Circuit breaker contact device with overheat protection function

Abstract

The present invention provides a circuit breaker contact device with an overheating protection function, which relates to the technical field of circuit breakers. When the temperature of the contact piece is high, the heat of the contact piece will be transferred to the compression spring and the expansion liquid in the hydraulic chamber through the support. The expansion liquid will expand when it heats up, thereby driving the mounting plate to slide toward the notch of the mounting groove, further squeezing the compression spring, so that the contact piece can be pressed tightly against the static contact, thereby solving the heating problem caused by poor contact between the contact piece and the static contact; if the temperature of the contact piece continues to rise after the contact piece can be pressed tightly against the static contact, the volume of the expansion liquid continues to increase at this time, and when the pressure in the hydraulic chamber is greater than the threshold value, the thin wall will be broken under pressure. At this time, the negative pressure of the negative pressure chamber will suck the expansion liquid into the negative pressure chamber, so that the pressure in the hydraulic chamber is reduced, and the mounting plate moves toward the bottom of the mounting groove. The mounting plate drives the contact piece to rotate through the compression spring, so that the contact piece is disconnected from the static contact, thereby realizing the overheating protection function.

Description

Technical Field

[0001] The invention relates to the technical field of circuit breakers, in particular to a circuit breaker contact device with an overheat protection function. Background Art

[0002] Circuit breakers are divided into high-voltage circuit breakers and low-voltage circuit breakers according to their scope of use. A low-voltage circuit breaker is an electrical appliance that has both manual switch function and automatic protection against loss of voltage, undervoltage, overload and short circuit, and the contact system structure is a key structure of low-voltage electrical products. In the prior art, the contact system structure usually uses a spring to drive the moving contact to press the static contact. When the temperature of the moving contact is too high for some reason, the spring will have a reduced stiffness coefficient due to the high temperature, resulting in reduced pressure between the moving and static contacts and poor contact.

[0003] The information disclosed in the background technology section of this application is only intended to deepen the understanding of the general background technology of this application, and should not be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to those skilled in the art. Summary of the invention

[0004] Based on this, it is necessary to provide a circuit breaker contact device with overheat protection function to address the problem that when the temperature of the moving contact of the current circuit breaker is too high for some reason, the spring coefficient will decrease due to the high temperature, resulting in reduced pressure between the moving and static contacts and poor contact.

[0005] The above purpose is achieved through the following technical solutions:

[0006] A circuit breaker contact device with overheat protection function comprises:

[0007] A support, wherein the support is provided with a receiving hole, a mounting groove and a partition located in the mounting groove; the support has a heat conducting function;

[0008] The contact assembly comprises a rotating shaft and a plurality of contact pieces for contacting the stationary contacts; the rotating shaft is connected to the support; the contact piece passes through the receiving hole and is rotatably connected to the rotating shaft, and the contact piece can abut against the support;

[0009] The elastic component includes a compression spring, a mounting plate and a connecting piece for connecting a plurality of the contact pieces; the mounting plate is slidably arranged in the mounting groove; one end of the compression spring is connected to the mounting plate, and the other end of the compression spring is connected to the connecting piece; the side wall of the mounting groove, the mounting plate and the cavity between the partition are hydraulic chambers for accommodating expansion fluid, and the expansion fluid will expand in volume after being heated; the cavity between the side wall of the mounting groove and the partition is a negative pressure chamber; the partition has a thin wall, and when the pressure of the hydraulic chamber is greater than a threshold value, the thin wall will be broken under pressure.

[0010] Furthermore, the contact assembly also includes multiple adjustment springs; the number of the contact pieces is N, the number of the adjustment springs is N+1, and N is an integer greater than or equal to 1; the adjustment springs are sleeved on the rotating shaft, and a single contact piece is located between two adjacent adjustment springs.

[0011] Furthermore, the contact assembly further comprises a plurality of telescopic members; the rotating shaft comprises an inner shaft and an outer shaft sleeved with each other;

[0012] The support is provided with a first limiting groove located on the side wall of the accommodating hole, and the first limiting groove has a pair of parallel first limiting surfaces;

[0013] The shaft end of the inner shaft is provided with a first limit block, and the first limit block has a pair of parallel second limit surfaces; the outer side wall of the inner shaft is circumferentially provided with multiple groups of spiral grooves; the shaft end of the outer shaft is provided with a second limit block, and the second limit block has a pair of parallel third limit surfaces; the second limit surface and the third limit surface are both used to fit the first limit surface; the outer shaft is circumferentially provided with multiple groups of mounting holes corresponding to the spiral grooves, and each group of mounting holes is distributed along a spiral path; different groups of mounting holes are located at different positions in the axial direction of the outer shaft;

