Bending die for electric contact assembly, electric contact assembly and manufacturing method thereof

Abstract

The present invention provides a bending die for an electric contact assembly, an electric contact assembly and a manufacturing method thereof, the die comprising: a lower die, comprising a base and a movable module, the base having a die cavity with an opening at one end, a lower die bending mechanism being arranged in the die cavity, the movable module being arranged on a side of the lower die bending mechanism close to the opening, the movable module being used to limit the width of the electric contact assembly, the movable module being connected to an electric driving device for pushing the movable module to move along the width direction of the die bending mechanism; an upper die, being arranged above the lower die, the bottom of the upper die being provided with an upper die bending mechanism cooperating with the lower die bending mechanism; a guide assembly, being used for guiding and positioning between the upper die and the lower die. The present invention can improve the hardness of the electric contact assembly, effectively control the welding deformation of the electric contact assembly with bending made of low resistivity material, and significantly improve the overtravel of the dynamic and static electric contacts, thereby reducing the temperature rise of electrical appliances such as circuit breakers and improving the service life of electrical appliances such as circuit breakers.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical devices, and in particular to a bending die for an electric contact assembly, an electric contact assembly and a manufacturing method thereof. Background Art

[0002] Electrical contact assemblies are core components of circuit breakers, relays, contactors, control switches and other electrical switches, instruments and meters, electronic control devices, control mechanical equipment and other products. They are the key to connecting and disconnecting circuits and load currents. Their quality directly affects the reliable operation and service life of products such as circuit breakers and relays. Once they fail, they will lead to major safety accidents such as power system paralysis.

[0003] The general manufacturing procedure of the bent electrical contact components in products such as circuit breakers, relays, and contactors is to bend first and then weld. During welding, the components are easily softened and deformed by heat, and there are quality problems such as over-tolerance of dimensions and over-travel of moving and static contacts, which affect the electrical life of electrical products. Some manufacturers use tin-phosphor bronze, which is not easy to deform, to make bent electrical contact components. The high resistivity of tin-phosphor bronze will cause the electrical contact components to heat up and rise in temperature when powered on, which is not conducive to the reliable operation and service life of products such as circuit breakers.

[0004] After searching, the Chinese invention patent with publication number CN104816061A discloses a contact welding forming process and automatic processing equipment. The edge of the indexing plate of the contact welding forming automatic processing equipment of the patent is surrounded by a contact feeding and bending device, a welding device and a contact unloading and bending device. The contact feeding and bending device can perform the first bending on the contact piece and transfer the contact piece that has been bent for the first time to the welding device and the contact unloading and bending device in sequence through the indexing plate, thereby completing the welding of the silver solder point and the second bending process of the contact piece. However, the patent still has the following problems: the silver point is facing upward, and only the bending position of the electrical contact assembly is stamped; only the local position is bent, and the hardness of the entire electrical contact assembly cannot be improved.

[0005] Therefore, it is urgent to develop a method for manufacturing a bent electrical contact assembly that can control welding deformation, so as to improve the reliability and service life of electrical appliances such as circuit breakers. Summary of the invention

[0006] In view of the defects in the prior art, the purpose of the present invention is to provide a bending mold for an electrical contact assembly, an electrical contact assembly and a manufacturing method thereof, so as to solve the problems of easy deformation during welding and difficult size control of the bent electrical contact assembly, so as to achieve the purpose of ensuring the product performance without increasing the resistivity of the electrical contact assembly.

[0007] According to one aspect of the present invention, there is provided a bending die for an electrical contact assembly, the die comprising:

[0008] The lower mold comprises a base and a movable module, wherein the base is provided with a mold cavity with an opening at one end, a lower mold bending mechanism is arranged in the mold cavity, the movable module is arranged on a side of the lower mold bending mechanism close to the opening, the movable module is used to limit the width of the electric contact assembly, the movable module is connected to an electric driving device, and the electric driving device is used to drive the movable module to move along the width direction of the mold bending mechanism;

[0009] An upper mold is arranged above the lower mold, and an upper mold bending mechanism matching with the lower mold bending mechanism is arranged at the bottom of the upper mold;

[0010] The guide assembly is used for guiding and positioning between the upper mold and the lower mold.

