JPH0629876Y2 - Circuit protector - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] The present invention relates to an ultra-small circuit protector for the purpose of switching on and off the power supply of a small electric device and protecting against overcurrent.

2. Description of the Related Art Conventionally, the following methods are widely used for switching the power source of a small electric device and overcurrent protection.

(1) With a switch for opening and closing the power supply and a fuse.

(2) With an overcurrent protector that uses a switch for opening and closing the power source and a heating wire or bimetal.

(3) With a circuit protector that has both a power supply opening / closing switch and an overcurrent protection function.

In the case of (1) above, it is the cheapest method, but it is necessary to prepare a fuse with a suitable size and current capacity in case of fuse blowing, and maintenance work such as replacement work for restoration when the fuse is blown Is extremely bad.

Moreover, since the power source opening / closing switch and the fuse are separately mounted, a large space is required, and the assembly work at the time of manufacturing the device is disadvantageous in terms of labor saving. In the case of (2), it is slightly more expensive than in the case of (1), but it is not necessary to always have a replacement fuse and recovery after overcurrent protection can be performed only by button operation, which is good in terms of maintenance. However, the mounting space, assembling workability, etc. are the same as those in (1). The case of (3) is the most expensive, but is superior to (1) and (2) in other respects.

However, even though the current product has become smaller, there are advantages and disadvantages in that it is still large and expensive in terms of practical application to small electric devices.

Therefore, the inventors of the present application have previously reported that the actual exploitation method is 62-8134.
We devised a circuit protector as shown in No. 9 (hereinafter referred to as the prior application). In other words, the idea is that the shape is similar to a cylindrical fuse holder, it is made ultra-small, and the power supply switching function and overcurrent protection function are integrated in the mold case, and yet it is a just reset type trip-free mechanism. The structure is simple and can be provided at low cost.

However, in the prior application, the throwing force of the movable contact generated through the handle, the link, and the link bearing is received by the bimetal, and the force in the contact opening direction is received by the biasing force of the breaking spring by the bimetal. Therefore, the bimetal always receives a tensile force between the connecting conductor and the link bearing, and the direction of the tensile force is a direction that inhibits the deflection due to self-heating when the bimetal is energized.
Therefore, in a very large overcurrent region such as several A to several tens of A where the tensile force is overcome and the bimetal is flexed, the flexure of the bimetal can release the engagement between the link and the link bearing. But 0. In the small current range of several A to several A, the bending force cannot sufficiently overcome the tensile force and does not work, that is, it is difficult to manufacture a product with a small rated operating current, or the operation is not stable. Had. Therefore, the present invention is intended to provide a circuit protector which overcomes the problems of the prior application and is capable of tripping stably and accurately with high sensitivity even in a minute current region.

[Means and actions used to achieve the purpose]

