A low voltage vacuum circuit breaker

Abstract

The present invention discloses a low-voltage vacuum circuit breaker, which relates to the technical field of vacuum circuit breakers, and includes an electromagnet, a rotating bracket and a vacuum interrupter, wherein the axial direction of the electromagnet is parallel to the axial direction of the vacuum interrupter, and the electromagnet controls the moving and static contacts in the vacuum interrupter to contact or separate to realize closing and opening through the rotating bracket, and the moving direction of the moving iron core of the electromagnet is opposite to the moving direction of the moving contact in the vacuum interrupter. The vacuum circuit breaker disclosed by the present invention adopts an upper and lower layout, the axial direction of the electromagnet is parallel to the axial direction of the vacuum interrupter, the integration of product components is increased, the space is effectively utilized, and the overall structure of the circuit breaker is more compact.

Description

Technical Field

[0001] The present invention relates to the technical field of vacuum circuit breakers, and in particular to a low-voltage vacuum circuit breaker. Background Art

[0002] A vacuum circuit breaker currently on the market consists of a vacuum interrupter, a contact spring, a connecting rod assembly, an electromagnet, a reset spring, a mounting base, etc. The action process is as follows:

[0003] 1) After the electromagnet is energized, the moving iron core and the static iron core are closed, driving the connecting rod assembly to move, thereby pushing the moving and static contacts in the vacuum interrupter to close. At the same time, the contact spring is compressed to provide pressure for the contact, and the reset spring used to reset the electromagnet when the power is off is compressed to store energy;

[0004] 2) When the electromagnet loses power, the moving contact of the vacuum interrupter separates from the static contact under the action of the contact spring and the reset spring, and the moving iron core of the electromagnet resets under the action of the reset spring.

[0005] Problems with the current structure of vacuum circuit breakers:

[0006] 1. The electromagnet is installed vertically relative to the vacuum interrupter, which results in the overall height of the vacuum circuit breaker becoming larger and the space utilization rate is not high.

[0007] 2. The moving iron core of the electromagnet is directly connected to the connecting rod assembly, so that there is a reaction force when the moving iron core closes toward the static iron core. Therefore, a large initial suction force is required, and the load on the electromagnetic coil is increased.

[0008] 3. The stroke of the circuit breaker cannot be adjusted and quality consistency is difficult to ensure.

[0009] 4. The upper and lower layout is adopted, with the main circuit (vacuum interrupter) on the upper part and the electromagnet (control circuit) on the lower part. In the vertical installation mode of the circuit breaker, the opening / closing button needs to be installed on the guide rail of the switch cabinet separately, which increases the installation space of the product.

[0010] 5. No overload and short circuit protection function. Summary of the invention

[0011] The object of the present invention is to provide a low voltage vacuum circuit breaker to solve the above problems.

[0012] To achieve the above object, the present invention adopts the following technical solutions:

[0013] A low-voltage vacuum circuit breaker comprises an electromagnet, a rotating bracket and a vacuum interrupter. The axial direction of the electromagnet is parallel to the axial direction of the vacuum interrupter. The electromagnet controls the contact or separation of moving and static contacts in the vacuum interrupter through the rotating bracket to achieve closing and opening. The moving direction of the moving iron core of the electromagnet is opposite to the moving direction of the moving contact in the vacuum interrupter.

[0014] Furthermore, the electromagnet and the vacuum interrupter are located on the same side of the rotating bracket, the lower end of the rotating bracket is connected to the moving contact end of the vacuum interrupter, the upper end of the rotating bracket is connected to the electromagnet, and the rotating bracket can rotate around a fulcrum, which is located in the middle of the rotating bracket.

[0015] Furthermore, the rotating bracket and the electromagnet are connected through a tripping mechanism, and the positional relationship between the tripping mechanism and the electromagnet is configured so that the moving iron core of the electromagnet pushes the tripping mechanism under the normal working state of the circuit breaker, and a pre-travel gap is formed between the moving iron core and the tripping mechanism after the electromagnet loses power.

