Static contact

Abstract

The utility model discloses a static contact, which comprises a contact body and a contact lock accessory, the top of the contact body is provided with a mounting hole, two ends of the contact lock accessory are respectively provided with an insertion part and a lock accessory part, the insertion part is inserted in the mounting hole and is welded and fixed with the mounting hole, and the lock accessory part protrudes out of the outer side of the contact body; the cross section area of the plugging part is smaller than the cross section area of the mounting hole, so that a gap for filling welding flux is formed between the outer wall of the plugging part and the inner wall of the mounting hole, the outer wall of the plugging part is provided with a positioning feature, and the positioning feature is in transition fit with the mounting hole, so that the concentricity of the contact lock accessory and the mounting hole is consistent. According to the utility model, the verticality of the contact lock accessory and the contact body after being welded can be ensured, so that the concentricity of the contact lock accessory and the mounting hole is consistent, the contact lock accessory is prevented from skewing during welding, the abnormal fastening phenomena such as screw loosening, clamping, torque withdrawing and the like are not easy to occur during the installation of the lock accessory, and the welding strength is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of DC contactors, and particularly relates to a static contact. Background Art

[0002] DC contactors are widely used in various power systems and equipment, undertaking the key tasks of connecting and disconnecting circuits. With the continuous expansion of the application scenarios of DC contactors and the increasing improvement of their performance requirements, higher requirements are put forward for the reliability, convenience and stability of the installation and locking structure of static contacts. In some high-load and high-frequency switching working environments such as new energy vehicles, in order to ensure the reliability of the contactor locking, the installation and locking torque is continuously increased.

[0003] Existing static contacts are usually locked and fixed by means of threaded connection. For example, a new type of DC contactor static contact structure disclosed in a Chinese utility model patent with the application number 201721442531.1 and the publication date of May 22, 2018 includes a static contact body. A threaded portion for connecting with an external system is arranged in the middle of the upper end of the static contact body. Since the material of the static contact is generally oxygen-free copper, its yield strength is not high, and the installation torque of the threaded column made of the same material as the static contact will be significantly limited. When the torque is too large, phenomena such as slipping of the thread and reverse torsion are likely to occur.

[0004] At present, on the market, the threaded column and the static contact body are separately formed of different materials. The threaded column is inserted into the jack of the static contact and welded and fixed together. Although the problem of installation strength can be solved, the following defects will exist: if there is no gap between the threaded column and the inner wall of the jack of the static contact, the welding area between the static contact and the threaded column is small and the welding is not firm; if there is a gap between the threaded column and the inner wall of the jack of the static contact to allow the molten solder to fill the gap to increase the contact area and ensure reliable welding, due to the clearance fit between the static contact and the threaded column, it is easy to be skewed during welding, the solder filling is uneven, affecting the welding strength between the threaded column and the static contact, and resulting in uneven distribution of the locking stress of the threaded column. Therefore, it is necessary to improve the existing technology to overcome the defects in the existing technology. Summary of the Utility Model

[0005] The problem to be solved by the utility model is to provide a static contact to overcome the defects that the welding between the existing threaded column and the static contact is not firm, it is easy to be skewed, affecting the welding strength between the stud and the static contact point, and the stress distribution at the locking position of the stud and the copper bar is uneven.

[0006] The technical solution adopted by the present utility model to solve its technical problems is as follows: A static contact includes: a contact body and a contact locking accessory. An installation hole is provided at the top of the contact body. The two ends of the contact locking accessory are respectively provided with a plugging part and a locking part. The plugging part is inserted into the installation hole and fixed by welding with each other. The locking part protrudes outside the contact body. The cross-sectional area of the plugging part is smaller than the cross-sectional area of the installation hole, so as to form a gap for solder filling between the outer wall of the plugging part and the inner wall of the installation hole. And a positioning feature is provided on the outer wall of the plugging part. The positioning feature is in transitional fit with the installation hole, so that the concentricity between the contact locking accessory and the installation hole is consistent.

