An electromagnetic returnable short time delay release for frame circuit breaker

Abstract

The application discloses a frame circuit breaker electromagnetic returnable short-circuit delay release device, which comprises a static iron core, a dynamic iron core and a push rod, and further comprises a delay adjusting device, wherein the delay adjusting device comprises a supporting back plate, a matching block and a second spring; the matching block is movably arranged on the supporting back plate; the second spring is a tension spring, one end of the second spring is movably connected with the supporting back plate, and the other end of the second spring is fixedly connected with the matching block; the matching block is connected with a tripping half shaft and is used for driving the tripping half shaft to trip; one end of the push rod is movably connected with the matching block, and the other end of the push rod is connected with the dynamic iron core; the dynamic iron core is pulled by the static iron core to generate an electromagnetic force, the push rod moves away from the matching block, the matching block moves under the action of the pulling force of the second spring, and then the tripping half shaft is tripped. The delay release device can realize reliable short-circuit short delay protection and can be adjusted according to the up-down linkage relationship.

Description

Technical Field

[0001] This invention belongs to the field of circuit breaker technology, and particularly relates to an electromagnetic returnable short-circuit delay trip unit for frame circuit breakers. Background Technology

[0002] A frame circuit breaker is a high-capacity switch. As a protective electrical device, when a fault current occurs in the circuit, the circuit breaker will perform corresponding protection according to the settings, cut off the circuit, and protect the safety of other electrical equipment and personnel.

[0003] In a frame circuit breaker, a protective trip unit is a device that triggers protection based on abnormal current or voltage in the circuit and drives the mechanism to disconnect the circuit.

[0004] Most frame circuit breakers on the market today use electronic trip units. These units collect data through coil sampling and chip processing, and then make judgments based on the settings. When the data matches the set value, a trigger signal is sent to the magnetic flux, causing the circuit breaker mechanism to operate and cut off the faulty circuit.

[0005] While previous generation frame circuit breakers also had electromagnetic trip units, they were similar to molded case circuit breakers, generally only offering two-stage protection: long-delay and instantaneous overload protection. Furthermore, the operating mechanism, contact system, and arc-extinguishing system of current frame circuit breakers are completely different, making it impossible to improve their use; a new structure and tripping method need to be redesigned.

[0006] Electronic trip units involve numerous components and transmission mechanisms, complex calculations, long protection times, and are prone to failure during protection. They are also susceptible to malfunctions in environments with complex and variable EMC conditions. Furthermore, the sampling methods for AC and DC electronic protection systems differ, requiring the use of different sampling coils. Additionally, the electronic trip unit requires an external power supply. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides an electromagnetic returnable short-circuit time-delay trip device for frame circuit breakers. The short-delay protection value can be adjusted according to actual needs, and the delay time can also be adjusted by adjusting the spring and load of the delay mechanism. The device has a simple and compact structure and reliable operation.

[0008] This invention is achieved through the following technical solution:

[0009] An electromagnetic returnable short-circuit time-delay trip device for a frame circuit breaker includes a stationary iron core, a moving iron core, and a push rod, and also includes a time-delay adjustment device. The time-delay adjustment device includes a support back plate, a load-balanced block, and a second spring. The load-balanced block is movably mounted on the support back plate. The second spring is a tension spring, with one end movably connected to the support back plate and the other end fixedly connected to the load-balanced block. The load-balanced block is connected to the tripping half-shaft and is used to drive the tripping half-shaft to trip. One end of the push rod is linked to the load-balanced block, and the other end is connected to the moving iron core. The stationary iron core generates an electromagnetic force on the moving iron core, pulling the push rod away from the load-balanced block. The load-balanced block moves under the tension of the second spring, thereby driving the tripping half-shaft to trip.

[0010] Furthermore, the delay adjustment device also includes a second spring adjustment knob, which is rotatably mounted on the support back plate. One end of the second spring is connected to the second spring adjustment knob, and the other end is fixedly connected to the load block.

[0011] Furthermore, the loading block is provided with an elongated hole to form a limiting guide rail, and a guide screw is provided on the corresponding support back plate, the guide screw moving within the limiting guide rail.