[0011] Furthermore, the lower die bending mechanism includes a lower die bending top material portion and preset silver point portions located at both ends of the lower die bending top material portion, the lower die bending top material portion has a recessed structure recessed downward, and the preset silver point portions are used to place the silver points of the electrical contact assembly to be bent.

[0012] Furthermore, the upper die bending mechanism includes an upper die bending pressing part and flat plate parts located at both ends of the upper die bending pressing part, the upper die bending pressing part has a convex structure matching the concave structure, and the flat plate part is used to stamp the parts of the electrical contact assembly except the bending part.

[0013] Furthermore, the guide assembly includes a guide post arranged at the top of the lower mold and a guide sleeve arranged at the bottom of the lower mold, and the guide post is inserted into the guide sleeve when the upper mold is pressed downward.

[0014] According to a second aspect of the present invention, there is provided a method for manufacturing an electrical contact assembly, the method comprising:

[0015] Processing and shaping the plate or strip except for the bending of the electric contact assembly to obtain a planar support member;

[0016] Welding the planar support member and the electric contact to obtain a planar electric contact assembly;

[0017] The planar electric contact assembly is placed on the lower die bending mechanism of a bending die for the electric contact assembly, and then the upper die carries the upper die bending mechanism to punch the planar electric contact assembly downward to punch out a finished product with a bend.

[0018] Furthermore, the processing and forming of the plate or strip material except for the bending of the electric contact assembly includes: the processing and forming method includes any one of laser processing, mold punching, mechanical processing and chemical reaction.

[0019] Furthermore, the welding of the planar support member and the electric contact includes: the welding is any one of induction welding, resistance welding, ultrasonic welding and laser welding.

[0020] Furthermore, the upper mold carries the upper mold bending mechanism to punch the planar electric contact assembly downward to punch out a finished product with a bend, including: moving the movable module to a preset position of the planar electric contact assembly close to the opening side through an electric driving device to limit the width of the planar electric contact assembly after stamping, wherein the preset position is determined according to the width of the planar electric contact assembly after stamping.

[0021] Furthermore, the upper die carries the upper die bending mechanism to punch the planar electric contact assembly downward to form a finished product with a bend, including: placing the silver-dot surface of the planar electric contact assembly downward on the preset silver-dot part of the lower die bending mechanism.

[0022] According to a third aspect of the present invention, there is provided an electric contact assembly, which is manufactured by using the above-mentioned method for manufacturing an electric contact assembly.

[0023] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0024] 1. The bending mold provided by the present invention has an electrically driven movable module in the mold cavity of the lower mold. The movable module can set the movable range according to needs. When stamping a planar support member, the support member material extends and widens. The movable module can limit the extended width of the electric contact assembly as required, so that the width of the electric contact assembly is consistent, thereby improving the reliability of products such as circuit breakers.

[0025] 2. The bending die provided by the present invention has a lower die bending mechanism with a reserved silver dot placement area (pre-set silver dot portion), and the bending die includes a bending pressing portion and a flat plate portion, which can perform large deformation stamping processing on all areas of the planar electric contact assembly except the silver dot, effectively improving the hardness of the entire prepared electric contact assembly, thereby effectively controlling the welding deformation of the bent electric contact assembly manufactured using low resistivity materials.

[0026] 3. When the bending mold provided by the present invention is used to process an electric contact assembly, the welding and non-bending forming of the electric contact assembly can be completed in advance, and then the electric contact assembly can be processed in the bending mold. The size of the obtained electric contact assembly is easy to control, the mechanical properties are good, and the cost is low, which ensures the performance of products such as relays and circuit breakers.