[0007] As a further improvement of the present utility model, the positioning feature is an annular boss arranged around the outer wall of the plugging part for one week, and the cross-sectional area of the part where the annular boss is located on the contact locking accessory is not less than the cross-sectional area of the installation hole.

[0008] As a further improvement of the present utility model, the positioning feature is a pattern processed by a knurling process around the outer wall of the plugging part for one week, and the pattern protrudes out of the outer wall of the plugging part.

[0009] As a further improvement of the present utility model, the positioning feature is a plurality of positioning ribs arranged at intervals around the outer wall of the plugging part for one week, and the area enclosed by the outer contour formed by the plurality of positioning ribs is not less than the cross-sectional area of the installation hole.

[0010] As a further improvement of the present utility model, the positioning feature is provided at one end of the plugging part away from the locking part.

[0011] As a further improvement of the present utility model, an annular groove for placing a solder ring is provided at the connection between the plugging part and the locking part.

[0012] As a further improvement of the present utility model, a chamfer is provided at the upper end edge of the contact body along the installation hole.

[0013] As a further improvement of the present utility model, the locking part is a threaded post.

[0014] As a further improvement of the present utility model, the plugging part is in a cylindrical shape or a polygonal column shape.

[0015] As a further improvement of the present utility model, the contact locking accessory is made of a material with a yield strength higher than that of the contact body.

[0016] The beneficial effects of the present utility model are as follows: The present utility model provides a static contact, which is provided with a contact body and a contact locking accessory. By leaving a gap between the inner wall of the mounting hole of the contact body and the outer wall of the insertion part of the contact locking accessory for molten solder to fill, the welding area between the insertion part and the contact body is increased to ensure reliable welding. At the same time, positioning features are provided on the outer wall of the insertion part, and the positioning features are in transitional fit with the mounting hole to ensure the perpendicularity of the contact locking accessory and the contact body after welding, so that the concentricity of the contact locking accessory and the mounting hole is consistent, avoiding skew during the welding of the contact locking accessory, and thus being able to ensure that abnormal fastening phenomena such as slipping of teeth, jamming, and torque reduction are not likely to occur during installation and locking, ensuring uniform distribution of locking stress, and at the same time not affecting the filling of the gap between the outer wall of the insertion part and the inner wall of the mounting hole by the solder to ensure welding strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is a perspective view of the static contact of the present utility model;

[0018] Figure 2 is a cross-sectional view of the static contact of the present utility model;

[0019] Figure 3 is the static contact of the present utility model Figure 2 in an enlarged view of part A;

[0020] Figure 4 is a perspective view of the contact body of the present utility model;

[0021] Figure 5 is a perspective view of the contact locking accessory of the present utility model;

[0022] Figure 6 is a perspective view of another embodiment of the contact locking accessory of the present utility model;

[0023] Figure 7 is a perspective view of yet another embodiment of the contact locking accessory of the present utility model;

[0024] Figure 8 is a perspective view of the static contact of the present utility model assembled on a ceramic cover.

[0025] The following is an explanation with reference to the accompanying drawings:

[0026] 1. Contact body; 101. Mounting hole; 102. Gap; 103. Chamfer; 2. Contact locking accessory; 201. Insertion part; 202. Locking part; 203. Annular boss; 204. Pattern; 205. Positioning rib; 206. Annular groove; 3. Solder ring; 4. Ceramic cover. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0027] The following is a detailed description of the preferred embodiments of the present utility model with reference to the accompanying drawings.

[0028] Referring to Figures 1 to 8 , the present utility model provides a static contact, which includes a contact body 1 and a contact locking accessory 2. The contact body 1 can be, but is not limited to, a cylindrical shape. The lower end of the contact body 1 is usually located inside the ceramic cover 4 of the DC contactor, and is used to make or break contact with the moving contact piece of the DC contactor; the upper end of the static contact body 1 is usually located outside the ceramic cover 4 of the DC contactor, and is used for electrical connection with an external electrical connector such as a copper bar.

