Ultrasonic resistance welding electrode

Abstract

The utility model discloses an ultrasonic resistance welding electrode, which comprises an ultrasonic amplitude transformation mechanism, one end of the ultrasonic amplitude transformation mechanism directly contacts a workpiece to be welded or contacts the workpiece to be welded through an electrode cap, the other end of the ultrasonic amplitude transformation mechanism is directly connected with a transmitting transducer, or the other end of the ultrasonic amplitude transformation mechanism is connected with the transmitting transducer through a vibration transmission mechanism, or the other end of the ultrasonic amplitude transformation mechanism is connected with the transmitting transducer through an insulating material. The ultrasonic resistance welding electrode serves as both a carrier for transmitting ultrasonic waves to the workpiece to be welded and an electrode for loading resistance welding current. The position for applying ultrasonic waves to the workpiece to be welded and the position for inputting (or outputting) resistance welding current are the same position, the ultrasonic waves with specific amplitude and frequency can be well transmitted to the nugget position, the ultrasonic frequency and ultrasonic amplitude applied to the nugget can be accurately controlled, and thus the welding quality can be greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of welding technology. Specifically, it relates to an ultrasonic resistance welding electrode. Background Technology

[0002] In existing technologies, the resistance welding electrode and the amplitude transformer that transmits the ultrasonic waves generated by the transducer are separate components made of different materials. Ultrasonic resistance welding generally operates in two ways:

[0003] The first working method involves directly or indirectly mechanically connecting the amplitude transformer to the resistance welding electrode. This causes acoustic energy to be consumed by the resistance welding electrode, which not only fails to effectively transmit acoustic energy to the weld point, but also results in a significant difference between the ultrasonic frequency transmitted to the weld point and the ultrasonic frequency generated by the transmitting transducer. This makes it impossible to accurately control the ultrasonic frequency applied to the weld point. In other words, it cannot effectively transmit ultrasonic waves with specific amplitude and frequency to the weld nugget, and ultrasonic energy is more easily lost during propagation. Therefore, the applicable range of weldable workpieces is limited, and the welding quality needs to be improved.

[0004] The second working method involves directly transmitting ultrasonic waves to the workpiece using an amplitude transformer or vibrator, and electrically connecting the resistance welding electrode to the workpiece to provide the welding current. In this method, the amplitude transformer or vibrator and the resistance welding electrode are physically independent, and the contact areas between the amplitude transformer or vibrator and the workpiece are two completely different regions. Although this method results in less acoustic energy loss and the ultrasonic frequency transmitted to the workpiece is the same as or similar to the frequency generated by the transmitting transducer, thus expanding the range of workpieces suitable for welding compared to the first method, the improvement in welding quality is limited because the contact areas between the amplitude transformer or vibrator and the workpiece are two completely different regions. Typically, existing technologies employ a ring electrode with the acoustic electrode located at the center. This approach has the following drawbacks: electrode cooling is difficult, the overall structure is complex and not conducive to practical production applications, continuous welding is impossible without electrode cooling, and adhesion easily forms on the electrode head or cap (for example, when welding aluminum alloys with a copper electrode, copper-aluminum compounds are easily formed), affecting the electrode's lifespan; heat loss is significant, and energy utilization efficiency is low; furthermore, current needs to be transmitted to the ultrasonic position (the pressure application position), but the current flows through part of the workpiece when flowing to the welding area, making the weld nugget position uncertain. When the electrode pressure is high, the weld nugget may not be at the acoustic electrode position, and if the electrode is not pressed tightly enough, sparking may occur; if it is pressed too tightly, the current will not pass under the acoustic electrode, making it difficult to guarantee the welding position.

[0005] Some methods use a ring-shaped acoustic electrode with the electrode located at the center of the ring-shaped acoustic electrode. However, this method has the following disadvantages: the contact surfaces between the electrode and the acoustic electrode and the workpiece are two different contact surfaces. Ultrasonic waves cannot be transmitted to the weld nugget position more accurately, stably, or effectively. The overall structure is relatively complex and not conducive to practical production applications. It cannot effectively transmit ultrasonic waves with specific amplitude and frequency to the weld nugget position, and ultrasonic energy is more easily lost during the propagation process to the weld nugget.

[0006] In other words, the second working method in the prior art has limited improvement in welding quality because the contact area between the amplitude rod or oscillating rod and the workpiece to be welded and the contact area between the resistance welding electrode and the workpiece to be welded are two completely different areas in physical space. Utility Model Content

[0007] Therefore, the technical problem to be solved by this utility model is to provide an ultrasonic resistance welding electrode that serves as both an ultrasonic amplitude transformer for transmitting ultrasonic waves and an electrode for loading resistance welding current.

