Pulse-assisted metal brazing tool and process based on copper bar interface

Abstract

The invention discloses a pulse-assisted metal brazing tool and process based on a copper bar interface, a horizontal bearing surface is formed on the upper surface where a tool body is located, the horizontal bearing surface is used for bearing a copper bar interface product piece, and locking surfaces protrude upwards from the two sides of the horizontal bearing surface, so that the copper bar interface product piece can be locked. The two groups of locking surfaces clamp the two sides of the copper bar interface product piece; a locking piece is arranged at the rear end part where the tool body is located, so that the locking piece is integrally located between the panels where the two sides of the tool body are located. According to the method, the non-linear relation model between the pulse frequency and the brazing filler metal feeding speed is matched, continuity in the whole welding process is guaranteed, and the method has good mechanical strength and corrosion resistance and can be used for connection of various metal materials, especially materials difficult to weld.

Description

Technical Field

[0001] The present invention belongs to the technical field of brazing devices, and particularly relates to a pulse-assisted metal brazing process based on a copper bus interface. Background Art

[0002] With the rapid development of power electronics and new energy technologies, as an important component for electrical connection, the welding quality of copper buses directly affects the performance and reliability of electrical equipment. Traditional welding methods have many deficiencies in the welding process of copper bus interfaces, such as insufficient welding strength, poor welding uniformity, and material deformation caused by excessive heat input. Therefore, it is particularly important to develop an efficient and stable welding process.

[0003] Challenges in Welding Copper Bus Interfaces

[0004] The main challenges in welding copper bus interfaces include:

[0005] Insufficient welding strength: Traditional welding methods are prone to causing insufficient strength of the welded joint. Especially under high-load conditions, it may lead to joint failure.

[0006] Large heat-affected zone: The high temperature generated during the welding process will affect the metal structure of the welding area, resulting in a decline in material properties.

[0007] Unstable clamping: During the welding process, unstable clamping of the copper bus interface product parts may cause the welding position to shift, affecting the welding effect.

[0008] Application of Pulse-Assisted Welding Technology

[0009] The pulse-assisted welding technology realizes more precise heat control during the welding process by adjusting the welding current and welding frequency. This method can effectively reduce the heat input during the welding process, thereby reducing the heat-affected zone and improving the performance of the welded joint.

[0010] Improve welding quality: The pulse welding technology can achieve a more uniform heat distribution, improving the strength and toughness of the welded joint.

[0011] Strong adaptability: By adjusting the pulse frequency and wire feeding speed, it can flexibly cope with different materials and welding requirements.

[0012] Importance of Fixture Design

[0013] During the welding process, the design of the fixture has a crucial impact on the welding quality and efficiency. Good fixture design can ensure the stability and clamping effect of the product parts during the welding process, thereby improving the accuracy and consistency of welding.

[0014] Stability: Through a reasonable clamping structure, ensure that the position of the copper bus interface does not shift during the welding process.

[0015] Compactness: The tooling structure is designed to be compact, facilitating operation in narrow spaces and meeting the requirements of modern production.

[0016] Deficiencies of the prior art

[0017] Although there are already various welding toolings on the market at present, most of them still have the following deficiencies:

[0018] Poor adaptability: Existing toolings often can only be applicable to specific welding tasks and lack flexibility.

[0019] Complex operation: Some tooling designs are complex and difficult to operate, increasing production costs and time.

[0020] Unstable welding effect: Due to uneven clamping or improper control of heat input, the welding effect is often unstable. Summary of the invention

[0021] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a metal brazing device and process based on the workpiece notch, which solves the above technical problems existing in the prior art.

[0022] The purpose of the present invention can be achieved through the following technical solutions:

[0023] A pulse-assisted metal brazing tooling based on a copper busbar interface, comprising a tooling body and a locking member.

[0024] The upper surface where the tooling body is located forms a horizontal bearing surface, which is used to bear the copper busbar interface product through the horizontal bearing surface, and locking surfaces protrude upward on both sides of the horizontal bearing surface, so that the two groups of locking surfaces form clamping on both sides of the copper busbar interface product.

[0025] A locking member is arranged at the rear end where the tooling body is located, so that the whole locking member is located between the panels on both sides of the tooling body.

