Self-detection resistance spot welding machine

Abstract

A first electrode and a second electrode which are used for resistance spot welding are oppositely arranged on a machine body of the self-detection resistance spot welding machine, an ultrasonic piezoelectric vibrator used for emitting ultrasonic waves is installed in the first electrode, and an ultrasonic probe used for detecting the ultrasonic waves is installed in the second electrode. The output of the ultrasonic probe is connected to the control device, the first electrode and the second electrode are both of a hollow structure and are provided with cavities, the ultrasonic piezoelectric vibrator and the ultrasonic probe are arranged in the cavities of the respective electrodes, cooling medium channels are arranged in the first electrode and the second electrode, and the first electrode and the second electrode are communicated with the ultrasonic piezoelectric vibrator and the ultrasonic probe. The forced cooling device is connected with a cooling medium circulating system to implement forced cooling. According to the utility model, ultrasonic self-detection can be implemented in the welding process, so that the welding quality can be better ensured, and manpower is saved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of resistance spot welding machine, especially to self -detection resistance spot welding machine. BACKGROUND

[0002] As a kind of welding, resistance spot welding is the main welding method in automobile body manufacturing, and the quality of automobile manufacturing involves safety issues, especially the quality of automobile body welding is directly related to safety issues. However, the current resistance welding quality inspection is still manual sampling inspection, which cannot achieve 100% quality detection, and if there are pores, virtual welding and other quality problems in welding points, they cannot be found in time. The existing resistance welding machine can record welding parameters (current, voltage, welding) in real time, save welding process parameters and quality detection data, and be used for automobile manufacturing quality traceability, but cannot complete real-time detection of welding process quality. Especially with the introduction of intelligent manufacturing system in automobile manufacturing process, high-efficiency, high-reliability welding equipment and automatic welding quality detection equipment are needed to improve welding quality, intelligently match welding parameters, automatically detect welding quality and reduce manual sampling inspection. SUMMARY

[0003] The utility model aims at realizing that resistance spot welding machine implements ultrasonic self-detection in welding process, to better guarantee welding quality and save manpower.

[0004] The technical scheme of the utility model is: self-detection resistance spot welding machine, including machine body, first electrode and second electrode for resistance spot welding are oppositely arranged on the machine body, ultrasonic piezoelectric vibrator for emitting ultrasonic waves is installed in the first electrode, and ultrasonic probe for detecting ultrasonic waves is installed in the second electrode.

[0005] The end face (opposite end face of second electrode, or front end face) of the first electrode and the end face (opposite end face of first electrode, or front end face) of the second electrode are electrode head contact surfaces for directly contacting with welding base material. In use, the welding base material is placed between the first electrode and the second electrode, and the electrode head contact surfaces of the two electrodes are attached to the welding base material (pressure contact) through electrode driving mechanism (or welding tongs clamping and moving mechanism, or pressure applying mechanism).

[0006] Preferably, the first electrode and the second electrode adopt hollow structure (for example, cylindrical / cup-shaped structure), and are provided with cavities, and the ultrasonic piezoelectric vibrator and the ultrasonic probe are arranged in the cavities of the electrodes respectively.

[0007] For example, the first electrode and the second electrode can both adopt a copper electrode cap (cup / tube, open rear end, closed front end), and the electrode cap can be arranged and installed according to the prior art. The end surface of the electrode cap in direct contact with the welding base material during the welding process is abraded, and can be ground with a special tool. When the abrasion is serious, the entire electrode cap can be replaced.

[0008] Preferably, a first elastic support for tightly fixing the ultrasonic piezoelectric vibrator is arranged in the cavity of the first electrode, and a second elastic support for tightly fixing the ultrasonic probe is arranged in the cavity of the second electrode.

[0009] Preferably, the ultrasonic piezoelectric vibrator is located at the axial position of the cavity of the first electrode (the central position of the cross section of the cavity), and a gap constituting a first cooling medium channel is left between the peripheral surface (side surface) and the end surface of the ultrasonic piezoelectric vibrator and the corresponding inner wall of the cavity. The first cooling medium channel is provided with a water inlet and a water outlet, and is connected with an input pipe and an output pipe of the cooling medium to realize forced cooling.