Therefore, the present invention is directed to a case 1 made of an insulating material, and a terminal plate 1 fixed to the case 1 with a terminal portion 35 protruding outside the case and a fixed contact 13 fixed inside the case.
1, a connection conductor 9 that is also fixed to the case 1, projects the terminal portion 34 to the outside of the case, and has an engaging groove 30 for engaging with a link and an interruption spring suspension groove 32 inside the case, and a predetermined position inside the case. A handle 2 having a rotation center 15, an external operation portion, a link spring suspension portion 17, and a rotation width regulated to a predetermined width by a case; and a link spring suspension portion 17 of the handle 2. An elastic wire suspended between the link spring suspensions 28 of the links 7,
A link spring 3 formed in a substantially U-shape, and a handle spring that is attached to one end of the U-shaped link spring 3 on the handle side and urges the handle 2 and the link spring 3 by bending in the handle “cut” direction. 4 is provided with a V-shaped groove 27 that engages with the link bearing 6, has a link spring suspension portion 28, a bimetal contact surface 29, and is made of an insulator. The claw 20 that engages with the mating groove 30 is provided, the insulating bushing mounting hole 42 is provided on the free end side, and the link engaging portion 23 and the stop surface 2 of the link spring are provided substantially at the center.
4, and a link bearing 6 having a breaking spring suspension 26, a movable contact 12 fixed to the free end side, and a protrusion 22 inserted into the insulating bushing 8 provided on the base end side, and a lead wire fixing portion 19, And a bimetal 5 provided with a protrusion forming a stopper 18 with the case, the base end side of which is loosely sandwiched between the case 1 link bearings 6, and a protrusion 22 on the free end side of the bimetal 5 and the link bearing 6. The insulating bushing 8 interposed in the free end side mounting hole 42 and the lead wire 1 for connecting between the base end side of the bimetal and the connecting conductor.
4 and a breaking spring 10 suspended between the breaking spring suspension groove 32 of the connection conductor 9 and the breaking spring suspension portion 26 of the link bearing 6 by urging the link bearing 6 in the contact opening direction. , Between the rotation center 15 of the handle 2 and the link spring suspension portion 17 of the handle 2, and the second section is the end of the link spring 3 on the suspension side of the handle 2 and the link 7 of the link spring 3 as well. Between the ends on the suspension side, and the third joint between the V-shaped groove 27 that engages the link spring suspension portion 28 of the link 7 and the link bearing 6 of the link 7, and the fourth joint. Between the link engaging portion 23 of the link bearing 6 and the claw 20 which also engages with the engaging groove 30 of the connecting conductor 9 of the link bearing 6, the fifth section is the engaging groove 30 of the connecting conductor 9 and the handle 2. Between the rotation centers 15 of the above, and the five-lever lever link mechanism is formed by connecting the first to fifth nodes in the order of description. The second section connecting the two chain sections of the first section and the second section chain section 17 and the third section and the fourth section chain section 23 in the second section and the third section. With the line segment as the dead point, the chain portion 1 at both ends of the second line segment is determined by the urging force of the breaking spring 10 and the contact pressure generated at the time of contact.
A second over-center rolling link mechanism, which is urged in a direction to reduce the distance between 7 and 23, is constructed, and when the manual "ON" or "OFF" operation is performed, the second over-center rolling link mechanism is connected to the second section. The chain portion 28 of the third joint crosses the dead point of the second line segment toward the fourth joint and abuts against the fourth joint, so that the third joint is integrally restrained by the fourth joint, that is, the link spring. The end portion of the link suspension side of 3 is restrained by the stop surface 24 of the link spring of the link bearing 6 to form a limited chain, which is substantially 4th section working at the 1st section, the 2nd section, the 4th section and the 5th section. It becomes a lever link mechanism and the external operating portion of the handle 2 which is the first section is manually rocked to the "on" and "off" sides to rock the link bearing 6 which is the fourth section, thereby The movable contact 12 fixed to the free end side of the bimetal 5 held substantially integrally with 6 is brought into contact with and separated from the fixed contact 13. In Section 1 and Section 2, the first line segment connecting the chain sections 15 of Sections 1 and 5 and the chain section 28 of Sections 2 and 3 is the dead point. And the urging force of the breaking spring 10 and the contact pressure generated at the time of contact make the chain portion 1 at both ends of the first line segment.
The first over-center rolling link mechanism is urged in the direction of contracting between 5, 5 and 28, and the "off" side is held by the urging force of the breaking spring 10 in the contact opening direction. Is stabilized at the position of the contact opening side, and while the chain portion 28 of the second and third joints is in contact with the fourth joint, the handle spring 4 moves the handle 2 and the link spring 3 in the “off” direction. The bending urging force causes the handle 2 to rotate to the "off" side until the case 1 is fully rotated, and the "on" side is held from the "off" side holding state.
After the movable contact 12 contacts the fixed contact 13 by rotating the handle 2 to the "in" side, the handle 2 is further rotated in the "in" direction to move the first overcenter rolling link mechanism to the first position.
The connecting portion 17 of the joint and the second joint goes beyond the dead point of the first line segment to the side of the link bearing 6, and the urging force of the breaking spring 10 and the contact pressure are used as the urging force, so that the first and second joints. The chain portion 17 moves from the dead point of the first line segment toward the link bearing 6 side, and the link bearing 6 attempts to rotate from the contact closed side to the contact open side and the handle 2 toward the “entrance” side. That is, turning the handle 2 into the case 1
It is configured to prevent overcurrent interruption by restricting with the.
The bimetal 5 held substantially integrally with the base metal is deformed and the bimetal contact surface 29 of the link 7, which is restrained by the link bearing 6, is deformed.
Is pressed to rotate the link 7 about the engaging portion 23 with the link bearing 6, that is, the chain portion 28 of the second and third joints.
Is rotationally moved from the link bearing 6 side to the opposite side with respect to the second line segment, which is the dead center of the second overcenter rolling link mechanism, about the chain portion 23 of the third and fourth joints. , Third
The restraint of the link 7 that is the node to the link bearing 6 that is the fourth node is released to return to the unrestricted chain by the 5-node link, and the blocking spring 10 moves the link bearing 6 that is the fourth node in the contact opening direction. Then, the handle 2 and the link spring 3 are urged by the urging force of the handle spring 4 against the link bearing 6 which has moved to the contact opening side.
Is bent, the handle 2 is rotated to the "cut" side regulation to the full extent, and the link portion 28 of the link spring 3 which is the second joint and the link 7 which is the third joint is connected to the link bearing 6 which is the fourth joint.
It is configured such that it is brought into contact with the link spring stop surface 24 and is reset to the manual "OFF" state.

