JPS62276728A - Overcurrent protector - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Technical Field] The present invention relates to an overcurrent protection device, more specifically, a thermal type that releases the latched state of a latching device using heat generated when an overcurrent passes through. The present invention relates to an overcurrent protection device equipped with a tripping device.

BACKGROUND ART Generally, this type of overcurrent protection device includes a spring that opens a contact device inserted into the main circuit, a spring that accumulates force in a latch device when the contact device is closed, and a latch. Three types of springs are required, such as one that causes the reset button to protrude from the casing when the device is unlatched.

[Object of the Invention] The present invention has been made in view of the above points, and its main purpose is to provide an overcurrent protection device in which the number of springs is reduced compared to the conventional one. be.

[Disclosure of the Invention] (Example) As shown in FIGS. 1 and 2, basically, the contact device 2 inserted into the main circuit and the force in the direction of opening the contact device 2 are ! ! Contact device 2 in the loaded latched state
A latch device 3 that holds the terminal in a closed state, and a trip device 4 that releases the latched state of the latch device rf13 and opens the α device 2 when an overcurrent passes through the main circuit, are arranged in a #lI cylindrical shape. A reset button 5 for setting the latch device 3 to the latched state is inserted into the casing 1 so as to be movable forward and backward along the longitudinal direction of the casing 1. In the following explanation, the direction perpendicular to the lower surface, the left-right direction, and the up-down direction in FIG. It is stipulated that

As shown in FIG. 2, the casing 1 is formed into a longitudinally elongated cylindrical shape by a pair of left and right halves 11a, llb and a cover 12 attached to the front ends of the halves 11a, 11b. . Each of the half bodies 11a and 11b is formed in a shape in which one of the left and right sides and the front face are open, and when both the half bodies 11a and llb are combined, the half body 11a,
A cap 12 is fitted onto the outer circumferential surface of the front end portion 11b. The cap 12 is formed into a cylindrical shape, and each half body 11a,
A locking protrusion 13 protruding from the outer peripheral surface of the front end of the cap 11b engages with a locking hole 14 formed at the rear end of the cap 12.

The main electrical circuit into which the contact device 2 is inserted includes a first terminal plate 21 and a second terminal @22, each of which is attached to the rear end of the casing 1 and whose rear 4i portion protrudes from the rear end surface of the casing 1; A frame 6 formed of a conductive material such as a copper-containing material holding the latching device 3 and the tripping device 4, and the front end of the frame 6 having a seven-frame frame 6t are electrically and mechanically connected to the first terminal plate 21. Fixed contact 23 provided
It is formed by a movable contact spring 25 having a movable contact 24 at its rear end that moves into and out of contact with each other, and a heater resistor 26 that electrically connects between the second terminal plate 22 and the seventh frame 6. That is, the main electrical path is formed by the path of first terminal plate 21 - movable contact spring 25 - 7 frame 6 - heater resistor 26 - second terminal plate 22 . The contact device 2 is composed of a first terminal plate 21 and a movable contact spring 25, and the movable contact spring 25 is a leaf spring having a spring force in the direction of separating the movable contact 24 from the fixed contact 23. It is formed. As shown in Fig. 3, the 7-frame 6 is arranged in such a way that it almost partitions the inside of the casing 1 into left and right sides, and the contact device 2 is arranged in the right half (lower half in Fig. 3). It has become. A connecting piece 61afJr is provided at the rear end of the frame 6, and a connecting protrusion 61b is provided upwardly on the upper edge of the connecting piece 61a. Furthermore, a partition piece 61c extends forward from the front edge of the connection piece 61a, and a fixing piece 61d for fixing the movable contact spring 25 extends rightward from the lower edge of the front end of the partition piece 61c.

The front ya part of the movable contact spring 25 is vertically overlapped with this fixed piece 61cl, and both are fixed by welding or the like. Furthermore, a rotating shaft 3 (described later) is provided at the front end of the partition piece 61c.
2 is provided with a shaft hole 62 for holding the shaft.

