Electrical device and its electrical connection device

Abstract

The present invention discloses an electrical connection device, which is connected between the body of an electrical device with a draw-out structure and the draw-out device. The electrical connection device includes: a draw-out device connection component, a body connection component, and a flexible component. The draw-out device connection component is fixed on the draw-out device and is electrically connected to the incoming and outgoing line ends of the draw-out device. The body connection component includes a contact piece with a clamping mechanism, and the clamping mechanism enables the contact piece to closely adhere to and clamp the body busbar. The flexible component connects the draw-out device connection component and the body connection component, and the body connection component, the flexible component, and the draw-out device connection component form an electrically conductive path. The contact piece of the body connection component offsets in response to the position offset of the body busbar, so that the contact piece closely adheres to and clamps the body busbar, and the flexible component absorbs the offset of the contact piece through its own deformation, so that the offset is not transmitted to the draw-out device connection component.

Description

Technical Field

[0001] The invention relates to the field of medium and low voltage electrical appliances, and more particularly to an electrical connection component in an electrical appliance device with a drawable structure. Background Art

[0002] The electrical devices with a withdrawable structure include: universal circuit breakers, molded case circuit breakers, automatic transfer switches with drawer devices, medium voltage circuit breakers, medium voltage switch cabinets, etc. The device with a withdrawable structure includes a body and a withdrawable device. The bridge-type contact is used as the body busbar on the body, and the contact bridge is provided on the withdrawable device to achieve electrical connection with the body busbar. The contact bridge on the withdrawable device is connected to the external input and output terminals. When the body is pushed into the withdrawable device, the body busbar contacts the contact bridge to form a conductive path, and the body is connected to the external input and output terminals. When the body is pulled out of the drawer device, the body busbar is separated from the contact bridge, the conductive path is cut off, and isolation is achieved for testing or maintenance. The body busbar and the contact bridge constitute the electrical connection device of the withdrawable structure electrical device. In some products, the bridge-type contact is also set on the withdrawable device and the contact bridge is set on the body, but in this configuration, the busbar and the contact bridge still constitute the electrical connection device of the withdrawable structure electrical device, which is the same as the aforementioned structure in basic principle.

[0003] Figure 1a and Figure 1b The structure diagram of the prior art electrical connection device used in the drawable electrical device is disclosed. Figure 1a and Figure 1b As shown, the contact bridge installed on the pull-out device includes: a contact piece 101, a shaft 102, a tension spring 103 and a bracket 104. The contact piece 101 has a plurality of pieces, and two contact pieces 101 of the same shape and size are arranged opposite to each other to form a group. Several groups of contact pieces are stacked and assembled into two symmetrical rows of stacked contact pieces. A groove is formed near the middle of the outer side of each contact piece 101, and the shaft 102 is arranged in the groove. The middle of the tension spring 103 is located between the two rows of contact pieces 101, and the two ends of the tension spring 103 are respectively fixed on a pair of shafts 102. The bracket 104 used to reduce the mutual friction between the contact pieces and play a separating role is inserted between each group of contact pieces 101, and the bracket 104 is arranged at both ends and in the middle of the two rows of contact pieces. The contact piece 101, the shaft 102, the tension spring 103 and the bracket 104 together form the following. Figure 1a and Figure 1b The contact bridge shown. At one end of the contact bridge ( Figure 1a The left end shown in the figure) is composed of the ends of the two rows of contact pieces facing each other to form a clamping head for clamping the main busbar 105. Figure 1a The right side end shown in the figure) is connected to the external input and output line terminal 106 on the withdrawable device.

[0004] Each contact piece 101 forms a contact point that contacts the main body busbar 105. The two rows of contact pieces together form a multi-contact area. A gap is left between the two rows of contact pieces for placing the main body busbar 105. In order to ensure that the main body busbar 105 can form an effective contact when inserted into the gap, the width of the gap is set to be smaller than the thickness of the main body busbar 105. When the main body is pushed into the pull-out device, the main body busbar 105 is inserted into the gap between the two rows of contact pieces. Since the thickness of the main body busbar 105 is greater than the gap, the main body busbar 105 will stretch the two rows of contact pieces apart, and the stretched contact pieces will cause the tension spring 103 to deform. The spring force generated by the deformation of the tension spring 103 acts on the contact piece, clamping the two rows of contact pieces inward. Under such action, as the main body busbar continues to advance, the two rows of contact pieces will clamp the busbar more and more. In this way, more and more contact pieces will contact the busbar to form contacts. The more contacts there are, the smaller the contact resistance will be. In order to ensure reliable contact of the contacts during operation, the spring force of the tension spring is increased, so that the clamping force of the contact piece on the main body busbar is increased, the number of contact points and contact stability are ensured, and the contact resistance is reduced. However, the defects of increasing the spring force of the tension spring are also very obvious: when the main body is pushed into the pull-out device, the friction between the main body busbar and the contact piece and the force required for the main body busbar to open two rows of contact pieces are the main resistances that need to be overcome for advancement. When the spring force of the tension spring increases, the force required to open the contact piece and the friction between the main body busbar and the contact piece will increase significantly. Usually, the clamping force provided by a single contact bridge is about 800N. A three-pole circuit breaker has at least six electrical connection devices, including three incoming electrical connection devices and three outgoing electrical connection devices. Therefore, increasing the clamping force will multiply the resistance of the main body busbar to inserting the contact bridge, which will eventually make it difficult for the main body busbar to be inserted into the electrical connection device, and the operating force of the drive device of the entire drawer device will be too large to be accepted.