[0027] 4. The manufacturing method provided by the present invention pre-punches the support members in other dimensions except for the bending, welds the electric contacts and the planar support members, and then uses the above-mentioned bending mold to punch and bend the finished products with the required angle and width in the mold, which can improve the hardness of the electric contact assembly, effectively control the welding deformation of the bent electric contact assembly made of low resistivity materials, and significantly improve the overtravel of the dynamic and static contact, thereby reducing the temperature rise of electrical appliances such as circuit breakers and improving the service life of electrical appliances such as circuit breakers. The present invention has a simple production process, low cost, good processing performance, and easy size control, which ensures the performance of products such as relays and circuit breakers. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0029] Figure 1 It is a structural schematic diagram of a bending die for an electric contact assembly according to an embodiment of the present invention;

[0030] Figure 2 It is a partial structural schematic diagram of a lower mold of a bending mold for an electric contact assembly according to an embodiment of the present invention;

[0031] Figure 3 It is a partial structural schematic diagram of a lower mold of a bending mold for an electric contact assembly according to an embodiment of the present invention;

[0032] Figure 4 It is a schematic diagram of the partial structure of an upper mold of a bending mold for an electric contact assembly according to an embodiment of the present invention.

[0033] In the figure: 1 is the upper mold, 2 is the guide column, 3 is the upper mold bending mechanism, 31 is the upper mold bending and pressing part, 32 is the flat plate part, 4 is the lower mold, 5 is the guide sleeve, 6 is the base, 7 is the movable module, 8 is the electric driving device, 9 is the lower mold bending mechanism, 91 is the lower mold bending and pressing part, and 92 is the preset silver point part. DETAILED DESCRIPTION

[0034] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but do not limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several variations and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention. In the description of the embodiments of the present invention, it should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein.

[0035] The embodiment of the present invention provides a bending die for an electrical contact assembly, referring to Figure 1-4 The mold includes: a lower mold 4, an upper mold 1 and a guide assembly, wherein: the lower mold 4 includes a base 6 and a movable module 7, the base 6 is provided with a mold cavity with an opening at one end, a lower mold bending mechanism 9 is arranged in the mold cavity, and the movable module 7 is arranged on the side of the lower mold bending mechanism 9 close to the opening. During stamping, the thickness of the electric contact assembly becomes smaller and the width becomes wider. The movable module 7 is used to limit the width of the electric contact assembly. The position of the movable module 7 is determined according to the target width of the electric contact assembly. The movable module 7 is connected to an electric driving device 8, and the electric driving device 8 is used to push the movable module 7 to move along the width direction of the mold bending mechanism; the upper mold 1 is arranged above the lower mold 4, and the bottom of the upper mold 1 is provided with an upper mold bending mechanism 3 that cooperates with the lower mold bending mechanism 9; the guide assembly, when stamping and bending, the lower mold 4 is fixed differently, and the upper mold 1 moves up and down, and the guide assembly is used for guiding and positioning between the upper mold 1 and the lower mold 4.

[0036] The electric contact assembly to be bent during stamping is located on the lower die bending mechanism 9, and further reference is made to Figure 2-3 In some specific embodiments, the lower die bending mechanism 9 includes a lower die bending top material portion 91 and preset silver point portions 92 located at both ends of the lower die bending top material portion 91. The lower die bending top material portion 91 has a recessed structure recessed downward, and the bending angle of the recessed structure can be determined according to the bending angle of the electrical contact assembly to be bent. The preset silver point portion 92 is used to place the silver point of the electrical contact assembly to be bent. The preset silver point portion 92 has a groove matching the silver point contour on the electrical contact assembly, and the depth dimension of the groove is greater than the height dimension of the silver point, so that when the upper die stamps the electrical contact assembly, the silver point working surface is not stamped, thereby protecting the morphology of the silver point working surface.

[0037] The upper die bending mechanism 3 is used to press downwards and cooperate with the lower die bending mechanism 9 to form a bending portion of the electric contact assembly to be bent. Figure 4In some specific embodiments, the upper die bending mechanism 3 includes an upper die bending pressing portion 31 and flat plate portions 32 located at both ends of the upper die bending pressing portion 31. The upper die bending pressing portion 31 has a convex structure matching the concave structure. The flat plate portion 32 is used to stamp the portion of the electrical contact assembly other than the bending portion, so that the non-bending position of the flat plate support member such as a copper member is also pressed down together with the bending portion, thereby ensuring that the thickness and width of the non-bending position and the bending portion are consistent.