[0026] The locking member includes a driving rod, a locking surface, and a fixing frame. A limiter is arranged at the output end of the driving rod, and the limiter is located on the horizontally arranged fixing frame. An activity groove is horizontally arranged on the upper surface of the fixing frame, and barriers extend upward on both sides of the fixing frame. An activity spring member is arranged in the activity groove, and one end of the activity spring member is fixed in the activity groove, and the other end is fixed to the bottom of an L-shaped activity block embedded in the activity groove. The bottom of the L-shaped activity block is embedded in the activity groove and moves along the extension direction of the activity groove. Under the forward and backward pushing of the limiter, contact extrusion between the limiter and the L-shaped activity block is formed, and a movement change of the L-shaped activity block in the left and right directions is formed. The relatively inner sides of the two groups of L-shaped activity blocks form a locking surface, and clamping on both sides of the copper busbar interface product is formed through the locking surface.

[0027] Further, the horizontal bearing surface is composed of a plurality of positioning rods arranged horizontally, and the upper surfaces of multiple groups of positioning rods form the bearing for the copper busbar interface product parts.

[0028] Further, the limiter as a whole presents a tapered structure that is narrow in the front and wide in the rear, and a fixed block is provided at the front end where the limiter is located.

[0029] Further, a movable pressure roller is provided at the front end where the L-shaped movable block is located, so that when the limiter is pushed forward and backward, the movable pressure roller is in close contact with the side of the limiter and rolls.

[0030] The process of the pulse-assisted metal brazing tooling based on the copper busbar interface includes the following steps:

[0031] S1. First, sandblast or polish the position where the copper busbar interface product part is located to expose its surface;

[0032] S2. Preheat the copper busbar interface to 150°C to 300°C, and then transfer it to the horizontal bearing surface of the tooling body;

[0033] S3. Prepare a pulse welding machine, and use a locking part to clamp the copper busbar interface product part on the horizontal bearing surface from the side, and make the pulse welding machine cover each group of copper busbar interface product parts;

[0034] S4. Cover the upper surface of the copper busbar interface product part with a filler metal, and simultaneously turn on the pulse welding machine, so that the pulse frequency f Db and the filler metal feeding speed v Db are in a non-linear relationship model, as shown in the following formula:

[0035] v Db = a·f Db 2 + k·f Db + b

[0036] where: v Db is the filler metal feeding speed;

[0037] f Db is the pulse frequency;

[0038] a is the coefficient of the quadratic term, indicating the non-linear influence of the pulse frequency on the wire feeding speed;

[0039] k is the proportionality constant, indicating the influence degree of the pulse frequency on the wire feeding speed;

[0040] b is the constant term, indicating the wire feeding speed when the pulse frequency is zero;

[0041] After welding is completed, natural cooling is carried out.

[0042] Further, in S1, sandblasting or grinding treatment is carried out, and the surface roughness of the copper busbar interface product after sandblasting or grinding treatment is Ra3.2 - 5.5.

[0043] Further, the filler metal is a flux-cored wire with a diameter of 0.8mm - 1.0mm.

[0044] Further, the pulse frequency f Db is 13 - 17kHz.

[0045] Further, the copper busbar interface product after welding is cleaned and synchronously ultrasonically detected.

[0046] Advantages of the present invention:

[0047] 1. The brazing tooling adopted in the present invention can maintain the stability of the copper busbar interface product during the welding process, preventing displacement caused by thermal expansion or welding stress. This stability is of great significance for improving the welding quality and reducing the rework rate.

[0048] 2. The design of rapid assembly of the brazing tooling adopted in the present invention also enables the operator to quickly adjust and fix the workpiece during actual use, improving work efficiency and reducing production costs.

[0049] 3. The contact extrusion method of driving the L-shaped movable block by the driving rod adopted in the present invention can change the original linear motion mode to the movement of the L-shaped movable block in the left and right directions, greatly improving the utilization rate of the small size of the product.

[0050] 4. The pulse-assisted metal brazing process adopted in the present invention can effectively improve the welding quality and firmness of the copper busbar interface, and can flexibly adjust parameters during the welding process to adapt to different welding requirements. Description of the Drawings

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art.