[0005] In addition, the contact bridge composed of the contact piece 101, the shaft 102, the tension spring 103 and the bracket 104 only allows the contact piece to rotate within a small range within the plane where the contact piece is located, and the contact piece has extremely small freedom of movement. If there is a deviation in the angle of the main body busbar, the contact bridge of this structure cannot adapt to and eliminate the position or angle deviation of the main body busbar. This deviation will lead to a reduction in the number of contact pieces that are effectively in contact with the main body busbar, and the number of contacts and the contact area will be reduced, which is not conducive to performance and service life. Moreover, this deviation will make it impossible for the main body busbar to be inserted directly into the gap, resulting in deflection, resulting in an increase in the force of opening the two rows of contact pieces and the friction between the main body busbar and the contact piece. In some large shell frames such as products above 4000A, due to the wide lateral width, the position deviation of each electrical connection device is relatively large, and a single incoming or outgoing line end has two or three electrical connection devices, so the operating force of the drawer device will be multiplied.

[0006] In summary, the electrical connection devices used in the prior art have the following defects: there is an obvious contradiction between the difficulty of assembly and the performance in use. From the perspective of performance in use, it is hoped that the clamping force is as large as possible to increase the number of contacts, increase the contact area, and reduce the contact resistance. A larger contact area can also reduce the heat generated during use and extend the overall service life of the electrical connection device. However, an increase in the clamping force will greatly increase the installation resistance, making the installation difficulty multiplied, which is very unfavorable for the installation and maintenance of the equipment. If the clamping force is reduced to facilitate assembly, the insufficient clamping force will lead to insufficient engagement between the main body busbar and the contact piece, a small number of contacts, and some contacts being virtual. The small number of contacts will lead to a reduction in contact area, an increase in contact resistance, and the virtual contact will generate a lot of heat, which is easy to cause the contact point to burn out due to excessive temperature during use. The contact bridge has high requirements for installation accuracy and cannot adapt to and eliminate the angle or position deviation of the main body busbar. The angle or position deviation of the main body busbar will cause the contact performance to decrease, resulting in a decrease in performance and service life. However, increasing the angle and position accuracy of the main body busbar will increase the difficulty of installation.

[0007] The structure of the electrical connection device in the prior art makes it impossible to resolve the contradiction between assembly and performance, and only a compromise solution can be obtained between the two. However, the compromise solution cannot achieve the best performance. Summary of the invention

[0008] The present invention aims to provide an electrical connection device which separates the insertion and clamping operations and can fit the main body busbar as closely as possible to increase the contact area.

[0009] According to one embodiment of the present invention, an electrical connection device is provided, which is connected between the body of an electrical device of a pull-out structure and the pull-out device, and the electrical connection device includes: a pull-out device connection component, a body connection component, and a flexible component. The pull-out device connection component is fixed on the pull-out device and is electrically connected to the input and output terminals of the pull-out device. The body connection component includes a contact piece with a clamping mechanism, and the clamping mechanism makes the contact piece close to and clamp the body busbar. The flexible component connects the pull-out device connection component and the body connection component, and the body connection component, the flexible component and the pull-out device connection component form a conductive path. The contact piece of the body connection component is offset to adapt to the positional offset of the body busbar, so that the contact piece is close to and clamps the body busbar, and the flexible component absorbs the offset of the contact piece by its own deformation, so that the offset is not transmitted to the pull-out device connection component.

[0010] In one embodiment, the body connection assembly includes: a contact piece, a clamping mechanism, and a reset mechanism. The contact piece is close to and clamps the body busbar, and the contact piece is connected to the flexible assembly. The clamping mechanism applies a clamping force from the outside of the contact piece, so that the contact piece contracts inward to close to and clamp the body busbar. The reset mechanism applies a reset force from the inside of the contact piece, so that the contact piece opens outward to reset.

[0011] In one embodiment, the clamping mechanism includes: a fastener, a bearing, an elastic member and a force-applying member. The fastener is installed on the contact piece, and when the fastener is tightened, the contact piece shrinks inward. The elastic member and the force-applying member apply a clamping force to the contact piece. The bearing is installed between the fastener and the elastic member, and the bearing absorbs the rotation of the fastener when it is in motion, so that the rotation is not transmitted to the elastic member and the force-applying member.

[0012] In one embodiment, the contact pieces are two pieces, and the two contact pieces are tightly attached to and clamped against the main busbar from both sides. Fasteners are installed on the two contact pieces. When the fasteners are tightened, the two contact pieces shrink inward. A reset mechanism is installed on the inner side of the two contact pieces, and the reset mechanism causes the two contact pieces to open outward for reset.

[0013] In one embodiment, the fastener is a bolt and a nut, the bearing member is a plane bearing, the elastic member is a disc spring assembly, and the force-applying member is a pressure plate. The contact sheet is provided with a screw hole for the bolt to pass through, and the bolt passes through the first contact sheet and the second contact sheet in sequence from the outside of the first contact sheet, and the nut is rotatably installed on the second end of the bolt from the outside of the second contact sheet. A plane bearing, a disc spring assembly and a pressure plate are installed between the first end of the bolt and the first contact sheet, and the disc spring assembly includes a plurality of disc springs. The bolt and the nut rotate relative to each other and shrink, and the two contact sheets shrink inward, and the disc spring assembly and the pressure plate apply a clamping force to the contact sheet. The plane bearing absorbs the relative rotation of the bolt and the nut, so that the disc spring and the pressure plate do not rotate.

