JPH0727547Y2 - Earth leakage circuit breaker - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to an earth leakage circuit breaker that detects an earth leakage in an electric circuit and interrupts the electric circuit.

[Prior Art] This type of conventional earth leakage breaker basically consists of a contact device inserted in an electric circuit, a leakage detection device for detecting electric leakage in the electric circuit, and a contact device which is responsive to or connected to the leakage detection device. It is composed of an opening and closing device that opens and closes the contact device in conjunction with a handle that is manually operated to open and close. Such an earth leakage circuit breaker leakage detection device is composed of a zero-phase current transformer that detects an earth leakage and a solenoid that drives the switchgear with the output of the zero-phase current transformer. And a drive circuit for generating a drive signal for driving the solenoid. Further, there is a drive circuit which is provided with a sensitivity adjusting circuit section for adjusting the leakage sensitivity so that the leakage sensitivity can be adjusted by switching a sensitivity adjusting switch. FIG. 3 shows a main part of an earth leakage breaker having this kind of earth leakage sensitivity adjusting function. In this earth leakage breaker, the circuit component 3 of the sensitivity adjustment circuit section including the sensitivity adjustment switch 2 is mounted on the printed circuit board 1 separately from the drive signal generation circuit section due to space restrictions, and the printed circuit board 1 is mounted on the body 10a. The lower part was fixed and installed upright in the fixing groove 4 formed in the above.

[Problems to be solved by the invention] However, the switch 2 for adjusting the sensitivity is the body 10
Since the operation is performed from the operation window 5 formed on the cover 10b which is formed on the body 10a and constitutes the housing 10 together with a, the operation of the switch 2 causes the printed circuit board 1 to rattle.

As a method of solving this problem, it is conceivable to form a fixing groove for fixing the upper portion of the printed board 1 in the cover 10b and firmly fix the printed board 1. However, in this case, the cover 10b must be attached to the body 10a by inserting the upper portion of the printed circuit board 1 into the fixing groove of the cover 10b, which poses a problem that the mounting of the cover 10b becomes troublesome. In addition, in this type of earth leakage breaker, a switchgear (not shown) is incorporated in the body 10b, and the cover 10b has a handle integrally connected to the switchgear protruding from an opening formed in the upper surface of the body. It is attached to 10b. For this reason, when the printed circuit board 1 is firmly attached between the body 10a and the cover 10b, the positional relationship between the handle and the opening is restricted by the attachment of the printed circuit board 1, so that the handle is brought into sliding contact with the inner surface of the opening. This may cause a problem that the operability of the handle deteriorates. In addition to the handle, it is attached to the body 10a side and the cover 10b
The same problem may occur in the member projecting from.

The present invention has been made in view of the above points, and an object thereof is to provide an earth leakage breaker in which rattling of a printed circuit board can be reduced and a cover can be easily attached. .

[Means for Solving the Problems] In order to achieve the above-mentioned object, the present invention forms a contact piece that contacts one end side of an upper portion of a printed circuit board on a cover.

[Operation] As described above, according to the present invention, by forming the contact piece on the upper end of the printed circuit board on the cover, the printed circuit board is prevented from being bent toward the one end side when the switch is operated. The rattling of the board is reduced and the contact piece is formed only on one end side of the printed board, so that when the cover is attached to the body, the upper part of the printed board is fixed and the cover is covered. Even if the rattling of the printed circuit board can be reduced by eliminating the need to wear the cover, the cover can be easily attached.

[Embodiment] FIGS. 1 and 2 show an embodiment of the present invention. First, the overall configuration of an earth leakage breaker to which the present invention is applied will be described. The housing 10 of the earth leakage breaker is composed of a synthetic resin body 10a and a cover 10b attached to the body 10a, and is formed in a rectangular parallelepiped shape as a whole. At both ends of the housing 10 in the longitudinal direction, three power supply terminals 12 and three load terminals 11 for connecting a power supply line and a load line, respectively, are provided. Inside the housing 10, the power supply terminal 12 and the load terminal 11 are provided. The contact device 20 is inserted into each electric path between the contact and the device to form three poles. In addition to the contact device 20, a leakage detecting device 40 for detecting an electric leakage and a response or contact device 20 for the leakage detecting device 40. An opening / closing device 50 for opening / closing the contact device 20 is provided in association with a handle 16 for manually operating the opening / closing. In addition,
The earth leakage breaker of this embodiment also includes an abnormal current detection device 30 for detecting an abnormal current such as an overcurrent or a short circuit current.