[0012] Furthermore, it also includes a time delay trip adjustment device, which is provided with a time delay adjustment hole. The time delay adjustment hole is a horizontally arranged elongated hole, and one end of the time delay trip adjustment device is disposed in the time delay adjustment hole.

[0013] Furthermore, the delay trip adjustment device includes a first trip push rod and a second trip push rod. One end of the first trip push rod is engaged with the delay adjustment hole, and the other end is connected to the second trip push rod. The other end of the second trip push rod is engaged with the trip half shaft for linkage.

[0014] Furthermore, it also includes a current value adjustment device, which comprises a fixed plate, a first spring, a spring support, a first support, and an adjustment knob. A rear baffle, a front baffle, and a second support are sequentially fixed on the fixed plate. The stationary iron core has a C-shaped structure with a notch. The fixed plate is fixedly installed at the notch, and the fixed plate, the front baffle, and the rear baffle form a space surrounding the notch. The moving iron core is movably confined within the space. The spring support is movably disposed between the front baffle and the first support. The first spring is a compression spring and is disposed between the front baffle and the spring support. The adjustment knob moves sequentially through the second support and the first support and is fixedly connected to the spring support. The adjustment knob is used to adjust the elastic force of the first spring.

[0015] Furthermore, the current value adjustment device also includes a first spring guide shaft, one end of which is connected to the push rod, and the other end is limited on the first support member. The spring support member and the first spring are sleeved on the first spring guide shaft.

[0016] Furthermore, the push rod includes a metal rod and an insulating rod, the moving iron core is fixed on the metal rod, one end of the metal rod is connected to a first spring guide shaft on one side, the other end is connected to one end of the insulating rod, and the other end of the insulating rod is connected to the load block.

[0017] Furthermore, the stationary iron core includes a magnetic sheet, and a first magnetic block and a second magnetic block respectively connected to both ends of the magnetic sheet, with a C-shaped notch formed between the first magnetic block and the second magnetic block; the stationary iron core also includes clamping plates, which are disposed on the front and rear sides of the magnetic sheet, the first magnetic block and the second magnetic block.

[0018] Furthermore, it also includes a stationary iron core fixing device, wherein the stationary iron core is fixed on the stationary iron core fixing device, and the stationary iron core fixing device is fixed on the outgoing copper busbar.

[0019] Beneficial effects of this invention:

[0020] This invention discloses an electromagnetic returnable short-circuit time-delay trip unit for frame circuit breakers. The time-delay trip unit has a simple and compact structure, is compatible with both AC and DC, requires no external power supply, and reliably implements short-circuit short-delay protection. The short-circuit short-delay time can be set according to the linkage relationship between upper and lower levels, and the magnitude of the short-delay current value of the circuit breaker can be adjusted according to design requirements. Attached Figure Description

[0021] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0022] Figure 2 This is a schematic diagram of the static iron core of the present invention;

[0023] Figure 3 This is a three-dimensional structural diagram of the current value adjustment device of the present invention in cooperation with the moving iron core and the push rod;

[0024] Figure 4 This is a three-dimensional structural diagram of the cooperation between the moving iron core and the push rod of the present invention;

[0025] Figure 5 This is a three-dimensional structural diagram of the delay adjustment device, the delay trip adjustment device, and the tripping half-shaft of the present invention.

[0026] The components are as follows: 1. Static iron core; 101. Magnetic sheet; 102. First magnetic block; 103. Second magnetic block; 104. Clamping plate; 105. Rear baffle; 106. Front baffle; 2. Moving iron core; 3. Current value adjustment device; 301. Fixing plate; 302. First spring guide shaft; 303. First spring; 304. Spring support; 305. First support; 306. Second support; 307. Adjustment knob; 4. Push rod; 401. Metal rod; 402. Insulating rod; 5. Delay adjustment device; 501. Support back plate; 502. Loading block; 503. Second spring; 504. Second spring adjustment knob; 505. Guide screw; 6. Delay trip adjustment device; 601. First trip push rod; 602. Second trip push rod; 7. Opening half shaft; 8. Static iron core fixing device; 9. Outgoing copper busbar. Detailed Implementation

