Thermal tripping device of molded case circuit breaker

Abstract

The utility model relates to the technical field of low-voltage electric appliances, and discloses a thermal tripping device of a molded case circuit breaker, which comprises a molded case base and a thermal tripping mechanism, the thermal tripping mechanism comprises a wire outlet terminal, a mounting hole is formed in the middle of the top of the wire outlet terminal, a bimetallic strip is fixedly connected to one side of the wire outlet terminal, and the bimetallic strip is arranged in the mounting hole. One side of the interior of the bimetallic strip is fixedly connected with a static iron core, the top of one side of the bimetallic strip is fixedly connected with a release push rod, the top of the release push rod is fixedly connected with an adjusting screw, and the bottom of one side of the bimetallic strip is fixedly connected with a flexible connection copper wire belt; according to the utility model, one side of the static iron core is arranged to be groove-shaped, the groove of the static iron core is matched with the bottom of the bimetallic strip, and the bottom of the release push rod is located in the middle of the bottom of the bimetallic strip, so that elements such as the bimetallic strip, the static iron core, the release push rod and the like can be accurately limited at opposite positions; and the consistency of the relative positions of the elements can be improved.

Description

Technical Field

[0001] The utility model relates to the technical field of low-voltage electrical appliances, and more specifically to a thermal tripping device for a molded case circuit breaker. Background Art

[0002] Molded case circuit breakers are also called device-type circuit breakers. Plastic case refers to the use of plastic insulators as the outer shell of the device, which is used to isolate the conductors and the grounded metal parts. All parts are sealed in the plastic shell. Auxiliary contacts, undervoltage releases and shunt releases are mostly modular. Molded case circuit breakers can automatically cut off the current after the current exceeds the trip setting; due to the very compact structure, molded case circuit breakers are basically impossible to repair. Molded case circuit breakers are contacts, arc extinguishing chambers, releases and operating mechanisms are all installed in a plastic shell. Maintenance is generally not considered. It is suitable for branch protection switches. Overcurrent releases are of two types: thermal magnetic and electronic. Generally, thermal magnetic molded case circuit breakers are non-selective circuit breakers with only two protection modes: overload long delay and short circuit instantaneous. Electronic molded case circuit breakers have four protection functions: overload long delay, short circuit short delay, short circuit instantaneous and ground fault.

[0003] Existing deficiencies: In the existing technology, when the static iron core is superimposed and fixed with the thermal element, the bimetallic strip and the conductive element, the positioning of each element can only be based on the experience of the welding personnel. The relative positions of the components are greatly affected by human factors, and the relative positions of the components are difficult to keep consistent; secondly, in the existing thermal release, the thermal bimetallic elements are all single-piece thermal bimetallic elements. When the temperature of the thermal bimetallic element changes, it is necessary to generate a driving force to push the traction rod to trip the circuit breaker mechanism. The driving force of the single-piece thermal bimetallic is small, and the adjustable space is small. Utility Model Content

[0004] In order to overcome the above-mentioned defects of the prior art, the utility model provides a thermal tripping device for a molded case circuit breaker to solve the problems existing in the above-mentioned background technology.

[0005] The utility model provides the following technical solution: a thermal trip device for a molded case circuit breaker, comprising a molded case base and a thermal trip mechanism, wherein the thermal trip mechanism is fixedly connected to the front of the top of the molded case base, a spring mechanism is fixedly connected to the middle of the top of the molded case base, an operating mechanism is fixedly connected to the middle of the top of the spring mechanism, a contact system is fixedly connected to the back of the top of the molded case base, an arc extinguishing device is fixedly connected to the top of the contact system, the thermal trip mechanism comprises an outlet terminal, a mounting hole is provided in the middle of the top of the outlet terminal, a bimetallic strip is fixedly connected to one side of the outlet terminal, a static iron core is fixedly connected to the inner side of the bimetallic strip, a releaser push rod is fixedly connected to the top of one side of the bimetallic strip, an adjusting screw is fixedly connected to the top of the releaser push rod, and a soft-connected copper ribbon is fixedly connected to the bottom of one side of the bimetallic strip.

[0006] Furthermore, the spring mechanism comprises a spring mechanism housing, a release half-shaft is fixedly connected to the inner middle portion of the spring mechanism housing, and a strong spring is fixedly connected to the outer side of the release half-shaft.

