WO2024051203A1

WO2024051203A1 - Welding method using high-frequency vibration-caused collision within micro distance

Info

Publication number: WO2024051203A1
Application number: PCT/CN2023/094409
Authority: WO
Inventors: 程青青
Original assignee: 湖北鑫鼎泰自动化科技有限公司
Priority date: 2022-09-09
Filing date: 2023-05-16
Publication date: 2024-03-14
Also published as: CN115570291A

Abstract

A welding method using high-frequency vibration-caused collision within a micro distance. First, a first welding part (1) and a second welding part (2) are relatively vibrated at high frequency, so that a first welding face located on the first welding part and a second welding face located on the second welding part collide at high frequency within a micro distance, which is 0.1-3 mm; after heat generated by collision makes the first welding face and/or the second welding face be melted, high-frequency vibration stops; and then, two workpieces to be welded are butt-jointed under a certain pressure in a vibration direction, and are pressed continuously and then released, so that welding is completed. In the method, by means of high-frequency vibration, welding surfaces perform high-speed and high-frequency collision and friction to generate heat, thereby realizing welding; the requirements for the appearance and structure of a product are low; no dust is generated; the welding quality is good; the energy consumption is low; and the precision is high.

Description

Micro-pitch high-frequency vibration collision welding method

Technical field

The present invention relates to the field of welding technology, and in particular to a micro-pitch high-frequency vibration impact welding method.

Background technique

Welding is a manufacturing process and technology that uses heat, high temperature or high pressure to join metal or other thermoplastic materials such as plastics. During the welding process, the workpiece and the solder melt to form a molten area. After the molten pool cools and solidifies, a connection between the materials is formed. This process usually requires the application of pressure. There are many energy sources for welding, including gas flame, arc, laser, electron beam, friction and ultrasonic wave.

Among them, friction welding is a commonly used welding technology in recent years. It uses the heat generated by friction on the contact surface of the workpiece as a heat source to cause plastic deformation of the workpiece under pressure for welding. Under the action of pressure, the relative motion between the welding contact end faces is used to generate friction heat and plastic deformation heat on the friction surface and its nearby areas, causing the temperature of the friction surface and its nearby areas to rise to a temperature range close to but generally lower than the melting point. The material The deformation resistance is reduced, the plasticity is improved, and the oxide film at the interface is broken. Under the action of upsetting pressure, the material undergoes plastic deformation and flow, and the welding is realized through molecular diffusion and recrystallization at the interface.

The applicant's research found that if the weldments do not rub along the friction surface but collide with each other, the temperature will also rise. This finding can be used in welding technology, especially for some welding needs that are not suitable for vibration friction welding due to structural reasons.

Contents of the invention

The purpose of the present invention is to provide a micro-pitch high-frequency vibration collision welding method in view of the shortcomings of the existing technology, which uses high-frequency collision to generate heat for welding and provides a new welding method.

The technical solution adopted by the present invention to solve the technical problem is: a micro-pitch high-frequency vibration collision welding method. First, the first welding part and the second welding part are relatively vibrated at high frequency, so that the first welding part located on the first welding part is The surface collides with the second welding surface located on the second welding piece at high frequency within a small distance, which is 0.1-3mm. After the heat generated by the collision causes the first welding surface and/or the second welding surface to melt, the high-frequency collision is stopped. Frequent vibration, then connect the two workpieces to be welded under a certain pressure along the vibration direction, continue to press and then release to complete the welding.

Preferably, during high-frequency vibration, the second welding part vibrates at high frequency through a vibration generator, and the first welding part moves toward the second welding part under the action of external force.

Preferably, the melting point of the first welding part is lower than or equal to the melting point of the second welding part.

Preferably, the first welding part and the second welding part are made of thermoplastic plastic.

Preferably, the micro distance is 0.1-0.5mm, 0.5-1mm or 1-3mm.

Preferably, the vibration frequency of the high-frequency vibration is 50-1000 Hz.

Preferably, the vibration frequency of the high-frequency vibration is 80-120Hz, 200-240Hz or 240-1000Hz.

Preferably, before high-frequency vibration, the first welding surface and the second welding surface are preheated.

Preferably, during high-frequency vibration, the frequency and amplitude of the first welding part and the second welding part relative to the high-frequency vibration remain unchanged.

Preferably, during high-frequency vibration, the frequency of the first welding part and the second welding part relative to the high-frequency vibration gradually increases, and the amplitude gradually decreases.

The present invention provides a new welding method, which has the following advantages:

1. The biggest advantage of this application is that the requirements for product appearance and structure are low. The vibration direction of linear vibration friction welding in the existing technology is along the welding surface. When the shape of the welding surface is complex, relative motion cannot occur due to swinging, so it is impossible to Welding, and this application uses high-frequency vibration to make the welding surface collide with high-speed and heat to achieve welding. It only requires that there are no obstacles in the vibration direction, that is, other parts outside the welding surface will not collide, so it can be used for complex shapes and structures. products for welding.