[0014] One end of the telescopic member abuts against the outer wall of the inner shaft, and the other end of the telescopic member passes through the mounting hole, and the telescopic member can be embedded in the spiral groove; the length of the telescopic member is greater than the depth of the mounting hole but less than or equal to the sum of the depths of the mounting hole and the spiral groove; wherein,

[0015] When the spiral groove corresponds to the mounting hole, the second limit surface intersects with the third limit surface; when the second limit surface and the third limit surface coincide with each other, the spiral groove is misaligned with the mounting hole, and at this time the telescopic member can detach from the spiral groove and abut against the outer wall of the inner shaft, and the axial sides of each contact piece abut against at least one of the telescopic members respectively.

[0016] Furthermore, the telescopic member includes a telescopic spring and two positioning blocks; both ends of the telescopic spring are connected to one of the positioning blocks respectively, and the mounting hole and the spiral groove both cooperate with the positioning blocks.

[0017] Furthermore, a restraining block is provided on the side wall of the positioning block, and a restraining groove cooperating with the restraining block is provided on the side wall of the mounting hole, wherein the restraining groove is used to restrict the positioning block from being separated from the mounting hole from the inner shaft to the outer shaft.

[0018] Furthermore, one end of the positioning block away from the telescopic spring is rounded; the side of the spiral groove includes a right-angled surface and a guide bevel, and when the positioning block cooperates with the spiral groove, the right-angled surface and the guide bevel are respectively located on both sides of the positioning block; the right-angled surface is used to limit the circumferential rotation of the positioning block, and the guide bevel is used to assist the positioning block to disengage from the spiral groove along the guide bevel.

[0019] Furthermore, the contact assembly also includes a torsion spring; the torsion spring is sleeved on the outer side of the inner shaft, the inner ring of the torsion spring is connected to the inner shaft, and the outer ring of the torsion spring is connected to the outer shaft; when the torsion spring is not subjected to force, the spiral groove and the mounting hole correspond; when the second limiting surface and the third limiting surface are parallel, the torsion spring is twisted.

[0020] Furthermore, the contact assembly also includes a limit strip; the support is provided with a second limit slot passing through the support and connected to the first limit slot; the limit strip cooperates with the second limit slot and is used to prevent the first limit block and the second limit block from detaching from the first limit slot.

[0021] Furthermore, the contact assembly also includes a fixing seat; the contact piece is provided with a first card block and a first card slot; the fixing seat is provided with a second card slot for clamping a plurality of the first card blocks and a second card block cooperating with the first card slot.

[0022] Furthermore, the contact piece is provided with a first connecting groove and a connecting block, the connecting member cooperates with the first connecting groove, and the connecting member is provided with a second connecting groove that cooperates with the connecting block.

[0023] The beneficial effects of the present invention are:

[0024] The compression spring of the present invention acts on a connecting piece connected to the contact piece, so that the contact piece rotates around the rotating shaft and abuts against the support. The end of the contact piece away from the rotating shaft is used to contact the static contact. When the temperature of the contact piece is high, the heat of the contact piece will be transferred to the compression spring and the expansion fluid in the hydraulic chamber through the support. After the compression spring is heated, its elastic deformation capacity is reduced, so that the elastic force of the compression spring acting on the connecting piece is reduced; the expansion fluid will expand when it heats up, thereby driving the mounting plate to slide toward the notch of the mounting groove, further squeezing the compression spring, so that the contact piece can contact with the static contact. The static contact is pressed tightly, thereby solving the heating problem caused by poor contact between the contact piece and the static contact; if the contact piece can be pressed tightly against the static contact, the temperature of the contact piece continues to rise, and the volume of the expansion fluid continues to increase. When the pressure in the hydraulic chamber is greater than the threshold, the thin wall will be broken under pressure. At this time, the negative pressure in the negative pressure chamber will suck the expansion fluid into the negative pressure chamber, so that the pressure in the hydraulic chamber is reduced, and the mounting plate moves toward the bottom of the mounting groove. The mounting plate drives the contact piece to rotate through the compression spring, so that the contact piece is disconnected from the static contact, thereby realizing the overheating protection function. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic structural diagram of a circuit breaker contact device with an overheat protection function according to an embodiment of the present invention;

[0026] Figure 2 A cross-sectional view of a circuit breaker contact device with an overheat protection function according to an embodiment of the present invention;

[0027] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0028] Figure 4 A cross-sectional view of a circuit breaker contact device with an overheat protection function according to another embodiment of the present invention;

[0029] Figure 5 It is a structural schematic diagram of a contact assembly according to an embodiment of the present invention;

[0030] Figure 6 An exploded view of a contact assembly according to an embodiment of the present invention;

[0031] Figure 7 It is a schematic structural diagram of a telescopic member according to an embodiment of the present invention.