[0014] In one embodiment, the fasteners are bolts and nuts, the bearing member is a plane bearing, the elastic member is a disc spring assembly, and the force-applying member is a pressure plate. The two pressure plates are respectively attached to the outer sides of the two contact plates and are respectively fixed to the contact plates. The pressure plates are provided with screw holes for the bolts to pass through. The bolts pass through the first pressure plate and the second pressure plate in sequence from the outer side of the first pressure plate, and the nuts are rotatably installed on the second end of the bolts from the outer side of the second pressure plate. A plane bearing and a disc spring assembly are installed between the first end of the bolt and the first pressure plate, and the disc spring assembly includes a plurality of disc springs. The bolt and the nut rotate relative to each other and shrink, and the two pressure plates shrink inward, and the disc spring assembly and the pressure plate apply a clamping force to the contact plates. The plane bearing absorbs the relative rotation of the bolt and the nut, so that the disc spring and the pressure plate do not rotate.

[0015] In one embodiment, the reset mechanism is a reset spring, which is installed on the bolt and located between the two contact sheets or the two pressure plates. The bolt and the nut rotate relative to each other and contract, and the reset spring is compressed. The bolt and the nut rotate relative to each other and expand, and the reset spring returns to its original state. The reset spring applies a spring force to the inner sides of the two contact sheets or the two pressure plates, so that the two contact sheets open outward.

[0016] In one embodiment, the flexible assembly is formed from multiple layers of copper foil, multiple layers of copper tape, or copper braid.

[0017] In one embodiment, the drawable device connection assembly includes: a connecting piece and a heat dissipation mechanism. The connecting piece is fixed on the drawable device and electrically connected to the input and output terminals of the drawable device. The heat dissipation mechanism is installed on the connecting piece.

[0018] In one embodiment, the connecting sheet is two sheets, and the two connecting sheets are arranged separately. The heat dissipation structure includes: a pad and a fixing bracket. The pad is a hollow bracket structure, and the pad is arranged between the two connecting sheets. The fixing bracket fixes the pad from the outside of the two connecting sheets.

[0019] In one embodiment, the drawout device connection component and the body connection component include non-magnetic conductive materials to prevent the formation of a closed magnetic loop.

[0020] According to one embodiment of the present invention, a withdrawable electrical device is provided, comprising a body and a withdrawable device, wherein the body and the withdrawable device have a separation position and an insertion position, and the body and the withdrawable device are connected by an electrical connection device as described above, wherein, in the separation position, the body withdraws from the withdrawable device, the body busbar is separated from the body connection component, and the body busbar is not in contact with the contact piece. In the insertion position, the body is pushed into the withdrawable device, the body busbar is inserted into the body connection component, and the contact piece is tightly attached to and clamps the body busbar.

[0021] The electrical connection device of the present invention solves the contradiction between the insertion and clamping operations from a structural point of view. The clamping operation can be performed after the main body busbar is inserted between the contact pieces, and a sufficiently large clamping force can be applied to ensure contact, and the clamping force will not affect the assembly of the main body busbar. In addition, the electrical connection device is provided with a flexible component, which can absorb a certain offset through its own deformation, so that the contact piece can follow the position offset of the main body busbar to produce a certain offset, so as to fully fit the main body busbar and ensure the contact area and contact stability.

[0022] According to the present invention, when the main body busbar is inserted into the electrical connection device, it can be achieved that there is no mutual force between the main body busbar and the electrical connection device, such as the force of the contact piece to open the contact piece in the prior art, and the friction between the main body busbar and the contact piece. The driving device of the pull-out device can push the main body of the electrical device with a very small force, so that the main body busbar is inserted into the electrical connection device.

[0023] The electrical connection device can be configured with a large clamping force to clamp the main busbar as needed, so that the overall contact resistance of the electrical device is greatly reduced, especially in long-term use, the power consumption is greatly reduced, and the use cost is greatly saved. The higher the rated current of the electrical device, the more significant this advantage is. On the other hand, the reduction of contact resistance reduces the temperature rise of the product and the heat generation of the electrical device. There is no need to consider a large heat dissipation space, which is conducive to reducing the size of the product and improving the reliability of long-term use. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which the same reference numerals always represent the same features, wherein:

[0025] Figure 1a and Figure 1b The invention discloses a structural diagram of an electric connection device of the prior art used in an electrical device of a pull-out structure.

[0026] Figure 2a and Figure 2b A structural diagram of an electrical connection device according to a first embodiment of the present invention is disclosed.

[0027] Figure 3a and Figure 3b A structural diagram of a plane bearing used in an electrical connection device according to an embodiment of the present invention is disclosed.

[0028] Figure 4 A structural diagram of a pad used in an electrical connection device according to an embodiment of the present invention is disclosed.

[0029] Figure 5 The structure diagram of an electrical device using a withdrawable structure of an electrical connection device according to an embodiment of the present invention is disclosed.

[0030] Figure 6a and Figure 6b A structural diagram of an electrical connection device according to a second embodiment of the present invention is disclosed.

[0031] Figure 7a and Figure 7b A structural diagram of an electrical connection device according to a third embodiment of the present invention is disclosed.

[0032] Figure 8 and Fig. 9 The structural diagrams of the variations of the electrical connection device of the present invention are disclosed, and the various variations have body connection components of different structures to adapt to body busbars of different structures.

[0033] Fig.10a , Fig.10b and Fig.10c The invention discloses a schematic diagram of the principle of eliminating eddy current loss by the electrical connection device of the invention.