[Constitution of device]

 An embodiment of the present invention will be described below with reference to the drawings.

1 to 3 are views of the case with one side removed,
Fig. 1 shows "OFF", Fig. 2 shows "ON", Fig. 3 shows a state of "automatic shutoff" due to overcurrent, and Fig. 4 shows an exploded view of main parts.

Reference numeral 1 denotes a case, which is made of an insulating material, is divided into a rear side and a front side in the drawing, has a groove for extending a terminal portion at one end, and a handle 2 is axially locked at the other end to expose an operating portion. It is hollow with holes for insertion, and the partially assembled blocks are inserted and fitted together.

The handle 2 having the rotation center shaft 15 is rotatably fixed to the case, and has an operation part on the outside of the case and a link spring suspension part 17 on the inside.

The link spring 3 is formed of an elastic wire in a substantially U shape, and one end thereof penetrates the spiral center portion of the handle spring 4 and is rotatably inserted into the link spring suspension portion 17 of the handle 2.

The other end is rotatably inserted into the link spring suspension portion 28 of the link 7.

The handle spring 4 biases the handle 2 and the link spring 3 in the direction of bending the handle “off” side.

The movable contact 12 is fixed to the free end side, and the protruding portion 22 to be inserted into the insulating bushing 8 is provided, and the lead wire 14 is provided on the proximal end side.
The lead wire fixing surface 19 to which one end of the bimetal 5 is fixed, and the narrow portion 50 of the bimetal 5 provided with the protrusion forming the stopper 18 for stopping the leftward movement of the bimetal 5 in the figure by the case 1 at a predetermined position. The connecting conductor 9 is inserted into the cutout portion 47. Further, 41 indicates a high expansion side of the bimetal 5, and 40 indicates a low expansion side.

The link bearing 6 has a claw 2 that engages with the connecting conductor 9 on the base end side.
Nos. 0 and 21 are provided, a mounting hole 42 for the insulating bushing 8 is provided in the short piece bent portion on the free end side, a rectangular hole is formed in the substantially central portion, and a link engaging portion 23 with the link 7 and a link spring 3 are provided. Link spring stop surfaces 24 and 25 for stopping the movement of
Further, it has a breaking spring suspension portion 26 for suspending one end 49 of the breaking spring 10.