The second terminal plate 22 is a connecting piece 22a arranged parallel to and spaced from the left side with respect to the connecting piece 61a of the frame 6.
at the front end. Connection piece 22a of second terminal board 22
The terminals of the heater resistor 26 are electrically and mechanically connected to the connecting piece 61a of the frame 6, and the 22'
The a daughter board 22 and the 7th frame 6 are electrically connected to each other via the heater resistor 26.

The latch device 3 includes a latch link 31 made of an insulating material such as synthetic resin. The latch link 31 has a latch protrusion 33 protruding from its upper surface, and an engagement protrusion 34 protruding from its rear end lower surface.

The front surface of the latch protrusion 33 is an engagement surface 33a. A through hole 35 is formed in the latch link 31 below the latch protrusion 33 and extends from side to side, and the rotating shaft 32 is inserted through the through hole 35 . The rotation #32 is formed into a rivet shape, and one end thereof is inserted into the shaft hole 62 of the 717-m 6 to be held in the frame 6. In this way, the latch link 31 is rotatably attached to the frame 6.

Tripping device 4. is composed of a bimetal plate 41 formed in an elongated shape that is long in the front and back, and the heater resistor 26 described above. There are 7 frames 6 at the rear end of the bimetal plate 41.
The coupling protrusion 61b is inserted, the coupling protrusion 61b is caulked, and the bimetal plate 41 is held integrally with the seven frames 6. A locking piece 42 is provided at the front end of the bimetal plate 41 to extend toward the right side. The heater resistor 26 is disposed in close contact with the lower surface of the rear end of the bimetal plate 41.
1 is heated by the heater resistor 26, the bimetal plate 41
The front end is set to curve upward. The locking piece 42 is provided at a position where the locking surface 33a provided on the engagement protrusion 33 of the latch link 31 can be locked to the rear edge of the locking piece 42. Bimetal plate 41 and heater resistor 26
is arranged on the left side with respect to the partition piece 61c of the seven frames 6. In this way, by interposing the seven frames 6 made of a conductive material between the contact device 2 and the tripping device 4, the arc generated when the contact device 2 is opened can be prevented from flying to the tripping device 4. In addition, abrasion powder from the contact device 2 is prevented from adhering to the tripping device 4.

The reset button 5 is made of an insulating material such as synthetic resin. The rear surface of the left half of the reset button 5 is opened to form a spring storage section 51, and a connecting protrusion 52 is protruded from the rear surface of the right half.

A button return spring 53 whose one end abuts against the front surface of the left half body 11a is housed in the spring storage portion 51, and the reset button 5 is urged in a direction to protrude from the casing 1 by this button return spring 53. . A slider 7 that moves back and forth within the casing 1 is connected to the rear end of the connecting protrusion 52 . The slider 7 is provided with a pressing protrusion 71 on the lower surface of the rear end that can come into contact with the movable contact spring 25. When the suppressing protrusion 71 presses the upper surface of the movable contact spring 25, the contact device 2 is closed, and the pressing protrusion 71 The contact device 2 is opened when the pressing force on the upper surface of the movable contact spring 25 is relaxed. The engagement protrusion 3 of the latch link 31 is provided on the upper surface of the slider 7.
An engagement recess 72 is formed in which the engagement protrusion 34 can be engaged.
In a state where the engagement recess 72 is engaged with the engagement recess 72, the slider 7 is prevented from moving forward. The front surface of the slider 7 has an inclined surface 73 that is inclined downward toward the front.
is formed, and from the front of the slider 7, a pair of left and right
A side piece 74 is extended. A connecting bar 75 running in the left-right direction is interposed between the front ends of the guide pieces 74, and a connecting bar 75 is provided with a rear i of the connecting piece 54 provided on the reset button 5.
The slider 7 is connected to the reset button 5 so as to be able to swing up and down by the notch 54 formed in the part. The outer peripheral surface of the reset button 5 is cap 1
2, so that the reset button 5 can be smoothly operated back and forth without wobbling. A locking protrusion 7 is provided on the left side of the front end of the slider 7.
6 is provided protrudingly, and when the locking protrusion 76 is locked to the inner circumferential surface of the front end of the casing 1 with the reset button 5 protruding from the casing 1, the reset button 5 is moved forward of the casing 1. The amount of protrusion is regulated.