[0016] Furthermore, the moving contact end and the stationary contact end of the vacuum interrupter are respectively connected to a terminal block, the terminal block of the moving contact end of the vacuum interrupter is located between the vacuum interrupter and the tripping mechanism and extends toward the front of the circuit breaker, and the terminal block of the stationary contact end of the vacuum interrupter extends toward the rear of the circuit breaker.

[0017] Furthermore, the terminal board at the moving contact end of the vacuum interrupter is connected to a thermal-magnetic trigger unit, and a traction rod is provided between the thermal-magnetic trigger unit and the tripping mechanism. The tripping mechanism has a locked state and a tripping state. Under normal working conditions of the circuit breaker, the tripping mechanism is in a locked state. When the circuit breaker is overloaded or short-circuited, the thermal-magnetic trigger unit triggers the traction rod, and then the traction rod triggers the tripping mechanism to switch the tripping mechanism from the locked state to the tripping state.

[0018] Furthermore, the thermal-magnetic trigger unit includes a thermal trip element and a magnetic trip element. When the circuit breaker is overloaded, the thermal trip element triggers the traction rod, and when the circuit breaker is short-circuited, the magnetic trip element triggers the traction rod.

[0019] Furthermore, a reset alarm mechanism is connected above the tripping mechanism, and the reset alarm mechanism is electrically connected to the electromagnet. When a short circuit or overload fault occurs in the circuit breaker, the reset alarm mechanism causes the electromagnet to lose power and reset, and outputs an alarm signal to the user. By manually pressing the reset alarm mechanism, the tripping mechanism can be restored to a locked state from a tripped state.

[0020] Furthermore, an adjusting nut for adjusting the operating stroke of the circuit breaker is provided at the connection between the moving iron core of the electromagnet and the tripping mechanism.

[0021] Furthermore, the electromagnet is a direct-acting electromagnet, having a moving iron core, a stationary iron core, a coil and a push rod. The moving iron core is opposite to the stationary iron core and the moving iron core can slide axially along the stationary iron core. The push rod passes through the moving iron core and the stationary iron core. One end of the push rod is fixedly connected to the moving iron core and the other end passes through the stationary iron core. The moving iron core and the stationary iron core are arranged in the coil hole.

[0022] Furthermore, the low-voltage vacuum circuit breaker also includes a reset spring, one end of which is connected to the upper end of the rotating bracket and the other end is connected to the electromagnet. When the circuit breaker is closed, the reset spring is stretched to store energy.

[0023] Compared with the prior art, the present invention has the following advantages:

[0024] 1. With the top-bottom layout, the axial direction of the electromagnet is parallel to the axial direction of the vacuum interrupter, the integration of product components is increased, the space is effectively utilized, and the overall structure of the circuit breaker is more compact.

[0025] 2. By adopting an upper and lower layout, the electromagnet (control circuit) can be set above the main circuit (vacuum interrupter), so that the weak current circuit can be installed on the upper part of the circuit breaker closer to the human body, and the strong current circuit can be set at the lower part of the circuit breaker to stay away from the human body, thereby increasing safety. In the vertical installation mode of the circuit breaker, the opening and closing buttons of the circuit breaker can be installed on the upper part of the circuit breaker to make the circuit breaker structure more compact.

[0026] 3. A thermal magnetic trigger unit is provided on the main circuit wiring board, and a tripping mechanism is provided correspondingly. When an overload / short circuit fault occurs in the circuit, the thermal magnetic trigger unit triggers the tripping mechanism, so that the circuit breaker can trip quickly, thereby avoiding damage to the entire circuit system and improving safety.

