Positioning fixture for mica paper capacitor lead welding

Abstract

The utility model discloses a kind of positioning fixture for mica paper capacitor lead welding, including base, core group positioning seat, lead positioning block, cross link and lead positioning column, four core group positioning seats are respectively installed on the top of base and are enclosed to form a core group installation area, the center position of the top of base in core group installation area is equipped with lead via hole, the middle lower part outer wall of lead positioning block is equipped with positioning block positioning groove, cross link is equipped with strip positioning hole, the upper end of two cross links is connected with four lead positioning blocks respectively by connecting screw, the middle part of two cross links is mutually crossed, lead positioning column is simultaneously passed through the middle section of the strip positioning hole of two cross links, lead positioning column is equipped with vertical center through-hole.The utility model realizes the reliable positioning of the core group and lead of mica paper capacitor to make the perpendicularity and centricity of lead meet the purpose of requirement, to significantly improve welding quality and welding efficiency.

Description

Technical Field

[0001] This utility model relates to a clamp for welding mica paper capacitors, and more particularly to a positioning clamp for welding the leads of mica paper capacitors. Background Technology

[0002] Mica paper capacitors are capacitor products that use natural mica material, which has excellent insulating properties, as the core dielectric. Structurally, mica paper capacitors are typically designed as regular cubes. In terms of the welding process, individual mica paper capacitor cores are matched and screened based on their electrical properties (such as capacitance and withstand voltage) to form cores with consistent performance. After the individual cores are grouped together, the core leads (usually metal foil) are overlapped and arranged, then welded in parallel. Welding establishes electrical connections between multiple cores, forming a core group with a specific capacitance value to meet the capacity requirements of the circuit design. Leads (such as pins, wire terminals, etc.) serve as the connection medium between the core group and the external circuit. They are fixed to the core group leads by welding, ensuring stable transmission of the core group's electrical signals to the external circuit while providing mechanical support.

[0003] The welding process between leads and cores plays a crucial role in several aspects: it ensures the consistency of electrical performance of the product, guarantees the stability of parameters such as capacitance and withstand voltage after multiple cores are connected in parallel, and ensures uniform core performance, avoiding core failure due to differences in individual cores; the symmetry of parallel welding and the positional accuracy of lead welding are important for ensuring uniform electric field distribution and heat dissipation of the capacitor.

[0004] For the reasons mentioned above, the welding process of mica paper capacitors requires high precision in the perpendicularity and centering of the leads. However, in traditional welding processes, because there are no suitable fixtures for positioning the core assembly and leads, operators can only use calipers and visual inspection to try to improve the perpendicularity and centering of the leads. This traditional welding method reduces welding quality and efficiency, and the welding quality has the following two main defects: Lead wire misalignment: Traditional soldering relies on operators using calipers to measure, which can only ensure the centering in the length direction. However, due to the limitations of caliper measurement, it is difficult to accurately locate the center in the width direction, causing the lead wire to deviate in the width direction during soldering. This results in uneven contact area between the lead wire and the core assembly, leading to increased local resistance. During circuit operation, uneven resistance will cause abnormal current distribution, resulting in local overheating, affecting the normal charging and discharging function of the capacitor, and may even cause short circuit faults, leading to instability in the entire circuit system.

[0005] Crack defects: The perpendicularity of the leads is controlled solely by the operator's visual judgment and manual adjustment. During the soldering process, if a perpendicularity deviation is found when the solder is nearing solidification, manual adjustment will be made, which will apply stress to the solder. After the solder solidifies, this stress will remain inside the solder joint, forming microcracks. The presence of microcracks not only weakens the mechanical strength of the solder joint, but the cracked solder joint is also very prone to breakage, causing the capacitor to disconnect from the circuit and causing equipment failure. It may also increase the surface area of ​​the solder joint exposed to air during use, accelerating the oxidation and corrosion process of the solder joint, leading to electrical connection failure, seriously affecting the reliability and service life of the mica paper capacitor. Moreover, when the circuit experiences voltage fluctuations or current surges, the uneven distribution of electrical stress on the solder joint with microcracks may cause the cracks to expand rapidly, triggering a sudden electrical connection interruption, causing equipment shutdown, and even potentially leading to more serious safety accidents.

[0006] In addition, the aforementioned traditional welding methods also have drawbacks such as poor product consistency and low welding efficiency in mass production. Utility Model Content

[0007] The purpose of this invention is to provide a positioning fixture for welding mica paper capacitor leads, which can improve the welding quality and efficiency between the leads and the core assembly, in order to solve the above problems.

