A sub-harmonic vibration welding device and a method for sub-harmonic vibration welding

Abstract

The present invention provides a sub-harmonic vibration welding device and a method for sub-harmonic vibration welding, belonging to the technical field of sub-harmonic vibration welding, including: a welding device and a control system, the welding device is connected to the control system; a sub-harmonic generating device, which is electrically connected to the control system, the sub-harmonic generating device can be connected to a welding workpiece, when the sub-harmonic generating device is connected to the welding workpiece and the welding device welds the welding workpiece, the control system can control the sub-harmonic generating device to continuously apply sub-harmonic vibration to the welding workpiece. The beneficial effects of the present invention: Sub-harmonic vibration is applied while welding. At this time, the weld metal is in a molten state. When the weld metal is in a molten state, the sub-harmonic vibration can easily change the tissue morphology at the weld, and can make the grains finer, thus significantly improving the mechanical properties at the weld.

Description

Technical Field

[0001] The present invention belongs to the technical field of sub - harmonic vibration welding, and particularly relates to a sub - harmonic vibration welding device and a method for sub - harmonic vibration welding. Background Art

[0002] Applying vibration after the workpiece welding is completed is a commonly used welding technique at present. Although such a welding technique can also reduce the residual stress and thus improve the welding quality, the effect of reducing the residual stress by such a welding technique is very small at present. Therefore, the improved welding quality is not significant either. Because after welding is completed, the temperature of the weld at most positions has dropped to room temperature, and at this time, the microstructure of the weld that has dropped to room temperature has basically taken shape, and it is very difficult to further significantly reduce the residual stress of the weld by applying vibration to such a weld state. Therefore, there is a large room for improvement in view of the above - mentioned technical problems. Summary of the Invention

[0003] The object of the present invention is to propose a sub - harmonic vibration welding device and a method for sub - harmonic vibration welding in view of the above problems existing in the prior art.

[0004] The object of the present invention can be achieved by the following technical solutions: A sub - harmonic vibration welding device includes:

[0005] A welding device and a control system, the welding device is connected to the control system;

[0006] A sub - harmonic generating device, which is electrically connected to the control system, and the sub - harmonic generating device can be connected to a welding workpiece. When the sub - harmonic generating device is connected to the welding workpiece and the welding device welds the welding workpiece, the control system can control the sub - harmonic generating device to continuously apply sub - harmonic vibration to the welding workpiece.

[0007] Preferably, the welding device is electrically connected or signal - connected to the control system, and the control system can adjust the sub - harmonic vibration frequency emitted by the sub - harmonic generating device according to the magnitude of the current and voltage of the welding device.

[0008] Preferably, the control system includes a sub - harmonic scanning system, and the sub - harmonic scanning system can control the sub - harmonic generating device to scan the welding workpiece to determine the fundamental frequency of the welding workpiece.

[0009] Preferably, the sub - harmonic generating device is provided with a movable locking screw, and the locking screw is used to fixedly install the sub - harmonic generating device on the welding workpiece.

[0010] Secondly, a method for sub - harmonic vibration welding is also provided. The method includes a sub - harmonic vibration welding device and further includes the following steps:

[0011] S1: Fix and install the sub - harmonic generating device on the welding workpiece, and measure the fundamental frequency of the welding workpiece through analysis and measurement by the sub - harmonic scanning system.

[0012] S2: The control system determines the sub - harmonic vibration frequency according to the fundamental frequency of the welding workpiece.

[0013] S3: The welding device starts to weld the welding workpiece. While welding, the sub - harmonic generating device continuously applies vibration to the welding workpiece at the sub - harmonic vibration frequency determined in step S2.

[0014] Preferably, in step S2, the control system can perform microwave sub - harmonic spectrum analysis based on the fundamental frequency of the welding workpiece to select at least two suitable sub - harmonic vibration frequencies, and then the control system automatically selects the optimal sub - harmonic vibration frequency according to the magnitude of the current and voltage of the welding device.

[0015] Preferably, in step S1, the linear distance between the fixed position of the sub - harmonic generating device and the welding operation position is set to be less than or equal to 5 meters.

[0016] Preferably, it further includes step S4: After the welding device finishes welding, the sub - harmonic generating device continues to apply sub - harmonic vibration to the welding workpiece for at least one minute.

[0017] Preferably, during the welding process of the welding device, the control system can adjust the vibration frequency of the sub - harmonic in real - time according to the magnitude of the current and voltage of the welding device.

[0018] Preferably, in step S1, it is also necessary to check whether the welding workpiece is firmly installed, and it is necessary to ensure that the welding workpiece does not shake or swing during the working process.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] 1. Apply sub - harmonic vibration while welding. At this time, the weld metal is in a molten state. When the weld metal is in a molten state, the sub - harmonic vibration can easily change the tissue morphology at the weld, and can make the grains finer, thus significantly improving the mechanical properties at the weld.