[0027] 4. The moving contact end and the stationary contact end of the vacuum interrupter are respectively connected to a wiring board. The wiring board of the moving contact end of the vacuum interrupter is arranged between the vacuum interrupter and the tripping mechanism. The thermal magnetic trigger unit is connected to the wiring board of the moving contact end of the vacuum interrupter. The thermal magnetic trigger unit triggers the tripping mechanism through a traction rod. The thermal magnetic trigger unit and the traction rod are located between the tripping mechanism and the vacuum interrupter. This structure effectively utilizes the space and makes the overall structure of the circuit breaker more compact. In addition, the thermal magnetic trigger unit, the traction rod and the tripping mechanism are close to each other, which is conducive to the transmission of the action.

[0028] 5. There is a pre-travel gap between the moving iron core of the electromagnet and the tripping mechanism. When the moving and static iron cores of the electromagnet are closed, there is no reaction force and they start without load, which reduces the required electromagnetic suction force and reduces the load on the electromagnetic coil.

[0029] 6. An adjusting nut is provided at the connection between the tripping mechanism and the moving iron core to adjust the action stroke of the circuit breaker, making the assembly and testing of the circuit breaker convenient and improving the quality and performance of the product. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a three-dimensional diagram of an assembly state of a low-voltage vacuum circuit breaker according to an embodiment of the present invention;

[0031] Figure 2 is an exploded view of a low-voltage vacuum circuit breaker according to an embodiment of the present invention;

[0032] Figure 3 is a three-dimensional diagram of a portion of the internal structure of a low-voltage vacuum circuit breaker according to an embodiment of the present invention;

[0033] Figure 4 is a front view of a part of the internal structure of a low-voltage vacuum circuit breaker according to an embodiment of the present invention;

[0034] Figure 5 is a three-dimensional diagram of the internal structure of a low-voltage vacuum circuit breaker according to an embodiment of the present invention;

[0035] Figure 6 is a three-dimensional diagram of a portion of the internal structure of a low-voltage vacuum circuit breaker according to an embodiment of the present invention;

[0036] Figure 7 yes Figure 6 Another angle view of the partial internal structure stereogram of the low-voltage vacuum circuit breaker shown;

[0037] Figure 8 is a schematic diagram of the trip mechanism in a locked state;

[0038] Fig. 9 is a cross-sectional view of the trip mechanism in a locked state;

[0039] Fig.10 is a schematic diagram of the tripping mechanism in a tripping state;

[0040] Fig.11 It is a cross-sectional view of the tripping mechanism in the tripping state. DETAILED DESCRIPTION

[0041] To further illustrate the various embodiments, the present invention provides drawings. These drawings are part of the disclosure of the present invention, which are mainly used to illustrate the embodiments and can be used in conjunction with the relevant descriptions in the specification to explain the operating principles of the embodiments. With reference to these contents, a person of ordinary skill in the art should be able to understand other possible implementations and advantages of the present invention. The components in the figures are not drawn to scale, and similar component symbols are generally used to represent similar components.

[0042] In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate directions or positional relationships based on the attached Figure 2 The orientation or position relationship shown.

[0043] like Figures 1 to 7As shown, a low-voltage vacuum circuit breaker includes an electromagnet 1, a rotating bracket 4 and a vacuum interrupter 5. The axial direction of the electromagnet 1 is parallel to the axial direction of the vacuum interrupter 5 and the electromagnet 1 is located above the vacuum interrupter 5. The electromagnet 1 controls the contact or separation of the moving and static contacts in the vacuum interrupter 5 through the rotating bracket 4 to achieve closing and opening. The moving direction of the moving iron core of the electromagnet 1 is opposite to the moving direction of the moving contact in the vacuum interrupter 5.

[0044] The low voltage described in this article refers to a voltage not greater than 1500 volts. With an up-down layout, the electromagnet 1 and the vacuum interrupter 5 are both arranged horizontally. In the vertical installation mode of the circuit breaker, the opening and closing button 10 of the circuit breaker can be installed on the upper part of the circuit breaker, the integration of product parts is increased, the space is effectively utilized, and the overall structure of the circuit breaker is more compact. With an up-down layout, the control circuit (electromagnet) can be set above the main circuit (vacuum interrupter), that is, the weak current circuit is installed on the front of the circuit breaker, and the strong current circuit is installed at the bottom of the circuit breaker, which enhances safety.

