JPH09318468A - Contact pressure measuring device and switch - Google Patents

Abstract

(57) Abstract: An object of the present invention is to reduce the contact pressure measurement work, improve the measurement accuracy, and shorten the measurement time. A main body base (11) is formed with an accommodating portion (12) for accommodating a switch, and a cylinder (18).
A support plate 19 that is moved up and down by is provided. A measurement unit 20 is attached to the support plate 19, a pulling force detector and a control circuit are provided inside a case 21 of the measurement unit 20, and a display 24 is provided on the front surface of the case 21. There is. The pulling force detector has a connecting portion 25. The main body base 11 is provided with a separation detection circuit and a control circuit for controlling the measurement operation.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a contact pressure measuring device for measuring a contact pressure of a movable contact in a switch such as a circuit breaker or an earth leakage breaker, and a switch to be measured by the contact pressure measuring device.

[0002]

Conventionally, as a contact pressure measuring device of this type, there is one having a structure shown in FIG.
That is, a fixed contact 2 and a movable contact 3 are provided in a case 1 of a switch, for example, a circuit breaker. The fixed contact 2 includes a fixed contact arm 2a and a fixed contact 2b, and the movable contact 3 includes a movable contact arm 3a and a movable contact 3b. A contact pressure is applied to the movable contact 3 by a spring (not shown).

On the other hand, the contact pressure measuring device 4 is provided with a clip 5 as a connecting portion, and the contact pressure measuring device 4 is connected with the clip 5 near the movable contact 3b of the movable contact 3. Pull up by hand. In this case, although not shown, a buzzer is provided and the movable contact 3
This buzzer sounds in a state in which is connected to the fixed contact 2.

When the contact pressure measuring device 4 is pulled up, however, the load applied to the contact pressure measuring device 4, that is, the pulling force is sequentially displayed on the display portion of the contact pressure measuring device 4. Then, the operator recognizes that the movable contact 3 is separated from the fixed contact 2 by the interruption of the buzzer sound, and the operator keeps the contact pressure measuring device 4 at this position while The pulling force, that is, the contact pressure is read from the display unit.

However, in the above-mentioned conventional technique, the measuring operator must raise the contact pressure measuring device 4 while listening to the buzzer sound and judging the read timing of the contact pressure, and when the read timing is judged. It is necessary to stop the contact pressure measuring device 4 at that position and maintain the state, and it is necessary to pay attention to the measurement work as a whole, and the work is considerably troublesome. Depending on the situation, it could vary. Moreover, if the contact pressure measuring device rises quickly, the stop timing of the contact pressure measuring device 4 deviates from the proper timing, and accurate measurement cannot be performed.
Therefore, there is a problem that the ascending speed must be slowed down and the measurement takes time.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a contact pressure measuring device and a switch which improves the measurement accuracy.

[0007]

SUMMARY OF THE INVENTION The present invention is for measuring the contact pressure of a movable contact with respect to a fixed contact, and a connecting portion connected to the movable contact in a state where the movable contact is in contact with the fixed contact. Pressure measuring means for measuring a load applied to the connecting portion, measurement result displaying means for displaying a measurement result by the pressure measuring means, and the pressure measuring means are displaced in a direction in which the movable contact is separated. The drive means, the separation detecting means for detecting the movable contact when it is separated from the fixed contact, and the measurement result of the pressure measuring means when the separation is detected by the separation detecting means. A control means for displaying and holding the result display means and for stopping the measurement operation is also provided.

In the above structure, when the driving means displaces the connecting portion of the pressure measuring means in the direction in which the movable contact is opened, the force for opening the movable contact through the connecting portion is gradually increased. I'm becoming. Then, when the movable contact is separated by the driving means, this is detected by the separation detecting means. At this time, the control means causes the measurement result display means to display and hold the measurement result of the pressure measurement means, and stops the measurement operation. Therefore, the operator can know the contact pressure of the movable contact by recognizing the measurement result displayed by the measurement result display means when the measurement operation is stopped.

According to this, the pressure measuring means is automatically displaced by the driving means, and when the movable contact is opened, the measurement result by the pressure measuring means is displayed and held, so that the buzzer sound is stopped. The conventional troublesome work of holding the contact pressure measuring device 4 and recognizing the measurement result in that state can be eliminated according to the timing, and the measurement result does not vary depending on the operator. It can contribute to the improvement of accuracy. Moreover, since the opening of the movable contact is automatically detected and the measurement result is automatically displayed at that timing, an accurate measurement result can be automatically obtained even if the displacement speed of the pressure measuring means is increased. Can contribute to shortening the

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to FIGS. First, in FIG. 1, the main body base 11 of the contact pressure measuring device has a rectangular shape,
A housing portion 12 for housing the switch is formed in this, and a plurality of connection terminals 13 and 14 are provided upright at both bottom end portions (left and right end portions in FIG. 2) of the housing portion 12. There is. A fixing pin 15 is movably provided on the upper left portion of the main body base 11, and a holding mechanism 16 is provided on the upper surface on the right side.