[0052] Figure 1 is a schematic side structure diagram of the overall tooling in the embodiment of the present invention;

[0053] Figure 2 is a schematic top view structure diagram of the overall tooling in the embodiment of the present invention;

[0054] Figure 3 is a schematic overall structure diagram of the locking part of the tooling in the embodiment of the present invention;

[0055] Figure 4is a partial structural schematic diagram of part A of the embodiment of the present invention Figure 3 ;

[0056] Figure 5 is a front cross-sectional structural schematic diagram of the locking member of the embodiment of the present invention

[0057] Figure 6 is a structural schematic diagram of the limiter of the embodiment of the present invention

[0058] Figure 7 is a structural schematic diagram of the L-shaped movable block of the embodiment of the present invention

[0059] Figure 8 is a process flow schematic diagram of the brazing tooling of the embodiment of the present invention Detailed implementation manners

[0060] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present invention

[0061] As Figure 1 , Figure 2 shown, the embodiment of the present invention provides a pulse-assisted metal brazing tooling based on a copper bus interface, including a tooling body 1 and a locking member 2

[0062] A horizontal bearing surface 101 is formed on the upper surface where the tooling body 1 is located. The copper bus interface product parts are carried through the horizontal bearing surface 101, and locking surfaces 11 protrude upward on both sides of the horizontal bearing surface 101, so that the two groups of locking surfaces 11 clamp both sides of the copper bus interface product parts; it can achieve the stability of the copper bus interface product parts during the welding process. The horizontal bearing surface 101 is composed of a plurality of laterally arranged positioning rods 12, and the upper surfaces of multiple groups of positioning rods 12 form the bearing of the copper bus interface product parts. This structural design method can meet the rapid assembly of the equipment during use, and at the same time ensure the uniformity and stability of the bearing

[0063] As Figure 3 shown, the locking member 2 is arranged at the rear end where the tooling body 1 is located, and is integrally configured between the panels on both sides of the tooling body 1 to form a compact structure. Such a design helps to reduce the overall volume of the tooling and is convenient for operation in a narrow space. The locking member 2 is integrally located between the panels on both sides of the tooling body 1

[0064] As Figure 3 , Figure 4 , Figure 5As shown in the figure, the locking member 2 includes a driving rod 21, a locking surface 11, and a fixing bracket 22. A stopper 211 is provided at the output end where the driving rod 21 is located, and the stopper 211 is located on the horizontally arranged fixing bracket 22. A movable groove 221 is horizontally arranged along the upper surface of the fixing bracket 22. Barriers are formed by extending upward on both sides of the fixing bracket 22. A movable spring member 222 is arranged in the movable groove 221, and one end of the movable spring member 222 is fixed in the movable groove 221, and the other end is fixed to the bottom of an L-shaped movable block 223 embedded in the movable groove 221, so that the bottom of the L-shaped movable block 223 is embedded in the movable groove 221 and moves along the extending direction of the movable groove 221. The existence of the movable spring member 222 not only provides elastic support but also can absorb a certain impact force during the clamping process to prevent damage. Under the forward and backward pushing of the stopper 211, contact extrusion between the stopper 211 and the L-shaped movable block 223 is formed, and a movement change of the L-shaped movable block 223 in the left-right direction is formed. The relatively inner sides of the two groups of L-shaped movable blocks 223 form the locking surface 11, and the two sides of the copper busbar interface product part are clamped through the locking surface 11.

[0065] As Figure 6 shown, the stopper 211 as a whole presents a tapered structure that is narrow at the front and wide at the back, and a fixed block 2111 is provided at the front end where the stopper 211 is located. This shape helps self-aligning during locking to ensure the clamping effect. That is, when the stopper 211 contracts, at this time, the L-shaped movable block 223 is compressed inward under the action of the movable spring member 222, so as to realize the clamping of the upper locking surface 11 on the copper busbar interface product part. When the stopper 211 is pushed forward, at this time, the L-shaped movable block 223 is squeezed by the stopper 211 to both sides, so that the two groups of locking surfaces 11 are separated outward, achieving the purpose of relaxation, thus facilitating loading and unloading.

[0066] As Figure 4 、 Figure 7 shown, a movable pressure roller 2231 is provided at the front end where the L-shaped movable block 223 is located, so that when the stopper 211 is pushed forward and backward, the movable pressure roller 2231 is in close contact with and rolls along the side of the stopper 211. Specifically, after use, a movable pressure roller 2231 is provided at the front end of the L-shaped movable block 223, which can be in close contact with and roll along the side of the stopper 211 when the stopper 211 is pushed forward and backward. This design helps to reduce friction, improve the stability of clamping, and at the same time protect the surface of the copper busbar interface product part to avoid damage caused by clamping.