[0008] This utility model achieves the above objectives through the following technical solutions: A positioning fixture for lead wire soldering of mica paper capacitors includes a base with a horizontally planar upper surface, and core assembly positioning seats, lead wire positioning blocks, cross links, and lead wire positioning posts. Four core assembly positioning seats are respectively mounted on the base and enclose a horizontally rectangular core assembly mounting area. The vertical surface of each core assembly positioning seat near the core assembly mounting area is planar. A vertical lead wire through-hole is provided at the center of the core assembly mounting area on the upper surface of the base. The lower outer wall of each lead wire positioning block has a positioning block positioning groove with a vertical length direction and a lower end extending to the lower surface. The horizontal cross-section of the positioning block positioning groove is "L" shaped. The lead positioning block is located above the four core group positioning seats. The horizontal cross link has a vertical through-hole with a length direction in the same direction as the cross link. The two ends of the two cross links are respectively connected to the upper ends of the four lead positioning blocks by connecting screws, and the stud of the connecting screw passes through the corresponding cross link's strip positioning hole. The middle parts of the two cross links intersect each other, and one cross link is located above the other cross link. The vertical and cylindrical lead positioning post passes through the middle section of the strip positioning hole of the two cross links. The lead positioning post has a vertical central through hole.

[0009] Preferably, in order to facilitate reliable vertical positioning of both ends of the cross link, the upper end of the lead wire positioning block is provided with a positioning block screw hole. The stud of the connecting screw passes through the central through hole of the vertical positioning cylinder and connects to the corresponding positioning block screw hole. The positioning cylinder passes through the corresponding strip positioning hole. The outer circumferential wall of the positioning cylinder has one or two positioning cylinder protrusions that protrude outward in the circumferential direction. The outer diameter of the positioning cylinder protrusion is larger than the lateral width of the strip positioning hole.

[0010] Preferably, to facilitate the installation of the core assembly positioning seat and enable it to have initial position locating and subsequent position fine-tuning functions, the core assembly positioning seat is an "L"-shaped seat with two vertically penetrating positioning pin holes and two vertically penetrating mounting through holes on its horizontal plate. The upper part of the base has two vertical positioning blind holes and two vertical mounting screw holes. The lower ends of the two positioning pins corresponding to each core assembly positioning seat pass through the two positioning pin holes and are placed in the two positioning blind holes. The lower ends of the studs of the two mounting screws corresponding to each core assembly positioning seat pass through the two mounting through holes and are connected to the two mounting screw holes. The diameter of the mounting through hole is larger than the diameter of the stud of the mounting screw, and the diameter of the nut of the mounting screw is larger than the diameter of the mounting through hole. The above structure utilizes the gap between the stud of the mounting screw and the wall of the mounting through hole to achieve the position fine-tuning function. Alternatively, the mounting through hole can be designed as a strip-shaped through hole, which can achieve a wider range of position adjustment functions.

[0011] Preferably, to prevent the lead wire positioning post from falling off, the outer diameter of the upper end of the lead wire positioning post is increased to form a positioning post baffle, and the central through hole of the lead wire positioning post passes through the positioning post baffle. The outer diameter of the positioning post baffle is larger than the lateral width of the strip positioning hole.

[0012] The beneficial effects of this utility model are as follows: This invention utilizes a design that integrates a base, core assembly positioning seat, lead wire positioning block, cross linkage, and lead wire positioning post. The four core assembly positioning seats reliably position and clamp the core assembly of the mica paper capacitor. The four lead wire positioning blocks, two cross linkages, and one lead wire positioning post ensure that the central through-hole of the lead wire positioning post is centered above the core assembly. Passing the lead wire of the mica paper capacitor through the central through-hole of the lead wire positioning post ensures that the lead wire is centered above the core assembly. Ultimately, this design achieves reliable positioning of the core assembly and lead wire of the mica paper capacitor, ensuring that the verticality and centering of the lead wire meet the requirements, thereby significantly improving welding quality and efficiency. Attached Figure Description

[0013] Figure 1 This is a perspective view of the base and core assembly positioning seat of the positioning fixture for welding the lead wires of the mica paper capacitor described in this utility model. Figure 2 This is a top view of the base and core assembly positioning seat of the positioning fixture for welding the lead wires of the mica paper capacitor described in this utility model. Figure 3 This is a perspective view of the lead positioning block, cross link, and lead positioning post of the positioning fixture for welding lead wires of mica paper capacitors according to this utility model. Figure 4 This is a top view of the lead positioning block, cross link, and lead positioning post of the positioning fixture for welding lead wires of mica paper capacitors according to this utility model. Figure 5 This is a perspective view of the positioning fixture for welding the leads of mica paper capacitors as described in this utility model. Detailed Implementation

