Soldering process for threaded springs with pins

Abstract

This invention discloses a welding process for pinned helical springs, relating to the field of spring processing technology. The technical solution of this invention develops a welding process for pinned helical springs based on a designed welding fixture. By utilizing the annular and strip grooves and guide structures on the base surface of the welding fixture, the semi-finished pinned helical spring can be easily fixed to the fixture base and facilitate further welding, thereby ensuring the stability and efficiency of the welding process. This maintains a high level of production quality and efficiency for pinned helical springs.

Description

Technical Field

[0001] This invention relates to the field of spring processing technology, and in particular to a welding process for a pinned helical spring. Background Technology

[0002] In implantable cardiac pacemakers, a ring-shaped knurled spring is typically used as the electrical contact to achieve a stable electrical connection between the pulse generator and the electrode leads. The knurled spring, through its radial elastic deformation, fits tightly against the wall of the annular central hole of the electrical connector, thus adapting to the size of the central hole and ensuring installation stability.

[0003] A helical spring consists of a spring body, a first lead, and a second lead. The spring body is made of wound metal wire, forming a spiral structure that extends in an arc. The two leads are connected to the two ends of the spring body to achieve electrical connection with the pacemaker circuit. Helical springs directly manufactured by spring processing equipment include... Figure 1 As shown, the two pins are in a separated state; in the existing processing procedure, a technician operates under a microscope, using clamps such as tweezers to clamp and align the two pins and form the spring body into a ring structure, and then welds the two pins together to form a ring structure. Figure 2 The helical spring shown is an example; however, during the welding process, due to the extremely small size of the spring and the lack of auxiliary support fixtures and reasonable operating procedures, the welding efficiency is low and the welding quality is unstable. Summary of the Invention

[0004] The main objective of this invention is to develop a welding process for pinned threaded springs, aiming to create an efficient welding process that can both ensure the connection strength between the pins and the spring body and significantly improve the welding efficiency and quality of pinned threaded springs.

[0005] To achieve the above objectives, this invention proposes a welding process for a pinned threaded spring, comprising the following steps: S1. Use a clamp to pick up the helical spring and move it above the base of the welding fixture, aligning the bearing surfaces of the helical spring and the base; embed the spring body of the helical spring into the annular groove of the base of the welding fixture and embed the two pins into the strip groove of the base, and fix the helical spring to the base; S2. The mating portion of the two pins forms a welding area. A welding torch is used to weld at least three points in the welding area to complete the welding.

[0006] In one embodiment, aligning the helical spring and the base in step S1 includes the following steps: Align the connection point of the spring body and one pin of the helical spring with the junction point of the annular groove and the strip groove on the bearing surface of the base.

[0007] In one embodiment, in step S1, after aligning the helical spring and the base, one pin of the helical spring is placed into the strip groove, and then the spring body is pressed to make it fall into the annular groove and elastically close. The other pin is pressed into the strip groove, and the helical spring is fixed to the base.

[0008] In one embodiment, in step S1, after aligning the helical spring and the base, press the pin to embed it into the strip groove, press the spring body along the same direction of the annular groove of the base to gradually embed it into the annular groove and elastically close it; after closing, the other pin stays at the joint point and is in an upward tilted state, press it to embed it into the strip groove, and the helical spring is fixed to the base.

[0009] In one embodiment, in step S2, the spacing between adjacent sites is 1.4 mm to 1.8 mm.

[0010] In one embodiment, the welding fixture further includes a guide mechanism detachably disposed on the bearing surface of the base.

[0011] In one embodiment, aligning the helical spring and the base in step S1 includes the following steps: Use a clamp to hold the helical spring so that the two pins are close together and aligned. Then, hold the helical spring so that the ends of the two pins closest to the spring body are inserted into the notch of the guide mechanism and the spring body is in contact with the inner wall of the guide mechanism.

[0012] In a more specific embodiment, in step S1, after aligning the helical spring and the base, a downward pressure and a pulling force along the pin direction are applied to the spring body, so that the helical spring maintains a horizontal posture and slides downward along the inner wall of the guide mechanism until the spring body of the helical spring is embedded in the annular groove of the base and the two pins of the helical spring are embedded in the strip groove of the base.

