JPS63109348A - Overload separating device in tensile apparatus - Google Patents

Abstract

PURPOSE:To easily perform re-starting after separation, by providing a solenoid device composed of a main body part and an insert rod and supplying a constant current to the solenoid device from a constant current power source circuit. CONSTITUTION:A solenoid device 10 consisting of a main body part 11 having winding 11a and the insert rod 12 inserted in the winding 11a is provided. Then, a constant current is supplied to the device 10 from a constant current power source circuit 13 to magnetically attract the main body part 11 and the insert rod 12 and, at the time of this magnetic attraction, an apparatus to be pulled is pulled by a tensile apparatus. When the tensile load determined by the current supplied to the device 10 becomes excessive, the output of the circuit 13 is stopped corresponding to the pulsation current induced in the winding 11a by the change in magnetic flux generated when the insert rod 12 is pulled off from the winding 11a. By this method, re-starting after separation can be easily performed.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to an overload disconnection device for a tensioning device, and in particular, it The present invention relates to an overload disconnection device for a tensioning device that protects the tensioning device and the device under tension by quickly separating the two when a load greater than the load is applied.

(Prior Art) Various tension tests have been performed on throttle valve actuators of carburetors.

In such a test, a load exceeding the set value may be applied due to a failure of the throttle valve actuator, etc. In this case, it is necessary to separate the throttle valve actuator and tension device to protect them.

Therefore, as a conventional method for disconnecting the throttle valve actuator and the tension device, a fuse bolt or spring pin, etc. is provided at the point where the throttle valve actuator and the tension device are connected. The two were separated by being damaged.

In addition to the above method, a separation method shown in FIG. 2 is also known. In this method, when the wire 1 is pulled by a tensioning device (not shown), the load cell 2, the air cylinder 3, and the flange 4 adsorbed on the air cylinder 3 are pulled.
As a result, the throttle valve actuator connected to the tip of the wire 5 is pulled.

When a load exceeding a set value is applied due to a failure of the throttle valve actuator or the like, a voltage signal to that effect is output from the load cell 2 and supplied to the control circuit 7 via the amplifier 6. The control circuit 7 outputs a signal to the valve device 8 to open the valve in response to the voltage signal.

For this purpose, air flows through the air cylinder 3 through the pipes 9a and 9b.
is supplied inside. As a result, the air cylinder 3 and flange 4 are separated. That is, the throttle valve actuator and the tension device are separated.

(Problems to be Solved by the Invention) The above-described conventional techniques had the following problems.

(1) If a fuse bolt, spring pin, etc. is used to disconnect in the event of an overload, the damaged fuse bolt, etc. must be replaced with a new one when restarting.
It takes time to reboot.

Furthermore, since the load upon disconnection is determined by the strength of the fuse bolt, spring pin, etc., the fuse bolt etc. must be replaced each time the overload setting is changed. That is, it was not possible to continuously change the overload setting.

(2) The device shown in Figure 2 that disconnects in the event of overload uses a load cell, which requires periodic adjustment and has a relatively short lifespan, so it must be replaced frequently. Moreover, since the load cell is expensive, the entire device is also expensive.

In addition, since an air cylinder is also used in addition to the load cell, air supply pipes, etc. are required, making the entire device complex and
Become larger. As a result, it was inconvenient to carry.

The present invention has been made to solve the above-mentioned problems.

(Means and effects for solving the problems) In order to solve the above problems, the present invention provides a solenoid device consisting of a main body having a winding and an insertion rod inserted into the winding, By supplying a constant current to the solenoid device by a constant current power supply circuit, the main body and the insertion rod are magnetically attracted,
During this magnetic adsorption, the tension device is used to pull the device to be pulled, and when the pulling load determined by the current supplied to the solenoid device becomes excessive, the insertion rod is pulled out of the winding. In the constant current power supply circuit, the same reference numerals as in FIG. 2 indicate the same or equivalent parts.

11 is a solenoid device 10 in which a winding 11a is installed.
12 is an insertion rod of the solenoid device 10 inserted into the winding 11a, and 13 is a constant current power supply circuit.

15-23 are resistors, 24°25 are capacitors, 26.2
7 is a transistor, and 28 is a comparator. Above 15~
28 constitutes the detection circuit 14. 29 is a display device.

In FIG. 1, the constant current power supply circuit 13 causes the winding 11a to
When a predetermined constant current is supplied to the main body 11, the insertion rod 12 inserted in advance is magnetically attracted to the main body 11. Therefore, in this state, by pulling the wire 1 with a tensioning device (not shown), the wire 5 is pulled through the solenoid device 10, and the throttle valve actuator (not shown) connected to the tip of the wire 5 is pulled. You'll start to feel drawn to it.

By the way, when a load greater than the set value determined by the constant current is applied to the solenoid device 10 due to a failure of the throttle valve actuator or the like, the insertion rod 12 is removed from the winding 11a.

At this time, a change in magnetic flux occurs within the solenoid device 10, so a pulsating current flows through the winding 11a.

In this embodiment, this pulsating current is detected by the resistor 15 as a voltage change. The detected voltage change is capacitor 2
4, resistors 17 and 18, and the differential signal is supplied to the (-) input terminal of comparator 28.