[0007] Furthermore, a conductive element housing is fixedly connected to the middle inner portion of the spring mechanism housing, a conductive element is movably connected to the middle inner portion of the conductive element housing, a movable contact conductive rod is fixedly connected to the middle back portion of the conductive element, and a movable contact is fixedly connected to the bottom back portion of the movable contact conductive rod.

[0008] Furthermore, the operating mechanism includes an operating bracket, the top of which is fixedly connected to an operating handle, the inner sides of the operating bracket are fixedly connected to connecting pieces, and the front side of the connecting piece is fixedly connected to a release rod.

[0009] Furthermore, the contact system includes a stationary contact terminal, a connection hole is opened in the middle of the top of the stationary contact terminal, a stationary contact conductive bar is fixedly connected to the middle of the front of the stationary contact terminal, and a stationary contact is fixedly connected to the top front of the stationary contact conductive bar.

[0010] Furthermore, the arc extinguishing device comprises an arc extinguishing hood, an arc extinguishing grid is fixedly connected to the interior of the arc extinguishing hood, and an arc extinguishing chamber is provided on the outer side of the arc extinguishing grid.

[0011] Technical effects and advantages of the utility model:

[0012] 1. The utility model is provided with a thermal release device. One side of the static iron core is designed to be grooved. The length of the groove of the static iron core is matched with the width of the bimetallic strip. The bottom of the releaser push rod is located in the middle of the bottom of the bimetallic strip. During processing and welding, the bimetallic strip, the static iron core, the releaser push rod and other components can be accurately limited to relative positions, which is beneficial to improving the consistency of the relative positions between the components and improving the quality of the thermal release device.

[0013] 2. The utility model is provided with a plurality of thermal release devices. One side of the bimetallic strip is made of iron and the other side is made of copper. When the current flows through the bimetallic strip through the soft-connected copper ribbon, the heat temperature will cause the bimetallic strip to bend toward the iron side. When the bending degree of the bimetallic strip exceeds the threshold value, the bimetallic strip will push the release push rod to move upward, and the adjusting screw will touch the release rod of the operating mechanism to separate the moving contact from the static contact to realize line disconnection. Multiple bimetallic strips bend synchronously, and the driving force is improved, which is conducive to providing a larger adjustment space. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the utility model.

[0015] Figure 2 It is a schematic diagram of the structure of the thermal tripping mechanism of the utility model.

[0016] Figure 3 It is a schematic diagram of the spring mechanism structure of the utility model.

[0017] Figure 4 It is a schematic diagram of the structure of the operating mechanism of the utility model.

[0018] Figure 5 It is a schematic diagram of the structure of the contact system and arc extinguishing device of the utility model.

[0019] The accompanying drawings are marked as follows: 1. plastic shell base; 2. thermal release mechanism; 201. outlet terminal; 202. mounting hole; 203. bimetallic strip; 204. static iron core; 205. release push rod; 206. adjusting screw; 207. soft connection copper wire; 3. spring mechanism; 301. spring mechanism housing; 302. release half shaft; 303. strong spring; 304. conductive element housing; 305. conductive element; 306. moving contact conductive rod; 307. moving contact; 4. operating mechanism; 401. operating bracket; 402. operating handle; 403. connecting piece; 404. release rod; 5. contact system; 501. static contact terminal; 502. connecting hole; 503. static contact conductive bar; 504. static contact; 6. arc extinguishing device; 601. arc extinguishing cover; 602. arc extinguishing grid; 603. arc extinguishing chamber. DETAILED DESCRIPTION

[0020] The technical solution of the present invention will be clearly and completely described below in conjunction with the drawings in the present invention. In addition, the forms of the various structures recorded in the following embodiments are only examples. The thermal trip device of a molded case circuit breaker involved in the present invention is not limited to the various structures recorded in the following embodiments. All other implementations obtained by ordinary technicians in this field without making creative work belong to the scope of protection of the present invention.