With the above configuration, the second terminal plate 22, the movable contact spring 25
, the heater resistor 26, and the latch link 31 are held by the frame 6, and can be assembled into the casing 1 with the parts attached to the frame 6 in advance, making assembly work easy.

(motion) The operation will be explained below based on FIGS. 4 to 9.

When the contact device 2 is in the closed state, as shown in FIGS. 4 and 5, the front surface of the casing 1 and the reset button 5
is flush with the front surface of the latch link 31, and the engagement protrusion 3 of the latch link 31
The locking surface 33a of No. 3 is in a latched state in contact with the rear edge of the locking piece 42 of the bimetal plate 41. At this time, since the slider 7 is located at the rear, the movable contact spring 25 is pressed downward by the suppressing protrusion 71 of the slider 7, and the movable contact 24 contacts the fixed contact 23, and the slider 7 is locked. The engagement of the locking protrusion 34 of the latch link 31 with the recess 72 prevents the slider 7 from moving in the +1rI direction. That is, in this state, the latch link 31 and the slider 7 are urged upward by the force that causes the movable contact spring 25 to open the contact device [2], and the latch link 31 and the bimetal plate 41 are biased upward. By engaging, the contact device 2 is maintained in a closed state. Further, the button return spring 53 is also compressed, thereby accumulating a force that causes the reset button 5 to protrude from the casing 1. Thus, the latch device 3 is composed of the latch link 31, the bimetal plate 41, the slider 7, and the movable contact spring 25.

When an overcurrent flows in the main circuit between the first terminal plate 21 and the second terminal plate 22 in the above-mentioned state, the heater resistor 26 generates heat, and the bimetal plate 41 is heated.
The front end of is curved upward.

As a result, the engagement state between the locking surface 33a and the locking piece 42 is released, and as shown in FIG.
The rear end portion of the latch link 31 and the rear end portion of the slider 7 are pressed upward by the spring force 5.

Since the latch link 31 has a smaller rotation radius than the slider 7, the engagement protrusion 34 disengages from the engagement recess 72, and the slider 7 moves forward due to the spring force of the button return spring 53. When the slider 7 moves forward, the lower surface of the front i of the latch link 31 comes into contact with the inclined surface 73 formed on the front surface of the slider 7, and as the slider 7 moves forward, the latch link 31 moves backward. (around the cloth in Figure 1). Slider 7 moves forward to a predetermined position and resets fa5
When the latch link 3 protrudes from the casing 1, the latch link 3 is attached to the top surface of the slider 7, as shown in FIGS. 7 and 8.
1 comes into contact with the lower surface of the placing end, and the latch link 31 returns to the same position where the contact device 2 was closed. Here, since the contact device fi2 is open, the bimetal plate 41 also returns to its original position, and the latch link 31 and bimetal @4
1 automatically returns to the latched state. Since the latch link 31 and the slider 7 are made of insulating material, the latch! Since the device 3 is not inserted into the main electrical circuit, no leakage occurs in the latch device 3 when the contact device 2 is opened, and the latch devices 1 and 3 are not welded or worn out. . In other words, the rI of the contact! Since the latch device 3 is not damaged in extreme situations, it can be used repeatedly.

As described above, when the contact device 2 is closed, the front surface of the reset button 5 is flush with the front surface of the casing 1, and the contact device 2! ! Since the reset button 5 protrudes from the front surface of the casing 1 when the contact device 2 is opened, the reset button 5 can be used as a reference for identifying the state of the contact device 2.