[0032] Among them: 100, support; 101, receiving hole; 102, first limiting groove; 1021, first limiting surface; 1022, first arc surface; 103, second limiting groove; 104, mounting groove; 105, hydraulic chamber; 106, negative pressure chamber; 200, contact assembly; 210, inner shaft; 211, first limiting block; 2111, second limiting surface; 2112, second arc surface; 212, spiral groove; 220, outer shaft; 221, second limiting block; 2211, third limiting surface; 2212, The third arc-shaped surface; 230, telescopic member; 231, telescopic spring; 232, positioning block; 240, contact piece; 241, moving contact; 242, first clamping block; 243, first clamping slot; 244, first connecting slot; 245, connecting block; 250, adjusting spring; 260, torsion spring; 270, fixing seat; 271, second clamping block; 272, second clamping slot; 310, compression spring; 320, mounting plate; 330, connecting member; 331, second connecting slot; 340, partition; 341, thin wall. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below through embodiments and in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] The serial numbers assigned to the components herein, such as "first", "second", etc., are only used to distinguish the objects described and do not have any order or technical meaning. The "connection" and "coupling" mentioned in this application, unless otherwise specified, include direct and indirect connections (couplings). In the description of the present invention, it should be understood that the orientation or position relationship indicated by the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", etc. are based on the orientation or position relationship shown in the accompanying drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0035] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0036] Combine the following Figure 1-Figure 7 , describing a circuit breaker contact device with overheat protection function according to an embodiment of the present invention.

[0037] A circuit breaker contact device with an overheat protection function comprises: a support 100, the support 100 is provided with a receiving hole 101, a mounting groove 104 and a partition 340 located in the mounting groove 104; the support 100 has a heat conduction function; a contact assembly 200, comprising a rotating shaft and a plurality of contact pieces 240 for contacting a stationary contact; the rotating shaft is connected to the support 100; the contact piece 240 passes through the receiving hole 101 and is rotatably connected to the rotating shaft, and the contact piece 240 can abut against the support 100; an elastic assembly, comprising a compression spring 310, a mounting plate 320 and a plurality of contact pieces 240 for connecting the plurality of contact pieces 240; The connecting piece 330 of the contact piece 240; the mounting plate 320 is slidably arranged in the mounting groove 104; one end of the compression spring 310 is connected to the mounting plate 320, and the other end of the compression spring 310 is connected to the connecting piece 330; the side wall of the mounting groove 104, the cavity between the mounting plate 320 and the partition 340 is a hydraulic cavity 105 for accommodating an expansion fluid, and the volume of the expansion fluid will expand after being heated; the cavity between the side wall of the mounting groove 104 and the partition 340 is a negative pressure cavity 106; the partition 340 has a thin wall 341, and when the pressure of the hydraulic cavity 105 is greater than a threshold value, the thin wall 341 will be broken under pressure.

[0038] There are usually two reasons why the contact piece 240 heats up:

[0039] 1. The larger the power of the electrical appliance, the larger the current flowing through the contact piece 240;

[0040] 2. The moving contact 241 and the static contact of the circuit breaker are in poor contact.

[0041] The compression spring 310 acts on the connecting piece 330 connected to the contact piece 240, so that the contact piece 240 rotates around the rotating axis and abuts against the support 100. The end of the contact piece 240 away from the rotating axis is used to contact the static contact. When the temperature of the contact piece 240 is high, the heat of the contact piece 240 will be transferred to the compression spring 310 through the support 100. After the compression spring 310 is heated, the elastic deformation ability of the compression spring 310 is reduced, so that the elastic force of the compression spring 310 acting on the connecting piece 330 is reduced, thereby causing the contact piece 240 to be unable to be pressed tightly against the static contact, that is, poor contact.