[0021] Reference Figure 1-Figure 5 The utility model provides a thermal tripping device for a molded case circuit breaker, comprising a molded case base 1, and also comprising a thermal tripping mechanism 2, the top front of the molded case base 1 is fixedly connected with the thermal tripping mechanism 2, the top middle of the molded case base 1 is fixedly connected with a spring mechanism 3, the top middle of the spring mechanism 3 is fixedly connected with an operating mechanism 4, the top back of the molded case base 1 is fixedly connected with a contact system 5, the top of the contact system 5 is fixedly connected with an arc extinguishing device 6, the thermal tripping mechanism 2 comprises an outlet terminal 201, the top middle of the outlet terminal 201 is provided with a mounting hole 202, one side of the outlet terminal 201 is fixedly connected with a bimetallic strip 203, the inner side of the bimetallic strip 203 is fixedly connected with a static iron core 204, and the bimetallic strip 203 is fixedly connected with a static iron core 204. A release push rod 205 is fixedly connected to the top of one side of the metal sheet 203, an adjusting screw 206 is fixedly connected to the top of the release push rod 205, and a soft-connected copper ribbon 207 is fixedly connected to the bottom of one side of the bimetallic strip 203. By designing one side of the static iron core 204 into a groove shape, the length of the groove of the static iron core 204 is adapted to the bottom width of the bimetallic strip 203, and the bottom of the release push rod 205 is located in the middle of the bottom of the bimetallic strip 203. During processing and welding, the bimetallic strip 203, the static iron core 204, the release push rod 205 and other components can be accurately limited to relative positions, which is beneficial to improving the consistency of the relative positions between the components and improving the quality of the thermal release device.

[0022] In a preferred embodiment, the spring mechanism 3 includes a spring mechanism housing 301 , a release half-shaft 302 is fixedly connected to the inner middle of the spring mechanism housing 301 , and a strong spring 303 is fixedly connected to the outer side of the release half-shaft 302 .

[0023] In a preferred embodiment, a conductive element housing 304 is fixedly connected to the inner middle of the spring mechanism housing 301, a conductive element 305 is movably connected to the inner middle of the conductive element housing 304, a moving contact conductive rod 306 is fixedly connected to the middle of the back of the conductive element 305, and a moving contact 307 is fixedly connected to the bottom back of the moving contact conductive rod 306.

[0024] In a preferred embodiment, the operating mechanism 4 includes an operating bracket 401, the top of which is fixedly connected to an operating handle 402, the inner sides of the operating bracket 401 are fixedly connected to connecting pieces 403, the front of the connecting piece 403 is fixedly connected to a tripping rod 404, one side of the bimetallic strip 203 is made of iron and the other side is made of copper. When current flows through the bimetallic strip 203 through the soft-connected copper ribbon 207, the heat temperature will cause the bimetallic strip 203 to bend toward the iron side. When the bending degree of the bimetallic strip 203 exceeds the threshold value, the bimetallic strip 203 will push the releaser push rod 205 to move upward, and the adjusting screw 206 will touch the tripping rod 404 of the operating mechanism 4 to disengage the moving contact 307 from the static contact 504 to achieve line disconnection. Multiple bimetallic strips bend synchronously, the driving force is improved, and it is beneficial to provide a larger adjustment space.

[0025] In a preferred embodiment, the contact system 5 includes a stationary contact terminal 501, a connection hole 502 is opened in the middle of the top of the stationary contact terminal 501, a stationary contact conductive bar 503 is fixedly connected to the middle of the front of the stationary contact terminal 501, and a stationary contact 504 is fixedly connected to the top front of the stationary contact conductive bar 503.

[0026] In a preferred embodiment, the arc extinguishing device 6 comprises an arc extinguishing cover 601 , an arc extinguishing grid 602 is fixedly connected to the interior of the arc extinguishing cover 601 , and an arc extinguishing chamber 603 is provided on the outer side of the arc extinguishing grid 602 .