The link 7 is located in the rectangular hole of the link bearing 6 and engages with the link engaging portion 23 of the link bearing 6 to form the V-shaped groove 2
7 is provided and has a link spring suspension portion 28 with the link spring 3 and a bimetal contact surface 29 with the bimetal 5 and is made of an insulator.

In the insulating bushing 8, the protrusion 22 of the bimetal 5 has a hole 43.
Is inserted into the mounting hole 42 of the link bearing 6 and maintains the insulation between the bimetal 5 and the link bearing 6.

The connecting conductor 9 is formed in an L shape, and the short piece portion has a notch portion 4 through which the bimetal 5, the link bearing 6, and the lead wire 14 can pass.
7, and the claws 20 and 21 of the link bearing 6 on the outer surface of the short piece portion.
Engagement grooves 30 and 31 for engaging with and interruption spring suspension grooves 32 and 33 for interruption spring 10 are provided on the inner surface of the short piece portion, and the long piece portion extends from case 1 to form terminal portion 34. To do.

The breaking spring 10 is made of an elastic material, and the portion 48 is suspended in the suspending spring suspension grooves 32 and 33 of the connecting conductor 9, and the portion 49 is suspended in the suspending spring suspension portion 26 of the link bearing 6.

A fixed contact 13 is fixed to the terminal board 11, and the other end is the case 1.
The extending terminal portion 35 is formed from.

One end 46 of the lead wire 14 is fixed to the surface 19 of the bimetal 5, and the other end 45 is fixed to the inner side surface position 44 of the connection conductor 9 to form an electric path between the connection conductor 9 and the bimetal 5.

Reference numeral 16 denotes a protrusion provided on the case 1, which faces the stopper 18 of the bimetal 5 and prevents the bimetal from moving leftward in the drawing.

Note that reference numerals 36, 37, 38, 39 denote notches for fitting with the case 1.

The circuit protector according to the present invention assembled by the above-described component structure has a shaft 15 of the handle 2 and a link spring suspension portion 17 of the handle 2 as shown in the mechanism diagrams of FIGS. Form the first section between
A second joint is formed between both ends of the link spring 3, and a third joint is formed between the link spring suspension portion 28 of the link 7 and the V-shaped groove 27 of the link 7 as well. A fourth joint is formed between the engaging portion 23 and the pawls 20 and 21 of the link bearing 6, and a fifth joint is formed between the pawls 20 and 21 of the link bearing 6 and the shaft 15 of the handle 2. 1st to 5th
The five-section lever link mechanism is configured by chaining the sections in the order of description.

Here, the claws 20 and 21 of the link bearing 6 are engaged with the engaging grooves 30 and 31 of the connection conductor 9 fixed to the case 1, and the shaft 15 of the handle 2 is fixed to the hole of the case 1 not shown. Therefore, the fifth section between 20, 21, and 15 is a section that functions as a frame that supports the so-called first to fourth section chains.

Note that FIG. 5 is a diagram in which the state of FIG. 1 described above, FIG. 6 is the state of FIG. 2 described above, and FIG. 7 is the state of FIG.

In FIGS. 5 to 7, the cutoff spring 10 shown in FIGS. 1 to 4 is shown as a coil spring in order to make its function easy to understand.

The operation of the circuit protector of the present invention will be described below with reference to the mechanical diagrams of FIGS. 5 to 7, but for the sake of simplicity of explanation, the handle 2, the link spring 3, the link 7, the link unless otherwise stated. The parts 6 and 2, respectively, the first part, the third part, the second part, the third part, the third part, the sixth part, the fourth part, the link spring suspension part 17,
The link spring suspension portion 28 of the link 7 and the link engaging portion 23 of the link bearing 6 are respectively designated by 17 at the first and second linking portions, and at 28 as the second and third linking portions. , 23 will be described as a chain portion of the third and fourth sections.