[0042] If the reason for the heating of the contact piece 240 is "poor contact between the moving contact and the static contact of the circuit breaker", the temperature of the contact piece 240 is transmitted to the expansion fluid in the hydraulic chamber 105 and the compression spring 310 through the support 100. The expansion fluid will expand as it continues to heat up, thereby driving the mounting plate 320 to slide toward the slot of the mounting slot 104, further squeezing the compression spring 310, so that the contact piece 240 can be pressed tightly against the static contact, thereby solving the heating problem caused by the poor contact between the contact piece 240 and the static contact, and realizing the overheating protection function.

[0043] If the reason why the contact piece 240 heats up is that "the power of the electrical appliance is large, resulting in a large current flowing through the contact piece 240", the moving contact 241 is in close contact with the static contact of the circuit breaker. The high temperature of the contact piece 240 is transmitted to the expansion fluid in the hydraulic chamber 105 through the support 100. The expansion fluid will expand as it continues to heat up, and the expansion fluid drives the mounting plate 320 to squeeze the compression spring 310, so that the moving contact 241 can be further pressed against the static contact of the circuit breaker. At this time, the temperature of the contact piece 240 continues to rise, and the expansion fluid continues to expand. When the pressure of the hydraulic chamber 105 is greater than the threshold, the thin wall 341 will be compressed and broken. At this time, the negative pressure of the negative pressure chamber 106 sucks the expansion fluid into the negative pressure chamber 106, so that the pressure of the hydraulic chamber 105 is reduced, and the mounting plate 320 moves toward the bottom of the mounting groove 104. The mounting plate 320 drives the contact 241 to rotate through the compression spring 310, so that the moving contact 241 is disconnected from the static contact of the circuit breaker, thereby cutting off the current flow in the contact piece 240, so that the contact piece 240 can cool down and realize the overheating protection function.

[0044] The long sides of the connecting piece 330 and the contact piece 240 can be arranged in an L shape. When the contact piece 240 contacts the static contact, the contact piece 240 will drive the connecting piece 330 to squeeze the compression spring 310 to be compressed. The elastic force of the compression spring 310 acts on the connecting piece 330 to drive the contact piece 241 to rotate relative to the rotation axis, so that the side of the contact piece 240 close to the connecting piece 330 can abut against the support 100.

[0045] In one embodiment, the contact assembly 200 further includes a plurality of adjustment springs 250 ; the number of contact pieces 240 is N, the number of adjustment springs 250 is N+1, and N is an integer greater than or equal to 1; the adjustment springs 250 are sleeved on the rotating shaft, and a single contact piece 240 is located between two adjacent adjustment springs 250 .

[0046] The number of the adjusting springs 250 and the contact pieces 240 can be determined as needed, for example, N is 3. When the rotating shaft and the support 100 are assembled, each of the two shaft ends of the rotating shaft has an adjusting spring 250 abutting against the support 100, and the multiple adjusting springs 250 can perform preliminary axial positioning on the contact pieces 240, so that the spacing between the contact pieces 240 is evenly distributed.

[0047] In one embodiment, the contact assembly 200 further includes a plurality of telescopic members 230; the rotating shaft includes an inner shaft 210 and an outer shaft 220 which are sleeved with each other; the support 100 is provided with a first limiting groove 102 located on the side wall of the accommodating hole 101, and the first limiting groove 102 has a pair of parallel first limiting surfaces 1021; the shaft end of the inner shaft 210 is provided with a first limiting block 211 and the first limiting block 211 has a pair of parallel second limiting surfaces 2111; the outer side wall of the inner shaft 210 is circumferentially provided with a plurality of groups of spiral grooves 212; the shaft end of the outer shaft 220 is provided with a second limiting block 221 and the second limiting block 221 has a pair of The third limiting surface 2211 is parallel to the inner shaft 210; the second limiting surface 2111 and the third limiting surface 2211 are both used to fit the first limiting surface 1021; the outer shaft 220 is circumferentially provided with a plurality of groups of mounting holes corresponding to the spiral groove 212, and each group of mounting holes is distributed along a spiral path; different groups of mounting holes have different positions in the axial direction of the outer shaft 220; one end of the telescopic member 230 abuts against the outer side wall of the inner shaft 210, and the other end of the telescopic member 230 passes through the mounting hole, and the telescopic member 230 can be embedded in the spiral groove 212; the length of the telescopic member 230 is greater than the depth of the mounting hole but less than or equal to the sum of the depths of the mounting hole and the spiral groove 212; wherein,

[0048] When the spiral groove 212 corresponds to the mounting hole, the second limiting surface 2111 intersects with the third limiting surface 2211; when the second limiting surface 2111 and the third limiting surface 2211 coincide with each other, the spiral groove 212 is misaligned with the mounting hole. At this time, the telescopic member 230 can be disengaged from the spiral groove 212 and abut against the outer wall of the inner shaft 210, and each contact piece 240 abuts against at least one telescopic member 230 on both axial sides.