[0008] To solve the above-mentioned technical problems, this utility model provides the following technical solution:

[0009] An ultrasonic resistance welding electrode is composed of or constituted by an ultrasonic amplitude-modulating mechanism. One end of the ultrasonic amplitude-modulating mechanism is in direct contact with the workpiece to be welded or is in contact with the workpiece to be welded through an electrode cap. The other end of the ultrasonic amplitude-modulating mechanism is directly connected to the transmitting transducer, or the other end of the ultrasonic amplitude-modulating mechanism is connected to the transmitting transducer through a vibration transmission mechanism, or the other end of the ultrasonic amplitude-modulating mechanism is connected to the transmitting transducer through an insulating material. The ultrasonic amplitude-modulating mechanism serves both as a carrier for transmitting ultrasonic waves to the workpiece to be welded and as an electrode load for inputting or outputting resistance welding current to the workpiece to be welded.

[0010] The ultrasonic resistance welding electrode and the node of the ultrasonic amplitude transformer are the electrical connection points for resistance welding current input or resistance welding current output.

[0011] The acoustic impedance of the ultrasonic resistance welding electrode and the ultrasonic amplitude-changing mechanism is 1.00 × 10⁻⁶. 7 -11.00×10 7 kg / (m 2 ·s), with an elastic modulus of 60-360 GPa.

[0012] The ultrasonic resistance welding electrode described above uses an ultrasonic amplitude-changing mechanism, which is an amplitude-changing rod or an amplitude converter. The amplitude-changing rod can be a single amplitude-changing rod or a combination of amplitude-changing rods.

[0013] The ultrasonic resistance welding electrode described above has an ultrasonic amplitude transformation mechanism that is a copper-chromium-zirconium alloy ultrasonic amplitude transformation mechanism, a copper-tungsten alloy ultrasonic amplitude transformation mechanism, or a copper-beryllium alloy ultrasonic amplitude transformation mechanism.

[0014] The aforementioned ultrasonic resistance welding electrode uses a vibration transmission mechanism consisting of a vibration transmission rod or an amplitude transformer.

[0015] The ultrasonic resistance welding electrode mentioned above has an ultrasonic amplitude-changing mechanism that includes at least one amplitude-changing electrode segment, which is a single amplitude-changing rod or a single amplitude converter.

[0016] The ultrasonic resistance welding electrode described above has an electrical connection flange designed at the node of the amplitude-changing electrode section. The outer surface of the electrical connection flange at the node extends in a direction away from the amplitude-changing electrode section.

[0017] The ultrasonic resistance welding electrode mentioned above has a first amplitude-changing electrode segment adjacent to the transmitting transducer. The transmitting transducer is encapsulated in a metal shell, and the first amplitude-changing electrode segment is fixedly installed together with the metal shell through its nodes.

[0018] The ultrasonic resistance welding electrode described above has a mounting flange at the node of the first amplitude electrode segment. A Teflon upper washer and a Teflon lower washer are mounted on the metal shell, and the mounting flange is pressed between the Teflon upper washer and the Teflon lower washer.

[0019] The aforementioned ultrasonic resistance welding electrode, the transmitting transducer includes a front driver, a piezoelectric ceramic, an electrode plate, an insulating sleeve, a rear driver, and a preload bolt. The electrode plate is located between two adjacent piezoelectric ceramics and is fitted onto the insulating sleeve. The preload bolt passes through the tube hole of the insulating sleeve, and both ends of the preload bolt are threadedly connected to the mounting through holes of the front driver and the rear driver, respectively. The preload bolt has a water-cooling through hole along the axial direction and is in fluid communication with the water-cooling through hole along the axial direction of the amplitude-modulated electrode section. One end of the amplitude-modulated electrode section adjacent to the transmitting transducer is connected to the front driver for ultrasonic propagation.

[0020] The technical solution of this utility model has achieved the following beneficial technical effects:

[0021] 1. The ultrasonic resistance welding electrode adopts an ultrasonic amplitude-changing mechanism, which makes the ultrasonic resistance welding electrode both a carrier for transmitting ultrasonic waves to the workpiece to be welded and an electrode load for inputting or outputting resistance welding current to the workpiece to be welded. This ensures that the position where ultrasonic waves are applied to the workpiece to be welded is the same as the position where the resistance welding current is input (or output). This can effectively transmit ultrasonic waves with specific amplitude and frequency to the weld nugget position, and can more accurately control the ultrasonic frequency and ultrasonic amplitude applied at the weld nugget, thereby significantly improving the welding quality.

