detects the generated pulses and compares the pulse interval (the interval between rising or falling pulses) with the pulse interval set by the pulse reset timer 6. ing. This discriminator 7 is connected to a clutch operation mechanism 8 and an alarm mechanism 9, and alerts the alarm mechanism 9 when the time interval of pulses generated from the pulse generator 5 exceeds a first preset value. When the pulse interval becomes larger than a second set value, which is preset larger than the first set value, a signal is output that causes the clutch operating mechanism 8 to disengage the clutch 3.

Next, the operation of the control device configured as above will be explained.

When the conveyor 4 is operated in a steady state, pulses generated by the rotating body are generated at predetermined short intervals as shown in FIG. 3a. However, if the rotational load on conveyor 4 increases for some reason,
The torque applied to the input shaft 4a increases, and the engine 1
The rotational speed of the conveyor 4 decreases or the clutch slips, resulting in a decrease in the operating speed of the conveyor 4. Along with this, the rotational speed of the rotating body to which the pulse generator 5 is attached also decreases, and the interval between generated pulses becomes longer as shown in FIG. 3b. When this pulse interval becomes larger than the first set value preset in the pulse reset timer 6, the discriminator 7 outputs a signal to the alarm mechanism 9, and the alarm mechanism 9 issues an alarm. This alarm usually gives a warning to humans through the five senses, such as a siren or a warning lamp. In response to this alarm, the operator takes measures such as reducing the amount loaded onto the conveyor 4 and removing trapped foreign objects, thereby reducing the load and bringing the rotation speed of the rotating body 4b back to the normal value. Return to However, if such measures are not taken or are insufficient, the rotational speed will further decrease and the pulse interval will increase. Then, when the pulse interval becomes larger than a second set value preset in the pulse reset timer 6, a signal is output from the discriminator 7 to the clutch operating mechanism 8, and the clutch operating mechanism 8 operates to close the clutch 3. is cut and the conveyor 4 stops. By this operation, engine 1, conveyor 4
is safely protected without failure due to overload.

Note that although the above explanation has been made using a conveyor as a representative, it is not limited to conveyors, and the power transmission mechanism between a drive device and a device driven by this drive device is performed via a clutch. It can be applied to any device if there is one.

As described above, this invention uses a pulse generator that generates pulses based on the rotation of a rotating body, and an alarm that alerts the user when the time interval between the pulses generated from this pulse generator exceeds a preset first setting value. and a mechanism that disconnects the clutch when the pulse interval becomes larger than a second set value, which is set in advance to be larger than the first set value. In some cases, an alarm is first issued, at which point the operator can take appropriate measures to avoid the overload condition, and it is only when the overload has progressed that the clutch is disengaged and the rotating body is rotation and equipment operation stop. Therefore, even if the second setting value is set in a relatively safe range, that is, a range with a short pulse interval that does not cause clutch slippage or engine stalling, the problem is that the clutch often disengages and the reset work becomes troublesome. It will be resolved. In addition, by measuring the rotation speed with a pulse generator attached directly to the rotating body rather than the engine, if the clutch is slipping, the rotation speed will further decrease, causing an alarm or disconnection of the clutch. There is no delay in the timing of As the rotation speed detection device uses a pulse generator rather than a device like a tacho generator that exchanges rotational energy into electrical energy, accurate values can be obtained even when the rotation speed is low. This has excellent effects such as preventing mistakes in the timing of alarm generation and clutch disengagement.

[Brief explanation of drawings]

1 and 2 show an example of the present invention, FIG. 1 is a diagram showing a typical example of a device to which a control device is applied, FIG. 2 is a block diagram showing an embodiment of the control device, 3a and 3b are pulse waveform diagrams generated by the pulse generator, where a is a waveform diagram in the case of steady operation, and FIG. 3b is a waveform diagram in the case where the torque increases and the rotation speed decreases. 3...Clutch, 4...Conveyor, 4a...Conveyor input shaft, 4b...Rotating body of conveyor, 5...
...Pulse generator, 6...Pulse reset timer,
7... Discriminator, 8... Clutch operation mechanism.

Claims (1)

[Scope of utility model registration request] In a drive system that transmits the rotational force of a drive device to a rotating body via a clutch and drives the device by this rotating body, there is a pulse generator that generates pulses based on the rotation of the rotating body, and a pulse generator that generates pulses based on the rotation of the rotating body. a mechanism that issues an alarm when the time interval of the pulses exceeds a preset first set value; and a mechanism that disconnects the clutch when the pulse interval exceeds a second set value that is preset larger than the first set value. 1. A control device for a rotating body, comprising: a mechanism for controlling a rotating body;