[0014] The present invention will be further described below with reference to the accompanying drawings: like Figures 1-5 As shown, the positioning fixture for lead welding of mica paper capacitors according to this utility model includes a base 2 with a horizontally planar upper surface, core assembly positioning seats 3, lead wire positioning blocks 7, cross links 9, and lead wire positioning posts 13. Four core assembly positioning seats 3 are respectively installed on the base 2 and enclose a horizontally rectangular core assembly mounting area (not marked in the figure). The vertical surface of the core assembly positioning seat 3 near the core assembly mounting area is planar. A vertical lead wire through hole 6 is provided at the center of the core assembly mounting area on the upper surface of the base 2. The lower outer wall of the lead wire positioning block 7 has a positioning block positioning groove 10 with a vertical length direction and its lower end extending to the lower surface. The horizontal cross-section of the positioning block positioning groove 10... The surface is L-shaped, with four lead positioning blocks 7 located above four core group positioning seats 3. The horizontal cross link 9 has a vertical through-hole 16 with the same length direction as the cross link 9. The two ends of the two cross links 9 are respectively connected to the upper ends of the four lead positioning blocks 7 by connecting screws 8, and the studs of the connecting screws 8 pass through the corresponding cross link 9's strip positioning hole 16. The middle parts of the two cross links 9 intersect each other, and one cross link 9 is located above the other cross link 9. The vertical and cylindrical lead positioning post 13 passes through the middle section of the strip positioning hole 16 of the two cross links 9. The lead positioning post 13 has a vertical central through hole 12.

[0015] like Figures 1-5 As shown, this utility model also discloses the following more optimized specific structures: To facilitate reliable vertical positioning of both ends of the cross link 9, the upper end of the lead wire positioning block 7 is provided with a positioning block screw hole (not visible in the figure). The stud of the connecting screw 8 passes through the central through hole of the vertical positioning cylinder 15 and connects to the corresponding positioning block screw hole. The positioning cylinder 15 passes through the corresponding strip positioning hole 16. The outer circumferential wall of the positioning cylinder 15 has one or two positioning cylinder protrusion rings 14 that protrude outward in the circumferential direction. The outer diameter of the positioning cylinder protrusion ring 14 is larger than the lateral width of the strip positioning hole 16.

[0016] To facilitate the installation of the core assembly positioning seat 3 and enable it to perform initial position locating and subsequent position fine-tuning, the core assembly positioning seat 3 is an "L"-shaped seat with two vertically penetrating positioning pin holes 4 and two vertically penetrating mounting through holes 5 on its horizontal plate. The base 2 has two vertical positioning blind holes (not visible in the figure) and two vertical mounting screw holes (not visible in the figure) on its upper surface. The lower ends of the two positioning pins (not shown in the figure, but easy to understand) corresponding to each core assembly positioning seat 3 pass through the two positioning pin holes 4 and are placed in the two positioning blind holes. The lower ends of the studs of the two mounting screws (not shown in the figure, but easy to understand) corresponding to each core group positioning seat 3 pass through the two mounting through holes 5 and are connected to the two mounting screw holes. The diameter of the mounting through hole 5 is larger than the diameter of the stud of the mounting screw, and the diameter of the nut of the mounting screw is larger than the diameter of the mounting through hole 5. The above structure uses the gap between the stud of the mounting screw and the hole wall of the mounting through hole 5 to realize the position fine adjustment function. Alternatively, the mounting through hole 5 can be designed as a strip through hole, which can realize a wider range of position adjustment functions.

[0017] To prevent the lead wire positioning post 13 from falling off, the outer diameter of the upper end of the lead wire positioning post 13 is increased to form a positioning post baffle 11, and the central through hole 12 of the lead wire positioning post 13 passes through the positioning post baffle 11. The outer diameter of the positioning post baffle 11 is greater than the lateral width of the strip positioning hole 16.

[0018] Figure 1 , Figure 2 and Figure 5 The image also shows handles 1 located at both ends of the base 2, which are conventional and adaptable structures.