[0010] The water inlet and the water outlet of the first cooling medium channel can be arranged on the clamp fixing frame (or the electrode driving mechanism) to connect the part of the rear end of the first electrode (the cup opening end of the cup-shaped structure), and to communicate with the area (the first cooling medium channel) of the corresponding end of the cavity of the first electrode which is not covered by the ultrasonic piezoelectric vibrator, or can be arranged on the side wall of the rear part of the first electrode. The water inlet and the water outlet are symmetrically arranged (mirror-symmetric with respect to any longitudinal section of the cavity) on the two sides (the two sides of the symmetric surface). A partition plate can be arranged between the peripheral surface of the ultrasonic piezoelectric vibrator and the inner wall of the cavity to separate the annular gap therebetween into a water inlet channel communicating with the water inlet and a water outlet channel communicating with the water outlet. After the cooling medium (for example, cooling water or cooling oil) flows into the water inlet, it flows through the water inlet channel to the gap between the front end surface of the ultrasonic piezoelectric vibrator and the cavity, and then flows into the water outlet channel and flows out of the water outlet.

[0011] Preferably, the first elastic support is a water-permeable support, for example, connected by a plurality of bent elastic sheets, and gaps are left between the elastic sheets. The cooling medium can pass through the gaps, thereby meeting the water-permeable requirement.

[0012] Preferably, the ultrasonic probe adopts a water-immersed ultrasonic probe.

[0013] Preferably, the ultrasonic probe is located at the axial position of the cavity of the second electrode (the central position of the cross section of the cavity), and a gap constituting a probe cooling medium channel is left between the peripheral surface (side surface) and the end surface of the ultrasonic probe and the corresponding inner wall of the cavity. The probe cooling medium channel is provided with a water inlet and a water outlet, and is connected with an input pipe and an output pipe of the cooling medium to realize forced cooling.

[0014] Preferably, the ultrasonic probe is located at the cavity axis position (central position of the cavity cross section) of the second electrode, and the gap between the peripheral surface (side surface) and end surface of the ultrasonic probe and the corresponding inner wall of the cavity forms a second cooling medium channel, which is provided with a water inlet and a water outlet, and an input pipe and an output pipe for the cooling medium to achieve forced cooling.

[0015] The water inlet and water outlet of the second cooling medium channel can be arranged on the clamping fixture (or the electrode driving mechanism) at the position connecting the rear end of the second electrode (the cup opening end of the cup-shaped structure), and communicate with the area (the second cooling medium channel) of the corresponding end of the cavity of the second electrode which is not covered by the sensor, or arranged on the side wall of the rear part of the second electrode, and the water inlet and water outlet are symmetrically arranged (mirror symmetric with respect to any longitudinal cross section of the cavity) on both sides (the two sides of the symmetric surface). A partition can be arranged between the peripheral surface of the ultrasonic probe / ultrasonic sensor and the inner wall of the cavity to divide the annular gap between the peripheral surface of the ultrasonic probe / ultrasonic sensor and the inner wall of the cavity into a water inlet channel communicating with the water inlet and a water outlet channel communicating with the water outlet. After the cooling medium (such as cooling water or cooling oil) flows into the water inlet, it flows through the water inlet channel to the gap between the front end surface of the ultrasonic piezoelectric vibrator and the cavity, and then flows into the water outlet channel and flows out of the water outlet.

[0016] Preferably, the second elastic support is a water-permeable support, for example, connected by a plurality of bent elastic pieces, and gaps are left between the elastic pieces, through which the cooling medium can pass, thereby meeting the water-permeable requirement.

[0017] Preferably, the machine body is provided with a clamping fixture (also referred to as a clamping fixture), and the first electrode and the second electrode are respectively mounted at the two ends of the clamping fixture.

[0018] Preferably, at least one of the first electrode and the second electrode is provided with an electrode driving mechanism, and the corresponding electrode is movably connected on the clamping fixture through the electrode driving mechanism. In this way, the corresponding electrode can be moved up and down by the electrode driving mechanism to change the distance between the two electrodes and clamp or release the welding base material.

[0019] Preferably, the output access point of the ultrasonic probe is connected to the control device of the spot welder.

[0020] Preferably, the control device of the spot welder is provided with a communication interface for connecting to the upper computer.