[0049] The receiving hole 101 passes through the support 100, and the receiving hole 101 has at least a pair of parallel inner side walls. The number of the first limiting grooves 102 can be two and they are relatively arranged on the parallel side walls of the receiving hole 101. The opening of the first limiting groove 102 passes through the support 100, so that the first limiting block 211 and the second limiting block 221 can enter the first limiting groove 102 from the opening of the first limiting groove 102.

[0050] The outer shaft 220 is shaped like a sleeve, and the second limit block 221 is provided with a through hole for the inner shaft 210 to pass through; the length of the inner shaft 210 is greater than the length of the outer shaft 220, the inner shaft 210 is sleeved in the outer shaft 220, and the first limit block 211 can axially abut the second limit block 221.

[0051] The contact piece 240 is provided with a through hole that matches with the outer shaft 220 .

[0052] Let the inner diameter of the adjustment spring 250 be a; when one end of the telescopic member 230 abuts against the outer wall of the inner shaft 210, and the other end of the telescopic member 230 passes through the mounting hole, the distance from the end of the telescopic member 230 away from the inner shaft 210 to the axis of the inner shaft 210 is b, then a>b.

[0053] The process of installing the contact piece 240 on the support 100:

[0054] Before the outer shaft 220 and the inner shaft 210 are assembled into the first limiting groove 102, the inner shaft 210 and the outer shaft 220 are rotated so that the mounting hole corresponds to the spiral groove 212. At this time, the second limiting surface 2111 intersects with the third limiting surface 2211. Since the length of the telescopic member 230 is greater than the depth of the mounting hole but less than or equal to the sum of the depths of the mounting hole and the spiral groove 212, at this time, one end of the telescopic member 230 is embedded in the spiral groove 212, and the other end is located in the mounting hole but does not pass through the outer shaft 220. The contact piece 240 and the adjusting spring 250 can be sleeved on the outer shaft 220. 240 and the adjusting spring 250 are arranged at intervals, and the plurality of contact pieces 240 are passed through the accommodating hole 101, so that the first limiting block 211 and the second limiting block 221 are both matched with the first limiting groove 102. At this time, the adjusting spring 250 located at the axial end of the inner shaft 210 abuts against the support 100, and the plurality of adjusting springs 250 can perform preliminary axial positioning on the contact piece 240, so that the spacing between the contact pieces 240 is evenly distributed; when the first limiting block 211 and the second limiting block 221 are matched with the first limiting groove 102, the third limiting surface 2211 of the second limiting block 221 is first First, the outer shaft 220 cooperates with the first limiting surface 1021. When the second limiting block 221 moves from the notch of the first limiting groove 102 to the bottom of the first limiting groove 102, the outer shaft 220 does not rotate. When the first limiting block 211 cooperates with the first limiting groove 102, the second limiting surface 2111 changes from the intersection state with the third limiting surface 2211 to the parallel state with the third limiting surface 2211, so that the inner shaft 210 rotates relative to the outer shaft 220. At this time, the spiral groove 212 is misaligned with the mounting hole, and the spiral groove 212 squeezes the telescopic member 230 so that the telescopic member 230 moves from the spiral groove 212 to the outer shaft 220. When the second limiting surface 2111 is in contact with the first limiting surface 1021, one end of the telescopic member 230 abuts against the outer wall of the inner shaft 210, the other end of a part of the telescopic member 230 directly passes through the mounting hole, and the other end of the telescopic member 230 radially abuts against the contact piece 240; referring to the figure, since different groups of mounting holes have different positions in the axial direction of the outer shaft 220, each contact piece 240 abuts against at least one telescopic member 230 on both axial sides. At this time, the telescopic member 230 further fixes the axial position of the contact piece 240 to prevent the contact piece 240 from axial movement.

[0055] It should be noted that the smaller the spacing between each group of mounting holes, the more groups of mounting holes are circumferentially arranged on the inner shaft 210, the more telescopic parts 230 are axially abutted against each contact piece 240, and the better the axial limiting effect of the telescopic parts 230 on the contact piece 240.