The contact device 20 includes a fixed contact plate 22 to which a fixed contact 21 connected to the power supply terminal 12 is fixed, and a movable contact that separates from and contacts the fixed contact 21.
A pair of arc-extinguishing coils 23 is formed of a movable contact plate 24 fixed to the contact device 20. The contact device 20 is formed in a substantially U-shape open downward and sandwiches the fixed contact 21 to face each other.
26, and a substantially U-shaped arc-extinguishing coil opened downward
An arc extinguishing device comprising an arc extinguishing yoke 25 arranged above the arc extinguishing coil 26 to the left of the arc extinguishing coil 26 in FIG. 2 was provided, and the fixed contact 21 and the movable contact 23 were opened. The arc generated at that time is extinguished. The movable contact plate 24 is inserted into the contact plate holding portion 28 on the base side, and is pivotally supported at an appropriate position in the contact holding portion 28. Further, a contact pressure spring 29 is arranged in the contact plate holding portion 28, and the contact pressure is applied by the contact pressure spring 29 when the contact device 20 is closed, and the contact device 20 is opened. At this time, a force is applied to move the movable contact 23 away from the fixed contact 21. Each contact plate holder
28 is connected by a crossbar 27, and when the contact device 20 of one pole is opened, the contact device 20 of the other pole is also opened via the crossbar 27.

The abnormal current detection device 30 is an electromagnet device that detects a short-circuit current.
30a and a bimetal device 30b for detecting overcurrent. Here, the electromagnet device 30a operates so as to move the plunger 31 biased upward by the return spring 32 downward when a short-circuit current flows, and the coil 33 to which the load current of the electromagnet device 30a is energized. One end is connected to the internal terminal 13 and the other end is connected to the bimetal device 30b. The bimetal device 30b includes a heater plate 34 having a coil 33 connected to the lower end thereof and a bimetal plate 35 heated by the heater plate 34.
Are formed so as to face each other, a pressing screw 36 is screwed to the upper end of the bimetal plate 35, and the upper end of the heater plate 34 is connected to the movable contact plate 24 by a braided wire 37.

Here, the electric path between the internal terminal 13 and the power supply terminal 12 will be described. In the route of the internal terminal 13, the coil 33, the heater plate 34, the braided wire 37, the movable contact plate 24, the fixed contact plate 31, and the power supply terminal 12. When an electric path is formed and a short-circuit current flows in this electric path, the plunger 31 is pulled downward against the spring force of the return spring 32, and when an overcurrent flows in this electric path, the bimetal plate
35 is heated by the heater plate 34, and the upper end portion of the bimetal plate 35 bends leftward in FIG.

The earth leakage detection device 40 includes a zero-phase current transformer 41 arranged between the load terminal 11 and the internal terminal 13, and a solenoid 42 that responds to the output of the zero-phase current transformer 41. Solenoid 42
2 is provided with a plunger 46 that is pulled in on the left side in FIG. 2B when a leakage current is detected. In response to the plunger 46 being pulled leftward, a switchgear 50, which will be described later, opens the contact device 20. I am going to do it. Further, when the plunger 46 is pulled in, the earth leakage detection device 40 is covered with the cover 10b.
Is provided with a display button 48 protruding from the upper surface of the display for displaying the leakage state. That is, by providing the display button 48, it is possible to identify whether the contact is opened due to the leakage current or the other abnormal current. Further, by providing a test switch 14 for electrically connecting the electric paths through a resistor by pressing a test button 15 protruding from the upper surface of the cover 10b, the test switch 14 creates a pseudo electric leakage state, and the electric leakage detection device 40 The operation of can be confirmed.

The switchgear 50 is provided with the abnormal current detector 30 through the interlocking bar 51.
It is designed to interlock with the electric leakage detection device 40, and is constituted by holding a large number of links 52a to 52f and springs 53a and 53b on a frame 54. The interlocking bar 51 is engaged with the link 52a and rotates counterclockwise in FIG.
52a is operated, and the plunger 31 moves downward, the bimetal plate 35 of the bimetal device 30b bends, or the plunger 46 of the solenoid 42 of the leakage detection device 40 moves to the left side in FIG. The interlocking bar 51 rotates counterclockwise depending on whether it moves. Therefore, due to the short circuit current, overcurrent and leakage current, the interlocking bar 51
Is rotated and the link 52a is operated. The link 52d and the link 52e are linked to the link 52f via a spring 53b, and the link 52f is linked to the handle 16 protruding from the upper surface of the cover 10b. Further, the link 52e is connected to the movable contact plate 24.