[0021] The utility model discloses an advantageous effect is: because setting the mutual matching ultrasonic probe and ultrasonic piezoelectric vibrator, through the ultrasonic piezoelectric vibrator produces ultrasonic wave, through the ultrasonic probe gathers ultrasonic wave signal, can be in the welding process and / or when welding is completed automatic implementation ultrasonic detection, obtains the detection result, need not after welding implementation artificial detection, just can obtain all product's welding quality, because the ultrasonic vibration excitation effect produced through the ultrasonic piezoelectric vibrator in the welding process, it is favorable to reduce the welding blowhole, improve product welding quality, because the cooling medium channel has been set up in the electrode, through the access cooling medium circulation system to ultrasonic piezoelectric vibrator, ultrasonic probe and motor's forced cooling, it is favorable to guarantee the stability and service life of work, because the water -permeable support has been set up and ultrasonic piezoelectric vibrator and ultrasonic probe are pressed from the front end, it is favorable to guarantee the stability under the vibration condition, and through the water -permeable of support, do not hinder the flow of cooling medium. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is the schematic diagram of the utility model and matched control device;

[0023] Figure 2 It is the section schematic drawing of the utility model related electrode internal structure and clamp type fixing frame;

[0024] Figure 3 It is the section schematic drawing of the utility model related cooling medium channel and elastic water -permeable support;

[0025] Figure 4 It is Figure 3 The A-A view shown in.

[0026] Mark in drawing: 1, spot welder;101, first electrode;102, second electrode;103, gap;104, ultrasonic probe;105, electrode head contact surface;106, welding core;107, welding base material;108, first cooling medium channel;109, ultrasonic piezoelectric vibrator;110, electrode drive mechanism;111, clamp type fixing frame;112, second elastic support;113, bending elastic sheet;114, elastic sheet connecting ring;115, water inlet;116, water outlet;2, spot welder's control device. DETAILED DESCRIPTION

[0027] Referring to Figures 1 to 4The utility model discloses a self -detection resistance spot welding machine's spot welding machine 1's frame is provided with the fixed frame of pincers 111, and the both ends of fixed frame of pincers 111 are used to install first electrode 101 and second electrode 102, and the first electrode and the second electrode can be arranged up and down generally, and according to actual needs, can set first electrode 101 installed with ultrasonic transducer below, also can set above. The electrode head contact surface (front end surface) 105 of first electrode and second electrode is opposite, and first electrode 101 and second electrode 102 all adopt hollow structure, wherein first electrode 101 is installed with ultrasonic piezoelectric transducer 109 for emitting ultrasonic wave, and ultrasonic piezoelectric transducer 109 converts ultrasonic sound energy into vibrating mechanical energy, which can provide vibration excitation in the welding process to refine the metal grain structure inside the spot welding core, reduce welding porosity and improve product processing quality. Ultrasonic probe 104 is installed in second electrode 102 for detecting ultrasonic wave, and ultrasonic signal is collected by ultrasonic probe 104 during the whole welding process. According to the prior art, the change of welding spot fusion characteristics during welding operation can be monitored in real time by analyzing the ultrasonic signal. The welding operation quality is determined by collecting scanning data.

[0028] The ultrasonic probe and transducer can be set according to the prior art to detect the required ultrasonic signal of the object between the two electrodes. Through the matched data processing device, for example, the data processing capability of the existing spot welding machine control device can be used to analyze the ultrasonic signal collected by the spot welding machine probe and obtain the detection result.

[0029] A first elastic support (for example, a spring support relying on spring force) for fixing the ultrasonic piezoelectric transducer is arranged in the cavity of first electrode 101, and a second elastic support 112 for fixing the ultrasonic probe is arranged in the cavity of second electrode 102, which tightly fixes the ultrasonic piezoelectric transducer and ultrasonic probe 104, respectively. Both elastic supports are water-permeable supports provided with a bottom ring 114 as a spring base and a plurality of bent springs 113 arranged on the bottom ring. In use, the water-permeable support is placed in the electrode cavity, and then the part to be fixed (probe or transducer) is placed, so that the support is located between the front end face of the cavity and the front end face of the part to be fixed. The bottom ring is attached to the front end inner wall of the cavity, and the bent springs extend backward and inward (radially inward) by bending, and the end portion abuts against the front end face of the part to be fixed, pushing the part to be fixed backward and tightly against the fixing structure behind the part to be fixed.