[0038] In order to realize the guiding function of the upper mold 1 when pressing downward, in some specific embodiments, the guiding assembly includes a guide column 2 arranged at the top of the lower mold 4 and a guide sleeve 5 arranged at the bottom of the lower mold 4, wherein the guide column 2 is distributed at the four corners of the top of the upper mold 1, and the guide sleeve 5 is distributed at the four corners of the bottom of the lower mold 4. When the upper mold 1 is pressed downward, the guide column 2 is inserted into the guide sleeve 5, so that the upper mold bending mechanism 3 and the lower mold bending mechanism 9 of the lower mold 4 can be precisely matched when the upper mold 1 is stamped downward.

[0039] It can be understood by those skilled in the art that, in order to realize the downward stamping of the upper die 1, a driving mechanism that can drive the upper die 1 to move up and down is also included. In addition, the electric driving device 8 can be a motor, and the movement of the electric driving device 8 can be realized by the control of the control module. Specifically, according to the width of the electric contact assembly to be bent, the position of the movable module 7 on the side close to the opening of the lower die bending mechanism 9 is determined, and the control module controls the electric driving device 8 through a predetermined program to transport the movable module 7 to the corresponding position, thereby limiting the width of the electric contact assembly to be bent after stamping.

[0040] The bending die in the embodiment of the present invention has the following specific working process: when the upper die 1 is pressed down, the cooperation of the guide assembly provides guidance for the downward pressing of the upper die 1. Specifically, the guide post 2 is inserted into the guide sleeve 5. The cooperation of the guide post 2 and the guide sleeve 5 provides guidance and positioning for the downward pressing of the upper die 1. The electric contact assembly to be bent is planar. When bending the electric contact assembly to be bent, the planar electric contact assembly is first placed on the lower die bending mechanism 9. Specifically, the surface of the electric contact assembly to be bent with the silver point facing downward is placed. Place it on the preset silver point part 92; the electric driving device 8 transports the movable module 7 to the corresponding position on one side of the electric contact assembly to be bent, and limits the width of the electric contact assembly to be bent after stamping; under the guiding action of the guide assembly, the upper mold 1 is moved downward, and the upper mold bending mechanism 3 is moved downward together with the upper mold 1, and the upper mold bending mechanism 3 cooperates with the lower mold bending mechanism 9. Specifically, the upper mold bending pressing part and the lower mold bending top part 91 on the upper mold bending mechanism 3 are used to complete the bending forming of the electric contact assembly to be bent.

[0041] Correspondingly, an embodiment of the present invention further provides a method for manufacturing an electric contact assembly, the method being implemented by using the bending mold for the electric contact assembly in the above embodiment, the method comprising:

[0042] S1. Processing and shaping the plate or strip except for the bending of the electric contact assembly to obtain a planar support member;

[0043] S2, welding the planar support member and the electric contact to obtain a planar electric contact assembly;

[0044] S3, placing the planar electric contact assembly on the lower die bending mechanism 9 of the bending die for the electric contact assembly in the above embodiment, and then the upper die 1 carrying the upper die bending mechanism 3 punches the planar electric contact assembly downward to punch out a finished product with a bend.

[0045] In some specific embodiments, in step S1, the plate or strip is processed and formed except for the bending of the electrical contact assembly, including: the material of the plate or strip is any one of metal, alloy, layered composite material, inlaid composite material, and dispersion reinforced composite material; the processing and forming method includes any one of laser processing, mold punching, mechanical processing and chemical reaction.

[0046] In some specific embodiments, in step S2, the planar support member and the electric contact are welded, including: welding is any one of induction welding, resistance welding, ultrasonic welding and laser welding.

[0047] In some specific embodiments, in step S3, the upper die 1 carries the upper die bending mechanism 3 to punch the planar electric contact assembly downward to form a finished product with a bend, including: placing the surface with the silver dot of the planar electric contact assembly downward on the preset silver dot portion 92 of the lower die bending mechanism 9. The movable module 7 is moved to a preset position of the planar electric contact assembly close to the opening side by the electric driving device 8 to limit the width of the planar electric contact assembly after punching, wherein the preset position is determined according to the width of the planar electric contact assembly after punching.