In FIG. 5, the fourth joint 6 is urged in the opening direction of the contacts 12 and 13 by the breaking spring 10 around 20 and 21,
Since the first joint 2 and the second joint 3 are urged by the handle spring 4 to be bent in a V shape in the figure, the chain portion 28 of the second joint 3 and the third joint 7 is the fourth joint 6, that is, the link. Restrained by the stop surface 24 of the bearing, the first joint 2, that is, the handle, is urged to rotate about the shaft 15 in the counterclockwise direction in the figure, but the rotation in that direction is restricted by the case (Δ in the figure). (Marked), the contacts 12 and 13 are stable in the open state (“off” state).

From the state shown in FIG. 5, the movable contact 12 is fixed to the fixed contact 13.
In order to shift to the closed (“on”) state, the first section 2 in the figure, that is, the handle, is manually rotated around the shaft 15 in the clockwise direction in the figure. At this time, the chain section 28 of the second section 3 and the third section 7 is the second line connecting the chain section 17 of the first section 2 and the second section and the chain section 23 of the third section 7 and the fourth section 6. Since it is below the minute, the chain portion 28 remains constrained by the above-mentioned stop surface 24, that is, the third joint 7 is constrained by the fourth joint 6 to form a limited chain, and substantially the first joint 2, the second joint. It functions as a 4-joint lever link mechanism by the 2nd joint 3 and the 4th joint 6 and the 5th joint between 20, 21 to 15, and the 4th joint 6 becomes 2 by the rotation of the 1st joint 2.
The movable contact 12 fixed to the free end side of the bimetal 5 held substantially integrally with the fourth joint 6 contacts the fixed contact 13 by rotating clockwise about 0, 21 in the drawing.

When the first section 2 is further rotated in the clockwise direction in the figure after contact with the contact points, the chain portion 17 of the first section 2 and the second section 3 becomes the shaft 15, and the chain section of the second section 3 and the third section 7. The first line segment connecting 28 is crossed from the upper part of the figure to the lower part of the figure. Between the shaft 15 and the chain portion 28,
Due to the biasing force of the breaking spring 10 and the contact pressure of the contacts 12 and 13, the blocking line 10 is always biased in the direction in which it is contracted. Section 2
And section 2 and 3 act as overcenter rolling links,
When the chain portion 17 crosses the line segment from the upper side to the lower side in the figure, this time, the chain portion 17 tries to move further away from the first line segment in the lower side in the figure. Therefore, the first section 2 is the shaft 15
6 further tries to rotate clockwise in the figure and the fourth joint 6 tends to move in the contact opening direction, but before the contact opens, as shown in FIG. 6, the first joint 2 or the handle is the case. Rotation is restricted by (△ mark in the figure), contact 1
With 2 and 13 closed, the mechanism stabilizes in the "on" state.

At this time, the chain portion 28 of the second section 3 and the third section 7 becomes the first section 2
Is located below the second line segment connecting the chain section 17 of the second section 3 and the chain section 23 of the third section 7 and the fourth section 6, and the chain section 1
Since 7 and the chain portion 23 are constantly subjected to a force in the contracting direction by the urging force of the breaking spring 10 and the urging force of the contact of the contacts 12 and 13 in the contact opening direction of the fourth joint 6, It is continuously restrained by the stop surface 24.

It should be noted that when the contact is opened (“off”) in FIG. 5 to the contact closed (“on”) state in FIG.
After the contact between 2 and 13, the position of the fourth joint 6 is almost fixed, so that the positional relationship between the shaft 15 and the chain portion 23 is also almost fixed, and the chain portion 17 is formed by the first line segment described above. In the vicinity of passing the dead point from the upper part of the drawing to the lower part of the drawing, the link spring 3 made of a U-shaped elastic material, that is, the second joint slightly bends, so that the distance between the chain portion 17 and the chain portion 28 slightly shrinks. The deflection serves as a force for pressing the movable contact 12 against the fixed contact 13 substantially as contact contact pressure.