[0034] Fig.11a and Fig.11b A schematic diagram of the separation position and insertion position of an electrical device of a withdrawable structure applicable to the electrical connection device of the present invention is disclosed. DETAILED DESCRIPTION

[0035] The present invention provides an electrical connection device which separates the insertion and clamping operations and can fit the main body busbar as closely as possible to increase the contact area. Figure 2a and Figure 2b The structure diagram of the electrical connection device according to the first embodiment of the present invention is disclosed, wherein Figure 2a is a three-dimensional structural diagram of the electrical connection device, Figure 2b 2 is a side view of the electrical connection device. As shown in the figure, the electrical connection device includes: a pull-out device connection component 202, a body connection component 204 and a flexible component 206. The pull-out device connection component 202 is fixed on the pull-out device and is electrically connected to the input and output terminals of the pull-out device. The body connection component 204 includes a contact piece with a clamping mechanism, and the clamping mechanism makes the contact piece close to and clamp the body busbar. The flexible component 206 connects the pull-out device connection component 202 and the body connection component 204. The body connection component 204, the flexible component 206 and the pull-out device connection component 202 form a conductive path. The contact piece of the body connection component 204 adapts to the positional deviation of the body busbar and produces a deviation, so that the contact piece is close to and clamps the body busbar. The flexible component 206 absorbs the deviation of the contact piece by its own deformation, so that the deviation is not transmitted to the pull-out device connection component 202. During the installation process, the main body busbar will inevitably have a slight deviation in position, angle or shape. The electrical connection device of the present invention absorbs this deviation of the main body busbar through the flexible component 206. The contact piece of the main body connection component of the electrical connection device of the present invention can follow the actual state of the main body busbar, close to and clamp the main body busbar. If the main body busbar has a position or angle offset, the contact piece of the main body connection component 204 will also produce a corresponding position or angle offset. In this way, the position or angle offset of the main body busbar will not affect the contact performance, and the contact piece of the main body connection component can ensure the contact area and contact stability with the main body busbar. The flexible component 206 has the ability to deform within a certain range. In one embodiment, the flexible component 206 is formed by multiple layers of copper foil, multiple layers of copper strip or copper braided wire. If the contact piece of the main body connection component 204 deviates following the position or angle offset of the main body busbar, the flexible component 206 absorbs the offset of the contact piece with its own deformation, so that the offset is not transmitted to the pull-out device connection component 202. The drawer base connection assembly 202 is fixedly mounted on the drawer device and connected to the input and output terminals of the drawer device. The drawer base connection assembly 202 is a rigid structure, and its position and installation angle cannot change. By using the deformation of the flexible assembly 206, the position or angle deviation of the contact piece of the body connection assembly 204 is absorbed and will not be transmitted to the drawer base connection assembly.

[0036] Continue to refer Figure 2a and Figure 2bAs shown, the main body connection assembly 204 includes: a contact piece 241, a clamping structure and a reset mechanism. The contact piece 241 is two pieces, and the two contact pieces 241 are closely attached to and clamp the main body busbar 208 from both sides (refer to Figure 5 ). The contact piece is connected to the flexible component. In the illustrated embodiment, the flexible component 206 also consists of two pieces, and each contact piece 241 is respectively connected to one flexible component 206. The clamping mechanism applies a clamping force from the outside of the two contact pieces 241, so that the two contact pieces shrink inward to fit tightly against and clamp the main body busbar 208. The reset mechanism applies a reset force from the inside of the two contact pieces 241, so that the two contact pieces 241 open outward to reset. In one embodiment, the clamping mechanism includes: a fastener, a bearing member, an elastic member and a force-applying member. The fastener is installed on the two contact pieces 241, and when the fastener is tightened, the two contact pieces shrink inward. The elastic member and the force-applying member apply a clamping force to the two contact pieces 241. The bearing member is installed between the fastener and the elastic member, and the bearing member absorbs the rotation of the fastener when it is in action, so that the rotation is not transmitted to the elastic member and the force-applying member. Figure 2a and Figure 2bIn the first embodiment shown, the fastener is a bolt 242 and a nut 243, the bearing member is a plane bearing 244, the elastic member is a disc spring assembly 245, and the force-applying member is a pressure plate 246. The contact piece 241 has a screw hole for the bolt 242 to pass through. The bolt 242 passes through the first contact piece (upper contact piece) and the second contact piece (lower contact piece) in sequence from the outer side (upper side) of the first contact piece, and the nut 243 is rotatably mounted on the second end of the bolt from the outer side (lower side) of the second contact piece. In the first embodiment, the bolt 242 is a single-head bolt, the head of the bolt 242 is larger, and the head is located on the outer side of the first contact piece, the rod of the bolt 242 passes through the first contact piece and the second contact piece, and the nut 243 is tightened on the rod of the bolt 242. The plane bearing 244, the disc spring assembly 245 and the pressure plate 246 are installed between the first end (head) of the bolt 242 and the first contact piece (upper contact piece). The disc spring assembly 245 includes a plurality of disc springs. The number of disc springs in the disc spring assembly 245 can be determined according to the size of the required clamping force. When a larger clamping force is required, the number of disc springs can be increased, and when only a smaller clamping force is required, a smaller number of disc springs can be used. In actual use, a suitable number of disc springs will be configured to enable a single electrical connection device to generate a clamping force of more than 1500N, and its effective clamping force is much greater than the 800N clamping force of the electrical connection device in the prior art. In order to evenly distribute the clamping force generated by the disc spring to the contact piece 241, a pressure plate 246 will be used. The pressure plate 246 evenly distributes the clamping force to the contact piece to clamp the main body busbar. The evenly distributed clamping force makes the contact area between the contact piece and the main body busbar larger and the contact more stable. When performing the clamping operation, the bolt 242 and the nut 243 rotate relative to each other and shrink, and the two contact pieces 241 shrink inward, and the disc spring assembly 245 and the pressure plate 246 apply a clamping force to the contact piece 241 to clamp the main body busbar. On one hand, the plane bearing 244 absorbs the relative rotation between the bolt and the nut so that the above rotation will not be transmitted to the disc spring and the pressure plate. On the other hand, the plane bearing 244 can reduce the rotational operating force required for the relative rotation between the bolt 242 and the nut 243 by its own rotation. Figure 3a and Figure 3b The structure diagram of the plane bearing used in the electrical connection device according to one embodiment of the present invention is disclosed. Figure 3a This is the exploded structure diagram of the plane bearing. Figure 3b This is a combined structural diagram of a plane bearing. In the illustrated embodiment, the plane bearing uses a roller plane bearing. In other embodiments, a ball plane bearing may also be used. Back Figure 2a and Figure 2bIn the first embodiment shown, the reset mechanism is a reset spring 247, which is mounted on the bolt 242. The reset spring 247 is located between the two contact pieces 241. When the clamping operation is performed, the bolt and the nut rotate relative to each other and contract, and the reset spring 247 is compressed. When the reset operation is performed, the bolt and the nut rotate relative to each other and expand, and the reset spring 247 is restored. The reset spring 247 applies a spring force to the inner side of the two contact pieces 241, so that the two contact pieces 241 open outward and reset. Under the action of the reset spring 247, after the bolt and the nut are loosened, the two contact pieces 241 can return to their initial position with a large spacing, so that the main body busbar can be easily pulled out.