[0029] In the present utility model, an installation hole 101 is provided along the central axis at the top of the contact body 1, and the installation hole 101 is used for the insertion and fixation of the contact locking accessory 2. The lower end and the upper end of the contact locking accessory 2 are respectively provided with a plugging part 201 and a locking part 202. The shape of the plugging part 201 is similar to that of the installation hole 101, but its size is smaller than that of the installation hole 101. The plugging part 201 is inserted into the installation hole 101 and fixed by welding; the locking part 202 protrudes upward outside the contact body 1 and is used for cooperating with a fastener to lock and fix the static contact with an external electrical connector.

[0030] Among them, the plugging part 201 can be cylindrical, or can be a multi-sided column such as a cube column, etc. The shape of the installation hole 101 corresponds to it. In this embodiment, a cylindrical shape is preferably used, which is easier to process.

[0031] Further, the cross-sectional area of the plugging part 201 is smaller than the cross-sectional area of the installation hole 101. For the cylindrical plugging part 201 in this embodiment, that is, the outer diameter of the plugging part 201 is smaller than the inner diameter of the installation hole 101, so as to form a gap 102 between the outer wall of the plugging part 201 and the inner wall of the installation hole 101. During welding, the molten solder fills the gap 102 to increase the welding area between the plugging part 201 and the contact body 1 and ensure reliable welding.

[0032] It is worth mentioning that a positioning feature is provided on the outer wall of the plugging part 201. The positioning feature is in transitional fit with the installation hole 101, which is used to ensure the perpendicularity of the contact locking accessory 2 and the contact body 1 after welding, so that the concentricity of the contact locking accessory 2 and the installation hole 101 is consistent, avoiding skew during the welding of the contact locking accessory 2, and further being able to ensure that abnormal fastening phenomena such as slipping teeth, jamming, and torque withdrawal are not likely to occur during installation and locking, ensuring uniform distribution of locking stress, and at the same time not affecting the filling of the gap 102 between the outer wall of the plugging part 201 and the inner wall of the installation hole 101 by the solder and ensuring the welding strength.

[0033] Among them, the positioning feature is set at one end of the plugging part 201 far from the locking part 202. Such a setting can leave enough space for the gap 102 above the positioning feature for the solder to fill.

[0034] It can be understood that the interference fit between the positioning feature and the mounting hole 101 includes both the interference fit between the positioning feature and the mounting hole 101 and the clearance fit between the positioning feature and the mounting hole 101. Preferably, the absolute value of the interference amount is less than or equal to 0.01 mm, so as to facilitate assembly on the premise of ensuring the concentricity between the contact locking accessory 2 and the mounting hole 101.

[0035] Refer to Figure 3 and Figure 5 In this embodiment, the positioning feature is an annular boss 203 provided around the outer wall of the insertion part 201, and the cross-sectional area of the part where the annular boss 203 is located on the contact locking accessory 2 is not less than the cross-sectional area of the mounting hole 101. For the cylindrical insertion part 201 in this embodiment, the annular boss 203 is correspondingly in the shape of a ring with the same wall thickness at each part, and the outer diameter of the annular boss 203 is not less than the inner diameter of the mounting hole 101. Thus, when the insertion part 201 is inserted into the mounting hole 101, the annular boss 203 can be in an interference fit with the mounting hole 101 to ensure the concentricity between the contact locking accessory 2 and the mounting hole 101.

[0036] It should be noted that the annular boss 203 needs to have a certain thickness in the axial direction. If the thickness is too small, it cannot play a role in ensuring the perpendicularity of the contact locking accessory 2, and if the thickness is too large, it will occupy the space of the gap 102. The specific thickness of the annular boss 203 is determined according to the depth of the mounting hole 101, and preferably it is 20% - 50% of the depth of the mounting hole 101.