[0013] The technical solution in this invention develops a welding process for leaded helical springs based on the designed welding fixture for helical springs. By utilizing the annular groove, strip groove, and guide structure on the base surface of the welding fixture, the semi-finished product of the leaded helical spring can be easily fixed to the fixture base and facilitate further welding, thereby ensuring the stability and efficiency of the welding process, and thus maintaining the production quality and efficiency of leaded helical springs at a high level. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of a twisted spring in its unfolded state. Figure 2 A schematic diagram of a twisted spring in its closed state; Figure 3 This is a schematic diagram of the base in a welding fixture. Figure 4 for Figure 3 A magnified view of a section at point A in the middle; Figure 5 This is a schematic diagram of the structure of an embodiment of the welding fixture provided by the present invention; Figure 6 This is a structural diagram of a portion of the welding fixture; Figure 7 This is a schematic diagram of the guiding mechanism in a welding fixture. Figure 8 for Figure 7 A magnified view of a section at point B.

[0016] Explanation of icon numbers: 100. Welding fixture; 1. Base; 11. Annular groove; 12. Strip groove; 13. Bearing surface; 2. Guide mechanism; 21. Guide component; 211. Guide hole; 212. Notch; 2121. Flared structure; 213. Movable hole; 22. Limiting rod; 200. Twill spring; 201. Spring body; 202. First pin; 203. Second pin.

[0017] The realization of the objectives, functional features, and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indicators will also change accordingly.

[0020] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0021] The technical problem solved by this application is that in implantable cardiac pacemakers, threaded springs are typically used as electrical contacts to achieve stable electrical connections. The threaded spring is installed in the central hole of the electrical connector, utilizing its radial elastic deformation capability to form a tight abutment with the hole wall, thereby adapting to central holes of different sizes and ensuring the reliability of the electrical connection.

[0022] To achieve the above functions, the shear spring 200 needs to be processed from its unfolded state into a closed ring structure. For example... Figure 1 As shown, the helical spring 200, produced by specialized spring processing equipment, includes a spring body 201, a first pin 202, and a second pin 203. The spring body 201 is helical and has an overall arc-shaped structure. The two pins are connected to the two ends of the spring body 201, respectively. After the two ends of the spring body 201 are brought close together and wound into a ring, the two pins need to be soldered together for electrical connection with the pacemaker circuit.

[0023] In existing technologies, technicians typically operate under a microscope, using clamping mechanisms such as tweezers to clamp and align the two pins, forming a ring structure in the spring body 201. Subsequently, welding tools are used to weld the two pins together, forming a ring structure. Figure 2 The closed-loop helical spring 200 is shown. However, during the welding process, the welding tool applies pressure to the two pins from one side. Due to the lack of a corresponding support fixture on the other side, the two pins are suspended in the air and are prone to shaking, resulting in unstable welding quality and making it difficult to guarantee the welding quality and efficiency of the product.

[0024] It should be noted that the helical spring in this invention is extremely small, with the inner diameter of the circle formed by winding the spring body being only about 2 mm and the length of the pin being only about 3 mm. In related technologies, a clamp is directly used to clamp the two pins together for welding. However, due to the small size and smooth surface of the helical spring, it is extremely easy for it to slip off the clamp or deform, resulting in reduced welding quality and welding efficiency.

[0025] To address the aforementioned problems, this invention proposes a welding process for a threaded spring with leads, comprising the following steps: S1. Use a clamp to pick up the helical spring 200 and move it above the base 1 of the welding fixture 100, aligning the helical spring 200 and the bearing surface 13 of the base 1; embed the spring body 201 of the helical spring 200 into the annular groove 11 of the base 1 of the welding fixture 100 and embed the two pins into the strip groove 12 of the base 1, and fix the helical spring 200 to the base 1; S2. The mating portion of the two pins forms a welding area. A welding torch is used to weld at least three points in the welding area to complete the welding.

[0026] Specifically, refer to Figure 1 The welding fixture 100 includes a base 1. The surface of the base 1 has an intersecting annular groove 11 and a strip groove 12. The annular groove 11 accommodates the spring body 201, and the strip groove 12 limits and supports the welding areas of the first pin 202 and the second pin 203. Specifically, a protrusion is provided at the center of the annular groove 11, forming an annular gap between the protrusion and the groove wall of the annular groove 11. This annular gap accommodates the spring body 201. The outer periphery of the protrusion matches the inner ring profile of the spring body 201, providing radial limiting support for the inner ring of the spring body 201. Through the interaction between the protrusion and the groove wall, the spring body 201 is limited both internally and externally within the annular gap. When the first pin 202 and the second pin 203 are accommodated in the strip groove 12, the spring body 201 abuts within the annular groove 11 to form a closed ring.

[0027] It should also be noted that, due to the diagonal pattern of the helical spring 200, the spring body 201 has a certain elastic deformation capacity in the radial direction. When there is a slight deviation between the size of the spring body 201 and the annular gap, the spring body 201 can adjust through the elastic deformation of the helical structure to adapt to the size of the annular gap, thereby ensuring stability during installation and welding.