[0037] exist Figure 2a and Figure 2b In the first embodiment shown, the pull-out device connection component 202 includes: a connecting piece 221 and a heat dissipation mechanism. The connecting piece 221 is fixed on the pull-out device and electrically connected to the input and output terminals of the pull-out device. In the illustrated embodiment, the connecting piece 221 is divided into two pieces, and the two connecting pieces 221 are separated and arranged, and the two connecting pieces 221 are respectively connected to a flexible component 206. In other words, each contact piece 241 is connected to a connecting piece 221 through a flexible component 206, and there are two groups in total, upper and lower. The heat dissipation mechanism is installed on the connecting piece. In the illustrated embodiment, the heat dissipation structure includes: a pad 222 and a fixed bracket 223. The pad 222 is a hollow bracket structure, and the pad 222 is arranged between the two connecting pieces 221. Figure 4 The structure diagram of the pad used in the electrical connection device according to an embodiment of the present invention is disclosed. The hollow bracket structure of the pad 222 is conducive to heat dissipation. Two fixing brackets 223 fix the pad 222 from the outside of the two connecting pieces 221, and fix the pad 222 between the two connecting pieces 221 to form a gap to facilitate the installation of the busbar of the input and output terminals.

[0038] Figure 5 The structural diagram of an electrical device with a pull-out structure using an electrical connection device of an embodiment of the present invention is disclosed. Electrical devices with a pull-out structure include: universal circuit breakers, molded case circuit breakers, automatic transfer switches with drawer devices, medium-voltage circuit breakers, medium-voltage switch cabinets, etc. The device with a pull-out structure includes a main body and a pull-out device. The electrical connection device of the present invention is connected between the main body of the electrical device with a pull-out structure and the pull-out device. The pull-out device connection assembly is fixed on the pull-out device and is electrically connected to the input and output terminals of the pull-out device. The clamping mechanism of the main body connection assembly allows the contact piece to fit tightly against and clamp the main body busbar 208.

[0039] Figure 6a and Figure 6bThe structural diagram of the electrical connection device according to the second embodiment of the present invention is disclosed. The structure of the pull-out device connection component and the flexible component in the electrical connection device of the second embodiment is basically the same as that of the first embodiment. The structure of the contact piece and the reset mechanism in the main body connection component is also basically the same as that of the first embodiment, except that the clamping mechanism is different. For the sake of simplicity, the pull-out device connection component, the flexible component, the contact piece and the reset mechanism in the main body connection component of the electrical connection device of the second embodiment will not be described again, and the relevant content can refer to the previous description of the first embodiment. Reference Figure 6a As shown, the function of the clamping mechanism of the electrical connection device of the second embodiment is also to apply a clamping force from the outside of the two contact pieces, so that the two contact pieces shrink inward to fit tightly against and clamp the main body busbar. The clamping mechanism includes: a fastener, a bearing member, an elastic member, and a force-applying member. The fastener is installed on the two contact pieces. When the fastener is tightened, the two contact pieces shrink inward. The elastic member and the force-applying member apply a clamping force to the two contact pieces. The bearing member is installed between the fastener and the elastic member. The bearing member absorbs the rotation of the fastener when it is in motion, so that the rotation is not transmitted to the elastic member and the force-applying member. Figure 6a and Figure 6b In the second embodiment shown, the fastener is a stud bolt 342 , the bearing member is a plane bearing 344 , the elastic member is a disc spring assembly 345 , and the force-applying member is a pressure plate 346 . Figure 6b The structure diagram of the stud bolt 342 is disclosed. The middle section of the stud bolt 342 is a connecting portion 301, and the two sides of the connecting portion are two threaded areas 302. The threads in the two threaded areas 302 are opposite to each other. If one is defined as a forward thread, the other is a reverse thread. On the outside of the threaded area 302, there is a passive part 303 at each end of the stud bolt 342. Back Figure 6a, the contact piece has a screw hole for the stud bolt 342 to pass through. The stud bolt 342 passes through the first contact piece and the second contact piece (lower contact piece) from the outside (upper) of the first contact piece (upper contact piece) in sequence. The pressure plate 346 of the second embodiment is provided with a threaded hole, and two pressure plates 346 are used to cooperate with the two threaded areas of the stud bolt 342 respectively. The upper pressure plate 346 is rotatably mounted on the upper threaded area, and the upper threaded area is defined as the positive thread here. The lower pressure plate 346 is rotatably mounted on the lower threaded area, and the lower threaded area is defined as the reverse thread. The upper threaded area of ​​the stud bolt 342 is located on the outside (upper) of the first contact piece, and the lower threaded area is located on the outside (lower) of the second contact piece. In this way, the two pressure plates 346 are respectively located above the first contact piece and below the second contact piece, and are tightly attached to the two contact pieces from the outside. On the stud bolt 342, a plane bearing 344 and a disc spring assembly 345 are installed between the upper pressure plate 346 and the first contact piece (upper contact piece). The disc spring assembly 345 includes several disc springs. The number of disc springs in the disc spring assembly 345 can be determined according to the required clamping force. In this embodiment, the pressure plate 346 not only plays the role of evenly distributing the clamping force to the contact piece, but also replaces the role of the nut in the first embodiment, and cooperates with the stud bolt 343 to tighten or loosen. The reset mechanism in the second embodiment is still the reset spring 347, which is installed on the stud bolt 342. The reset spring 347 is located between the two contact pieces. When performing the clamping operation, at least one of the two ends of the stud bolt 342 is rotated, and under the joint action of the forward and reverse threaded areas of the stud bolt, the upper and lower pressure plates 346 simultaneously contract and act on the contact piece, so that the contact piece clamps the main body busbar. When performing the loosening operation, the upper and lower pressure plates also loosen the busbar at the same time. The stud bolt and the two pressure plates act simultaneously to clamp or loosen, which can speed up the operation speed and double it, which is conducive to saving the operation time and operation space of the drawer device.