[0027] The preferred mechanism and method of motion implementation of the present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0028] It should be noted that the terms "width", "height", "longitudinal", "front end", "rear end", "bottom end", "both ends", "one side", "the other side", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0029] like Figure 1-5 As shown, an electromagnetic returnable short-circuit time-delay trip device for a frame circuit breaker includes a stationary iron core 1, a moving iron core 2, a current value adjustment device 3, a push rod 4, a time delay adjustment device 5, and a time delay trip adjustment device 6.

[0030] For ease of description, it is hereby stipulated that... Figure 1 For example, the length direction of the stationary iron core 1 is left and right, that is, the side on which the current value adjustment device 3 is set on the stationary iron core 1 is the left side and the other side is the right side; the side on which the current value adjustment device 3 is set on the time delay trip is the front side, and the side on which the time delay adjustment device 5 is set is the rear side.

[0031] The stationary iron core 1 is composed of a magnetic sheet 101 and a first magnetic block 102 and a second magnetic block 103 connected to both ends of the magnetic sheet 101, forming a C-shaped cavity assembly. A C-shaped notch is formed between the first magnetic block 102 and the second magnetic block 103, and the moving iron core 2 is disposed at this notch and can move back and forth at this notch. The stationary iron core 1 also includes clamping plates 104, which are disposed on the front and rear sides of the magnetic sheet 101, the first magnetic block 102, and the second magnetic block 103. A front baffle 106 and a rear baffle 105 are respectively disposed on the front and rear sides of the notch for limiting the movement of the moving iron core.

[0032] The push rod 4 includes a metal rod 401 and an insulating rod 402, with the insulating rod 402 located at one end of the metal rod 401. The moving iron core 2 is fixed to the metal rod 401. Push rod holes are provided on the front baffle 106 and the rear baffle 105 to facilitate the passage of the metal rod 401. One end of the metal rod 401 is connected to the first spring guide shaft 302 of the current value adjusting device 3, and the other end is threadedly fastened to one end of the insulating rod 402. The other end of the insulating rod 402 is connected to the load block 502 of the delay adjusting device 5. The function of the insulating rod 402 is to prevent the short-circuit current on the outgoing copper busbar 9 from affecting the operation of the tripping half shaft 7.

[0033] The current value adjustment device 3 is located on the front side of the notch in the stationary iron core 1. It is used to adjust the short-circuit current value of the time-delay trip device according to the design requirements, that is, to adjust the current value that can cause the moving iron core to move. The current value adjustment device 3 includes a fixed plate 301, a first spring guide shaft 302, a first spring 303, a spring support 304, a first support 305, a second support 306, and an adjustment knob 307.

[0034] The fixing plate 301 includes two plates, which are respectively set on the left and right sides of the notch of the stationary iron core 1. They are used to fix the entire current value adjustment device 3 to the stationary iron core 1. The ends of the fixing plate 301 are fixed with the second support member 306 and the first support member 305 from the outside to the inside. The adjustment knob 307 passes through the second support member 306 and the first support member 305 in sequence, and its end is fixed with a spring support member 304. One end of the first spring guide shaft 302 is fixed to the first support member 305, and the other end has a protrusion. The protrusion is connected to the metal rod 401 of the push rod 4. The spring support member 304 and the first spring 303 are sleeved on the first spring guide shaft 302. The first spring 303 is stuck between the protrusion at the end of the first spring guide shaft 302 and the spring support member 304. According to design requirements, by adjusting the adjustment knob 307, the spring support 304 is driven to move on the first spring guide shaft 302, and the initial compression of the first spring 303 is adjusted, thereby adjusting the short-circuit current value of the time-delay trip device. That is, by changing the elastic force of the first spring 303, the magnitude of the thrust of the push rod 4 in horizontal movement is changed, thereby adjusting the operating current value of the moving iron core 2. This current is the short-circuit current (also known as the fault current). When the short-circuit current passes through, the magnetic force generated by the stationary iron core 1 pushes the moving iron core 2 to move in the direction of the current value adjustment device 3. That is, the moving iron core 2 must overcome the thrust of the first spring 303 in order to continue to move in the direction of the current value adjustment device 3.