[0045] like Figure 4 As shown, the electromagnet 1 and the vacuum interrupter 5 are located on the same side of the rotating bracket 4, the lower end of the rotating bracket 4 is connected to the moving contact end of the vacuum interrupter 5, the upper end of the rotating bracket 4 is connected to the tripping mechanism 2, and the rotating bracket 4 can rotate around a fulcrum 9, which is located in the middle of the rotating bracket.

[0046] The rotating bracket 4 and the electromagnet 1 are connected through the tripping mechanism 2. The positional relationship between the electromagnet 1 and the tripping mechanism 2 is configured so that the moving iron core of the electromagnet 1 pushes the tripping mechanism 2 under normal working conditions, and a pre-travel gap is formed between the moving iron core and the tripping mechanism 2 after the electromagnet 1 loses power. In this way, when the electromagnet 1 is powered off and reset, it starts without load due to the absence of reaction force, which reduces the required electromagnetic suction force and reduces the load on the coil.

[0047] The moving contact end and the stationary contact end of the vacuum interrupter are each connected to a terminal block 8. The terminal block 8 at the moving contact end of the vacuum interrupter is located between the vacuum interrupter and the tripping mechanism and extends toward the front of the circuit breaker. The terminal block 8 at the stationary contact end of the vacuum interrupter extends toward the rear of the circuit breaker.

[0048] The terminal block 8 at the moving contact end of the vacuum interrupter is connected to a thermal magnetic trigger unit. A traction rod is provided between the thermal magnetic trigger unit 7 and the tripping mechanism 2. The tripping mechanism 2 has a locked state and a tripping state. Under normal working conditions of the circuit breaker, the tripping mechanism 2 is in a locked state. When the circuit breaker is overloaded or short-circuited, the thermal magnetic trigger unit 7 triggers the traction rod 6, and then the traction rod 6 triggers the tripping mechanism 2 to switch the tripping mechanism 2 from the locked state to the tripping state.

[0049] Specifically, the thermal magnetic trigger unit 7 includes a thermal trip element and a magnetic trip element, and the thermal trip element and the magnetic trip element are connected to the wiring board 8. The thermal trip element includes a bimetallic strip, and the magnetic trip element includes a yoke and an armature. When the circuit is overloaded, the bimetallic strip of the thermal trip element heats up and deforms to trigger the traction rod 6, and the triggered traction rod 6 drives the trip mechanism 2 to switch from the locked state to the tripped state; when the circuit is short-circuited, the yoke of the magnetic trip element attracts the armature, and the armature rotates to trigger the traction rod 6, and the triggered traction rod 6 switches the trip mechanism 2 from the locked state to the tripped state.

[0050] The electromagnet 1 is a direct-acting electromagnet, having a moving iron core, a static iron core, a coil and a push rod, the moving iron core is opposite to the static iron core and can slide along the axial direction of the static iron core, the push rod passes through the moving iron core and the static iron core, one end of the push rod is fixedly connected to the moving iron core, and the other end passes through the static iron core, and the moving iron core and the static iron core are arranged in the coil hole. The direct-acting electromagnet, the vacuum interrupter 5, the tripping mechanism 2, the thermal tripping element (including the bimetallic part) and the magnetic tripping element (including the yoke and the armature) are all common structures in low-voltage vacuum circuit breakers, and the existing ones can be used.

[0051] An adjusting nut for adjusting the operating stroke of the circuit breaker is provided at the connection between the moving iron core of the electromagnet 1 and the tripping mechanism 2. The adjusting nut is installed on the moving iron core of the electromagnet. The pre-travel gap between the moving iron core of the electromagnet and the tripping mechanism 2 is changed by rotating the adjusting nut, thereby changing the operating stroke of the circuit breaker, making the assembly and testing of the circuit breaker convenient and improving the quality performance of the product.