A vertical frame 17 is vertically installed on the right end of the main body base 11, and the support plate 1 is moved up and down by a cylinder 18 as a driving means.
9 are provided. Further, a measurement unit 20 is attached to the support plate 19, and the measurement unit 2
As shown in FIG. 3, inside the case 21 of 0, the pulling force detector 22 as a pressure measuring means and the control circuit 2 as a control means.
3 and a display device 24 as a measurement result display means is provided so as to be located on the front surface of the case 21.

The pull-up force detector 22 is composed of, for example, a strain gauge, is fixed to the unit case 21, and moves integrally with the unit case 21.
5 (see FIG. 2). The connecting portion 25 has a clamp 25a and a tension coil spring 26, which is a spring member detachably attached to the tip of the clamp 25a. Then, the pulling force detector 22 generates a detection signal (measurement result) according to the load (load) applied to the clamp 25.

The control circuit 23 is constituted by including, for example, a microcomputer, and when a detection signal is given from the pulling force detector 22, it causes the display 24 to display the measurement result in response to the detection signal. In addition to this, the control circuit 23 controls the overall measurement, and its control function will be described later.

On the other hand, the main body base 11 is provided with a disconnection detection circuit 27 as a disconnection detection means, which connects the connection terminal 13 to the power supply terminal Vcc and pulls down the other connection terminal 14. It is configured to be connected to the GND via the resistor 28, and when the detection output thereof changes to the low level, the disconnection detection signal Sk is provided with this low level signal.
And Further, the operation unit 29 includes a power-on switch,
A power-off switch, a zero-point adjustment switch, a measurement start switch, and the like are provided, and the switch signal is given to the control circuit 23. The control circuit 23
Controls the drive of the cylinder 18 via a drive circuit 30.

A circuit breaker 31 which is a switch to be measured
As generally known, the case 32 is provided with a fixed contact 33 and a movable contact 34 on a case 32, and an opening / closing mechanism 35 for opening and closing the movable contact 34.
Is provided. The fixed contact 33 includes a fixed contact arm 33a and a fixed contact 33b, and the movable contact 34 includes a movable contact arm 34a and a movable contact 3.
4b. A contact pressure is applied to the movable contact 34 by a spring (not shown). A movable side connection terminal portion 34c is provided on the left side of the circuit breaker 31 so as to be electrically connected to the movable contact 34. The movable arm 34a of the movable contact 34 has a movable contact 34b.
A connecting hole portion 36 serving as an engaging portion is formed at a predetermined position near the connecting hole portion 36.

Now, the case of measuring the contact pressure of the movable contact 34 will be described together with the control function of the control circuit 23. First, the circuit breaker 31 is arranged in the housing portion 12 of the main body base 11. In this case, the movable side connection terminal portion 34c is brought into contact with the connection terminal 13, and the fixed side connection terminal portion 33a is brought into contact with the connection terminal 14. Then, the movable side connection terminal portion 34c is fixed to the connection terminal 13 by the fixing pin 15, and the fixed side connection terminal portion 33b is fixed to the connection terminal 14 by the holding mechanism 16. The fixing pin 15 and the pressing mechanism 16 prevent the circuit breaker 31 from moving upward. In this case, the movable contact 34 is in contact with the fixed contact 33, so that the terminals 13 and 14 in FIG. 3 are closed.

Thereafter, the hook 26a at the lower end of the tension coil spring 26 of the connecting portion 25 is hooked in the connecting hole 36 of the movable contact 34. Then, after turning on the power switch of the operation unit 29 to turn on the power of the contact pressure measuring device, and turning on the zero point adjustment switch to adjust the output level of the pulling force detector 22 to zero, Turn on the measurement start switch. Then, the control circuit 23 drives the cylinder 18 to move the unit case 21 of the measurement unit 20 upward. As a result, the pulling force detector 22 also rises and detects the load applied to the connecting portion 25. In this case, the connecting portion 25
Since the tension coil spring 26 is provided at the tip of the connecting portion 25, a large force is not applied to the connecting portion 25 at once. Then, the pulling force detection circuit 22 sequentially detects the load applied to the connecting portion 25 and gives the detection signal (measurement result) to the control circuit 23. The control circuit 23 sequentially displays the measurement results on the display 24 according to the detection signal.

When the control unit 20 is moved upward by driving the cylinder 18, the force for separating the movable contact 34 is gradually increased via the connecting portion 25 and the tension coil spring 26. Then, when a separation force equal to or greater than the contact pressure of the movable contact 34 acts, the movable contact 34 separates from the fixed contact 33. Then, the detection output of the separation detection circuit 27 changes to a low level, that is, the separation detection signal Sk is generated and the control circuit 23
Given to. The control circuit 23 causes the display 24 to display and hold the measurement result at this time, that is, the contact pressure, and stops driving the cylinder 18 (stops the measurement operation).

