Contact box and assembling assembly

Abstract

The contact box comprises a contact box body and a base which are integrally formed by using an insulating material, a movable contact channel is arranged in a connecting area of the base and the contact box body, and the sectional size of the movable contact channel is matched with the size of an opening of the contact box body; the contact box comprises a shielding layer, and the shielding layer is in embedded connection with at least part of the inner wall of the contact box. The static contact is assembled and connected with the inner wall of the contact box, and the moving contact is inserted into the moving contact channel and then is engaged and connected with the static contact. According to the invention, the integrated design of the contact box and the base is adopted, and the same insulating material is used, so that the problems of insufficient inter-phase creepage distance and insufficient inter-electrode creepage distance are solved, the installation of the contact box is enabled to be fast and convenient, the installation centering degree is also ensured, and the good contact between the contacts can be kept during working.

Description

Technical Field

[0001] The invention relates to the field of circuit breakers, and in particular to a contact box and an assembly thereof. Background Art

[0002] The contact box is an important insulating accessory on the removable AC metal-enclosed switchgear, which plays the role of insulation isolation and connection transition. The existing contact box is generally made of insulating materials such as epoxy resin through integral injection molding, and is mostly single-phase split type, that is, the contact box is an independent individual, which is installed at the A phase, B phase and C phase mounting holes on the upper and lower layers of the trolley area in the cabinet. Each phase of the conventional contact box is independent. When installing the contact box, it is necessary to fix the contact box one by one to the grounded metal plate, and then install the mounting plate to the frame of the circuit breaker in the cabinet. The installation process is relatively cumbersome, and deviations are likely to occur during the installation process, affecting the centering degree, resulting in poor contact between the moving and static contacts. In order to ensure mechanical stability and reliable electrical connection, the installation position of the contact box is relatively compact, and the insulation creepage distance between the contact and the metal plate is small, resulting in limited overall insulation performance of the switchgear. When the three phases are assembled side by side, there will be a small air gap between the two contact boxes. When the insulation level of the contact box drops to a certain level, especially when overvoltage occurs, the discharge of a single contact box will develop into interphase discharge through the two-phase gap, which will cause phase breakdown and short circuit in severe cases.

[0003] At the same time, the traditional contact box does not have the function of uniform shielding, and there may be discharge problems inside the contact box. The reason is that industrial dirt (dirty particles such as dust in the air, metal debris, etc.) has strong adhesion to the inner surface of the contact box and is easy to accumulate between the plum blossom contact and the frame. These dirt particles will form a conductive liquid film when wet, which will reduce the resistivity of the dirt layer and cause insulation failure in the box. At the same time, most of the moving contacts inserted into the contact box adopt plum blossom-shaped "claw-type" (commonly known as plum blossom contacts). In a strong electric field environment, the irregular outer edge of the structure causes uneven electric field distribution, and the outer edge of the stainless steel frame of the plum blossom contact finger spring is not far from the inner wall of the contact box, which easily forms a line plate electric field between the conductor and the inner wall of the box. Among them, the electric field between the high-voltage conductor and the inner wall is less than 27kV / cm under dry air. Once the air insulation strength decreases, such as high humidity or dirty dryness, the air insulation strength of the space decreases or the pressure difference of this part expands, exceeding the tolerable electric field strength, which easily excites the conductor itself in the narrow space of the contact box. Corona discharge will cause energy loss and corrode organic insulators. Long-term corrosion will destroy the insulating properties of the insulating material of the contact box, thereby forming a leakage channel, causing the contact box to break down and cause equipment failure to short-circuit to the ground. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a contact box and an assembly to solve the problem that insulation failure is easy to occur in the contact box.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is: A contact box comprises a contact box and a base integrally formed of insulating material, wherein a moving contact channel is provided in a connection area between the base and the contact box, and a cross-sectional dimension of the moving contact channel matches an opening dimension of the contact box; the contact box comprises a shielding layer, and the shielding layer is engaged and connected with at least a portion of an inner wall of the contact box.

[0006] In order to solve the above technical problems, another technical solution adopted by the present invention is: An assembly assembly comprises a contact box, a moving contact and a stationary contact; the stationary contact is assembled and connected with the inner wall of the contact box, and the moving contact is inserted into the moving contact channel and meshed with the stationary contact.