[0067] The pulse-assisted metal brazing tooling based on the copper busbar interface of the present invention provides good load-bearing, clamping and stability through the carefully designed tooling body, locking parts and their internal structures, greatly improving the efficiency and quality of the welding process. Future improvement directions can consider further optimization in material selection and automation level to meet more complex welding requirements.

[0068] As Figure 8 shown, the process of the pulse-assisted metal brazing tooling based on the copper busbar interface includes the following steps:

[0069] S1. First, sandblast or polish the position where the copper busbar interface product part is located to expose its surface; the surface roughness of the copper busbar interface product part after sandblasting or polishing is Ra3.2 - 5.5, which can make the contact surface between the surface of the copper busbar interface product part and the filler metal fit better, improving the overall firmness after brazing.

[0070] S2. Preheat the copper busbar interface to 150°C to 300°C to improve the subsequent welding effect, and then transfer it to the horizontal bearing surface 101 of the tooling body 1;

[0071] S3. Prepare the pulse welding machine, and form side clamping on the copper busbar interface product part located on the horizontal bearing surface 101 through the locking part 2, and make the pulse welding machine cover each group of copper busbar interface product parts;

[0072] S4. Cover the filler metal on the upper surface where the copper busbar interface product part is located, and simultaneously turn on the pulse welding machine, so that the pulse frequency f Db and the filler metal feeding speed v Db present a non-linear relationship model, and the pulse frequency is 13 - 17 kHz. As the following formula:

[0073] v Db = a·f Db 2 + k·f Db + b

[0074] where: v Db is the filler metal feeding speed;

[0075] f Db is the pulse frequency;

[0076] a is the coefficient of the quadratic term, representing the non-linear influence of the pulse frequency on the wire feeding speed;

[0077] k is the proportionality constant, representing the influence degree of the pulse frequency on the wire feeding speed;

[0078] b is the constant term, representing the wire feeding speed when the pulse frequency is zero.

[0079] By adjusting the pulse frequency, the feeding speed of the welding wire can be effectively controlled, the welding effect can be optimized, and the stability and consistency of the welding process can be ensured.

[0080] Hypothesis:

[0081] a = 0.1

[0082] k = 0.5

[0083] b = 2

[0084] We will calculate the feeding speed of the welding wire through different pulse frequency values and present the results (shown in Table 1 below).

[0085] Table 1

[0086]

[0087]

[0088] As can be seen from Table 1, as the pulse frequency f Db increases, the feeding speed v Db of the welding wire also increases. This further confirms the positive correlation between the pulse frequency and the feeding speed of the welding wire, indicating that during the welding process, by adjusting the pulse frequency, the feeding speed of the welding wire can be effectively controlled, thereby optimizing the welding effect.

[0089] And the filler metal used at this time is a flux-cored wire with a diameter of 0.8 mm to 1.0 mm.

[0090] The following Table 2 is a design table regarding the pulse frequency parameters and the corresponding welding wire, listing multiple embodiments and reflecting the functional characteristics of gas shielded welding.

[0091] Table 2

[0092]

[0093] As shown in Table 2, the flux-cored wire: filled with flux inside, suitable for specific welding applications, can provide better protection and welding quality. Using the flux-cored wire can provide better protection and welding quality, has strong adaptability, and the weld has better crack resistance.

[0094] S5. After welding is completed, natural cooling is carried out. Further, the copper busbar interface product parts after welding are cleaned and ultrasonic inspection is carried out synchronously.

[0095] Through this pulse-assisted metal brazing process, the welding quality and firmness of the copper busbar interface can be effectively improved, and the parameters can be flexibly adjusted during the welding process to meet different welding requirements.