[0022] 2. The resistance welding current is input or output from the nodes of the ultrasonic amplitude transformer, which can ensure that the resistance welding current can be input or output stably and reliably, and can more effectively ensure that the ultrasonic waves of a specific amplitude and frequency are transmitted to the weld nugget position, reducing energy leakage and mechanical loss.

[0023] 3. Enclose the transmitting transducer in a metal shell to reduce the influence of the electromagnetic field generated when the ultrasonic resistance welding electrode passes through the resistance welding current on the piezoelectric ceramic of the transmitting transducer.

[0024] 4. By using air cooling and water cooling, the high temperature of the ultrasonic resistance welding electrode during operation can be avoided from affecting the normal operation of the piezoelectric ceramic. Attached Figure Description

[0025] Figure 1 A schematic diagram of the external structure of the ultrasonic resistance welding electrode of this utility model;

[0026] Figure 2 A schematic diagram of the internal structure of the ultrasonic resistance welding electrode of this utility model;

[0027] Figure 3 for Figure 2 Enlarged structural diagram at point A in the middle.

[0028] The reference numerals in the figure are as follows: 100-ultrasonic resistance welding electrode; 200-transmitting transducer; 1-front driver; 2-water-cooled through hole; 3-workpiece to be welded; 4-amplifier electrode section; 4-1-first node; 4-2-mounting flange; 4-n-second node; 5-metal shell; 5-1-Teflon upper gasket; 5-2-Teflon lower gasket; 6-piezoelectric ceramic; 7-rear driver; 8-preload bolt; 9-electrical connection; 10-air inlet connector; 11-exhaust port; 12-insulating sleeve; 13-electrode plate. Detailed Implementation

[0029] like Figure 1 , Figure 2 and Figure 3As shown (taking resistance spot welding as an example), the ultrasonic resistance welding electrode in this embodiment consists of an ultrasonic amplitude transformer mechanism (the main function of the ultrasonic amplitude transformer mechanism is to amplify the displacement or velocity of the mechanically vibrating particles, or to concentrate ultrasonic energy on a small area, i.e., energy focusing; this is common knowledge). One end of the ultrasonic amplitude transformer mechanism is in direct contact with the workpiece 3 to be welded (in other embodiments, it can also be in contact with the workpiece 3 to be welded through an electrode cap; installing an electrode cap on one end of the electrode is existing technology and will not be described further). The other end of the ultrasonic amplitude transformer mechanism is directly connected to the transmitting transducer 200 (in other embodiments, the other end of the ultrasonic amplitude transformer mechanism is connected to the transmitting transducer 200 through a vibration transmission mechanism, or the other end of the ultrasonic amplitude transformer mechanism is connected to the transmitting transducer 200 through an insulating material; both of these forms can refer to the ultrasonic vibration system in the prior art and will not be described further here). The nodes of the ultrasonic amplitude transformer mechanism are the electrical connection points for the resistance welding current input or the resistance welding current output. The electrical conductivity of the material used to fabricate the ultrasonic amplitude transformer mechanism is greater than or equal to 30% IACS; preferably, it is greater than or equal to 45% IACS, such as 45%, 50%, 55%, 60%, 65%, 70%, 80%, or 85%. A higher percentage of conductivity results in better conductivity and lower energy consumption. The elastic modulus of the material used in the ultrasonic amplitude transformer mechanism can be any value between 60 and 360 GPa, such as 68.5 GPa, 100 GPa, 120 GPa, 200 GPa, 234 GPa, or 354 GPa. The acoustic impedance of the material used in the ultrasonic amplitude transformer mechanism is 1.00 × 10⁻⁶. 7 -11.00×10 7 kg / (m 2 Any value between ·s), for example, 1.76 × 10 7 kg / (m 2 ·s), 2.2×10 7 kg / (m 2 ·s), 4.0×10 7 kg / (m 2 ·s), 5.16×10 7 kg / (m 2 ·s), 5.75×10 7 kg / (m 2 ·s), 6.58×10 7 kg / (m 2 ·s), 7.25×10 7 kg / (m 2 ·s), 7.65×10 7 kg / (m 2 ·s), 8.215×107 kg / (m 2 ·s), or 8.91×10 7 kg / (m 2 The requirements for conductivity, elastic modulus and acoustic impedance of the materials used in the manufacture of ultrasonic amplitude transformers are existing technologies. You can refer to the existing technologies for the material requirements when manufacturing resistance welding electrodes and ultrasonic amplitude transformers, and will not repeat them here.