[0007] The beneficial effects of the present invention are: providing a contact box and an assembly, arranging a shielding layer on the inner wall of the contact box, the shielding layer can reduce the leakage and uneven distribution of the electric field inside the contact box, provide uniform charge distribution, help reduce charge accumulation in the electric field, make the electric field around the uneven surface of the contact uniform, and effectively avoid internal harmful discharge.

[0008] However, the provision of the shielding layer will cause the clearance distance in the contact box to be further encroached by the shielding net. In addition, due to installation problems, there is a grounded metal plate between phases in the traditional contact box. In order to ensure mechanical stability and reliable electrical connection, the installation position is relatively compact, and the insulation creepage distance between the contact and the metal plate is small, resulting in limited overall insulation performance of the switchgear. The present invention adopts an integrated design of the contact box and the base, and uses the same insulating material to solve the problems of insufficient phase-to-phase creepage distance and insufficient pole-to-pole creepage distance. At the same time, the contact box is installed quickly and conveniently, and the installation alignment is guaranteed, so that the contacts can maintain good contact during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a schematic diagram of a contact box in an embodiment of the present invention; Figure 2 is a top view of a contact box in an embodiment of the present invention; Figure 3 is a back view of a contact box in an embodiment of the present invention; Figure 4 is a cross-sectional view of an assembly in an embodiment of the present invention; Description of labels: 1. Contact box; 11. Shielding layer; 12. Insulating shed; 13. Moving contact channel; 14. Boss; 15. Annular shed at the bottom of the box; 2. Base; 21. Blind hole; 3. First reinforcing rib; 4. Second reinforcing plate; 5. Crossbeam; 6. Static contact; 7. Moving contact. DETAILED DESCRIPTION

[0010] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings.

[0011] Please refer to Figures 1 to 4 A contact box 1 comprises a contact box 1 and a base 2 integrally formed of insulating material, wherein a moving contact channel 13 is provided in a connection area between the base 2 and the contact box 1, and a cross-sectional dimension of the moving contact channel 13 matches an opening dimension of the contact box 1; the contact box 1 comprises a shielding layer 11, and the shielding layer 11 is embeddedly connected with at least a portion of an inner wall of the contact box 1.

[0012] It should be noted that when the clearance distance between the spring or stainless steel frame outer edge of the plum blossom contact finger inserted into the moving contact channel 13 of the contact box 1 is insufficient from the inner wall of the contact box 1, a line plate electric field will be formed in the clearance distance between the conductor and the inner wall of the static contact 6 box 1. Under normal circumstances, the electric field between the clearance distance between the high-voltage conductor and the inner wall of the static contact 6 under dry air is less than 27kV / cm. Once the air insulation strength decreases, such as high humidity or dirty dryness, causing the air insulation strength of the space to decrease or the pressure difference in this part to expand, exceeding the tolerable electric field strength, corona tip discharge will be formed, generating ozone, and ozone will corrode the surrounding plum blossom contact fingers, springs, and frames, and organically degrade the insulating material of the contact box 1, further aggravating the overall degradation, causing the spring to fail and the plum blossom contact fingers to oxidize, forming dirty flash inside the contact box 1, and accelerating the reduction of the overall life.

[0013] In order to solve this problem, the present invention arranges a shielding layer 11 on the inner wall of the contact box 1. The shielding layer 11 can reduce the leakage and uneven distribution of the electric field inside the contact box 1, provide uniform charge distribution, help reduce charge accumulation in the electric field, make the electric field around the uneven surface of the contact uniform, and effectively avoid internal harmful discharge.

[0014] However, the provision of the shielding layer 11 will cause the clearance distance in the contact box 1 to be further encroached by the shielding net. In addition, due to installation problems, the traditional contact box 1 has a grounded metal plate between phases. In order to ensure mechanical stability and reliable electrical connection, the installation position is relatively compact, and the insulation creepage distance between the contact and the metal plate is small, resulting in limited overall insulation performance of the switchgear. The present invention adopts an integrated design of the contact box 1 and the base 2, and uses the same insulating material to solve the problems of insufficient phase-to-phase creepage distance and insufficient pole-to-pole creepage distance. At the same time, the contact box 1 is installed quickly and conveniently, and the installation alignment is also guaranteed, so that the contacts can maintain good contact during operation.