[0040] Figure 7a and Figure 7b The structure diagram of the electrical connection device according to the third embodiment of the present invention is disclosed. The electrical connection device of the third embodiment can be considered as a simplification of the electrical connection device of the first embodiment. In the third embodiment, the contact sheet 241, the flexible component 206 and the connecting sheet 221 are all one piece. Figure 7a In the example shown, the upper contact piece 241, the flexible component 206 and the connecting piece 221 are retained, while the lower contact piece, the flexible component and the connecting piece are removed, and only a pressing plate 246 is retained. Under the action of the clamping mechanism, the upper contact piece and the lower pressing plate clamp the main body busbar together, and the upper contact piece is close to the main body busbar. Figure 7b In the example shown, Figure 7aOn the contrary, the lower contact sheet 241, the flexible component 206 and the connecting sheet 221 are retained, while the upper contact sheet, the flexible component and the connecting sheet are eliminated, and only one pressing plate 246 is retained. Except for using a single contact sheet instead of two contact sheets, the electrical connection device of the third embodiment is similar to the electrical connection device of the first embodiment in other components.

[0041] As mentioned above, there are many types of electrical devices with a withdrawable structure, including: universal circuit breakers, molded case circuit breakers, automatic transfer switches with drawer devices, medium voltage circuit breakers, medium voltage switch cabinets, etc. The main body busbars in different electrical devices may have different structures. In order to adapt to the main body busbars with different structures, the present invention also proposes various variations. In the electrical connection devices of these variations, there are main body connection components with different structures to adapt to the main body busbars with different structures. Figure 8 and Fig. 9 The structural diagram of the variation of the electrical connection device of the present invention is disclosed. It should be noted that, for the sake of indirect description, the description and illustration of the variation mainly focus on the main body busbar of different structures and the main body connection assembly matching therewith. For the remaining universal structures, such as the same structures in the pull-out device connection assembly, the flexible assembly and the main body connection assembly, no detailed description is made in the specification, and the relevant description can refer to the aforementioned description. Similarly, these universal structures are also simplified in the accompanying drawings, and the structures shown may be different from the corresponding components in the aforementioned first or second embodiments, but it should be understood that this is a simplification in expression, and the structure of the corresponding components disclosed in the first or second embodiment can also be applied to these variations.

[0042] First reference Figure 8 The variation shown, Figure 8 In the variation shown, the main body busbar 408 has a relatively wide dimension, and accordingly, the contact piece 441 also has a relatively wide dimension. When the contact piece 441 and the main body busbar 408 are relatively wide, using only a single bolt and nut cannot ensure that the clamping force can be effectively distributed to the entire contact piece and the main body busbar. Figure 8 In the variation shown, two sets of bolts 442 and nuts 443 are used on the contact piece 441. The two sets of bolts 442 and nuts 443 are arranged side by side, and the structure of each set of bolts and nuts and the corresponding bearing parts, elastic parts and force-applying parts is similar to Figure 3a and Figure 3b The contact sheet 441 has two screw holes arranged side by side for two bolts 442 to pass through respectively, and two nuts 443 are tightened on the two bolts 442 respectively. Figure 8 In the variation of , a return spring can still be installed on the bolt. Figure 8In the embodiment shown, there are two U-shaped grooves 481 on the main body busbar 408. The positions of the U-shaped grooves 481 correspond to the positions of the bolts 442. The U-shaped grooves can play a guiding and positioning role when the main body busbar is inserted between the contact pieces. It should be noted that in the description of the first and second embodiments, although it is not mentioned whether the main body busbar is provided with a U-shaped groove, it can be understood that providing the main body busbar with a U-shaped groove is a universal structure and can also be applied to the first or second embodiment.