[0037] As Figure 6 shown, in other embodiments of the present invention, the positioning feature can also be an oblique pattern 204 processed by a knurling process around the outer wall of the insertion part 201, and the pattern 204 protrudes out of the outer wall of the insertion part 201 to be in an interference fit with the inner wall of the mounting hole 101, which can also ensure the perpendicularity of the contact locking accessory 2 after being welded to the contact body 1, and make the concentricity between the contact locking accessory 2 and the mounting hole 101 consistent.

[0038] As Figure 7 shown, in another embodiment of the present invention, the positioning feature can also be a plurality of positioning ribs 205 arranged at intervals around the outer wall of the insertion part 201, and the area enclosed by the outer contour formed by the plurality of positioning ribs 205 is not less than the cross-sectional area of the mounting hole 101. For the cylindrical insertion part 201 in this embodiment, the outer contour formed by the outer surfaces of the plurality of positioning ribs 205 is circular, and its diameter is not less than the inner diameter of the mounting hole 101. Thus, when the insertion part 201 is inserted into the mounting hole 101, the plurality of positioning ribs 205 can be in an interference fit with the mounting hole 101 to ensure the concentricity between the contact locking accessory 2 and the mounting hole 101.

[0039] By setting the positioning features in the form of patterns 204 or positioning ribs 205, etc., the present utility model can reduce the assembly resistance when the insertion part 201 is inserted into the mounting hole 101, making the assembly easier.

[0040] Refer to Figure 2 and Figure 5 , a circular groove 206 is provided at the connection between the insertion part 201 and the locking part 202. The circular groove 206 is used to place the solder ring 3. The solder ring 3 is an annular shape with a notch. Before the contact locking part 2 and the contact body 1 are assembled, the solder ring 3 can be first sleeved along the bottom of the insertion part 201 and slid upward into the circular groove 206 to prevent it from falling off. A chamfer 103 is provided along the upper edge of the mounting hole 101 of the contact body 1 (as Figure 4 shown), and the solder ring 3 is located at a position opposite to the chamfer 103. The setting of the chamfer 103 can, on the one hand, facilitate the insertion of the insertion part 201 into the mounting hole 101, and on the other hand, allow the molten solder to accumulate, improving the welding strength.

[0041] The contact body 1 in the present utility model is made of materials such as oxygen-free copper. It is worth mentioning that the contact locking part 2 in the present utility model is made of a material with a yield strength higher than that of the contact body 1, such as stainless steel, low-carbon steel, etc. When the contact locking part 2 is locked and fixed with an external electrical connector, it can withstand higher installation torques and is not prone to abnormal tightening phenomena such as slipping of the threads, jamming, and torque withdrawal, improving the installation strength of the DC contactor.

[0042] In this embodiment, the locking part 202 is a threaded post. It can be understood that the threads on the outer surface of the locking part 202 in Figures 1 to 8 are not shown.

[0043] The static contact of the present utility model can be used on a DC contactor. As Figure 8 shown, the static contacts are usually arranged in pairs, which can be one pair or two pairs, etc., and are fixed side by side on the ceramic cover 4 of the DC contactor. The lower end of the contact body 1 extends into the ceramic cover 4 and is used to make or break contact with the moving contact piece of the DC contactor; the upper end of the static contact body 1 and the contact locking part 2 are located at the top of the ceramic cover 4 and are used to lock and fix with an external electrical connector such as a copper busbar. During assembly, after the copper busbar is sleeved on the threaded post, it can be connected to the threaded post through a nut to achieve the locking and fixing of the copper busbar and the static contact.