[0056] When the contact piece 240 is detached from the support 100, the end of the contact piece 240 can be pressed to disengage the first limit block 211 and the second limit block 221 from the first limit groove 102. First, remove the two adjusting springs 250 at the shaft end, and then use a tool to clamp the outer shaft 220 and keep it still. Specifically, the second limit block 221 can be clamped, and the first limit block 211 can be clamped with a tool and drive the first limit block 211 to rotate, so that the inner shaft 210 rotates relative to the outer shaft 220. The rotation direction is determined according to needs. When the inner shaft 210 rotates a certain angle, the spiral groove 212 will correspond to the mounting hole. At this time, all telescopic parts 230 can slide and embed into the spiral groove 212. The telescopic parts 230 no longer limit the axial displacement of the contact piece 240. At this time, the contact piece 240 and the remaining adjusting springs 250 can be removed from the outer shaft 220.

[0057] In one embodiment, a moving contact 241 is provided at the end of the contact piece 240 away from the outer shaft 220 .

[0058] In one embodiment, the telescopic member 230 includes a telescopic spring 231 and two positioning blocks 232 ; two ends of the telescopic spring 231 are respectively connected to a positioning block 232 , and the mounting hole and the spiral groove 212 are both matched with the positioning block 232 .

[0059] When the telescopic spring 231 is not compressed, the distance between the end faces of the two positioning blocks 232 is greater than the depth of the mounting hole but less than the sum of the depths of the mounting hole and the spiral groove 212. When the spiral groove 212 is staggered from the mounting hole, one end of a part of the telescopic member 230 abuts against the outer wall of the inner shaft 210, and the other end extends out of the mounting hole, that is, one positioning block 232 abuts against the outer wall of the inner shaft 210, and the other positioning block 232 partially extends out of the mounting hole, and the telescopic spring 231 is not compressed. There are also some telescopic members 230 with one end abutting against the outer wall of the inner shaft 210, and the other end passes through the mounting hole and abuts against the side wall of the inner hole of the contact piece 240 (the inner hole is used to match the outer shaft 220), and the telescopic member 230 is in a compressed state, that is, one positioning block 232 abuts against the outer wall of the inner shaft 210, and the other positioning block 232 partially passes through the mounting hole and abuts against the side wall of the inner hole of the contact piece 240, and the telescopic spring 231 is in a compressed state.

[0060] The width of the positioning block 232 may be smaller than the width of the spiral groove 212 , so that the positioning block 232 can slide into the spiral groove 212 more smoothly.

[0061] In one embodiment, a restraining block is provided on the side wall of the positioning block 232, and a restraining groove cooperating with the restraining block is provided on the side wall of the mounting hole. The restraining groove is used to limit the positioning block 232 from detaching from the mounting hole from the inner shaft 210 to the outer shaft 220.

[0062] In one of the embodiments, one end of the positioning block 232 away from the telescopic spring 231 is rounded; the side of the spiral groove 212 includes a right-angle surface and a guide bevel. When the positioning block 232 cooperates with the spiral groove 212, the right-angle surface and the guide bevel are respectively located on both sides of the positioning block 232; the right-angle surface is used to limit the circumferential rotation of the positioning block 232, and the guide bevel is used to assist the positioning block 232 to disengage from the spiral groove 212 along the guide bevel.

[0063] refer to Figure 6 When the mounting hole corresponds to the spiral groove 212, one positioning block 232 is located in the spiral groove 212, and the other positioning block 232 is located in the mounting hole. If the outer shaft 220 remains stationary and the inner shaft 210 rotates in the direction of arrow P, the positioning block 232 located in the spiral groove 212 is squeezed by the guide slope and slides out of the spiral groove 212 along the guide slope. The direction from the guide slope to the right angle surface is the direction of arrow P.

[0064] In one embodiment, the contact assembly 200 also includes a torsion spring 260; the torsion spring 260 is sleeved on the outer side of the inner shaft 210, the inner ring of the torsion spring 260 is connected to the inner shaft 210, and the outer ring of the torsion spring 260 is connected to the outer shaft 220; when the torsion spring 260 is not subjected to force, the spiral groove 212 corresponds to the mounting hole; when the second limiting surface 2111 and the third limiting surface 2211 are parallel, the torsion spring 260 is twisted.