On the other hand, a reference voltage obtained by dividing the power supply voltage by resistors 19 and 20 is supplied to the (+) input terminal of the comparator 28 .

This reference voltage is set so that the differential signal is higher.

As a result, when a differential signal is generated, a low level pulse signal is output from the comparator 28, so the transistor 28 outputs a low level pulse signal.
6 and 27 become conductive.

Depending on the conduction state of the transistor 27, a disconnection detection signal is output from the transistor 27 and is supplied to the constant current power supply circuit 13 and the display 29. The output of the constant current power supply circuit 13 is stopped in response to the disconnection detection signal.

As a result, the supply of current to the winding 11a is stopped. Further, in response to the disconnection detection signal, the display 29 displays disconnection by, for example, lighting a pilot lamp.

In this embodiment, a differential signal is supplied to the (-) input terminal of the comparator 28 even when the device is started up (immediately after the constant current is supplied to the winding 11a).
5 so that the reference voltage is higher than the potential of the differential signal at this time. As a result, no disconnection detection signal is output during this startup.

The solenoid device 10 generates heat, which causes the resistance of the winding 11a to change. However, in this embodiment, the constant current power supply circuit 13 is used to keep the current flowing through the winding 11a constant. Therefore, the set load for disconnection does not change due to changes in current.

After the disconnection is performed as described above, when restarting the device, the insertion rod 12 is inserted into the winding 11a, and then the constant current power supply circuit 13 is turned on.

Further, in this embodiment, from the constant current power supply circuit 13 to the winding 11
By changing the constant current value supplied to a by a known appropriate means and/or by changing the number of windings, the set load for disconnection can be arbitrarily changed.

FIG. 3 is a circuit diagram showing another embodiment of the present invention. In the figure, the same reference numerals as in FIG. 1 represent the same or equivalent parts. 30 is a permanent magnet, 30a is a detection coil wound around the permanent magnet, 31 is a flange member that magnetically attracts the permanent magnet, 32 is a diode, and 14a is a detection circuit.

In FIG. 3, when the permanent magnet 30 and the flange member 31 are magnetically attracted to each other, when the wire 1 is pulled by a tensioning device (not shown), the wire 5 is pulled. A throttle valve actuator (not shown) connected to becomes pulled.

By the way, in this embodiment, if a load exceeding a set value determined by the magnetic force of the permanent magnet 30 is applied due to a failure of the throttle valve actuator or the like, the permanent magnet 30
The magnetically attracted state between the flange member 31 and the flange member 31 is released.

As the magnetic attraction state is released, the magnetic flux acting on the detection coil 30a changes, so that a pulsating current flows through the detection coil 30a. In this embodiment, only the forward current is taken out by passing this pulsating current through the diode 32, and the forward current is supplied to the (-) input terminal of the comparator 28.

A reference voltage obtained by dividing the power supply voltage by resistors 19 and 20 is supplied to the (+) input terminal of the comparator 28 . This reference voltage is set so that the potential corresponding to the forward current is higher.

As a result, when the pulsating current occurs, a low-level pulse signal is output from the comparator 28, so that the transistors 26 and 27 become conductive and are disconnected by the indicator 29, similar to the embodiment related to FIG. This can be detected.

However, in this embodiment, in order to change the set separation load, it is necessary to replace the permanent magnet with a new one with a different magnetic force each time, or to provide a bypass for the permanent magnet 30 and adjust the bypass. This is an inconvenience.

(Effects of the Invention) As is clear from the above description, according to the present invention, which uses a solenoid device to perform disconnection at the time of overload, the following effects are achieved.

(1) Restarting after disconnection can be performed more easily than in the conventional example using fuse bolts, spring pins, etc.

(2) The set load for disconnection can be easily changed by simply changing the current value flowing through the winding.

(3) There is no need for periodic inspection or conversion unlike the conventional example using a load cell.

(4) Compared to the conventional example using a load cell, the device can be made simpler and smaller, and therefore the device can be easily carried.

(5) Compared to the conventional example using an expensive load cell, the cost of the device can be significantly reduced.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing one embodiment of the present invention, Fig. 2 is a configuration diagram showing an example of a conventional overload disconnection device for a tension device, and Fig. 3 is a circuit diagram showing another embodiment of the present invention. It is. 1.5... Wire, 10... Solenoid device, 11
... Main body, lla... Winding wire, 12... Insertion rod,
13... constant current power supply circuit, 14... detection circuit, 29
···display

Claims (2)

[Claims] (1) A solenoid device consisting of a main body having a winding and an insertion rod inserted into the winding, and a part of the main body corresponding to one end in the axial direction of the solenoid device and an insertion rod corresponding to the other end. a constant current power supply circuit that supplies a constant current to the winding; An overload disconnection device for a tension device, comprising: a detection means for outputting a disconnection detection signal that causes at least the constant current power supply circuit to stop its output in response to a pulsating current. (2) The overload disconnection device for a tension device according to claim 1, further comprising display means for displaying that the disconnection detection signal has been output.