[0027] The working principle of the utility model is as follows: by designing one side of the static iron core 204 into a groove shape, the length of the groove of the static iron core 204 is adapted to the bottom width of the bimetallic strip 203, and the bottom of the release push rod 205 is located in the middle of the bottom of the bimetallic strip 203, the bimetallic strip 203, the static iron core 204, the release push rod 205 and other components can be accurately limited to relative positions during processing and welding, which is beneficial to improve the consistency of the relative positions between the components and improve the quality of the thermal trip device; when the molded case circuit breaker is closed, the moving contact 307 is locked on the static contact 504, and the current flows from the static contact terminal 501 through the static contact conductive row 503, and then flows through the static contact 504 to the moving contact 307, and then flows through the moving contact conductive rod 306 and flows from the conductive element 305 to the soft connection copper ribbon 2 07; The main body of the thermal release device is a bimetallic strip 203, one side of the bimetallic strip 203 is made of iron and the other side is made of copper. When current flows through the bimetallic strip 203 through the soft-connected copper ribbon 207, the heat temperature will cause the bimetallic strip 203 to bend toward the iron side. When the bending degree of the bimetallic strip 203 exceeds the threshold value, the bimetallic strip 203 will push the releaser push rod 205 to move upward, and the adjusting screw 206 will touch the tripping rod 404 of the operating mechanism 4, causing the operating handle 402 to trip. The tripping rod 404 causes the conductive element 305 and the moving contact conductive rod 306 to lift up under the elastic force of the strong spring 303, so that the moving contact 307 is separated from the static contact 504 to achieve line disconnection. Multiple bimetallic strips are bent synchronously, and the driving force is improved, which is conducive to providing a larger adjustment space.

[0028] Finally: The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present utility model should be included in the protection scope of the present utility model.

Claims

1. A thermal trip device for a molded case circuit breaker, comprising a molded case base (1), characterized in that: The invention also comprises a thermal tripping mechanism (2), wherein the front top portion of the molded case base (1) is fixedly connected to the thermal tripping mechanism (2), the middle top portion of the molded case base (1) is fixedly connected to a spring mechanism (3), the middle top portion of the spring mechanism (3) is fixedly connected to an operating mechanism (4), the back top portion of the molded case base (1) is fixedly connected to a contact system (5), the top of the contact system (5) is fixedly connected to an arc extinguishing device (6), the thermal tripping mechanism (2) comprises an outlet terminal (201), the outlet terminal ( A mounting hole (202) is provided in the middle of the top of the output terminal (201); a bimetallic strip (203) is fixedly connected to one side of the output terminal (201); a static iron core (204) is fixedly connected to one side of the inner side of the bimetallic strip (203); a release push rod (205) is fixedly connected to the top of one side of the bimetallic strip (203); an adjusting screw (206) is fixedly connected to the top of the release push rod (205); and a soft connection copper wire (207) is fixedly connected to the bottom of one side of the bimetallic strip (203).

2. A thermal trip device for a molded case circuit breaker according to claim 1, characterized in that: The spring mechanism (3) comprises a spring mechanism housing (301), a release half-shaft (302) is fixedly connected to the middle of the interior of the spring mechanism housing (301), and a strong spring (303) is fixedly connected to the outer side of the release half-shaft (302).

3. A thermal trip device for a molded case circuit breaker according to claim 2, characterized in that: A conductive element housing (304) is fixedly connected to the middle of the inner part of the spring mechanism housing (301), a conductive element (305) is movably connected to the middle of the inner part of the conductive element housing (304), a movable contact conductive rod (306) is fixedly connected to the middle of the back of the conductive element (305), and a movable contact (307) is fixedly connected to the bottom back of the movable contact conductive rod (306).

4. A thermal trip device for a molded case circuit breaker according to claim 1, characterized in that: The operating mechanism (4) comprises an operating bracket (401), the top of the operating bracket (401) is fixedly connected to an operating handle (402), the inner sides of the operating bracket (401) are fixedly connected to connecting pieces (403), and the front side of the connecting piece (403) is fixedly connected to a tripping rod (404).

5. A thermal trip device for a molded case circuit breaker according to claim 1, characterized in that: The contact system (5) comprises a stationary contact terminal (501), a connection hole (502) is provided in the middle of the top of the stationary contact terminal (501), a stationary contact conductive row (503) is fixedly connected to the middle of the front of the stationary contact terminal (501), and a stationary contact (504) is fixedly connected to the front of the top of the stationary contact conductive row (503).

6. A thermal release device for a molded case circuit breaker according to claim 1, characterized in that: The arc extinguishing device (6) comprises an arc extinguishing cover (601), an arc extinguishing grid (602) is fixedly connected inside the arc extinguishing cover (601), and an arc extinguishing chamber (603) is provided outside the arc extinguishing grid (602).

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