Now, when a current is applied to the circuit protector of the present invention in the state shown in FIG. 6 in which the contacts are held closed, the current is the terminal portion 34, the connecting conductor 9, the lead wire 14 in FIGS. 1 to 4. , Bimetal 5, contacts 12, 13, terminal board 1
1, the bimetal 5 flows in the path of the terminal portion 35, and due to the Joule heat due to the electric current, the bimetal 5 has a high expansion side 41 on the link bearing 6 side and a low expansion side 40 on the opposite side in FIG. 2 or 6. It is curved in a V shape because it is arranged in.
At this time, if the current value is less than the rated operating current of the circuit protector, the bimetal does not reach the bimetal contact surface 29 of the link 7, but if the current value is the rated operating current or more, the bimetal curving is more likely to occur. It becomes excessively large, and finally the bimetal contact surface 29 of the link 7 is pushed upward from the lower side of the drawing.

In FIG. 6, the bimetal 5 has a bimetal contact surface 29.
Is pushed upward from the bottom of the figure, the bimetal contact surface 29 is formed integrally with the link 7, that is, the third joint, so that the third joint 7 rotates clockwise about the chain portion 23 in the figure. , The chain portion 28 crosses the dead point consisting of the second line segment connecting the chain portion 17 and the chain portion 23 from the lower part to the upper part of the figure, and at the time point when the dead point is exceeded, the breaking spring 1
After the contacts are separated by the biasing force of 0 and the contact pressure of the contacts, the chain portion 17 and the chain portion 23 are separated by the biasing force of the breaking spring 10.
Is urged in a direction to contract, the chain portion 28 automatically moves in a direction away from the fourth joint 6. Therefore, the restraint of the chain portion 28 to the stop surface 24 is eliminated, the link system becomes an unrestricted chain by the original 5-bar linkage, and the fourth bar 6 is moved to the base end 2 by the urging force of the breaking spring 10.
Rotate about 0, 21 counterclockwise in the figure,
The contacts 12 and 13 are opened to cut off the current.

At this time, even if the first joint 2, that is, the handle is restrained in the position shown in FIG. 6, a new joint formed between the chain portions 17 and 20, 21 and the second joint 3, the third joint 7, and the fourth joint are formed. The joint 6 constitutes a four-joint lever link mechanism, and the fourth joint 6 can be moved in the contact opening direction by the urging force of the breaking spring 10 to cut off the current in the state shown in FIG.

When the position restraint of the handle 2 is released from the state of FIG. 7 from the state of FIG. 7, the bending biasing force of the handle spring 4 causes the handle 2 to fully rotate around the shaft 15 in the counterclockwise direction as shown in the figure. As the second link 3, that is, the link spring, rotates clockwise about the chain part 17, the chain part 28 contacts the stop surface 24 of the fourth node,
The system is reset to the contact open (“on”) state shown in FIG.

[Effect of device]

With the configuration as described above, the bimetal 5 is fitted with the width detail 50 at one end together with the link bearing 6 in the notch 47 of the connecting conductor 9 so as to be loosely held between the link bearing 6 and the protrusion 16 of the case 1. The rocking base end is formed, and the other end of the bimetal 5 is loosely pierced and held in the mounting hole 42 of the link bearing 6 via an insulating bushing to form the rocking end, and is substantially integral with the link bearing 6. The movable contact 12 is fixed to the swing end side of the bimetal 5, so that the contact is changed in accordance with the swing of the link bearing 6. Since the link bearing 6 receives the contact inputting force by the operation of the handle 2 and the contact opening force by the breaking spring 10, the bimetal 5 does not receive an extra tensile force other than the bending force by Joule heat. So bimetal 5 Depending on the amount of heat generated can be bent precisely, the bimetal contact surface 29 of all the bending force link 7
Can be used to force the link 7 to reverse to the trip side.

Further, the link bearing is made of metal, but since the bimetal 5 and the link bearing 6 are insulated by the insulating bushing and the link, all the current flows from the contact 12 toward the lead wire 14 to the bimetal 5. When it is passed, it heats up accurately according to the amount of electricity.

Therefore, the deflection of the bimetal 5 can be accurately deflected according to the applied current.