[0096] The basic principles, main features and advantages of the present invention have been shown and described above. Those skilled in the art should understand that the present invention is not limited by the above embodiments, and what is described in the above embodiments and the specification only illustrates the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A pulse-assisted metal brazing tool based on a copper busbar interface, comprising a tool body (1), a locking member (2), and characterized in that: The upper surface of the tool body (1) forms a horizontal bearing surface (101), which is used to bear the copper busbar interface product, and locking surfaces (11) protrude upwards at both sides of the horizontal bearing surface (101), so that two groups of locking surfaces (11) clamp the two sides of the copper busbar interface product; A locking member (2) is provided at the rear end portion of the tool body (1), so that the locking member (2) is located as a whole between the panels located on both sides of the tool body (1); The locking member (2) comprises a driving rod (21), a locking surface (11), and a fixing frame (22); a stopper (211) is arranged at the output end where the driving rod (21) is located, and the stopper (211) is located on a transversely arranged fixing frame (22); a movable groove (221) is transversely arranged along the upper surface where the fixing frame (22) is located, and extends upward on both sides of the fixing frame (22) to form a barrier; a movable spring member (222) is arranged in the movable groove (221), and one end of the movable spring member (222) is fixed in the movable groove (221), and the other end is fixed to The bottom of the L-shaped movable block (223) is embedded in the movable groove (221), so that the bottom of the L-shaped movable block (223) is embedded in the movable groove (221) and moves along the extension direction of the movable groove (221). Under the forward and backward pushing action of the stopper (211), the stopper (211) and the L-shaped movable block (223) are contacted and squeezed, and the movement of the L-shaped movable block (223) in the left and right directions is changed. The opposite inner side surfaces of the two groups of L-shaped movable blocks (223) form locking surfaces (11), and the locking surfaces (11) are used to clamp the two sides of the copper busbar interface product.

2. The pulse-assisted metal brazing tool based on the copper busbar interface according to claim 1 is characterized in that: The horizontal bearing surface (101) is composed of a plurality of laterally arranged positioning rods (12), and the upper surfaces of the plurality of groups of positioning rods (12) are used to support the copper busbar interface product.

3. The pulse-assisted metal brazing tool based on the copper busbar interface according to claim 1 is characterized in that: The stopper (211) as a whole presents a conical structure that is narrow at the front and wide at the rear, and a fixing block (2111) is arranged at the front end where the stopper (211) is located.

4. The pulse-assisted metal brazing tool based on the copper busbar interface according to claim 1 is characterized in that: A movable pressure roller (2231) is provided at the front end portion of the L-shaped movable block (223), so that when the stopper (211) is pushed forward and backward, the movable pressure roller (2231) and the side of the stopper (211) are attached to each other and roll.

5. The process of pulse-assisted metal brazing tooling based on copper busbar interface according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. First, sandblast or polish the copper busbar interface product to expose its surface; S2, preheating the copper busbar interface at 150° C. to 300° C., and then transferring it to the horizontal bearing surface (101) of the tooling body (1); S3, preparing a pulse welding machine, using a locking member (2) to clamp the copper busbar interface product pieces located on the horizontal bearing surface (101) on the side, and allowing the pulse welding machine to cover each group of copper busbar interface product pieces; S4, cover the upper surface of the copper busbar interface product with solder, and simultaneously turn on the pulse welding machine to make the pulse frequency f Db and solder feed speed v Db The nonlinear relationship model between them is as follows: v Db =a·f Db 2 +k·f Db +b Where: v Db is the solder feed speed; f Db is the pulse frequency; a is the coefficient of the quadratic term, which represents the nonlinear effect of pulse frequency on wire feed speed; k is a proportional constant, which indicates the influence of pulse frequency on wire feed speed; b is a constant term, which represents the wire feed speed when the pulse frequency is zero; S5. After welding is completed, allow to cool naturally.

6. The process of pulse-assisted metal brazing tooling based on copper busbar interface according to claim 5 is characterized in that: In S1, sandblasting or grinding is performed, and the surface roughness of the copper busbar interface product after sandblasting or grinding is Ra3.2-5.

5.

7. The process of pulse-assisted metal brazing tooling based on copper busbar interface according to claim 5 is characterized in that: The brazing material is flux-cored welding wire with a diameter of 0.8 mm to 1.0 mm.

8. The process of pulse-assisted metal brazing tooling based on copper busbar interface according to claim 5 is characterized in that: The pulse frequency f Db It is 13-17kHz.

9. The process of pulse-assisted metal brazing tooling based on copper busbar interface according to claim 5 is characterized in that: The copper busbar interface products are cleaned after welding and ultrasonically inspected simultaneously.

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