[0028] In one specific embodiment, the inner diameter of the closed ring formed by the spring body 201 within the annular groove 11 is 1.5mm to 2.5mm.

[0029] In one embodiment, reference is made to Figure 4 The depth of the annular groove 11 is greater than the depth of the strip groove 12. It should be noted that the connection point of the first pin 202 and the second pin 203 at the spring body 201 is located near the center of the cross-section of the spring body 201; therefore, the height of the first pin 202 and the second pin 203 is higher than the bottom surface of the spring body 201. Correspondingly, when the first pin 202 and the second pin 203 are supported on the bottom wall of the strip groove 12, the spring body 201 is supported on the bottom wall of the annular groove 11, thereby making the herringbone spring 200 more stable after being fixed to the base 100 and facilitating welding.

[0030] Specifically, in step S1, the first pin 202 and the spring body 201 are sequentially embedded into the strip groove 12 and the annular groove 11, and finally the second pin 203 is pressed to embed into the strip groove 12, thereby fixing the herringbone spring 200 and further improving welding quality and efficiency. It should also be noted that the order of operations for the first pin 202 and the second pin 203 in step S1 can be interchanged.

[0031] In a preferred embodiment, in step S1, after the helical spring 200 is fixed on the base 100, a clamp such as tweezers is used to make the first pin 202 and the second pin 203 horizontally fit and align in the strip groove 12 so that the welding point is facing the welding operator, which facilitates welding.

[0032] Specifically, the two pins can be directly pressed into the slot 12. The total width of the first pin 202 and the second pin 203 after they are attached matches the width of the slot 12. The opposite side walls of the slot 12 form a clamping limit on the first pin 202 and the second pin 203, keeping them fixed during the soldering process. Alternatively, a clamp such as tweezers can be used for auxiliary adjustment. The slot 12 needs to provide additional space to accommodate the clamp. In this case, the width of the slot 12 is slightly larger than the total width of the first pin 202 and the second pin 203 after they are attached, so that the clamping mechanism can extend into the slot 12 for operation.

[0033] In one embodiment, the sidewall of the strip 12 can be configured as a vertical wall or a slightly outward-sloping wall, so that the first pin 202 and the second pin 203 or the clamping mechanism can extend into it.

[0034] In one embodiment, reference is made to Figure 3 and Figure 4 The strip groove 12 includes two, and the two strip grooves 12 are symmetrically distributed with respect to the center of the annular groove 11, and are located on opposite sides of the annular groove 11 respectively.

[0035] Optionally, the number of strip slots 12 can be further increased to meet usage requirements. For example, four strip slots 12 can be provided, with an included angle of 90 degrees between two adjacent strip slots 12. Alternatively, three strip slots 12 can be provided, with an included angle of 120 degrees between two adjacent strip slots 12.

[0036] In one embodiment, aligning the helical spring and the base in step S1 includes the following steps: Align the connection point of the spring body 201 and the pin of the helical spring 200 with the junction point of the annular groove 11 and the strip groove 12 of the bearing surface 13 of the base 1.

[0037] Further, in step S1, during the alignment of the helical spring 200 and the base 1, the connection point of the spring body 201 and a pin of the helical spring 200 is aligned with the junction point of the annular groove 11 and the strip groove 12 of the bearing surface 13 of the base 1, and the pin is aligned with the strip groove 12 to complete the alignment operation of the helical spring 200 and the base 1.

[0038] Further, in one embodiment, in step S1, after aligning the helical spring 200 and the base 1, the pin is pressed to embed it into the strip groove 12, then the spring body 201 is pressed to fall into the annular groove 11 and elastically close, then the other pin is pressed to embed it into the strip groove 12, and the helical spring 200 is fixed to the base 1.

[0039] More specifically, in step S1, after aligning the helical spring 200 and the base 1, press the pin to embed it into the strip groove 12, press the spring body 201 along the same direction of the annular groove 11 of the base 1 to gradually embed it into the annular groove 11 and elastically close it; after closing, the other pin stays at the joint point and is in an upward tilted state, press it to embed it into the strip groove 12, and the helical spring 200 is fixed to the base 1.

[0040] It is understandable that the operation process in step S1 is relatively easy for operators to learn and master, and the shear spring 200 rarely falls off the welding fixture 100 during the fixing process, making it suitable for application on the production line.

[0041] In one embodiment, in step S2, the spacing between adjacent sites is 1.4 mm to 1.8 mm. It is understood that by further controlling the spacing between the soldering sites, a more stable connection can be achieved between the first and second pins after soldering.