[0030] The circumferential surface and front end face of the ultrasonic probe (for example, ultrasonic sensor) and ultrasonic piezoelectric transducer leave a gap 103 between the inner wall of the cavity, which constitutes a cooling medium channel (first and second cooling medium channels). The second cooling medium channel is provided with a water inlet and a water outlet, an input pipe and an output pipe for the cooling medium, and realizes forced cooling.

[0031] The water inlet 115 and the water outlet 116 of the cooling medium channel (the first cooling medium channel and the second cooling medium channel) can be arranged on the pincer fixing frame (or the electrode driving mechanism if the corresponding electrode is installed on the electrode driving mechanism) at the position connecting the rear end (the cup opening end of the cup-shaped structure) of the corresponding electrode (the first electrode or the second electrode) and the area (the position of the cooling medium channel) not covered by the ultrasonic voltage sonotrode, or on the side wall of the rear part of the corresponding electrode, and the water inlet and the water outlet are symmetrically arranged on both sides (on both sides of the symmetric plane) with respect to any longitudinal section mirror image of the cavity. A partition can be arranged between the circumferential surface of the ultrasonic piezoelectric sonotrode and the inner wall of the cavity to separate the annular gap between the circumferential surface of the ultrasonic piezoelectric sonotrode and the inner wall of the cavity into a water inlet channel connected to the water inlet and a water outlet channel connected to the water outlet. After the cooling medium (for example, cooling water or cooling oil) flows into the water inlet, it flows through the water inlet channel to the gap between the front end surface of the ultrasonic piezoelectric sonotrode and the cavity, and then flows into the water outlet channel and flows out of the water outlet.

[0032] The cooling water in the cavity of each electrode cools and lowers the temperature of the probe, the sonotrode and the electrode itself. The ultrasonic probe 104 and the ultrasonic piezoelectric sonotrode 109 are immersed in water when they work, which adapts to the working environment in water and facilitates the protection of the normal working temperature range of the ultrasonic probe 104 and the ultrasonic piezoelectric sonotrode 109, that is, the protection of the normal working of the sensor, and the cooling water provides a good coupling medium for the propagation of ultrasonic waves and a good working environment for non-destructive testing, which can complete the non-destructive testing work under the condition of ensuring the working temperature and water pressure.

[0033] The first elastic support 108 and the second elastic support 103 are both water-permeable supports that do not hinder the flow of the cooling medium.

[0034] The elastic supports (between the first elastic support and the second elastic support) can be thin stainless steel sheets punched and folded, or can be replaced by high-temperature-resistant materials. The mounting supports fix the sensor at the center position so that the inner wall of the electrode cavity and the sensor maintain a certain distance, and the mounting supports, the inner wall of the electrode cavity and the sensor together form the cooling water inlet channel and the cooling water outlet channel.

[0035] The front end surface of the first electrode 101 and the second electrode 102 is the electrode head contact surface 105. The welding position of the welding base material 107 is located between the first electrode 101 and the second electrode 102 during use, and the electrode head contact surface 105 is in close contact with the welding base material 107. The electrode head contact surface 105 directly contacts the welding base material 107, the electrode head contact surface 105 is clamped on the surface of the welding base material 107 during the welding process, high temperature is generated by electric current, the welding base material 107 is completely fused together, and the welding core 106 is formed between the welding base material 107 after the welding process is completed and the pressure is maintained and cooled.

[0036] The body (frame) 1 is provided with a clamp fixing frame 111, and the electrode driving mechanism 110 is arranged on the clamp fixing frame 111, and the number of the electrode driving mechanism 110 can usually be one, for driving a certain electrode to move, and can also be two, for driving two electrodes to move respectively. In Figure 2 In the embodiment shown, the first electrode 101 is installed on the electrode driving mechanism 110 (the moving end base of the driving mechanism), and the electrode driving mechanism 110 drives the electrode to move towards each other (move towards the other electrode) under the action of the driving electrode (or air cylinder, oil cylinder, etc.), clamps / presses the welding base material 107 and maintains a certain pressure, so as to realize welding.

[0037] The ultrasonic probe 104 can adopt a suitable ultrasonic sensor.