[0035] The function of the spring here is twofold: first, to provide initial pressure to the moving iron core 2 to control the short-circuit current value. When the short-circuit current exceeds the set value, the magnetic force generated by the stationary iron core 1 must be greater than the thrust of the first spring 303 to push the moving iron core 2 toward the current value adjustment device 3; second, to provide a reset thrust to the moving iron core 2 after the circuit breaker is tripped.

[0036] In other words, the current value adjustment device 3 is a device for adjusting the initial force value of the first spring 303, which can adjust and set the instantaneous operating current value.

[0037] The delay adjustment device 5 includes a support back plate 501, a loading block 502, a second spring 503, a second spring adjustment knob 504, and a guide screw 505.

[0038] The load block 502 is movably mounted on the support back plate 501. The upper and lower ends of the load block 502 are equipped with second spring adjustment knobs 504. The second spring adjustment knobs 504 are rotatably mounted on the support back plate 501. One front end of the second spring 503 is connected to the second spring adjustment knob 504, and the other rear end is fixedly connected to the load block 502. Therefore, the second spring 503 can pull the load block 502 to move forward (i.e., towards the current value adjustment device 3).

[0039] The loading block 502 can be made of different materials according to the delay time requirements. It is preferred to use high-density metal material, which is heavy. The loading block 502 is provided with an elongated hole to form a limiting guide rail for the loading block 502 to move back and forth in the horizontal direction. The corresponding support back plate 501 is provided with a guide screw 505. The guide screw 505 is inserted into the elongated hole, which not only supports the loading block 502, but also guides the loading block 502 to move back and forth in the horizontal direction.

[0040] The end of the load-bearing block 502 is provided with a delay adjustment hole, which is connected to the delay trip adjustment device 6. The delay trip adjustment device 6 includes a first trip push rod 601 and a second trip push rod 602. One end of the first trip push rod 601 engages with the delay adjustment hole, and the other end is connected to one end of the second trip push rod 602. The other end of the second trip push rod 602 is then connected to the tripping half shaft 7. Here, the delay adjustment hole is a horizontally arranged elongated hole, so that the movement of the load-bearing block 502 pushes the first trip push rod 601 with a certain delay effect. The first trip push rod 601 and the second trip push rod 602 can also be made as a whole, while making them as separate parts is more convenient for assembly.

[0041] When the moving iron core 2 is attracted, it drives the push rod 4 to move forward. The delay adjustment device 5 starts to move forward along the limit guide rail of the elongated hole (i.e., towards the current value adjustment device 3) to start timing. Due to the large weight and inertia of the load block 502, the load block 502 has a delay effect when it moves forward. The elastic force of the second spring 503 and the length of the second spring adjustment knob 504 can be adjusted according to the design requirements to adjust the stroke and force value to achieve the effect of adjusting the delay time. After being pushed by the delay adjustment device 5, the delay trip adjustment device 6 pushes the opening half shaft 7 of the mechanism to rotate, causing the opening half shaft 7 to trip.

[0042] In other words, based on the weight of the load block 502, the elastic force of the second spring 503, the tripping stroke of the second spring adjustment knob 504, and the coordination of the delay tripping adjustment device 6, the design can meet the delay time adjustment requirements from 30ms to 100ms.

[0043] The stationary iron core fixing device 8 is used to fix the stationary iron core 1 to the outgoing copper busbar 9. The stationary iron core fixing device 8 and the support back plate 501 of the delay adjustment device 5 are the fixing devices for the entire delay trip unit.