[0042] In one embodiment, reference is made to Figure 5The welding fixture 100 also includes a guide mechanism 2, which is detachably disposed on the bearing surface 13 and has a guide channel communicating with the annular groove 11 and a notch 212 communicating with the guide channel. The guide channel is used to guide the spring body 201 into the annular groove 11, and the notch 212 is used to guide the first pin 202 and the second pin 203 into the strip groove 12.

[0043] Specifically, the guide mechanism 2 is detachably mounted on the bearing surface 13. Its internal guide channel is aligned and connected with the annular groove 11, forming the entry path of the spring body 201. The notch 212 is opened on the side wall of the guide mechanism 2, connected with the guide channel and aligned with the strip groove 12, to form the entry path of the first pin 202 and the second pin 203. The pressing mechanism acts on the spring body 201 from above, pushing the spring body 201 to move downward along the guide channel. During this process, the spring body 201 drives the first pin 202 and the second pin 203 at both ends to move synchronously. The first pin 202 and the second pin 203 slide into the strip groove 12 along the extension direction of the notch 212, realizing the synchronous positioning of the spring body 201 and the pins.

[0044] Optionally, the detachable connection between the guide mechanism 2 and the bearing surface 13 can be a bolt connection, a magnetic connection, or a snap-fit ​​connection, and the pressing mechanism can be a manual press rod, a pneumatic cylinder, or an electric push rod.

[0045] In one embodiment, please refer to Figure 5 and Figure 6 The guiding mechanism 2 includes a limiting rod 22 and a guide member 21. The limiting rod 22 protrudes from the bearing surface 13. The guide member 21 is sleeved on the limiting rod 22 and can move relative to the bearing surface 13 along the extension direction of the limiting rod 22. The guide member 21 has a guide hole 211 that penetrates the guide member 21, forming a guide channel. Specifically, the limiting rod 22 can be detachably connected to the base 1, for example, by bolt connection, magnetic connection, or snap-fit ​​connection. Alternatively, the limiting rod 22 can also be integrally formed with the base 1.

[0046] In one embodiment, the guide member 21 has a notch 212 on its sidewall, which communicates with a strip groove 12. The two sidewalls of the notch 212 are used to clamp the opposite sides of the first pin 202 and the second pin 203 after they are attached. It can be understood that the opposite sidewalls of the notch 212 can continuously provide lateral clamping during the movement of the first pin 202 and the second pin 203.

[0047] In a preferred embodiment, the limiting rod 22 includes two rods, which are disposed on opposite sides of the annular groove 11 along a first direction, and two strip grooves 12 are disposed on opposite sides of the annular groove 11 along a second direction. The first direction and the second direction are perpendicular to each other, ensuring that the notch 212 can always be aligned and connected with one of the strip grooves 12, regardless of whether the guide member 21 is installed at the current angle or rotated 180 degrees.

[0048] Optionally, in other embodiments, the angle between the first direction and the second direction can be set to 45 degrees, 60 degrees, or other angles. The number of limiting rods 22 and strip grooves 12 can be adjusted accordingly to ensure that once the guide member 21 is installed onto the limiting rod 22, the notch 212 will always be aligned and connected with one of the strip grooves 12. For example, when the angle between the first direction and the second direction is 45 degrees, four strip grooves 12 can be provided, with two grooves along the second direction and two along the direction perpendicular to the second direction. Simultaneously, four limiting rods 22 are provided, with two along the first direction and two along the direction perpendicular to the first direction. In this case, regardless of the angle at which the guide member 21 rotates, the notch 212 will still be aligned with one of the strip grooves 12 after installation. It should be noted that the length of the strip groove 12 and the distance between the limiting rods 22 need to be adjusted to avoid interference between the strip groove 12 and the limiting rod 22.

[0049] In one embodiment, reference is made to Figure 7 The guide hole 211 has its wall inclined relative to its axis, and the opening size of the end of the guide hole 211 facing the bearing surface 13 is smaller than the opening size of the end facing away from the bearing surface 13. It can be understood that the inclined wall of the guide hole 211 forms a tapered space that is wider at the top and narrower at the bottom. The external clamp simultaneously holds the ends of the first pin 202 and the second pin 203 away from the spring body 201 and applies downward pressure to the spring body 201, causing the connection point between the spring body 201 and the pin to abut against the wall of the guide hole 211. Simultaneously, the clamp applies a pulling force outward along the pin direction, ensuring that the connection point between the spring body 201 and the pin always abuts against the wall of the guide hole 211, forming a stable force balance state.