2. The pressure direction of the linear vibration friction welding in the existing technology is perpendicular to the vibration direction, and the welding is achieved entirely through pressure to generate friction and heat on the welding surface. When the weldment is not firmly fixed, the two weldments tend to swing synchronously, thus causing Unable to generate heat by friction. In this application, one weldment will not hinder the vibration of the other weldment, so welding can be achieved by simply fixing the weldment through the welding mold, and synchronous vibration of the two weldments will not occur.

3. In the initial stage of linear vibration friction welding, dust will be generated at the welding surface due to friction chips. In this application, the welding surface will not rub against each other during vibration, so no dust is generated, which is beneficial to improving the welding quality and reducing subsequent processes.

4. It overcomes the shortcoming of linear vibration friction welding that requires high strength of welded parts. Other parts of linear vibration friction welding also need to bear and transmit the pressure in the direction of pressure. However, this application performs high-frequency vibration in a very small range, and only the welding The surface and the vicinity of the welding surface can withstand the impact of high-frequency collisions, thus reducing the requirements for the strength of the weldment.

Therefore, the micro-pitch high-frequency vibration collision welding of this application is a new welding method with good welding quality, low energy consumption, high precision, and wide application range.

Description of the drawings

Figure 1 is a schematic diagram of the first embodiment of the welding structure of the present invention.

Figure 2 is a schematic diagram of the second embodiment of the welding structure of the present invention.

Figure 3 is a schematic diagram of a third embodiment of the welding structure of the present invention.

Figure 4 is a schematic diagram of the fourth embodiment of the welding structure of the present invention.

Figure 5 is a schematic diagram of the second vibration direction of the welded structure in Figure 1.

Figure 6 is a schematic diagram of the second vibration direction of the welded structure in Figure 2.

Figure 7 is a schematic diagram of the third vibration direction of the welded structure in Figure 1.

Figure 8 is a schematic diagram of the second vibration direction of the welded structure in Figure 4.

Figure 9 is a schematic structural diagram of a sample for welding quality testing according to the present invention.

Figure 10 is a specification diagram of the second weldment in Figure 9.

Figure 11 is a specification diagram of the first weldment in Figure 9.

Explanation of reference symbols:
1——The first welding part 11——Glue overflow tank
2——Second weldment 21——Welding rib
3——Threaded hole.

Detailed ways

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the implementation scope of the present invention is not limited thereto.

The micro-pitch high-frequency vibration impact welding method of this embodiment first vibrates the first welding part 1 and the second welding part 2 relatively at high frequencies, so that the first welding surface of the first welding part 1 and the second welding part 2 The second welding surface collides with high frequency within a small distance, which is 0.1-3mm. After the heat generated by the collision melts the first welding surface and/or the second welding surface, the high-frequency vibration is stopped, and then the vibration direction is The two workpieces to be welded are butted together under a certain pressure, and then released after continuous pressing to complete the welding. This welding process uses high-frequency collisions to generate heat to melt the surface of the welding parts for welding. The principle is that when the welding parts collide, part of the mechanical energy is converted into internal energy through internal friction, thereby generating heat. The heat generated by multiple high-frequency collisions accumulates and thus The surface of the weldment is melted.

The welding method of this application is compared with the frictional heat generation of vibration friction welding. The two welding methods generate heat in different ways and the directions of vibration are also different. Vibration friction welding must vibrate along the welding surface, that is, the pressure direction of the welding piece is in line with the welding surface. It is vertical. During the welding process, the two welding surfaces are always in contact under pressure, so it imposes greater restrictions on the shape of the welding surface. The vibration direction of the welding method of the present application is perpendicular to the welding surface, or at a certain angle, and the vibration direction is the A direction in the drawing. It can be used for welding structures of various shapes, as shown in Figures 1, 2, 3, and 4. The welding surface in Figure 1 is a flat surface; the welding surface in Figure 2 is a spatial curved surface; the welding surface in Figure 3 is a combination of two planes; The welding surface in Figure 4 is an inclined surface. The drawings are only examples to illustrate the welding structures that can be welded by the present invention. It is foreseeable that as long as there are no obstacles in the vibration direction, welding surfaces of various shapes, including combinations of the above welding surfaces, can be welded using the present invention.

The vibration direction during welding of the present invention is typically shown in Figures 1 and 8. The angle between the vibration direction and the welding surface is 90°, that is, the first welding part 1 and the second welding part 2 vibrate relative to each other in the vertical direction. When the welding surface is a curved surface, as shown in Figures 2 and 3, it can also be approximately considered that the first welding part 1 and the second welding part 2 vibrate relative to each other in the vertical direction. For Figures 4, 5, and 6, the angle between the vibration direction and the welding surface is not 90°. Regarding FIG. 7 , the second welding part 2 vibrates along an arc-shaped trajectory, thereby colliding with the first welding part 1 at high frequency.

The entire welding time of the present invention is about 1-20s.

When vibrating at high frequency, the second weldment vibrates at high frequency through the vibration generator, and the first weldment moves toward the second weldment under the action of an external force. The pressing direction of the external force is B in the drawing. direction, that is, it is parallel to or at a certain angle with the direction of vibration. Furthermore, in order to simplify the structure of the welding equipment, the first welding part 1 can be fixed during high-frequency vibration, and the second welding part 2 can be vibrated at high frequency by a vibration generator.