[0044] The working principle and process of this embodiment are as follows:

[0045] The stationary iron core 1 is fixed to the outgoing copper busbar 9 by the stationary iron core fixing device 8. The stationary iron core 1 is used to sense the current on the outgoing copper busbar 9 and form a magnetic circuit to apply electromagnetic attraction to the moving iron core 2. The moving iron core 2 is linked to the push rod 4, which is the starting component that enables the circuit breaker to trip under short-circuit protection. The current value adjustment device 3 is a device for adjusting the initial force value of the first spring 303, thereby enabling the adjustment and setting of the instantaneous operating current value. The time delay trip adjustment device 6 starts to move after the push rod 4 is activated. After a certain movement time, it comes into contact with the tripping half shaft 7 and pushes the tripping half shaft to rotate, causing the circuit breaker to trip. The time delay adjustment device 5 adjusts the delay time by adjusting the load block 502, the second spring 503, and the second spring adjustment knob 504 according to the linkage requirements of the upper and lower levels and the design requirements.

[0046] In other words, in the initial state, the first spring 303 of the current value regulating device 3 has a backward thrust (i.e., towards the delay regulating device 5), which means it can hold one end of the push rod 4 and prevent it from moving forward (i.e., towards the current value regulating device 3). At this time, the other end of the push rod 4 holds the mounting block 502 backward. The second spring 503 has a forward pulling force on the mounting block 502, but since the mounting block 502 is held by the push rod 4, and the backward thrust of the push rod 4 is greater than the forward pulling force of the second spring 503, the mounting block 502 is located behind the support back plate 501. That is, in the initial state, the backward thrust of the first spring 303 (i.e., towards the delay regulating device 5) is greater than the forward pulling force of the two second springs 503 on the mounting block 502 (i.e., towards the current value regulating device 3).

[0047] When the short-circuit current (i.e., fault current) passing through the outgoing copper busbar 9 exceeds the designed short-circuit current, the stationary iron core 1 senses the short-circuit current and forms a magnetic circuit, thereby applying an electromagnetic attraction force to the moving iron core 2 in the forward direction (i.e., towards the current value adjustment device 3). The moving iron core 2 drives the push rod 4 to move forward. The push rod 4 does not press against the load block 502, and the time-delay trip adjustment device 6 starts timing. Under the action of inertia, the load block 502 is driven forward by the second spring 503. After the set time is reached, the load block 502 pushes the time-delay trip adjustment device 6, which pushes the tripping half shaft 7 to rotate, thereby achieving tripping.

[0048] If the fault current duration is less than the set delay time, the moving iron core 2 loses the electromagnetic attraction of the stationary iron core 1, the first spring 303 resets, the push rod 4 drives the moving iron core 2 to reset, one end of the push rod 4 again presses against the load block 502, and pushes the delay trip adjustment device 6 to reset, forcing the tripping process to terminate. If there is a fault current again, the timing needs to be restarted.

[0049] In other words, when a fault current passes through, the moving iron core 2 provides space for the delay adjustment device 5 to move during the delay. After the set movement time is reached, the delay adjustment device 5 pushes the tripping half shaft 7 of the mechanism through the delay tripping adjustment device 6, causing the circuit breaker to trip. If the fault current disappears, the moving iron core 2 resets under the action of the first spring 303, thereby pushing the delay adjustment device 5 to reset, so that the delay time is reset.

[0050] This invention is a purely mechanical trip unit with a simple and compact structure, compatible with both AC and DC power supplies, and requiring no external power source. This invention reliably provides short-circuit short-delay protection, and the short-delay current value of the circuit breaker can be adjusted according to design requirements. The short-circuit short-delay time can be set accordingly based on the linkage relationship between upper and lower levels.