[0048] The embodiment of the present invention adopts a bending die to stamp a planar electric contact assembly. On the one hand, under the condition of room temperature or below the crystallization temperature, by stamping the entire planar support member such as a copper member except the silver point portion with a large deformation, a strong plastic deformation is generated, the lattice is distorted, and the grains are elongated, thereby improving the overall hardness of the electric contact assembly. Even if the electric contact assembly is made by welding a material with low resistivity and low hardness, the hardness of the material with low hardness will be significantly improved after processing in step S3. On the other hand, since the bending angle of the recessed structure of the bending top material portion of the lower die is determined according to the bending angle of the electric contact assembly to be bent, the electric contact assembly can be processed into a predetermined angle, and the width of the electric contact assembly is limited by stamping in the die cavity, thereby improving the consistency of the width and angle dimensions of the electric contact assembly, and effectively controlling the welding deformation of the bent electric contact assembly.

[0049] The embodiment of the present invention divides the forming process of the support member of the electric contact assembly to be bent into two steps, and pre-punches the support member in other dimensions except for bending, welds the electric contact and the planar support member, and then punches them in a bending mold to be bent and punched into a finished product with the required angle and width. The embodiment of the present invention can effectively solve the problems of easy deformation after welding, out-of-tolerance size after welding, and over-travel of dynamic and static contacts of the bent electric contact assembly made of low resistivity materials, greatly improve the welding quality and material hardness of the electric contact assembly, and reduce the resistance of the electric contact assembly, thereby reducing the temperature rise of the electrical product and increasing the electrical life of the electrical product. The process is simple and easy to mass produce.

[0050] The embodiment of the present invention also provides an electric contact assembly, which is manufactured by the manufacturing method of the electric contact assembly in the above embodiment. In the embodiment of the present invention, all bending and forming steps are placed after the welding process is completed, and all non-bending forming processes are completed before welding. After the welding process is completed, the planar electric contact assembly is placed in the bending mold with the silver point facing down, and the silver point is placed in the pit of the preset silver point part. While bending in the bending mold, all areas except the silver point are stamped, and the electric driving device can push the movable module close to one side of the stamped electric contact assembly according to the program set by the control module. The effect of this is to reserve a set gap to ensure that the width size of the stamped electric contact assembly is limited to the expected range in the plane direction. Stamping the entire area while bending can improve the hardness of the entire electric contact assembly. At the same time, the expansion range of the width of the electric contact assembly is limited, so that the overall size of the electric contact assembly is stable.

[0051] The bending die for the electric contact assembly, the electric contact assembly and the manufacturing method thereof in the embodiment of the present invention are further described with a specific embodiment.

[0052] This embodiment provides a method for preparing an AgSnO2 / T2 electrical contact assembly for a contactor, wherein the silver point material is AgSnO2 and the support member material is T2 pure copper, comprising the following steps:

[0053] S1. Punch and shape the T2 sheet material into other dimensions except for bending to obtain a planar T2 copper support.

[0054] S2. Induction welding is performed on the planar T2 copper support and the AgSnO2 electric contact to obtain a planar AgSnO2 / T2 electric contact assembly.

[0055] S3, place the planar AgSnO2 / T2 electrical contact assembly on Figure 1 On the lower die bending mechanism in the bending die cavity shown, the electric contact assembly with the AgSnO2 silver dot surface is placed downward on the preset silver dot portion, and the electric driving device transports the movable module to the corresponding position on one side of the AgSnO2 / T2 electric contact assembly to limit the stamping width of the AgSnO2 / T2 electric contact assembly; then the upper die of the bending die carries the upper die bending mechanism to stamp the AgSnO2 / T2 electric contact assembly downward, and the upper die bending pressing portion and the lower die bending top portion cooperate to obtain the bent AgSnO2 / T2 electric contact assembly.