Furthermore, the materials of the first welding part 1 and the second welding part 2 may be the same or different. When the materials are different, the melting point of the first welding part 1 is lower than or equal to the melting point of the second welding part. , that is, the low melting point welding parts are fixed and the high melting point welding parts are vibrated at high frequency.

Furthermore, the first welding part 1 and the second welding part 2 are made of thermoplastic plastic.

Further, the micro distance is 0.1-0.5mm, 0.5-1mm or 1-3mm, and the vibration frequency of the high-frequency vibration is 80-120Hz, 200-240Hz or 240-1000Hz. The smaller the distance, the higher the collision frequency. If the value is high, the heat will be generated faster and the heat loss will be smaller. However, considering the characteristics of the material and the accuracy of the welding equipment, it can be adjusted according to the welding requirements.

Furthermore, in order to increase the welding speed and stabilize the welding quality, the first welding surface and the second welding surface can be preheated before high-frequency vibration, for example, to 50°C.

During welding, the vibration frequency and amplitude of the second welding piece 2 (ie, the above-mentioned minute distance) may remain unchanged or may change. Preferably, as the high-frequency collision proceeds, the welding surface gradually melts or even fuses to a certain extent. The vibration frequency can be gradually increased and the amplitude gradually reduced. At this time, the vibration center of the first welding part 1 and the second welding part 2 The distance between them becomes smaller.

In this embodiment, different materials are used for welding and testing. The specific process and results are as follows.

The test materials are PP, PMMA, and ABS, including 4 tests, namely PP versus PP, PMMA versus PMMA, ABS versus ABS, and ABS (second weldment) versus PMMA (first weldment).

The test method is: process the welding material into a cylindrical shape as shown in Figures 9, 10, and 11, with a threaded hole in the middle. The threaded hole is used to connect to the tensile machine during testing, and the welding surface of the first weldment 1 is provided with an annular Glue overflow groove 11, the welding surface of the second welding part 2 is provided with an annular welding rib 21, which are welded together according to the welding plan of the present invention, and then a tensile machine is used to pull the first welding part 1 and the second welding part Open to obtain the maximum breaking force when the welding joint breaks. The test results are shown in the table below.

It can be seen from the test results that after welding, the welding strength basically meets the industrial application welding strength standards. Especially for high-melting point PMMA versus low-melting point ABS, PMMA is placed on the vibrating side of the high-frequency collision welding testing machine, and ABS is fixed. The strength after welding far exceeds the conventional welding strength requirements and is basically close to the welding strength of the main body. The welding method of the present invention has large development space and application prospects.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art will understand that , the technical solution of the present invention may be modified or equivalently substituted without departing from the essence and scope of the technical solution of the present invention.

Claims

The micro-pitch high-frequency vibration impact welding method is characterized in that: first, the first welding part and the second welding part are relatively vibrated at high frequency, so that the first welding surface of the first welding part and the second welding part of the second welding part are The surfaces collide at high frequency within a small distance, which is 0.1-3mm. After the heat generated by the collision causes the first welding surface and/or the second welding surface to melt, the high-frequency vibration is stopped, and then the two to-be-welded surfaces are moved along the vibration direction. The welding workpieces are butt-jointed under a certain pressure, and then released after continuous pressing to complete the welding.
The micro-pitch high-frequency vibration impact welding method according to claim 1, characterized in that: during high-frequency vibration, the second welding part vibrates at high frequency through the vibration generator, and the first welding part moves downward under the action of external force. The second weldment moves.
The micro-pitch high-frequency vibration impact welding method according to claim 2, wherein the melting point of the first welding part is lower than or equal to the melting point of the second welding part.
The micro-pitch high-frequency vibration impact welding method according to claim 1, wherein the first welding part and the second welding part are made of thermoplastic plastic.
The micro-pitch high-frequency vibration collision welding method according to claim 1, characterized in that: the micro distance is 0.1-0.5mm, 0.5-1mm or 1-3mm.
The micro-pitch high-frequency vibration collision welding method according to claim 1, characterized in that: the vibration frequency of the high-frequency vibration is 50-1000 Hz.
The micro-pitch high-frequency vibration collision welding method according to claim 6, characterized in that: the vibration frequency of the high-frequency vibration is 80-120Hz, 200-240Hz or 240-1000Hz.
The micro-pitch high-frequency vibration collision welding method according to claim 1, characterized in that: before high-frequency vibration, the first welding surface and the second welding surface are preheated.
The micro-pitch high-frequency vibration impact welding method according to claim 1, characterized in that: during high-frequency vibration, the frequency and amplitude of the relative high-frequency vibration of the first welding part and the second welding part remain unchanged.
The micro-pitch high-frequency vibration impact welding method according to claim 1, characterized in that: during high-frequency vibration, the frequency of the first welding part and the second welding part relative to the high-frequency vibration gradually increases, and the amplitude gradually decreases. .