[0052] The circuit breaker further comprises a reset spring 3, one end of which is connected to the upper end of the rotating bracket 4 and the other end is connected to the electromagnet 1. When the circuit breaker is closed, the reset spring 3 is stretched to store energy.

[0053] like Figures 8 to 11 The tripping mechanism 2 includes a push rod 201, a first connecting rod 202, a second connecting rod 203, a connecting rod 204 and a mounting plate. The push rod 201, the first connecting rod 202, the second connecting rod 203 and the connecting rod 204 are hingedly connected in sequence. The connecting rod 204 is fixedly connected to the mounting plate and is opposite to the electromagnet 1. A stop rod 206 and a tripping half-shaft 205 are assembled on the mounting plate. The stop rod 206 is equipped with a stop rod reset torsion spring, and the tripping half-shaft 205 is equipped with a tripping half-shaft reset torsion spring.

[0054] In the normal working state of the circuit breaker, if Figure 8 and Fig. 9As shown, the stop rod 206 presses the second connecting rod 203 under the action of the stop rod reset torsion spring, so that the first connecting rod 202 and the second connecting rod 203 are in a relatively straight state, and the tripping half shaft 205 presses the stop rod 206 under the action of the tripping half shaft reset torsion spring, thereby locking the stop rod 206. At this time, the tripping mechanism 2 is in a locked state, and the electromagnet 1 can move the tripping device by pushing the connecting rod 204, thereby pushing the rotating bracket to rotate, and then the moving and static contacts of the vacuum interrupter are in contact and closed. When the circuit breaker is normally de-energized, the tripping mechanism 2 remains in the locked state.

[0055] When a short circuit or overload fault occurs in the circuit breaker, the thermal magnetic trigger unit 7 moves the traction rod, and the traction rod moves the tripping half shaft 205, thereby releasing the restriction on the stop rod 206, and the reset spring 3 automatically shortens to pull the rotating bracket in the direction of the electromagnet 1. The rotating bracket 4 rotates around the fulcrum 9 under the action of the reset spring 3. The push rod 201 is pushed by the upper end of the rotating bracket to push the first connecting rod 202, and the second connecting rod 203 overcomes the pressure of the stop rod 206 and rotates, so that the first connecting rod 202 and the second connecting rod 203 are switched from a relatively straight state to a state as shown in the figure. Fig.10 and Fig.11 In the folded state shown, the tripping mechanism 2 enters the tripping state. At the same time, the lower end of the rotating bracket pulls the moving contact end of the vacuum interrupter 5 to separate the moving and static contacts, thereby tripping the circuit breaker.

[0056] like Figure 2 and Figure 5 As shown, a reset alarm mechanism 11 is provided above the tripping mechanism 2, and the reset alarm mechanism 11 includes an electromagnet-controlled micro switch, a signal alarm micro switch, and a reset button. The tripping mechanism also includes a reset rod 207, which abuts against the top of the first connecting rod 202, and the reset button is connected to the reset rod 207. By manually pressing the reset button, the tripping mechanism 2 can be restored from the tripping state to the locking state.

[0057] The electromagnet-controlled microswitch is electrically connected to the electromagnet 1. When the circuit breaker trips, the electromagnet-controlled microswitch resets the electromagnet 1 to cancel the thrust on the tripping mechanism 2, and the signal alarm microswitch outputs an alarm signal to the user. After the fault is cleared, the tripping mechanism 2 can be restored to the locked state from the tripping state by manually pressing the reset button, preparing for the next closing.

[0058] Although the present invention has been specifically shown and described in conjunction with the preferred embodiments, it should be understood by those skilled in the art that various changes may be made to the present invention in form and details without departing from the spirit and scope of the present invention as defined by the appended claims, all of which are within the scope of protection of the present invention.