Here, even if an external force acts on the reset button 5 due to circumstances such as the front surface of the reset button 5 being in contact with a wall surface, and the reset button 5 cannot protrude from the front surface of the casing 1, as described above, After latch link 31 ra
Since the rear end of the slider 7 and the rear end of the slider 7 are movable upward, as shown in FIG. ! 2 can be opened. That is, even if the reset button 5 does not move, the contact 7α device 2 can be opened.
The so-called trip-free 8! It is structured as follows.

In order to return the contact from the W4 pole state to the closed pole state, the reset button 5 may be pushed into the casing 1.

That is, by pushing in the reset fa5, the slider 7 moves rearward to close the contact device 2, and at that position, the latch link 31 is inserted into the engagement recess 72 of the slider 7.
The engaging projections 34 of the two engage with each other.

In the above embodiment, an indirect heating type device using a heater resistor 26 was shown as a heat generating device, but this is applied when the rated current is about 3 A or less, and when the rated current is about 5 A or more, the heater resistor 26 is used. IjfJ2ra child board 22 instead of resistor 26
A connecting wire made of a braided wire may be inserted and connected between the connecting piece 22a and the vicinity of the center of the bimetal plate 41. In this case, the overcurrent causes the bimetal plate 41 to self-heat and bend forward, resulting in a so-called direct heating type device.

[Effect of the invention 1] It has 7 frames made of conductive material, has a casing, a movable contact that forms a contact device inserted into the main electrical circuit together with a fixed contact, and has a spring force in the direction in which the contact device is rN poled. A movable contact spring and a position where a pressing force is applied to the movable contact spring so that the contact device closes when force is accumulated in the movable contact spring, which is supported by a rotating shaft provided at a fixed position in the casing, and a movable contact. The latch link is rotatable between the position where the pressing force on the contact device is released and the contact device is closed, and the latch link is rotated between the heating device inserted in the main circuit and the position where the contact device is closed. A bimetal plate is provided with an engaging part that engages with a part of the latch link, and is heated by a heat generating device to release the engagement state with the latch link when an overcurrent flows through the main path, and a button return spring that protrudes from the casing. The movable contact spring applies rotational force to the latch link, which is different from the conventional closing spring and latch spring. This has the advantage that one spring can be used for both purposes, and as a result, the number of springs used can be reduced.

[Brief explanation of the drawing]

#&1 Figure shows one embodiment of the present invention! fr[ili figure,
FIG. 2 is an exploded perspective view of the same, FIG. 3 is a horizontal sectional view of the same, and FIGS. 14 to 9 are explanatory views of the same. 1 is a casing, 2 is a contact device, 3 is a latch device, 4 is a tripping position, 5 is a reset button, 23 is a fixed contact, 24
is a movable contact, 25 is a movable contact spring, 26 is a heater resistor,
31 is a latch link, 33a is a locking surface, 41 is a bimetal plate, 42 is a locking piece, and 53 is a button return bone.

Claims (1)

[Claims] (1) A casing, a movable contact that forms a contact device inserted into the main electrical circuit together with a fixed contact, a movable contact spring having a spring force in the direction of opening the contact device, and a movable contact spring provided at a fixed position within the casing. The position where the pressing force is applied to the movable contact spring so that the contact device closes while it is supported by the rotating shaft and accumulates force in the movable contact spring, and the position where the pressing force on the movable contact is released and the contact device is opened. The main body is equipped with a latch link that is rotatable between the position where the contact is made and a heat generating device inserted into the main electrical circuit, and an engaging part that engages with a part of the latch link at the position where the contact device is closed. When an overcurrent flows through the electrical circuit, the bimetal plate is heated by a heat generating device to release the engagement with the latch link, and the bimetal plate is biased by a button return spring in a direction that projects from the casing, and is inserted into the casing so that it can move forward and backward. An overcurrent protection device comprising a reset button.