[0043] refer to Fig. 9 The variation shown in Fig. 9 In the variation shown, the bolt no longer passes through the contact piece 541 , but instead passes over both sides of the contact piece 541 , and a clamping force is applied to the contact piece 541 using a pressure plate 546 . Fig. 9 The clamping mechanism of the variation shown may include a fastener, a bearing, an elastic member and a force-applying member. The fastener is a bolt and a nut, the bearing is a plane bearing, the elastic member is a disc spring assembly, and the force-applying member is a pressure plate. Fig. 9 As shown, the two pressing plates 546 are respectively attached to the outside of the two contact plates 541 and fixed to the contact plates 541. The pressing plates 546 have screw holes for bolts to pass through, and the bolts 542 pass through the first pressing plate and the second pressing plate in sequence from the outside of the first pressing plate, and the nut is rotatably installed on the second end of the bolt from the outside of the second pressing plate. Fig. 9 In the variation shown, the bolt only passes through the pressure plate and not through the contact piece itself, and the bolt 542 passes over the contact piece 541 from both sides of the contact piece. A plane bearing and a disc spring assembly are installed between the first end of the bolt and the first pressure plate, and the disc spring assembly includes a plurality of disc springs. The bolt and the nut rotate relative to each other and shrink, and the two pressure plates shrink inward, and the disc spring assembly applies a clamping force to the contact piece through the pressure plate. The plane bearing absorbs the relative rotation of the bolt and the nut, so that the disc spring and the pressure plate do not rotate. Fig. 9 A return spring can also be installed on the bolt of the variation shown. The return spring is located between the two pressure plates. When the bolt and the nut rotate relative to each other and expand, the return spring returns to its original position. The return spring applies a spring force to the inner side of the two pressure plates, causing the two contact plates to open outward through the two pressure plates. Fig. 9 In the embodiment shown, since the bolts are moved to the outside of the contact pieces, no U-shaped groove is provided on the main body busbar 508. When the bolts do not pass through the contact pieces, the main body busbar 508 can extend deeper between the contact pieces (without being blocked by the bolts). When the main body busbar needs to extend further into the contact pieces, or when the main body busbar is longer, the U-shaped groove can be used. Fig. 9 The structure of the variation shown.

[0044] There is an AC magnetic field in the working environment of the electrical connection device of the present invention. When a material with strong magnetic conductivity is in the AC magnetic field, eddy currents will be induced inside. Especially when a closed magnetic loop is formed, the eddy current loss inside the material with strong magnetic conductivity is very large, resulting in very serious heating, which is also a safety hazard of the electrical device. Fig.10a , Fig.10b and Fig.10c The schematic diagram of the electrical connection device of the present invention for eliminating eddy current loss is disclosed. Fig.10a , Fig.10b and Fig.10c As shown, an alternating magnetic field loop B (i.e., an alternating magnetic field) is generated around the AC current I passing through. If the pull-out device connection component and the main body connection component are made of strong magnetic conductive materials as a whole, a vortex-shaped induced current i will be formed on the pull-out device connection component and the main body connection component under the action of the alternating magnetic field. The induced current i generates a large eddy current loss, resulting in serious heating. Therefore, in situations where a large current passes through, it is necessary to use non-magnetic conductive materials in at least one section of the magnetic loop generated by it to prevent the formation of a closed magnetic loop, thereby avoiding or greatly reducing the induced current i generated by the power frequency AC current, reducing eddy current losses and heat generation. Therefore, in an embodiment of the present invention, the pull-out device connection component and the main body connection component contain non-magnetic conductive materials to prevent the formation of a closed magnetic loop. Non-magnetic conductive materials can be used to constitute components such as pads, fixed brackets, and pressure plates.

[0045] An important function of the electrical connection device of the present invention is to solve the contradiction between the insertion and clamping operations. Therefore, the body of the electrical device with a withdrawable structure suitable for the electrical connection device of the present invention and the withdrawable device have two connection states: separation and insertion. Fig.11a and Fig.11b The schematic diagram of the separation position and insertion position of the withdrawable electrical device of the electrical connection device of the present invention is disclosed. As shown in the figure, the body 601 of the withdrawable electrical device and the withdrawable device 602 have a separation position and an insertion position. Fig.11a As shown, in the separation position, the body 601 withdraws from the withdrawable device 602, the body busbar 608 is separated from the body connection assembly 604, and the body busbar is not in contact with the contact piece. Fig.11b As shown, in the insertion position, the body 601 is pushed into the withdrawable device 602, the body busbar 608 is inserted into the body connection assembly 604, and then the clamping mechanism is actuated to make the contact piece close to and clamp the body busbar.

[0046] The electrical connection device of the present invention solves the contradiction between the insertion and clamping operations from a structural point of view. The clamping operation can be performed after the main body busbar is inserted between the contact pieces, and a sufficiently large clamping force can be applied to ensure contact, and the clamping force will not affect the assembly of the main body busbar. In addition, the electrical connection device is provided with a flexible component, which can absorb a certain offset through its own deformation, so that the contact piece can follow the position offset of the main body busbar to produce a certain offset, so as to fully fit the main body busbar and ensure the contact area and contact stability.

[0047] According to the present invention, when the main body busbar is inserted into the electrical connection device, it can be achieved that there is no mutual force between the main body busbar and the electrical connection device, such as the force of the contact piece to open the contact piece in the prior art, and the friction between the main body busbar and the contact piece. The driving device of the pull-out device can push the main body of the electrical device with a very small force, so that the main body busbar is inserted into the electrical connection device.

[0048] The electrical connection device can be configured with a large clamping force to clamp the main busbar as needed, so that the overall contact resistance of the electrical device is greatly reduced, especially in long-term use, the power consumption is greatly reduced, and the use cost is greatly saved. The higher the rated current of the electrical device, the more significant this advantage is. On the other hand, the reduction of contact resistance reduces the temperature rise of the product and the heat generation of the electrical device. There is no need to consider a large heat dissipation space, which is conducive to reducing the size of the product and improving the reliability of long-term use.