[0065] Before the first limit block 211 and the second limit block 221 are installed into the first limit groove 102, the spiral groove 212 corresponds to the mounting hole, and the torsion spring 260 remains in its original state without being subjected to force; after the first limit block 211 and the second limit block 221 are installed into the first limit groove 102, the second limit surface 2111 and the third limit surface 2211 both fit the first limit surface 1021, the inner shaft 210 rotates relative to the outer shaft 220, and the torsion spring 260 twists and accumulates force. At this time, if the inner shaft 210 and the outer shaft 220 are taken out of the first limit groove 102, the torsion spring 260 will drive the inner shaft 210 to rotate relative to the outer shaft 220 in the opposite direction of the arrow P, so that the spiral groove 212 corresponds to the mounting hole again, so that the telescopic member 230 can slide into the spiral groove 212, so as to remove the contact piece 240 from the outer shaft 220.

[0066] In one embodiment, the first limit block 211 has a second arc surface 2112 tangent to the two second limit surfaces 2111, and the second arc surface 2112 can be coaxial with the inner shaft 210; the second limit block 221 has a third arc surface 2212 tangent to the two third limit surfaces 2211, and the third arc surface 2212 can be coaxial with the outer shaft 220.

[0067] The bottom surface of the first limiting groove 102 is the first arc surface 1022, and the second arc surface 2112 and the third arc surface 2212 can both fit with the first arc surface 1022. When the first limiting block 211 cooperates with the first limiting groove 102, the second arc surface 2112 first contacts the first limiting surface 1021, and as the first limiting block 211 extends into the first limiting groove 102, the second arc surface 2112 slides along the first limiting surface 1021, so that the inner shaft 210 can rotate relative to the outer shaft 220. The second arc surface 2112 can be coaxial with the inner shaft 210, so that the inner shaft 210 can rotate relatively smoothly relative to the outer shaft 220.

[0068] In one embodiment, the contact assembly 200 also includes a limiting strip; the support 100 is provided with a second limiting slot 103 that passes through the support 100 and is connected to the first limiting slot 102; the limiting strip cooperates with the second limiting slot 103 and is used to prevent the first limiting block 211 and the second limiting block 221 from detaching from the first limiting slot 102.

[0069] When the second curved surface 2112 and the third curved surface 2212 are both in contact with the first curved surface 1022, a limiting bar (not shown in the figure) is inserted into the second limiting groove 103. At this time, the outer shaft 220 is located between the limiting bar and the first curved surface 1022. The limiting bar can prevent the first limiting block 211 and the second limiting block 221 from separating from the first limiting groove 102.

[0070] In one embodiment, the contact assembly 200 further includes a fixing seat 270 ; the contact piece 240 is provided with a first card block 242 and a first card slot 243 ; the fixing seat 270 is provided with a second card slot 272 for clamping a plurality of first card blocks 242 and a second card block 271 cooperating with the first card slot 243 .

[0071] The fixing seat 270 and the contact pieces 240 are engaged with each other, so that the circumferential positions of the plurality of contact pieces 240 are positioned, so that the fixing seat 270 can drive the plurality of contact pieces 240 to rotate around the outer shaft 220 at the same time.

[0072] In one embodiment, the contact piece 240 is provided with a first connecting groove 244 and a connecting block 245 , the connecting member 330 cooperates with the first connecting groove 244 , and the connecting member 330 is provided with a second connecting groove 331 that cooperates with the connecting block 245 .

[0073] The connecting member 330 may be plate-shaped, and the second connecting groove 331 may be located in the middle of the connecting member 330. The connecting member 330 may be integrally engaged in the first connecting groove 244, and the connecting block 245 is engaged with the second connecting groove 331, thereby connecting the connecting member 330 to the contact sheet 240.

[0074] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0075] The above-described embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A circuit breaker contact device with overheat protection function, characterized in that: include: A support, wherein the support is provided with a receiving hole, a mounting groove, and a partition located in the mounting groove; The support has a heat conduction function; The contact assembly comprises a rotating shaft and a plurality of contact pieces for contacting the stationary contacts; the rotating shaft is connected to the support; the contact piece passes through the receiving hole and is rotatably connected to the rotating shaft, and the contact piece can abut against the support; The elastic component includes a compression spring, a mounting plate and a connecting piece for connecting a plurality of the contact pieces; the mounting plate is slidably arranged in the mounting groove; one end of the compression spring is connected to the mounting plate, and the other end of the compression spring is connected to the connecting piece; the side wall of the mounting groove, the mounting plate and the cavity between the partition are hydraulic chambers for accommodating expansion fluid, and the expansion fluid will expand in volume after being heated; the cavity between the side wall of the mounting groove and the partition is a negative pressure chamber; the partition has a thin wall, and when the pressure of the hydraulic chamber is greater than a threshold value, the thin wall will be broken under pressure.