[0015] In an embodiment of the present invention, the number of the contact boxes 1 is greater than or equal to two, and a first reinforcing rib 3 is provided between the contact boxes 1; a second reinforcing plate 4 is provided on the side of the base 2 away from the contact box 1; an insulating crossbeam 5 is provided between the poles on the side of the base close to the contact box; the first reinforcing rib 3 and the second reinforcing plate 4 are used to enhance the strength of the integrally formed base 2. Specifically, the first reinforcing rib 3 is also connected to the base 2.

[0016] From the above description, it can be seen that the first reinforcing rib 3 and the second reinforcing plate 4 are arranged on the base 2, so that the overall structural strength of the contact box 1 is enhanced when the number increases, especially when multiple contact boxes 1 are connected, these reinforcing ribs can effectively prevent deformation, ensure the stability of the entire structure, and help extend the service life of the device. At the same time, the first reinforcing rib 3 and the second reinforcing plate 4 are used to simultaneously strengthen the base 2 of the integrated design to prevent it from being deformed due to stress concentration.

[0017] Specifically, the second reinforcing plate 4 is a grid-shaped trapezoidal rib. The design of the grid-shaped trapezoidal ribs reduces the material usage and weight while providing structural strength, improves the overall heat dissipation effect, further enhances the strength of the one-piece molded contact box 1, and reduces the stress concentration problem that may occur in the contact box 1 under high-voltage environment. An insulating crossbeam 5 is set between the poles of the contact box 1, and its semiconductor layer prevents unequal potential discharge between insulating parts, and also further enhances the structural stability.

[0018] In the embodiment of the present invention, the outer surface of the contact box 1 is provided with at least two groups of insulating sheds 12. Preferably, the bottom of the contact box 1 is provided with at least two groups of box bottom annular sheds 15.

[0019] From the above description, it can be seen that the insulating shed 12 and the annular shed 15 at the bottom of the box increase the creepage distance of the contact box 1, which helps to improve the equipment's anti-pollution flashover capability and overall insulation performance, is particularly suitable for long-term operation under high-voltage environments, and significantly reduces the risk of electrical failures.

[0020] In an embodiment of the present invention, a boss 14 is provided at the top of the inner wall of the contact box 1, and the boss 14 is provided with a mounting portion, and the mounting portion is used to assemble and connect with an external contact; a vertical channel is provided on the circumferential side wall of one end of the contact box 1 close to the boss 14, and the vertical channel is used to electrically connect with an external device.

[0021] From the above description, it can be seen that the boss 14 at the top of the inner wall and the vertical channel design facilitate the assembly and connection of external equipment, make the installation of the static contact 6 more stable and reliable, enhance the stability of the electrical connection, and the setting of the vertical channel facilitates the interconnection of electrical equipment and ensures the reliability of the conductive performance. Specifically, the static contact 6 is positioned by the boss 14 and assembled and connected with the mounting portion by bolts. In addition, external equipment such as a branch busbar enters the interior of the contact box 1 through the vertical channel and is electrically connected to the static contact 6, and can be assembled and connected through the mounting portion. Specifically, the mounting portion is a mounting hole, and the static contact and the branch busbar are connected by bolts through the mounting hole.

[0022] In an embodiment of the present invention, the insulating material is epoxy resin.

[0023] From the above description, it can be seen that epoxy resin as the main material has excellent insulation properties and can withstand high temperature and humidity, and is easy to shape, suitable for injection molding and die casting, so that the contact box 1 has excellent insulation properties, high temperature resistance and moisture resistance, and can adapt to long-term work in complex environments.

[0024] In an embodiment of the present invention, the shielding layer 11 of the contact box 1 is made of a copper mesh, which is in close contact with the inner wall of the contact box 1 and is used to evenly distribute the charge and form a high-voltage equipotential layer.

[0025] From the above description, it can be seen that the copper mesh shielding layer 11 is evenly covered on the inner wall of the contact box 1, and a high-voltage equipotential layer is formed through the copper mesh, which can evenly distribute the charge, thereby effectively preventing the generation of local arcs in the contact box 1, reducing the risk of dirty flash and hazardous discharge, and improving the safety performance of the equipment.

[0026] In the embodiment of the present invention, the base 2 is symmetrically provided with at least two blind holes 21, and the blind holes 21 are used to assemble and connect the base 2 with external equipment. Specifically, the upper and lower sides of the hole seat of the blind hole 21 are raised by 10 mm, so that weak ventilation can be achieved during installation, and the blind hole is embedded with a (M30) copper internal threaded sleeve for assembly and screw connection.