[0056] The production process steps of the bent AgSnO2 / T2 electric contact assembly in this embodiment are simple, easy to implement, low in investment cost, and the strength of the produced electric contact assembly is greatly improved, which can effectively solve the problems of easy deformation of the electric contact assembly during welding, unstable size after welding, and inability to use softer materials such as copper to make the bent electric contact assembly. The opening and closing performance of the contactor made of the bent AgSnO2 / T2 electric contact assembly is further improved. According to tests, the hardness of the copper support is increased by 20% compared with conventional products, the quality pass rate of the product after welding is increased by 18%, and the electrical life of the contactor made of the bent AgSnO2 / T2 electric contact assembly is increased by 15% compared with conventional products.

[0057] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various modifications or variations within the scope of the claims, which does not affect the essence of the present invention. The above preferred features can be used in any combination without conflicting with each other.

Claims

1. A bending die for an electrical contact assembly, characterized in that: include: The lower mold comprises a base and a movable module, wherein the base is provided with a mold cavity with an opening at one end, a lower mold bending mechanism is arranged in the mold cavity, the movable module is arranged on a side of the lower mold bending mechanism close to the opening, the movable module is used to limit the width of the electric contact assembly, the movable module is connected to an electric driving device, and the electric driving device is used to drive the movable module to move along the width direction of the mold bending mechanism; An upper mold is arranged above the lower mold, and an upper mold bending mechanism matching with the lower mold bending mechanism is arranged at the bottom of the upper mold; A guide assembly, used for guiding and positioning between the upper mold and the lower mold; The lower die bending mechanism comprises a lower die bending top material portion and preset silver point portions located at both ends of the lower die bending top material portion, the lower die bending top material portion has a recessed structure recessed downward, and the preset silver point portions are used to place the silver points of the electric contact assembly to be bent; The upper die bending mechanism comprises an upper die bending and pressing part and flat plate parts located at both ends of the upper die bending and pressing part, the upper die bending and pressing part has a convex structure matching the concave structure, and the flat plate part is used to stamp the part other than the bending of the electric contact assembly; The guide assembly comprises a guide post arranged at the top of the lower mold and a guide sleeve arranged at the bottom of the lower mold, and the guide post is inserted into the guide sleeve when the upper mold is pressed downward.

2. A method for manufacturing an electrical contact assembly, characterized in that: include: Processing and shaping the plate or strip except for the bending of the electric contact assembly to obtain a planar support member; Welding the planar support member and the electric contact to obtain a planar electric contact assembly; The planar electric contact assembly is placed on the lower die bending mechanism of the bending die for the electric contact assembly according to claim 1, and then the upper die carries the upper die bending mechanism to punch the planar electric contact assembly downward to punch out a finished product with a bend.

3. The method for manufacturing an electrical contact assembly according to claim 2, characterized in that: The processing and forming of the plate or strip material except the bending of the electric contact assembly includes: the processing and forming method includes any one of laser processing, mold punching, mechanical processing and chemical reaction.

4. The method for manufacturing an electrical contact assembly according to claim 2, characterized in that: The step of welding the planar support member and the electric contact includes: the welding is any one of induction welding, resistance welding, ultrasonic welding and laser welding.

5. The method for manufacturing an electrical contact assembly according to claim 2, characterized in that: The upper mold carries the upper mold bending mechanism to punch the planar electric contact assembly downward to punch out a finished product with a bend, including: moving the movable module to a preset position of the planar electric contact assembly close to the opening side through an electric driving device to limit the width of the planar electric contact assembly after stamping, wherein the preset position is determined according to the width of the planar electric contact assembly after stamping.

6. The method for manufacturing an electrical contact assembly according to claim 2, characterized in that: The upper die carries the upper die bending mechanism to punch the planar electric contact assembly downward to form a finished product with a bend, including: placing the silver-dot surface of the planar electric contact assembly downward on the preset silver-dot part of the lower die bending mechanism.

7. An electrical contact assembly, characterized in that: The electric contact assembly is manufactured by the manufacturing method of any one of claims 2 to 6.

Images