[0019] like Figures 1-5As shown, in application, first place the core group 18 of the mica paper capacitor vertically in the core group mounting area on the base 2, then move the four core group positioning seats 3 appropriately to move them closer to the center position until the eight positioning pin holes 4 are aligned with the eight positioning blind holes on the base 2. Then insert the eight positioning pins into the eight positioning pin holes 4 and the eight positioning blind holes on the base 2 respectively. At this time, the initial position of the four core group positioning seats 3 is found. Then, the studs of the eight mounting screws pass through the eight mounting through holes 5 from top to bottom and connect with the eight mounting screw holes on the base 2 to achieve the fixed clamping of the core group 18. Then, the four lead positioning blocks 7 are installed at the four upper corners of the core assembly 18, so that the groove wall of each positioning block 10 fits tightly with the corresponding upper outer wall of the core assembly 18. Then, the four connecting screws 8 are tightened. During this process, the lead positioning post 13, the stud of the connecting screw 8 and the positioning cylinder 1 move adaptively in the corresponding strip positioning hole 16, so as to achieve the purpose of placing the lead positioning post 13 in the center position above the core assembly 18. Then, the lead 17 is passed through the central through hole 12 of the lead positioning post 13 and placed in the corresponding hole at the upper end of the core assembly 18. The lead 17 and the lead-out piece of the core assembly 18 are welded with a welding gun. After the welding is completed, the connecting screws 8 and the mounting screws are loosened, the core assembly 18 is removed and inverted so that the welded lead 17 is inserted into the lead through hole 6 on the base 2. The above process is repeated to complete the welding of the lead 17 at the other end of the core assembly 18.

[0020] If the core group 18 of the lead wire 17 needs to be larger or smaller, the specific value of the size change can be calculated first, and then a high-precision measuring tool such as a vernier caliper can be used to measure the distance that each core group positioning seat 3 needs to move relative to the initial position (a scale line can also be set on the upper surface of the base 2 to replace the on-site measurement work). After moving the four core group positioning seats 3 to the center position or the outer periphery by the same distance, they are locked. This can achieve the function of fixing the core group 18 of different sizes. Other operation processes are the same as above and will not be described in detail here.

[0021] The above embodiments are merely preferred embodiments of this utility model and are not intended to limit the technical solutions of this utility model. Any technical solution that can be implemented based on the above embodiments without creative effort should be considered to fall within the scope of protection of this utility model patent.

Claims

1. A positioning fixture for soldering leads of mica paper capacitors, comprising a base with a transversely planar upper surface, characterized in that: It also includes a core assembly positioning seat, a lead wire positioning block, a cross link, and a lead wire positioning post. The four core assembly positioning seats are respectively mounted on the base and enclose a horizontally rectangular core assembly mounting area. The vertical surface of each core assembly positioning seat near the core assembly mounting area is flat. A vertical lead wire through-hole is provided at the center of the core assembly mounting area on the top of the base. The lower outer wall of each lead wire positioning block has a positioning slot that is vertical in length and extends to the lower surface. The horizontal cross-section of the positioning slot is "L". The four lead wire positioning blocks are located at the four core assembly positioning posts. Above the base, the horizontally connected crossbars are provided with vertically penetrating strip-shaped positioning holes with the same length direction as the crossbars. The two ends of the two crossbars are respectively connected to the upper ends of the four lead wire positioning blocks by connecting screws, and the studs of the connecting screws pass through the strip-shaped positioning holes of the corresponding crossbars. The middle parts of the two crossbars intersect each other, and one crossbar is located above the other crossbar. The vertical and cylindrical lead wire positioning post passes through the middle section of the strip-shaped positioning holes of the two crossbars. The lead wire positioning post is provided with a vertical central through hole.

2. The positioning fixture for welding leads of mica paper capacitors according to claim 1, characterized in that: The upper end of the lead positioning block is provided with a positioning block screw hole. The stud of the connecting screw passes through the central through hole of the vertical positioning cylinder and connects to the corresponding positioning block screw hole. The positioning cylinder passes through the corresponding strip positioning hole. The outer circumferential wall of the positioning cylinder has one or two positioning cylinder protrusions that protrude outward in the circumferential direction. The outer diameter of the positioning cylinder protrusion is larger than the lateral width of the strip positioning hole.

3. The positioning fixture for welding leads of mica paper capacitors according to claim 1, characterized in that: The core assembly positioning seat is an "L" shaped seat with two vertically penetrating positioning pin holes and two vertically penetrating mounting through holes on its horizontal plate. The top of the base has two vertically locating blind holes and two vertically locating screw holes. The lower ends of the two positioning pins corresponding to each core assembly positioning seat pass through the two positioning pin holes and are placed in the two positioning blind holes. The lower ends of the studs of the two mounting screws corresponding to each core assembly positioning seat pass through the two mounting through holes and are connected to the two mounting screw holes. The diameter of the mounting through hole is larger than the diameter of the stud of the mounting screw, and the diameter of the nut of the mounting screw is larger than the diameter of the mounting through hole.

4. The positioning fixture for welding leads of mica paper capacitors according to any one of claims 1-3, characterized in that: The outer diameter of the upper end of the lead positioning post is increased to form a positioning post baffle, and the central through hole of the lead positioning post passes through the positioning post baffle. The outer diameter of the positioning post baffle is larger than the lateral width of the strip positioning hole.

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