Further, the handle 2 and the first overcenter rolling link by the link spring 3 and the second overcenter rolling link mechanism by the link 7 and the link spring 3 are provided, and the second overcenter rolling link mechanism is reversed by the bimetal. As a result, the handle 2 has a structure for urging the link bearing 6 toward the contact closing side to release the holding force. Even in the case of overcurrent in a minute current region of several A to several A, there is an effect that automatic shutoff can be performed accurately, surely.

[Brief description of drawings]

 Fig. 1 is a sectional view in the "off" state. 2 is a sectional view in the "on" state. Fig. 3 is a sectional view in the "auto shutoff" state. Fig. 4 is an exploded view of the main parts. Diagram Fig. 6 is a mechanical diagram in the "ON" state Fig. 7 is a mechanical diagram in the "auto shut-off" state 1 …… Case 2 …… Handle 3 …… Link spring 4 …… Handle spring 5 …… Bimetal 6 ...... Link support 7 ...... Link 8 ...... Insulation bushing 9 ...... Connecting conductor 10 ...... Blocking spring 11 ...... Terminal plate 12 ...... Movable contact 13 ...... Fixed contact 14 ...... Lead wire

Claims (1)

[Scope of utility model registration request] 1. A case 1 made of an insulating material, a terminal plate 1 fixed to the case 1, projecting a terminal portion 35 to the outside of the case, and having a fixed contact 13 fixed inside the case.
1, a connection conductor 9 that is also fixed to the case 1, projects the terminal portion 34 to the outside of the case, and has an engaging groove 30 for engaging with a link and an interruption spring suspension groove 32 inside the case, and a predetermined position inside the case. A handle 2 having a rotation center 15, an external operation portion, a link spring suspension portion 17, and a rotation width regulated to a predetermined width by a case; and a link spring suspension portion 17 of the handle 2. An elastic wire suspended between the link spring suspensions 28 of the links 7,
A link spring 3 formed in a substantially U-shape, and a handle spring that is attached to one end of the U-shaped link spring 3 on the handle side and urges the handle 2 and the link spring 3 by bending in the handle “cut” direction. 4 is provided with a V-shaped groove 27 that engages with the link bearing 6, has a link spring suspension portion 28, a bimetal contact surface 29, and is made of an insulator. The claw 20 that engages with the mating groove 30 is provided, the insulating bushing mounting hole 42 is provided on the free end side, and the link engaging portion 23 and the stop surface 2 of the link spring are provided substantially at the center.
4, and a link bearing 6 having a breaking spring suspension 26, a movable contact 12 fixed to the free end side, and a protrusion 22 inserted into the insulating bushing 8 provided on the base end side, and a lead wire fixing portion 19, Also, a protrusion that forms a stopper 18 with the case is provided, and the base end side is loosely sandwiched between the case 1 and the link bearing 6, and the protrusion 22 on the free end side of the bimetal 5 and the link bearing 6 are provided. Of the insulating bushing 8 interposed in the mounting hole 42 on the free end side of the lead wire and the lead wire 1 for connecting between the base end side of the bimetal and the connecting conductor.
4 and a breaking spring 10 suspended between the breaking spring suspension groove 32 of the connection conductor 9 and the breaking spring suspension portion 26 of the link bearing 6 by urging the link bearing 6 in the contact opening direction. , Between the rotation center 15 of the handle 2 and the link spring suspension portion 17 of the handle 2, and the second section is the end of the link spring 3 on the suspension side of the handle 2 and the link 7 of the link spring 3 as well. Between the ends on the suspension side, and the third joint between the V-shaped groove 27 that engages the link spring suspension portion 28 of the link 7 and the link bearing 6 of the link 7, and the fourth joint. Between the link engaging portion 23 of the link bearing 6 and the claw 20 which also engages with the engaging groove 30 of the connecting conductor 9 of the link bearing 6, the fifth section is the engaging groove 30 of the connecting conductor 9 and the handle 2. Between the rotation centers 15 of the above, and the five-lever lever link mechanism is formed by connecting the first to fifth nodes in the order of description. The second section connecting the two chain sections of the first section and the second section chain section 17 and the third section and the fourth section chain section 23 in the second section and the third section. With the line segment as the dead point, the chain portion 1 at both ends of the second line segment is determined by the urging force of the breaking spring 10 and the contact pressure generated at the time of contact.