2. The circuit breaker contact device with overheat protection function according to claim 1, characterized in that: The contact assembly also includes a plurality of adjustment springs; the number of the contact pieces is N, the number of the adjustment springs is N+1, and N is an integer greater than or equal to 1; the adjustment springs are sleeved on the rotating shaft, and a single contact piece is located between two adjacent adjustment springs.

3. The circuit breaker contact device with overheat protection function according to claim 2, characterized in that: The contact assembly further comprises a plurality of telescopic parts; the rotating shaft comprises an inner shaft and an outer shaft which are sleeved with each other; The support is provided with a first limiting groove located on the side wall of the accommodating hole, and the first limiting groove has a pair of parallel first limiting surfaces; The shaft end of the inner shaft is provided with a first limit block, and the first limit block has a pair of parallel second limit surfaces; the outer side wall of the inner shaft is circumferentially provided with multiple groups of spiral grooves; the shaft end of the outer shaft is provided with a second limit block, and the second limit block has a pair of parallel third limit surfaces; the second limit surface and the third limit surface are both used to fit the first limit surface; the outer shaft is circumferentially provided with multiple groups of mounting holes corresponding to the spiral grooves, and each group of mounting holes is distributed along a spiral path; different groups of mounting holes are located at different positions in the axial direction of the outer shaft; One end of the telescopic member abuts against the outer wall of the inner shaft, and the other end of the telescopic member passes through the mounting hole, and the telescopic member can be embedded in the spiral groove; the length of the telescopic member is greater than the depth of the mounting hole but less than or equal to the sum of the depths of the mounting hole and the spiral groove; wherein, When the spiral groove corresponds to the mounting hole, the second limit surface intersects with the third limit surface; when the second limit surface and the third limit surface coincide with each other, the spiral groove is misaligned with the mounting hole, and at this time the telescopic member can detach from the spiral groove and abut against the outer wall of the inner shaft, and the axial sides of each contact piece abut against at least one of the telescopic members respectively.

4. The circuit breaker contact device with overheat protection function according to claim 3, characterized in that: The telescopic member comprises a telescopic spring and two positioning blocks; two ends of the telescopic spring are respectively connected to one of the positioning blocks, and the mounting hole and the spiral groove are both matched with the positioning blocks.

5. The circuit breaker contact device with overheat protection function according to claim 4, characterized in that: A restraining block is provided on the side wall of the positioning block, and a restraining groove matched with the restraining block is provided on the side wall of the mounting hole. The restraining groove is used to limit the positioning block from being separated from the mounting hole from the inner shaft to the outer shaft.

6. The circuit breaker contact device with overheat protection function according to claim 4, characterized in that: The end of the positioning block away from the telescopic spring is rounded; the side surface of the spiral groove includes a right-angled surface and a guide inclined surface. When the positioning block cooperates with the spiral groove, the right-angled surface and the guide inclined surface are respectively located on both sides of the positioning block; the right-angled surface is used to limit the circumferential rotation of the positioning block, and the guide inclined surface is used to assist the positioning block to disengage from the spiral groove along the guide inclined surface.

7. The circuit breaker contact device with overheat protection function according to claim 4, characterized in that: The contact assembly also includes a torsion spring; the torsion spring is sleeved on the outside of the inner shaft, the inner ring of the torsion spring is connected to the inner shaft, and the outer ring of the torsion spring is connected to the outer shaft; when the torsion spring is not subjected to force, the spiral groove and the mounting hole correspond; when the second limiting surface and the third limiting surface are parallel, the torsion spring is twisted.

8. The circuit breaker contact device with overheat protection function according to claim 4, characterized in that: The contact assembly also includes a limiting strip; the support is provided with a second limiting slot that passes through the support and is connected to the first limiting slot; the limiting strip cooperates with the second limiting slot and is used to prevent the first limiting block and the second limiting block from being separated from the first limiting slot.

9. The circuit breaker contact device with overheat protection function according to claim 1, characterized in that: The contact assembly also includes a fixing seat; the contact piece is provided with a first clamping block and a first clamping slot; the fixing seat is provided with a second clamping slot for clamping a plurality of the first clamping blocks and a second clamping block matched with the first clamping slot.

10. The circuit breaker contact device with overheat protection function according to claim 1, characterized in that: The contact piece is provided with a first connecting groove and a connecting block, the connecting member is matched with the first connecting groove, and the connecting member is provided with a second connecting groove matched with the connecting block.

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