According to this embodiment, the pull-up detector 22 is automatically displaced upward by the cylinder 18, and when the movable contact 34 is opened, the measurement result by the pull-up detector 22 is displayed. Since it is displayed and held on the display device 24, it is possible to eliminate the conventional troublesome work of holding the contact pressure measuring device and recognizing the measurement result in that state at the timing of the stop of the buzzer sound. The measurement result does not vary depending on the operator, which contributes to improvement in measurement accuracy. Moreover, since the separation of the movable contact 34 is automatically detected and the measurement result is automatically displayed at that timing, an accurate measurement result can be automatically obtained even if the pulling speed of the measurement unit 20 is increased. This can contribute to shortening the measurement time.

In particular, according to this embodiment, since the connecting portion 25 is composed of the clamp 25a and the tension coil spring 26, it is possible to absorb a sudden change in force, and the pulling speed of the measuring unit 20 can be used. It is possible to prevent variations in measurement results. Further, according to this embodiment, the circuit breaker 3
Since the connection hole portion 36 that engages with the connection portion 25 is formed at a predetermined portion of the movable contact 34 of No. 1, when the contact pressure is measured as in the present embodiment, the measurement conditions of the circuit breakers 31 are individually measured. Does not fluctuate, and the reliability of measurement results increases.

The present invention is not limited to the above embodiment, and for example, the connecting portion 25 may be composed of only the clamp 25a. The drive means is the cylinder 18
Instead, an elevating mechanism having a motor may be used. Further, when the opening of the movable contact 34 is detected, the buzzer may be notified to notify the opening. The switch is not limited to the circuit breaker, but may be an earth leakage breaker or the like. Further, the engaging portion formed on the movable contact 34 is not limited to the connecting hole portion 36, and may be a protrusion. Further, although the measurement results are sequentially displayed on the display 24, they may be displayed only at the time of opening.

[0022]

As apparent from the above description, the present invention has the following effects. According to the invention of claim 1, the pressure measuring means is automatically displaced by the driving means, and when the movable contact is opened, this is automatically detected and the measurement result by the pressure measuring means is displayed. Since the buzzer sound is stopped, the conventional troublesome work of holding the contact pressure measuring device and recognizing the measurement result in that state can be eliminated in accordance with the timing of the buzzer sound stop. It does not vary from person to person, and can contribute to improvement in measurement accuracy. Moreover, since the opening of the movable contact is automatically detected and the measurement result is automatically displayed at that timing, an accurate measurement result can be automatically obtained even if the displacement speed of the pressure measuring means is increased. Can contribute to shortening the

According to the second aspect of the present invention, since the connecting portion is configured to include the spring member, it is possible to absorb a sudden change in force, and the variation of the measurement result due to the displacement speed of the pressure measuring means can be prevented. Can be prevented. According to the invention of claim 3, since the engaging portion that engages with the connecting portion is formed at a predetermined portion of the movable contact of the switch, the measurement conditions do not vary from one switch to another and the measurement accuracy is improved. Increase.

[Brief description of drawings]

FIG. 1 is a perspective view of a contact pressure measuring device showing an embodiment of the present invention.

FIG. 2 is a vertical sectional view of a contact pressure measuring device and a circuit breaker.

FIG. 3 is a block diagram showing an electrical configuration of a contact pressure measuring device.

FIG. 4 is a side view of a contact pressure measuring device showing a conventional example.

[Explanation of symbols]

11 is a main body base, 13 and 14 are connection terminals, 15 is a fixing pin, 16 is a holding mechanism, 18 is a cylinder (driving means), 20 is a measuring unit, 22 is a pulling force detector (pressure measuring means), 23 Is a control circuit (control means), 24 is an indicator (measurement result display means), 25 is a connecting portion, 26 is a tension coil spring (spring member), 27 is an opening detection circuit (opening detection means), and 31 is a circuit. A circuit breaker (switch), 33 is a fixed contact, 34 is a movable contact, and 36 is a connecting hole portion (engaging portion).

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Masahiro Fukui Inventor Masahiro Fukui 2121 No. 21 Osamu, Asahi-cho, Mie-gun, Mie Prefecture Mie Factory, Toshiba Corporation

Claims (3)

[Claims] 1. A method for measuring a contact pressure of a movable contact with respect to a fixed contact, comprising a connecting portion connected to the movable contact in a state where the movable contact is in contact with the fixed contact,
Pressure measuring means for measuring a load applied to the connecting portion, measurement result displaying means for displaying a measurement result by the pressure measuring means, and driving means for displacing the pressure measuring means in a direction in which the movable contact is separated. A separation detecting means for detecting the movable contact when it is separated from the fixed contact; and a measurement result of the pressure measuring means when the separation is detected by the separation detecting means. And a holding means for displaying and holding the measurement operation and stopping the measurement operation. 2. The contact pressure measuring device according to claim 1, wherein the connecting portion includes a spring member. 3. A fixed contact and a movable contact that comes into contact with and separates from the fixed contact, and a predetermined portion of the movable contact is engaged with a connecting portion of the pressure measuring means in the contact pressure measuring device according to claim 1. A switch provided with an engaging portion for