[0021] 2. Apply sub - harmonic vibration while welding. At this time, the temperature at the weld is still in a high - temperature state. When the weld is at a high temperature, the yield limit of the material at the weld is very low. Therefore, the sub - harmonic vibration can easily relieve the thermal stress field, so that the constrained strain can be released, the stress - field gradient can be reduced, and the residual stress after welding can be reduced or homogenized.

[0022] 3. Apply sub - harmonic vibration during welding. Since sub - harmonic vibration can make bubbles, impurities, etc. float up during the crystallization process of welding, and at the same time, vibration can also make hydrogen easier to expel. In this way, the weld material after welding will be connected to the base material more evenly and smoothly, thereby effectively reducing stress concentration and greatly improving the welding quality.

[0023] 4. The control system can adjust the frequency of the sub - harmonic vibration emitted by the sub - harmonic generating device in real - time according to the current and voltage of the welding device, so that the quality after welding is higher and the weld is less likely to crack.

[0024] 5. The control system includes a sub - harmonic scanning system. The sub - harmonic scanning system can analyze and measure the natural frequency of the welded workpiece. In this way, the control system can select the optimal sub - harmonic vibration frequency according to the natural frequency of the welded workpiece. Brief Description of the Drawings

[0025] Figure 1 It is a schematic diagram of the overall structure of the welding device and the control system of the sub - harmonic vibration welding device of the present invention, electrically connected.

[0026] Figure 2 It is a schematic diagram of the overall structure of the welding device and the control system of the sub - harmonic vibration welding device of the present invention, communicatively connected.

[0027] Figure 3 It is a schematic diagram of the structure of the sub - harmonic generating device of the present invention.

[0028] Figure 4 It is the operating steps of the method of sub - harmonic vibration welding of the present invention.

[0029] Figure 5 It is the weld microstructure morphology without using sub - harmonic vibration during welding.

[0030] Figure 6 It is the weld microstructure morphology after using the sub - harmonic vibration welding device and the method of sub - harmonic vibration welding of the present invention during welding.

[0031] In the figure, 100, welding device; 200, control system; 210, sub - harmonic scanning system; 300, sub - harmonic generating device; 310, locking screw; 400, welded workpiece. Detailed Embodiment

[0032] The following are specific embodiments of the present invention and in combination with the drawings, the technical solutions of the present invention are further described, but the present invention is not limited to these embodiments.

[0033] Such as Figures 1 - 3As shown in the figure, a sub-harmonic vibration welding device includes: a welding device 100, a control system 200, and a sub-harmonic generating device 300. The welding device 100 is used to weld the weld of the welding workpiece 400. The control system 200 is the control center of the entire sub-harmonic vibration welding device 100. The control system 200 can control the start and stop of the sub-harmonic generating device 300. The sub-harmonic generating device 300 is used to generate a sub-harmonic frequency and apply this sub-harmonic frequency to the welding workpiece 400 so that the welding workpiece 400 performs sub-harmonic vibration. It should be noted that a sub-harmonic refers to each component obtained by performing Fourier series decomposition on a periodic non-sinusoidal alternating quantity that is less than an integer multiple of the fundamental frequency. The fundamental frequency in the present invention actually refers to the natural frequency of the welding workpiece 400. For example, when the fundamental frequency is 50 Hz, then 1 / 2(50HZ), 2 / 3(50HZ), etc. are all called sub-harmonics. The closer the sub-harmonic frequency applied to the welding workpiece 400 is to the fundamental frequency, the better the welding effect.

[0034] Specifically, the sub-harmonic generating device 300 is electrically connected to the control system 200, so that the control system 200 can control the start and stop of the sub-harmonic generating device 300 through electrical signals. And the sub-harmonic generating device 300 can be fixedly installed on the welding workpiece 400. In actual work, when the sub-harmonic generating device 300 is fixedly installed on the welding workpiece 400, the control system 200 will send an electrical signal to make the sub-harmonic generating device 300 continuously apply sub-harmonic vibration to the welding workpiece 400. At this time, start the welding device 100 to make the welding device 100 start to weld the weld of the welding workpiece 400. In this way, sub-harmonic vibration is applied to the welding workpiece 400 while welding.

[0035] It should be pointed out that sub-harmonic vibration is applied while welding. At this time, the weld metal is in a molten state. When the weld metal is in a molten state, sub-harmonic vibration can easily change the microstructure of the weld, make the grains finer, and thus significantly improve the mechanical properties of the weld.