[0027] From the above description, it can be seen that the design of the symmetrically distributed blind holes 21 of the base 2 simplifies the assembly process of the contact box 1 and the external equipment, increases the stability of the installation, improves the installation efficiency of the overall equipment, and ensures the accurate positioning and firm fixation of the contact box 1 in the switch cabinet.

[0028] An assembly assembly includes a contact box 1, a moving contact 7 and a stationary contact 6; the stationary contact 6 is assembled and connected with the inner wall of the contact box 1, and the moving contact 7 is inserted into the moving contact channel 13 and meshed with the stationary contact 6.

[0029] From the above description, it can be seen that the assembly combines and connects the moving contact 7, the stationary contact 6 and the contact box 1, so that the contact between the moving contact 7 and the stationary contact 6 is more reliable and stable, thereby ensuring the conductive performance of the entire electrical equipment and effectively improving the working efficiency and reliability of the equipment.

[0030] In the embodiment of the present invention, the distance between the moving contact 7 and the inner wall of the contact box 1 is in the range of 2-4 mm.

[0031] From the above description, it can be seen that the contact box 1 and the base 2 are integrally formed of insulating material, and a shielding layer 11 is provided in the contact box 1, which effectively solves the problem of insufficient phase-to-phase creepage distance and insufficient pole-to-pole creepage distance, so that the distance between the moving contact 7 and the inner wall of the contact box 1 is 2-4mm, which can ensure the safety of electricity use without additionally expanding the volume of the contact box 1, saving installation space.

[0032] The present invention provides a contact box 1 and an assembly, which are mainly used to solve the problem of insulation failure of the contact box 1, and are specifically described below in conjunction with embodiments.

[0033] Please refer to Figures 1 to 4 , Embodiment 1 of the present invention is: A contact box 1 includes a contact box 1 and a base 2 integrally formed by epoxy resin, a moving contact channel 13 is provided in the connection area between the base 2 and the contact box 1, and the cross-sectional size of the moving contact channel 13 matches the opening size of the contact box 1; the contact box 1 includes a shielding layer 11, and the shielding layer 11 is embedded and connected with at least part of the inner wall of the contact box 1. The shielding layer 11 of the contact box 1 is made of a copper mesh, which is close to the inner wall of the contact box 1 and is used to evenly distribute charges and form a high-voltage equipotential layer.

[0034] That is, in this embodiment, the shielding layer 11 is arranged on the inner wall of the contact box 1. The shielding layer 11 can reduce the leakage and uneven distribution of the electric field inside the contact box 1, provide uniform charge distribution, help reduce the charge accumulation in the electric field, make the electric field around the uneven surface of the contact uniform, and effectively avoid internal harmful discharge. However, the setting of the shielding layer 11 will cause the clearance distance in the contact box 1 to be further occupied by the shielding net. In addition, due to installation problems, the traditional contact box 1 has a grounded metal plate between phases. In order to ensure mechanical stability and reliable electrical connection, the installation position is relatively compact, and the insulation creepage distance between the contact and the metal plate is small, resulting in limited overall insulation performance of the switchgear. In the present invention, the contact box 1 and the base 2 are integrated and the same insulating material is used to solve the problem of insufficient creepage distance between phases and insufficient creepage distance between poles. At the same time, the contact box 1 is installed quickly and conveniently, and the installation alignment is also guaranteed, so that the contacts can maintain good contact during operation.

[0035] Please refer to Figures 1 to 4 , Embodiment 2 of the present invention is: On the basis of the first embodiment, the number of contact boxes 1 is six, and the six contact boxes 1 are arranged in a 2×3 array, and a first reinforcing rib 3 is provided between the contact boxes 1; an insulating beam 5 is provided between the poles of the contact box 1; the insulating beam is used to prevent unequal potential discharge between insulating parts, and also further enhance the structural strength. A second reinforcing plate 4 is provided on the side of the base 2 away from the contact box 1; the first reinforcing rib 3 and the second reinforcing plate 4 are used to enhance the strength of the one-piece molded base 2. Specifically, the second reinforcing plate 4 is a grid-like trapezoidal rib. The design of the grid-like trapezoidal ribs reduces the material usage and weight while providing structural strength, improves the overall heat dissipation effect, further enhances the strength of the one-piece molded contact box 1, and reduces the stress concentration problem that may occur in the contact box 1 under high-voltage environments.