Here, when the handle 16 is tilted to the left in FIG. 2 (a),
The movable contact plate 24 moves to close the contact device 20 due to the relationship between the links 52a to 52f and the springs 53a and 53b. At this time, a force in the direction of opening the contact device 20 is accumulated in the springs 53a and 53b, and the equilibrium state is maintained by the engagement relationship of the links 52a to 52f. On the other hand, when any one of the short-circuit current, the overcurrent, and the leakage current flows in the electric path and the interlocking bar 51 rotates counterclockwise in FIG. 2A, the engagement relationship between the links 52a to 52f collapses. The contact devices 20 are momentarily opened by releasing the power accumulated in the springs 53a and 53b. When the contact device 20 is opened in this way, the handle 16 is then tilted to the right in FIG. 2 (a) and the contact device 20 is opened.
It is visible depending on the position of the handle 16.

Hereinafter, the leakage detection device 40, which is a characteristic part of this embodiment
The fixing structure of the printed circuit board 1 on which the sensitivity adjustment switch 2 for adjusting the leakage detection sensitivity is mounted will be described. Also in this embodiment, the printed circuit board 1 is vertically mounted by inserting and fixing the lower part in the fixing groove 4 formed in the body 10a. An operation window 5 for operating the sensitivity adjustment switch 2 is formed in a portion of the cover 10b facing the operation button 2a of the sensitivity adjustment switch 2. A contact piece 6 that abuts the left end surface of the printed circuit board 1 is projected from the inner surface of the cover 10b on the left side of the operation window 5 in FIG. By forming the contact piece 6 on the cover 10b so as to contact one end side of the upper portion of the printed circuit board 1 in this manner, it is possible to prevent the printed circuit board 1 from bending to the left side in FIG. 1 when the sensitivity adjusting switch 2 is operated. The rattling of the printed circuit board 1 is reduced. Further, since the contact piece 6 is formed only on one end side of the printed circuit board 1, when the cover 10b is attached to the body 10a, the upper portion of the printed circuit board 1 is fixed and the cover 10b need not be attached. , Even if the rattling of the printed circuit board 1 is reduced,
The cover 10b can be easily attached. Further, even if the position of the contact piece 6 is deviated, the position deviation of the contact piece 6 can be absorbed within a range in which the printed circuit board 1 flexes to some extent. For example, the printed circuit board 1 can be strongly interposed between the body 10a and the cover 10b. As with the case of mounting, the handle 16
The positional relationship between the handle 16 and the opening through which the handle 16 projects is regulated, and the handle 16 slides into contact with the inner surface of the opening and the handle 16
There is no problem that the operability of is deteriorated.

[Advantage of the Invention] As described above, according to the present invention, the cover is formed with the abutment piece that abuts against one end side of the upper portion of the printed circuit board. Therefore, when the switch is operated, the abutment piece is formed on the side where the abutment piece is formed. Deflection of the printed circuit board can be prevented, and rattling of the printed circuit board can be reduced. Further, since the contact piece is formed only on one end side of the printed circuit board, when the cover is attached to the body, it is not necessary to fix the upper portion of the printed circuit board to attach the cover, and the printed circuit board is loosened. The cover can be easily attached even if the sticking is reduced. Further, even if the position of the contact piece is deviated, it is possible to absorb the position deviation of the contact piece within a range where the printed circuit board flexes to some extent. For example, when the printed circuit board is firmly attached between the body and the cover, The positional relationship between the handle and the opening through which the handle is projected is restricted by mounting the printed circuit board, and there is no problem that the handle slides on the inner surface of the opening and the operability of the handle deteriorates.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part of an embodiment of the present invention, FIGS. 2 (a) and 2 (b) are a longitudinal sectional view and a partially broken plan view showing the overall structure of the same, respectively, and FIG. It is sectional drawing of the principal part of a prior art example. 1 is a printed circuit board, 2 is a switch, 5 is an operation window, 6 is a contact piece, 16 is a handle, 10 is a housing, 10a is a body, 1
0b is a cover, 20 is a contact device, 40 is a leakage detection device, and 50 is a switch device.

Claims (1)

[Scope of utility model registration request] 1. A contact device inserted into an electric circuit, an earth leakage detection device for detecting an earth leakage, and a contact device which operates in response to the earth leakage detection device or which is manually operated to open and close the contact device to open and close the contact device. A printed circuit board consisting of a switchgear and a switch that adjusts the leakage detection sensitivity of the leakage detection device is mounted on the body with the lower part fixed and erected, and an operation window for operating the switch and a printed circuit board. And a contact piece that abuts on one end side of the upper part of the body, which constitutes a housing together with the body and is formed on a cover attached to the body.