[0050] In a preferred embodiment, refer to Figure 8The flared structure 2121 is located at the entrance end of the notch 212, that is, the end facing away from the bearing surface 13. Its opening size gradually increases in the direction away from the bearing surface 13, forming a trumpet-shaped inlet section. By setting the flared structure 2121, when the first pin 202 and the second pin 203 move down with the spring body 201, even if there is a certain clamping deviation in the clamp, the flared structure 2121 can guide the first pin 202 and the second pin 203 through its tapering sidewalls, so that the first pin 202 and the second pin 203 gradually close and finally align.

[0051] In one embodiment, when the welding fixture 100 further includes a guide mechanism 2, the step of aligning the helical spring 200 and the base 1 in step S1 becomes: Use a clamp to hold the helical spring 200 so that the two pins are close to each other and aligned. Then, hold the helical spring 200 so that the ends of the two pins near the spring body 201 are inserted into the notch 212 of the guide mechanism 2 and the spring body 201 is in contact with the inner wall of the guide mechanism 2.

[0052] In a specific embodiment, in step S1, after aligning the helical spring 200 and the base 1, a downward pressure and a pulling force along the pin direction are applied to the spring body 201, so that the helical spring 200 maintains a horizontal posture and slides downward along the inner wall of the guide mechanism 2 until the spring body 201 of the helical spring 200 is embedded in the annular groove 11 of the base 1 and the two pins of the helical spring 200 are embedded in the strip groove 12 of the base 1.

[0053] In a more specific embodiment, in step S1, after aligning the helical spring 200 and the base 1, a pressing device is used to apply downward pressure to the spring body 201. Specifically, the pressing device can be a rod-shaped piece with a circular bottom surface, or a rod-shaped piece with a conical or spherical bottom surface, the bottom surface of which can cover the spring body 201. Using this pressing device makes it easier for operators to operate and the helical spring 200 is less likely to deform or slip during clamping. Moreover, compared with the first welding process, the welding process in this embodiment is more efficient, and the helical spring 200 is less likely to slip or deform during operation.

[0054] The above description is merely an exemplary embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A welding process for a threaded spring with leads, characterized in that, The welding process for the pinned threaded spring includes the following steps: S1. Use a clamp to pick up the helical spring and move it above the base of the welding fixture, aligning the bearing surfaces of the helical spring and the base; embed the spring body of the helical spring into the annular groove of the base of the welding fixture and embed the two pins into the strip groove of the base, and fix the helical spring to the base; S2. The mating portion of the two pins forms a welding area. A welding torch is used to weld at least three points in the welding area to complete the welding.

2. The welding process for the threaded spring with leads as described in claim 1, characterized in that, In step S1, aligning the helical spring and the base includes the following steps: Align the connection point of the spring body and one pin of the helical spring with the junction point of the annular groove and the strip groove on the bearing surface of the base.

3. The welding process for the pinned threaded spring as described in claim 1, characterized in that, In step S1, after aligning the helical spring and the base, one pin of the helical spring is placed into the strip groove, and then the spring body is pressed to make it fall into the annular groove and elastically close. The other pin is pressed into the strip groove, and the helical spring is fixed to the base.

4. The welding process for the pinned threaded spring as described in claim 1, characterized in that, In step S1, after aligning the helical spring and the base, press the pin to embed it into the strip groove, press the spring body along the same direction of the annular groove of the base to gradually embed it into the annular groove and elastically close it; after closing, the other pin stays at the joint point and is in an upward tilted state, press it to embed it into the strip groove, and the helical spring is fixed to the base.

5. The welding process for the pinned threaded spring as described in claim 1, characterized in that, In step S2, the spacing between adjacent sites is 1.4 mm to 1.8 mm.

6. The welding process for the pinned threaded spring as described in claim 1, characterized in that, The welding fixture also includes a guiding mechanism, which is detachably disposed on the bearing surface of the base.

7. The welding process for the pinned threaded spring as described in claim 6, characterized in that, In step S1, aligning the helical spring and the base includes the following steps: Use a clamp to hold the helical spring so that the two pins are close together and aligned. Then, hold the helical spring so that the ends of the two pins closest to the spring body are inserted into the notch of the guide mechanism and the spring body is in contact with the inner wall of the guide mechanism.

8. The welding process for the pinned threaded spring as described in claim 7, characterized in that, In step S1, after aligning the helical spring and the base, a downward pressure and a pulling force along the pin direction are applied to the spring body to keep the helical spring in a horizontal position and slide it downward along the inner wall of the guide mechanism until the spring body of the helical spring is embedded in the annular groove of the base and the two pins of the helical spring are embedded in the strip groove of the base.

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