[0036] Please refer to Figures 1 to 4 , Embodiment 3 of the present invention is: On the basis of the first embodiment, the outer surface of the contact box 1 is provided with five groups of insulating sheds 12, and the bottom of the contact box 1 is provided with two groups of box bottom annular sheds 15. The insulating sheds 12 provided on the outer surface and the box bottom annular sheds 15 increase the creepage distance of the contact box 1, which helps to improve the anti-pollution flashover capability and overall insulation performance of the equipment, is particularly suitable for long-term operation under high-voltage environment, and significantly reduces the risk of electrical failure.

[0037] A boss 14 is provided at the top of the inner wall of the contact box 1, and the boss 14 is provided with a mounting portion, which is used to be assembled and connected with an external contact; a vertical channel is provided on the circumferential side wall of the contact box 1 at one end close to the boss 14, and the vertical channel is used to be electrically connected with an external device. The boss 14 and the vertical channel design at the top of the inner wall facilitate the assembly and connection of external devices, make the installation of the static contact 6 more stable and reliable, enhance the stability of the electrical connection, and the setting of the vertical channel facilitates the interconnection of electrical equipment, ensuring the reliability of the conductive performance. Specifically, the static contact 6 is positioned by the boss 14 and assembled and connected with the mounting hole by bolts. In addition, external devices such as branch busbars enter the interior of the contact box 1 through the vertical channel and are electrically connected with the static contact 6, and can be assembled and connected through the mounting hole.

[0038] Please refer to Figures 1 to 4 , Embodiment 4 of the present invention is: An assembly includes a contact box 1, a moving contact 7 and a stationary contact 6; the stationary contact 6 is assembled and connected to the inner wall of the contact box 1, and the moving contact 7 is inserted into the moving contact channel 13 and meshed with the stationary contact 6. The distance between the moving contact 7 and the inner wall of the contact box 1 is in the range of 2-4mm. The contact box 1 and the base 2 are integrally formed of insulating material, and a shielding layer 11 is provided in the contact box 1, which effectively solves the problem of insufficient creepage distance between phases and insufficient creepage distance between poles, so that the distance between the moving contact 7 and the inner wall of the contact box 1 is 2-4mm, which can ensure the safety of electricity use, and there is no need to additionally expand the volume of the contact box 1, saving installation space.

[0039] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent transformations made using the contents of the present invention's specification and drawings, or directly or indirectly applied in related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A contact box, characterized in that: It comprises a contact box and a base integrally formed of insulating material, wherein a moving contact channel is provided in the connection area between the base and the contact box, and the cross-sectional size of the moving contact channel matches the opening size of the contact box; the contact box comprises a shielding layer, and the shielding layer is embedded and connected with at least part of the inner wall of the contact box.

2. A contact box according to claim 1, characterized in that: The number of the contact boxes is greater than or equal to two, and a first reinforcing rib is provided between the contact boxes; a crossbeam is provided between the poles of the base close to the contact box; a second reinforcing plate is provided on the side of the base away from the contact box; the first reinforcing rib and the second reinforcing plate are used to enhance the strength of the one-piece molded base.

3. A contact box according to claim 2, characterized in that: The second reinforcing plate is a grid-like trapezoidal rib.

4. A contact box according to claim 1, characterized in that: The outer surface of the contact box is provided with at least two groups of insulating sheds.

5. A contact box according to claim 1, characterized in that: A boss is provided at the top of the inner wall of the contact box, and the boss is provided with a mounting portion, and the mounting portion is used for assembly and connection with an external contact; a vertical channel is provided on the circumferential side wall of one end of the contact box close to the boss, and the vertical channel is used for electrical connection with an external device.

6. A contact box according to claim 1, characterized in that: The insulating material is epoxy resin.

7. A contact box according to claim 1, characterized in that: The shielding layer of the contact box is made of a copper mesh, which is closely attached to the inner wall of the contact box and is used to evenly distribute the charge and form a high-voltage equipotential layer.

8. A contact box according to claim 1, characterized in that: The base is symmetrically provided with at least two blind holes, and the blind holes are used to assemble and connect the base with external equipment.

9. An assembly, characterized in that: It comprises a contact box as described in any one of claims 1 to 5, a moving contact and a stationary contact; the stationary contact is assembled and connected with the inner wall of the contact box, and the moving contact is inserted into the moving contact channel and meshed with the stationary contact.

10. An assembly according to claim 6, characterized in that: The distance between the moving contact and the inner wall of the contact box is in the range of 2-4 mm.

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