[0036] It should also be pointed out that sub-harmonic vibration is applied while welding. At this time, the temperature at the weld is still in a high-temperature state. When the weld is at a high temperature, the yield limit of the material at the weld is very low. Therefore, sub-harmonic vibration can easily relieve the thermal stress field, release the constrained strain, reduce the stress field gradient, and thus reduce or equalize the residual stress after welding.

[0037] It should also be noted that, when applying sub-harmonic vibration during welding, since sub-harmonic vibration can make gas bubbles and impurities in the welding crystallization process float up, and at the same time vibration can also make hydrogen easy to remove, the weld material after welding will be more evenly and smoothly connected to the base material, thereby effectively reducing stress concentration and greatly improving the welding quality.

[0038] As Figure 1 , Figure 2 shown, on the basis of the above-mentioned embodiment, the welding device 100 and the control system 200 can be electrically connected or communicatively connected. As Figure 1 shown, the control system 200 and the welding device 100 transmit information through electrical signals. As Figure 2 shown, the control system 200 and the welding device 100 transmit information through communication.

[0039] Specifically, the welding device 100 can convert the magnitude of the current and voltage during welding into electrical signals or communication signals, and transmit these signals to the control system 200. In this way, the control system 200 can adjust the magnitude of the sub-harmonic vibration frequency emitted by the sub-harmonic generating device 300 according to the magnitude of the current and voltage of the welding device 100.

[0040] It should be noted that the control system 200 can adjust the magnitude of the sub-harmonic vibration frequency emitted by the sub-harmonic generating device 300 in real time according to the magnitude of the current and voltage of the welding device 100, so that the quality after welding is higher and the weld is less likely to crack.

[0041] As Figure 1 , Figure 2 shown, on the basis of the above-mentioned embodiment, the control system 200 includes a sub-harmonic scanning system 210, and the sub-harmonic scanning system 210 is used to confirm the fundamental frequency of the welding workpiece 400.

[0042] Specifically, in actual work, the control system 200 controls the sub-harmonic generating device 300 to emit a signal towards the welding workpiece 400. This signal will excite the welding workpiece 400 to vibrate and generate a natural frequency. The sub-harmonic scanning system 210 will receive this natural frequency. At this time, the sub-harmonic scanning system 210 will analyze and measure this natural frequency to obtain the specific value of the natural frequency, and the sub-harmonic scanning system 210 can transmit the natural frequency value to the control system 200. The control system 200 can control the sub-harmonic generating device 300 to emit the optimal sub-harmonic frequency according to the measured natural frequency.

[0043] It should be noted that the control system 200 includes a sub-harmonic scanning system 210, and the sub-harmonic scanning system 210 can analyze and measure the natural frequency of the welded workpiece 400, so that the control system 200 can select the optimal sub-harmonic vibration frequency through the natural frequency of the welded workpiece 400.

[0044] As Figure 3 shown, on the basis of the above embodiment, the sub-harmonic generating device 300 is provided with a movable locking screw 310, and the locking screw 310 is used to fixedly install the sub-harmonic generating device 300 on the welded workpiece 400.

[0045] As Figures 1 - 4 shown, on the basis of the above embodiment, there is also provided a method for sub-harmonic vibration welding, and the specific steps are as follows:

[0046] S1: Fix the sub-harmonic generating device 300 on the welded workpiece 400, and analyze and measure the fundamental frequency of the welded workpiece 400 through the sub-harmonic scanning system 210;

[0047] S2: The control system 200 determines the sub-harmonic vibration frequency according to the fundamental frequency of the welded workpiece 400;

[0048] S3: The welding device 100 starts to weld the welded workpiece 400, and while welding, the sub-harmonic generating device 300 continuously applies vibration to the welded workpiece 400 at the sub-harmonic vibration frequency determined in step S2.

[0049] Preferably, in step S2, after the control system 200 receives the fundamental frequency of the welded workpiece 400, the control system 200 will perform microwave sub-harmonic spectrum analysis according to the fundamental frequency to select at least two suitable sub-harmonic vibration frequencies, and then the control system 200 will also automatically select the optimal sub-harmonic vibration frequency by analyzing the magnitude of the current and voltage of the welding device 100.

[0050] Further preferably, in step S1, the linear distance between the fixed position of the sub-harmonic generating device 300 and the welding operation position is set to be less than or equal to 5 meters, so as to more significantly reduce the residual stress at the weld and improve the welding quality.

[0051] Further preferably, there is also step S4. After the welding device 100 finishes welding, the sub-harmonic generating device 300 continues to apply sub-harmonic vibration to the welded workpiece 400 for at least one minute.