A second over-center rolling link mechanism, which is urged in a direction to reduce the distance between 7 and 23, is constructed, and when the manual "ON" or "OFF" operation is performed, the second over-center rolling link mechanism is connected to the second section. The chain portion 28 of the third joint crosses the dead point of the second line segment toward the fourth joint and abuts against the fourth joint, so that the third joint is integrally restrained by the fourth joint, that is, the link spring. The end portion of the link suspension side of 3 is restrained by the stop surface 24 of the link spring of the link bearing 6 to form a limited chain, which is substantially 4th section working at the 1st section, the 2nd section, the 4th section and the 5th section. It becomes a lever link mechanism, and by manually swinging the external operation portion of the handle 2 which is the first section to the "on" and "off" sides, the link bearing 6 which is the fourth section is swung, and the link The movable contact 12 fixed to the free end side of the bimetal 5 held substantially integrally with the bearing 6 is brought into contact with and separated from the fixed contact 13. In the first and second sections, the first line segment connecting the chain sections 15 of the first and fifth sections and the chain section 28 of the second and third sections is connected. The point is a point, and the urging force of the breaking spring 10 and the contact pressure generated at the time of contact make the chain portion 1 at both ends of the first line segment.
The first over-center rolling link mechanism is urged in the direction of contracting between 5, 5 and 28, and the "off" side is held by the urging force of the breaking spring 10 in the contact opening direction. Is stabilized at the position of the contact opening side, and while the chain portion 28 of the second and third joints is in contact with the fourth joint, the handle spring 4 moves the handle 2 and the link spring 3 in the “off” direction. The bending urging force causes the handle 2 to rotate to the "off" side until the case 1 is fully rotated, and the "on" side is held from the "off" side holding state.
After the movable contact 12 contacts the fixed contact 13 by rotating the handle 2 to the "in" side, the handle 2 is further rotated in the "in" direction to move the first overcenter rolling link mechanism to the first position.
The connecting portion 17 of the joint and the second joint goes beyond the dead point of the first line segment to the side of the link bearing 6, and the urging force of the breaking spring 10 and the contact pressure are used as the urging force, so that the first and second joints. The chain portion 17 moves from the dead point of the first line segment toward the link bearing 6 side, and the link bearing 6 attempts to rotate from the contact closed side to the contact open side and the handle 2 toward the “entrance” side. That is, turning the handle 2 into the case 1
It is configured to prevent overcurrent interruption by restricting with the.
The bimetal 5 held substantially integrally with the base metal is deformed and the bimetal contact surface 29 of the link 7, which is restrained by the link bearing 6, is deformed.
Is pressed to rotate the link 7 about the engaging portion 23 with the link bearing 6, that is, the chain portion 28 of the second and third joints.
Is rotationally moved from the link bearing 6 side to the opposite side with respect to the second line segment, which is the dead center of the second overcenter rolling link mechanism, about the chain portion 23 of the third and fourth joints, The restraint of the link 7, which is the third section, to the link bearing 6, which is the fourth section, is released to restore the unrestricted chain by the 5-section link, and the cutoff spring 1
0 is the fourth section, the link bearing 6 is moved in the contact opening direction, and then the handle 2 and the link spring 3 are applied to the link bearing 6 moved to the contact opening side by the urging force of the handle spring 4.
Is bent, the handle 2 is rotated to the "cut" side regulation to the full extent, and the link portion 28 of the link spring 3 which is the second joint and the link 7 which is the third joint is connected to the link bearing 6 which is the fourth joint.
A circuit protector characterized in that the circuit protector is configured so as to be brought into contact with the link spring stop surface 24 and to be reset to a manually "off" state.