[0038] The working process of the utility model is as follows: the spot welding machine is powered on, the electrode driving mechanism 110 drives the first electrode 101 to move upwards under the action of the driving mechanism, clamps the welding base material 107 between the first electrode 101 and the second electrode 102, the voltage applied to the first electrode 101 and the second electrode 102 makes the current pass through the welding base material 107, the resistance effect generates heat energy, the welding base material 107 is fused, and after the welding is completed, the pressure is maintained for a period of time, so that the welding point base material (107) is completely fused together to form a welding nugget.

[0039] According to actual needs, during welding, the ultrasonic piezoelectric vibrator and the ultrasonic probe 104 work to implement ultrasonic detection. The welding point fusion feature change can be monitored in real time during the whole welding process, and the welding point post-welding nondestructive detection is implemented after the welding pressure maintaining stage or after completion, the ultrasonic scanning data collected by the probe is sent to the corresponding data processing device for analysis and processing, and the welding quality is analyzed and judged. In addition, because the ultrasonic acoustic energy is converted into vibration mechanical energy during welding, vibration excitation is provided, the metal grain structure inside the spot welding nugget 106 is refined, welding pores are reduced, and the product welding quality is improved.

[0040] The spot welding machine 1 can be provided with a control device 2, and the ultrasonic analysis and processing device can be integrated on the control device or the control device has ultrasonic analysis and processing capability under the support of software.

[0041] During use, the control device and the control network of the spot welding machine can be configured according to actual needs, for example, manual control, remote control network interface, welding basic parameter acquisition, ultrasonic excitation control module, ultrasonic excitation synchronization module, nondestructive detection data acquisition, nondestructive detection synchronization module, predictive quality analysis and storage and calculation module, etc. can be set, and the upper computer can be connected through the communication interface.

[0042] The utility model discloses each preferred and optional technical means, except special explanation and one preferred or optional technical means is another technical means's further limitation, can be arbitrary combination, forms several different specific embodiment.

Claims

1. A self-detecting resistance spot welding machine comprising a machine body, a first electrode and a second electrode for resistance spot welding oppositely arranged on the machine body, characterized in that The first electrode is provided with an ultrasonic piezoelectric vibrator for emitting ultrasonic waves, and the second electrode is provided with an ultrasonic probe for detecting ultrasonic waves.

2. The self-detecting resistance spot welder of claim 1, wherein The first electrode and the second electrode are both hollow structures provided with cavities, and the ultrasonic piezoelectric vibrator and the ultrasonic probe are arranged in the cavities of the respective electrodes.

3. The self-detecting resistance spot welder of claim 2, wherein The first electrode and the second electrode are both copper electrode caps.

4. The self-detecting resistance spot welder of claim 2, wherein The cavity of the first electrode is provided with a first elastic support for tightly fixing the ultrasonic piezoelectric vibrator, and the cavity of the second electrode is provided with a second elastic support for tightly fixing the ultrasonic probe.

5. The self-detecting resistance spot welder of claim 4, wherein The ultrasonic piezoelectric vibrator is located at the axis position of the cavity of the first electrode, and a gap between the peripheral surface and the end surface of the ultrasonic piezoelectric vibrator and the inner wall of the corresponding cavity forms a first cooling medium channel, which is provided with a water inlet and a water outlet for connecting the input pipeline and the output pipeline of the cooling medium to realize forced cooling.

6. The self-detecting resistance spot welder of claim 5, wherein The first elastic support is a water-permeable support.

7. The self-detecting resistance spot welder of claim 4, wherein The ultrasonic probe is a water-immersed ultrasonic probe, which is located at the axis position of the cavity of the second electrode, and a gap between the peripheral surface and the end surface of the ultrasonic probe and the inner wall of the corresponding cavity forms a probe cooling medium channel, which is provided with a water inlet and a water outlet for connecting the input pipeline and the output pipeline of the cooling medium to realize forced cooling.

8. The self-detecting resistance spot welder of claim 7, wherein The second elastic support is a water-permeable support.

9. The self-diagnostics resistance spot welding machine according to any of claims 1-8, characterized in that The machine body is provided with a clamp-type fixing frame, and the first electrode and the second electrode are respectively arranged at the two ends of the clamp-type fixing frame.

10. The self-detecting resistance spot welder of claim 9, wherein At least one of the first electrode and the second electrode is provided with an electrode driving mechanism, and the corresponding electrode driving mechanism is used to realize the movable connection on the clamp-type fixing frame.

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