[0051] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. However, any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An electromagnetic returnable short-circuit time-delay trip unit for a frame circuit breaker, comprising a stationary iron core (1), a moving iron core (2), and a push rod (4), characterized in that, It also includes a delay adjustment device (5), which includes a support back plate (501), a load block (502), and a second spring (503). The load block (502) is movably mounted on the support back plate (501). The second spring (503) is a tension spring, with one end movably connected to the support back plate (501) and the other end fixedly connected to the load block (502). The load block (502) is connected to the tripping half shaft (7) and is used to drive the tripping half shaft (7) to trip. One end of the push rod (4) is linked to the load block (502), and the other end is connected to the moving iron core (2). The static iron core (1) generates an electromagnetic force on the moving iron core (2) to pull the push rod (4) away from the load block (502). The load block (502) moves under the tension of the second spring (503), thereby driving the tripping half shaft (7) to trip. The delay adjustment device (5) further includes a second spring adjustment knob (504), which is rotatably mounted on the support back plate (501). One end of the second spring (503) is connected to the second spring adjustment knob (504), and the other end is fixedly connected to the load block (502). It also includes a current value adjustment device (3), which includes a fixed plate (301), a first spring (303), a spring support (304), a first support (305), and an adjustment knob (307). A rear baffle (105), a front baffle (106), and a second support (306) are sequentially fixed on the fixed plate (301). The stationary iron core (1) has a C-shaped structure with a notch. The fixed plate (301) is fixedly installed at the notch, and the fixed plate (301), the front baffle (106), and the rear baffle (105) are shaped like... The space surrounding the notch is formed, and the moving iron core (2) is movably confined within the space. The spring support (304) is movably disposed between the front baffle (106) and the first support (305). The first spring (303) is a compression spring and is disposed between the front baffle (106) and the spring support (304). The adjustment knob (307) moves through the second support (306) and the first support (305) in sequence and is fixedly connected to the spring support (304). The adjustment knob (307) is used to adjust the elastic force of the first spring (303).

2. The electromagnetic returnable short-circuit time-delay trip unit for a frame circuit breaker according to claim 1, characterized in that, The loading block (502) is provided with an elongated hole to form a limiting guide rail, and the corresponding support back plate (501) is provided with a guide screw (505), which moves within the limiting guide rail.

3. The electromagnetic returnable short-circuit time-delay trip unit for a frame circuit breaker according to claim 1, characterized in that, It also includes a delay trip adjustment device (6), on which a delay adjustment hole is provided. The delay adjustment hole is a horizontally arranged elongated hole, and one end of the delay trip adjustment device (6) is disposed in the delay adjustment hole.

4. The electromagnetic returnable short-circuit time-delay trip unit for frame circuit breakers according to claim 3, characterized in that, The delay trip adjustment device (6) includes a first trip push rod (601) and a second trip push rod (602). One end of the first trip push rod (601) is engaged with the delay adjustment hole, and the other end is connected to the second trip push rod (602). The other end of the second trip push rod (602) is engaged with the trip half shaft (7) in linkage.

5. The electromagnetic returnable short-circuit time-delay trip unit for a frame circuit breaker according to claim 1, characterized in that, The current value adjustment device (3) further includes a first spring guide shaft (302), one end of which is connected to the push rod (4), and the other end is limited on the first support member (305). The spring support member (304) and the first spring (303) are sleeved on the first spring guide shaft (302).

6. The electromagnetic returnable short-circuit time-delay trip unit for a frame circuit breaker according to claim 5, characterized in that, The push rod (4) includes a metal rod (401) and an insulating rod (402). The moving iron core (2) is fixed on the metal rod (401). One end of the metal rod (401) is connected to a first spring guide shaft (302) on one side, and the other end is connected to one end of the insulating rod (402). The other end of the insulating rod (402) is connected to the load block (502).

7. The electromagnetic returnable short-circuit time-delay trip unit for a frame circuit breaker according to claim 1, characterized in that, The stationary iron core (1) includes a magnetic sheet (101), and a first magnetic block (102) and a second magnetic block (103) respectively connected to both ends of the magnetic sheet (101), with a C-shaped notch formed between the first magnetic block (102) and the second magnetic block (103); the stationary iron core (1) also includes a clamping plate (104) disposed on the front and rear sides of the magnetic sheet (101), the first magnetic block (102) and the second magnetic block (103).

8. The electromagnetic returnable short-circuit time-delay trip unit for a frame circuit breaker according to claim 1, characterized in that, It also includes a stationary iron core fixing device (8), the stationary iron core (1) is fixed on the stationary iron core fixing device (8), and the stationary iron core fixing device (8) is fixed on the outgoing copper busbar (9).

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