[0044] It can be seen that the static contact of the present utility model is provided with a contact body 1 and a contact locking accessory 2. By leaving a gap 102 between the inner wall of the mounting hole 101 of the contact body 1 and the outer wall of the insertion part 201 of the contact locking accessory 2 for molten solder to fill, the welding area between the insertion part 201 and the contact body 1 is increased to ensure reliable welding. At the same time, a positioning feature is provided on the outer wall of the insertion part 201, and the positioning feature is in transitional fit with the mounting hole 101 to ensure the perpendicularity of the contact locking accessory 2 and the contact body 1 after welding, so that the concentricity of the contact locking accessory 2 and the mounting hole 101 is consistent, avoiding skew during the welding of the contact locking accessory 2, and thus being able to ensure that abnormal fastening phenomena such as slipping teeth, jamming, and reverse torque are not likely to occur during installation and locking, ensuring uniform distribution of locking stress, and at the same time not affecting the filling of the gap 102 between the outer wall of the insertion part 201 and the inner wall of the mounting hole 101 by the solder to ensure welding strength.

[0045] Many specific details are set forth in the above description in order to fully understand the present utility model. However, the above description is only a preferred embodiment of the present utility model, and the present utility model can be implemented in many other ways different from those described herein. Therefore, the present utility model is not limited by the specific embodiments disclosed above. At the same time, any person skilled in the art can make many possible changes and modifications to the technical solution of the present utility model by using the methods and technical contents disclosed above without departing from the scope of the technical solution of the present utility model, or modify it into an equivalent embodiment with equivalent changes. Any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present utility model without departing from the content of the technical solution of the present utility model still fall within the scope of protection of the technical solution of the present utility model.

Claims

1. A stationary contact, comprising a contact body (1) and a contact locking accessory (2), wherein a mounting hole (101) is provided at the top of the contact body (1), and an inserting portion (201) and a locking portion (202) are provided at both ends of the contact locking accessory (2), wherein the inserting portion (201) is inserted into the mounting hole (101) and fixed to each other by welding, and the locking portion (202) protrudes outside the contact body (1); characterized in that: The cross-sectional area of ​​the plug-in portion (201) is smaller than the cross-sectional area of ​​the mounting hole (101), so that a gap (102) for solder filling is formed between the outer wall of the plug-in portion (201) and the inner wall of the mounting hole (101), and a positioning feature is provided on the outer wall of the plug-in portion (201), and the positioning feature is transitionally matched with the mounting hole (101), so that the concentricity of the contact lock accessory (2) and the mounting hole (101) is consistent.

2. The stationary contact according to claim 1, characterized in that: The positioning feature is an annular boss (203) arranged around the outer wall of the plug-in portion (201), and the cross-sectional area of ​​the portion of the contact lock accessory (2) where the annular boss (203) is located is not less than the cross-sectional area of ​​the mounting hole (101).

3. The stationary contact according to claim 1, characterized in that: The positioning feature is a pattern (204) formed by knurling around the outer wall of the plug-in portion (201), and the pattern (204) protrudes outward from the outer wall of the plug-in portion (201).

4. The stationary contact according to claim 1, characterized in that: The positioning feature is a plurality of positioning convex ribs (205) arranged at intervals around the outer wall of the plug-in portion (201), and the area enclosed by the outer contour formed by the plurality of positioning convex ribs (205) is not less than the cross-sectional area of ​​the mounting hole (101).

5. The stationary contact according to claim 1, characterized in that: The positioning feature is arranged at an end of the plug-in portion (201) away from the locking portion (202).

6. The stationary contact according to claim 1, characterized in that: An annular groove (206) for accommodating a solder ring (3) is provided at the connection between the plug-in portion (201) and the locking portion (202).

7. The stationary contact according to claim 1, characterized in that: The contact body (1) is provided with a chamfer (103) along the upper edge of the mounting hole (101).

8. The stationary contact according to claim 1, characterized in that: The locking portion (202) is a threaded column.

9. The stationary contact according to claim 1, characterized in that: The plug-in portion (201) is cylindrical or polygonal.

10. The stationary contact according to claim 1, characterized in that: The contact lock accessory (2) is made of a material having a higher yield strength than the contact body (1).

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