[0049] The above embodiments are provided for persons familiar with the art to implement or use the present invention. Personnel familiar with the art can make various modifications or changes to the above embodiments without departing from the inventive concept of the present invention. Therefore, the protection scope of the present invention is not limited to the above embodiments, but should be the maximum scope of the innovative features mentioned in the claims.

Claims

1. An electrical connection device is connected between the body of an electrical device with a draw-out structure and the draw-out device. Characterized in that, It includes: A draw-out device connection component, which is fixed on the draw-out device and electrically connected to the incoming and outgoing wire ends of the draw-out device; A body connection component, which includes at least one set of clamping mechanism, reset mechanism and contact pieces. Each set of contact pieces includes two contact pieces. A fastener is installed on the two contact pieces. The clamping mechanism applies a clamping force from the outside of the two contact pieces through the fastener so that the two contact pieces are closely attached and clamped to the body busbar from both sides. The reset mechanism applies a reset force from the inside of the two contact pieces so that the two contact pieces open outward to reset; A flexible component, which connects the draw-out device connection component and the body connection component. The body connection component, the flexible component and the draw-out device connection component form an electrical conduction path. The contact piece is connected to the flexible component. The flexible component is formed by multiple layers of copper foil, multiple layers of copper strip or copper braided wire; Among them, the contact piece of the body connection component offsets according to the position offset of the body busbar so that the contact piece is closely attached and clamped to the body busbar. The flexible component absorbs the offset of the contact piece with its own deformation so that the offset is not transmitted to the draw-out device connection component.

2. The electrical connection device according to claim 1, Characterized in that, The clamping mechanism includes: the fastener, bearing parts, elastic parts and force-applying parts; The fastener is installed on the contact piece. When the fastener tightens, the contact piece contracts inward; The elastic part and the force-applying part apply a clamping force to the contact piece; The bearing parts are installed between the fastener and the elastic part. The bearing parts absorb the rotation when the fastener acts so that the rotation is not transmitted to the elastic part and the force-applying part.

3. The electrical connection device according to claim 2, Characterized in that, The fastener is a bolt and a nut. The bearing part is a plain bearing. The elastic part is a disc spring assembly. The force-applying part is a pressing plate; There are screw holes on the contact piece for the bolt to pass through. The bolt passes through the first contact piece and the second contact piece in sequence from the outside of the first contact piece. The nut is rotatably installed on the second end of the bolt from the outside of the second contact piece; A plain bearing, a disc spring assembly and a pressing plate are installed between the first end of the bolt and the first contact piece. The disc spring assembly includes several disc springs; The bolt rotates relative to the nut and contracts. The two contact pieces contract inward. The disc spring assembly and the pressing plate apply a clamping force to the contact piece; The plain bearing absorbs the relative rotation of the bolt and the nut so that the disc spring and the pressing plate do not rotate.

4. The electrical connection device according to claim 2, Characterized in that, The fastener is a bolt and a nut. The bearing part is a plain bearing. The elastic part is a disc spring assembly. The force-applying part is a pressing plate; Two pressing plates are respectively closely attached to the outside of the two contact pieces and are respectively fixed to the contact pieces. There are screw holes on the pressing plates for the bolt to pass through. The bolt passes through the first pressing plate and the second pressing plate in sequence from the outside of the first pressing plate. The nut is rotatably installed on the second end of the bolt from the outside of the second pressing plate; A plain bearing and a disc spring assembly are installed between the first end of the bolt and the first pressure plate. The disc spring assembly includes several disc springs; The bolt rotates relative to the nut and contracts, and the two pressure plates contract inward. The disc spring assembly applies a clamping force to the contact piece through the pressure plate; The plain bearing absorbs the relative rotation between the bolt and the nut, so that the disc spring and the pressure plate do not rotate.

5. The electrical connection device according to claim 3 or 4, characterized in that, The reset mechanism is a reset spring. The reset spring is installed on the bolt. The reset spring is located between the two contact pieces or the two pressure plates. The bolt rotates relative to the nut and contracts, and the reset spring is compressed. The bolt rotates relative to the nut and expands, and the reset spring restores. The reset spring applies a spring force to the inner sides of the two contact pieces or the two pressure plates, so that the two contact pieces open outward.

6. The electrical connection device according to claim 1, characterized in that, The draw-out device connection assembly includes: A connecting piece, which is fixed on the draw-out device and is electrically connected to the incoming and outgoing wire ends of the draw-out device; A heat dissipation mechanism, which is installed on the connecting piece.

7. The electrical connection device according to claim 6, characterized in that, There are two connecting pieces, and the two connecting pieces are arranged separately. The heat dissipation mechanism includes: A backing plate, which is a hollow bracket structure and is arranged between the two connecting pieces; A fixing bracket, which fixes the backing plate from the outside of the two connecting pieces.

8. The electrical connection device according to claim 1, characterized in that, The draw-out device connection assembly and the body connection assembly contain non-magnetic materials to prevent the formation of a closed magnetic loop.

9. An electrical device with a draw-out structure, including a body and a draw-out device, wherein the body and the draw-out device have a separation position and an insertion position, characterized in that, The body and the draw-out device are connected by the electrical connection device according to claim 1, wherein, In the separation position, the body withdraws from the draw-out device, the body busbar is separated from the body connection assembly, and the body busbar is not in contact with the contact piece; In the insertion position, the body is pushed into the draw-out device, the body busbar is inserted into the body connection assembly, and the contact piece closely adheres to and clamps the body busbar.

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