[0030] The ultrasonic amplitude-changing mechanism can be an amplitude transformer or an amplitude converter. The amplitude transformer can be a single amplitude transformer or a combined amplitude transformer. The fabrication of ultrasonic amplitude-changing mechanisms, including amplitude transformers, amplitude converters, single amplitude transformers, and combined amplitude transformers, is existing technology and will not be elaborated here. For example, please refer to: *Principles and Design of Ultrasonic Amplifiers*, by Du Zhongmao, Science Press, 1st edition, October 1987. In this embodiment, the ultrasonic amplitude-changing mechanism is an amplitude transformer composed of three amplitude-changing electrode segments.

[0031] In this embodiment, the materials used to fabricate the ultrasonic amplitude transformer are copper-chromium-zirconium alloy, copper-tungsten alloy, or copper-beryllium alloy, which meet both the material performance requirements of the ultrasonic amplitude transformer as an amplitude rod or amplitude transformer and the material performance requirements of the ultrasonic amplitude transformer as an electrode.

[0032] In this embodiment, the vibration transmission mechanism is a vibration transmission rod or an amplitude transformer. The vibration transmission rod or amplitude transformer is existing technology and will not be described in detail here. For example, you can refer to: "Principles and Design of Ultrasonic Amplitude Transformers", by Du Zhongmao, Science Press, 1st edition, October 1987.

[0033] The ultrasonic amplitude-changing mechanism in this embodiment includes three amplitude-changing electrode segments 4, each being a single amplitude-changing rod. An electrical connection flange 9 is designed at the nodes of each amplitude-changing electrode segment 4, and the outer surface of the electrical connection flange 9 extends away from the amplitude-changing electrode segment 4 at the nodes. The amplitude-changing electrode segment 4 adjacent to the transmitting transducer 200 is the first amplitude-changing electrode segment (the second and third amplitude-changing electrode segments are sequentially arranged away from the transmitting transducer 200). The transmitting transducer 200 is encapsulated within a metal housing 5, and the first amplitude-changing electrode segment is fixedly mounted to the metal housing 5 through its nodes. A mounting flange 4-2 is designed at the nodes of the first amplitude-changing electrode segment. A Teflon upper washer 5-1 and a Teflon lower washer 5-2 are mounted on the metal housing 5, and the mounting flange 4-2 is pressed between the Teflon upper washer 5-1 and the Teflon lower washer 5-2. The transmitting transducer 200 includes a front driver 1, a piezoelectric ceramic 6, an electrode plate 13, an insulating sleeve 12, a rear driver 7, and a preload bolt 8. The electrode plate 13 is located between two adjacent piezoelectric ceramics 6, and the piezoelectric ceramics 6 and the electrode plate 13 are fitted onto the insulating sleeve 12. The preload bolt 8 passes through the tube hole of the insulating sleeve 12, and both ends of the preload bolt 8 are threadedly connected to the mounting through hole of the front driver 1 and the mounting through hole of the rear driver 7, respectively. The preload bolt 8 has a water-cooling through hole 2 along the axial direction, and is in fluid communication with the water-cooling through hole 2 along the axial direction of the amplitude-modulated electrode section 4. One end of the amplitude-modulated electrode section 4 adjacent to the transmitting transducer 200 is ultrasonically connected to the front driver 1.

[0034] In this embodiment, an air inlet connector 10 is installed at one end of the metal casing 5, and an exhaust port 11 is opened on the side wall of the other end. A first amplitude-changing electrode segment, a second amplitude-changing electrode segment, and a third amplitude-changing electrode segment are sequentially fixedly connected. The first amplitude-changing electrode segment is fixedly installed to the metal casing 5 via a first node 4-1. A mounting flange 4-2 is formed at the first node 4-1. A Teflon upper washer 5-1 and a Teflon lower washer 5-2 are installed on the metal casing 5, and the mounting flange 4-2 is pressed between the Teflon upper washer 5-1 and the Teflon lower washer 5-2. One end of the first amplitude-changing electrode segment is ultrasonically connected to the transmitting transducer 200, and the other end is connected to the second amplitude-changing electrode segment. The resistance spot welding current is input or output from the second node 4-n of the second amplitude-changing electrode segment. An electrical connection portion 9 is integrally formed on the outer surface of the second node 4-n, and the outer surface of the electrical connection portion 9 at the second node 4-n extends away from the ultrasonic resistance welding electrode 100. In this embodiment, the electrical connection part 9 is a flange ring, and the outer diameter of the flange ring is larger than the outer diameter of the ultrasonic resistance welding electrode 100. When used as the upper electrode, the flange ring is electrically connected to the positive terminal of the resistance spot welding power supply; when used as the lower electrode, the flange ring is electrically connected to the negative terminal of the resistance spot welding power supply. In this embodiment, the amplitude-changing electrode section is a copper-tungsten alloy amplitude-changing electrode section, which meets both the material performance requirements of the ultrasonic amplitude-changing mechanism as an amplitude rod or amplitude converter and the material performance requirements of the ultrasonic amplitude-changing mechanism as an electrode.