[0052] Further preferably, in step S3, during the welding process of the welding device 100, the control system 200 can adjust the vibration frequency of the sub-harmonic in real time through the magnitude of the current and voltage of the welding device 100.

[0053] It should be noted that the control system 200 can adjust the vibration frequency of the sub-harmonic in real time according to the current and voltage of the welding device 100 during the welding process, which can make the quality of the welded product better and the weld more resistant to cracking.

[0054] Further preferably, in step S1, it is also necessary to check whether the welding workpiece 400 is firmly installed, and it is necessary to ensure that the welding workpiece 400 does not shake or swing during operation.

[0055] As Figure 5 、 Figure 6 shown, on the basis of the above embodiments, Figure 5 is the weld microstructure morphology without using sub-harmonic vibration during welding, Figure 6 is the weld microstructure morphology after using the present sub-harmonic vibration welding device 100 and the sub-harmonic vibration welding method during welding. It can be clearly seen that the weld microstructure crystallization using the sub-harmonic vibration device of the present invention is more uniform, while the weld microstructure without sub-harmonic vibration is very loose and not mixed together. The finer and more uniform the weld microstructure, the higher the quality of the weld and the more resistant it is to cracking. It is also found in the experiment that the weld position of the welding workpiece 400 without applying sub-harmonic vibration is particularly prone to cracking.

[0056] It should be noted that all directional indications (such as up, down, left, right, front, back...) in the embodiments of the present invention are only used to explain the relative position relationship and movement conditions between components in a specific posture (as shown in the drawings). If the specific posture changes, the directional indications will also change accordingly.

[0057] In addition, in the present invention, descriptions such as "first", "second", "one" are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the quantity of the indicated technical features. Thus, features defined as "first" and "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "a plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0058] In the present invention, unless otherwise clearly defined and limited, terms such as "connected" and "fixed" should be understood in a broad sense. For example, "fixed" can be a fixed connection, a detachable connection, or integrated; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the internal communication of two components or the interaction relationship between two components, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0059] In addition, the technical solutions between various embodiments of the present invention can be combined with each other, but it must be based on the fact that those of ordinary skill in the art can implement them. When the combination of technical solutions results in contradictions or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A method of sub-harmonic vibration welding, including a sub-harmonic vibration welding device, characterized in that, Including: A welding device and a control system, the welding device being connected to the control system; A sub-harmonic generating device, which is electrically connected to the control system, and the sub-harmonic generating device can be connected to a welding workpiece. When the sub-harmonic generating device is connected to the welding workpiece and the welding device welds the welding workpiece, the control system can control the sub-harmonic generating device to continuously apply sub-harmonic vibration to the welding workpiece; the welding device is electrically connected or communicatively connected to the control system, and the control system can adjust the sub-harmonic vibration frequency emitted by the sub-harmonic generating device according to the magnitude of the current and voltage of the welding device; the control system includes a sub-harmonic scanning system, and the sub-harmonic scanning system can control the sub-harmonic generating device to scan the welding workpiece to determine the fundamental frequency of the welding workpiece; the sub-harmonic generating device is provided with a movable locking screw, and the locking screw is used to fixedly mount the sub-harmonic generating device on the welding workpiece; It further includes the following steps: S1: Fix the sub-harmonic generating device on the welding workpiece, and analyze and measure the fundamental frequency of the welding workpiece through the sub-harmonic scanning system; S2: The control system determines the sub-harmonic vibration frequency according to the fundamental frequency of the welding workpiece; S3: The welding device starts to weld the welding workpiece, and at the same time, the sub-harmonic generating device continuously applies vibration to the welding workpiece at the sub-harmonic vibration frequency determined in step S2; S4: After the welding device finishes welding, the sub-harmonic generating device continues to apply sub-harmonic vibration to the welding workpiece for at least one minute; In step S2, the control system can perform microwave sub-harmonic spectrum analysis according to the fundamental frequency of the welding workpiece to select at least two suitable sub-harmonic vibration frequencies, and then the control system automatically selects the optimal sub-harmonic vibration frequency through the magnitude of the current and voltage of the welding device.

2. The method of sub-harmonic vibration welding according to claim 1, characterized in that: In step S1, the linear distance between the fixed position of the sub-harmonic generating device and the welding operation position is set to be less than or equal to 5 meters.

3. A method of sub-harmonic vibration welding according to claim 1, characterized in that: In step S3, during the welding process of the welding device, the control system can adjust the vibration frequency of the sub-harmonic in real time through the magnitude of the current and voltage of the welding device.

4. The method of sub-harmonic vibration welding according to claim 1, wherein: In step S1, it is also necessary to check whether the welding workpiece is firmly installed, and it is necessary to ensure that the welding workpiece does not shake or swing during operation.

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