Claims

1. A low voltage vacuum circuit breaker, characterized in that: It includes an electromagnet, a rotating bracket and a vacuum interrupter, wherein the axial direction of the electromagnet is parallel to the axial direction of the vacuum interrupter, and the electromagnet controls the moving and static contacts in the vacuum interrupter to contact or separate to realize closing and opening of the circuit breaker through the rotating bracket, and the moving direction of the moving iron core of the electromagnet is opposite to the moving direction of the moving contact in the vacuum interrupter; the rotating bracket and the electromagnet are connected through a tripping mechanism, and the positional relationship between the tripping mechanism and the electromagnet is configured such that the moving iron core of the electromagnet pushes the tripping mechanism under the normal working state of the circuit breaker, and a pre-travel gap is formed between the moving iron core and the tripping mechanism after the electromagnet loses power.

2. The low voltage vacuum circuit breaker according to claim 1, characterized in that: The electromagnet and the vacuum interrupter are located on the same side of the rotating bracket. The lower end of the rotating bracket is connected to the moving contact end of the vacuum interrupter. The upper end of the rotating bracket is connected to the electromagnet. The rotating bracket can rotate around a fulcrum located in the middle of the rotating bracket.

3. The low voltage vacuum circuit breaker according to claim 1, characterized in that: The moving contact end and the stationary contact end of the vacuum interrupter are respectively connected to a wiring board. The wiring board of the moving contact end of the vacuum interrupter is located between the vacuum interrupter and the tripping mechanism and extends toward the front of the circuit breaker. The wiring board of the stationary contact end of the vacuum interrupter extends toward the rear of the circuit breaker.

4. The low voltage vacuum circuit breaker according to claim 3, characterized in that: The terminal board at the moving contact end of the vacuum interrupter is connected to a thermal magnetic trigger unit, and a traction rod is provided between the thermal magnetic trigger unit and the tripping mechanism. The tripping mechanism has a locked state and a tripping state. Under the normal working state of the circuit breaker, the tripping mechanism is in the locked state. When the circuit breaker is overloaded or short-circuited, the thermal magnetic trigger unit triggers the traction rod, and then the traction rod triggers the tripping mechanism to switch the tripping mechanism from the locked state to the tripping state.

5. The low voltage vacuum circuit breaker according to claim 4, characterized in that: The thermal magnetic trigger unit comprises a thermal trip element and a magnetic trip element. When the circuit breaker is overloaded, the thermal trip element triggers the traction rod. When the circuit breaker is short-circuited, the magnetic trip element triggers the traction rod.

6. The low voltage vacuum circuit breaker according to claim 1, characterized in that: A reset alarm mechanism is connected above the tripping mechanism, and the reset alarm mechanism is electrically connected to the electromagnet. When a short circuit or overload fault occurs in the circuit breaker, the reset alarm mechanism resets the electromagnet and outputs an alarm signal to the user. By manually pressing the reset alarm mechanism, the tripping mechanism can be restored to a locked state from a tripped state.

7. The low voltage vacuum circuit breaker according to claim 1, characterized in that: An adjusting nut for adjusting the action stroke of the circuit breaker is arranged at the connection between the moving iron core of the electromagnet and the tripping mechanism.

8. The low voltage vacuum circuit breaker according to claim 1, characterized in that: The electromagnet is a direct-acting electromagnet, which has a moving iron core, a stationary iron core, a coil and a push rod. The moving iron core is opposite to the stationary iron core and the moving iron core can slide axially along the stationary iron core. The push rod passes through the moving iron core and the stationary iron core. One end of the push rod is fixedly connected to the moving iron core and the other end passes through the stationary iron core. The moving iron core and the stationary iron core are arranged in the coil hole.

9. The low voltage vacuum circuit breaker according to claim 1, characterized in that: The low-voltage vacuum circuit breaker also includes a reset tension spring, one end of which is connected to the upper end of the rotating bracket and the other end is connected to the electromagnet. When the circuit breaker is closed, the reset tension spring is stretched to store energy.

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