[0035] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of the claims of this patent application.

Claims

1. An ultrasonic resistance welding electrode, characterized in that, Composed of or formed by an ultrasonic amplitude-modulating mechanism, one end of the ultrasonic amplitude-modulating mechanism is in direct contact with the workpiece (3) to be welded or is in contact with the workpiece (3) to be welded through an electrode cap, and the other end of the ultrasonic amplitude-modulating mechanism is directly connected to the transmitting transducer (200), or the other end of the ultrasonic amplitude-modulating mechanism is connected to the transmitting transducer (200) through a vibration transmission mechanism, or the other end of the ultrasonic amplitude-modulating mechanism is connected to the transmitting transducer (200) through an insulating material; the ultrasonic amplitude-modulating mechanism serves as both a carrier for transmitting ultrasonic waves to the workpiece (3) to be welded and an electrode load for inputting or outputting resistance welding current to the workpiece (3) to be welded or from the workpiece (3) to be welded.

2. The ultrasonic resistance welding electrode according to claim 1, characterized in that, The nodes of the ultrasonic amplitude transformer are the electrical connection points for the input or output of resistance welding current.

3. The ultrasonic resistance welding electrode according to claim 1, characterized in that, The acoustic impedance of the ultrasonic amplitude transformer is 1.00 × 10⁻⁶. 7 -11.00×10 7 kg / (m 2 ·s), with an elastic modulus of 60-360 GPa.

4. The ultrasonic resistance welding electrode according to claim 1, characterized in that, The ultrasonic amplitude-changing mechanism is an amplitude-changing rod or amplitude converter, and the amplitude-changing rod can be a single amplitude-changing rod or a combination of amplitude-changing rods; the vibration transmission mechanism is a vibration transmission rod or an amplitude-changing rod.

5. The ultrasonic resistance welding electrode according to claim 1, characterized in that, The ultrasonic amplitude transformer is a copper-chromium-zirconium alloy ultrasonic amplitude transformer, a copper-tungsten alloy ultrasonic amplitude transformer, or a copper-beryllium alloy ultrasonic amplitude transformer.

6. The ultrasonic resistance welding electrode according to claim 1, characterized in that, The ultrasonic amplitude-changing mechanism includes at least one amplitude-changing electrode segment (4), which is a single amplitude rod or a single amplitude converter.

7. The ultrasonic resistance welding electrode according to claim 6, characterized in that, An electrical connection flange (9) is designed at the node of the amplitude-changing electrode segment (4). The outer surface of the electrical connection flange (9) at the node extends in a direction away from the amplitude-changing electrode segment (4).

8. The ultrasonic resistance welding electrode according to claim 7, characterized in that, The amplitude-changing electrode segment (4) adjacent to the transmitting transducer (200) is the first amplitude-changing electrode segment. The transmitting transducer (200) is encapsulated in a metal shell (5). The first amplitude-changing electrode segment is fixedly installed together with the metal shell (5) through its nodes.

9. The ultrasonic resistance welding electrode according to claim 8, characterized in that, The first amplitude electrode section is designed with a mounting flange (4-2) at the node. A Teflon upper gasket (5-1) and a Teflon lower gasket (5-2) are installed on the metal shell (5). The mounting flange (4-2) is pressed between the Teflon upper gasket (5-1) and the Teflon lower gasket (5-2).

10. The ultrasonic resistance welding electrode according to claim 9, characterized in that, The transmitting transducer (200) includes a front driver (1), a piezoelectric ceramic (6), an electrode plate (13), an insulating sleeve (12), a rear driver (7), and a preload bolt (8). The electrode plate (13) is located between two adjacent piezoelectric ceramics (6), and the piezoelectric ceramics (6) and the electrode plate (13) are fitted on the insulating sleeve (12). The preload bolt (8) passes through the tube hole of the insulating sleeve (12), and the two ends of the preload bolt (8) are threadedly connected to the mounting through hole of the front driver (1) and the mounting through hole of the rear driver (7), respectively. The preload bolt (8) has a water-cooling through hole (2) along the axial direction, and is fluidly connected to the water-cooling through hole (2) of the amplitude-modulated electrode section (4) along the axial direction. One end of the amplitude-modulated electrode section (4) adjacent to the transmitting transducer (200) is ultrasonically connected to the front driver (1).

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