Continuous machining device and method for ultrasonic welding of hard and brittle materials on surfaces of special-shaped parts

Abstract

The invention discloses a continuous machining device and method for ultrasonic welding of hard and brittle materials on the surface of a special-shaped part, and belongs to the technical field of workpiece surface strengthening. A continuous machining device for ultrasonic welding of hard and brittle materials on the surface of a special-shaped workpiece comprises a clamp assembly, an ultrasonic welding assembly, an ultrasonic welding assembly and a control assembly, and the clamp assembly is used for clamping and fixing the to-be-machined special-shaped workpiece; and the conveying system is used for continuously conveying the clamped workpieces. Through the synergistic effect of continuous heating and ultrasonic welding, full contact of a welding flux and a material is ensured, the welding stress is reduced, fragmentation of hard alloy is avoided, and the welding quality is improved; the traditional pressure head is replaced by the temperature-resistant soft particles, so that the equipment structure is simplified, and the equipment cost and the production and maintenance cost are reduced; the continuous heating and continuous welding production mode obviously improves the production efficiency, reduces the downtime and is suitable for large-scale production; the severe working environment of manual flame brazing is avoided, energy waste and environmental pollution are reduced, and production safety is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of workpiece surface strengthening, and specifically to a continuous processing device and method for ultrasonic welding of hard and brittle materials on the surface of special-shaped workpieces. Background Technique

[0002] For some special-shaped workpieces, it is usually necessary to weld a layer of cemented carbide on the surface to improve wear resistance and extend service life. For example, in the feed crushing process, the hammer head, as the component that impacts the material the most, needs to weld a layer of cemented carbide on its surface. Due to the high hardness and brittleness of cemented carbide, traditional welding processes have the following defects: manual flame brazing has a harsh working environment, high energy waste, unstable welding quality, and defects such as incomplete penetration, porosity, and slag inclusion are likely to occur; vacuum brazing equipment has a high input cost, cannot be continuously processed, has low efficiency, and improper process control is likely to lead to the scrapping of the entire furnace; traditional ultrasonic welding requires a complex indenter structure to adapt to special-shaped workpieces, has a high cost, and improper pressure control is likely to cause the cemented carbide to crack; therefore, we propose a continuous processing device and method for ultrasonic welding of hard and brittle materials on the surface of special-shaped workpieces to solve the above problems. Summary of the Invention

[0003] (1) Technical Problems to be Solved

[0004] In view of the deficiencies of the prior art, the present invention provides a continuous processing device and method for ultrasonic welding of hard and brittle materials on the surface of special-shaped workpieces, and solves the problems raised in the above background technique.

[0005] (2) Technical Solutions

[0006] The present invention specifically adopts the following technical solutions to achieve the above objectives:

[0007] A continuous processing device for ultrasonic welding of hard and brittle materials on the surface of special-shaped workpieces, comprising:

[0008] A fixture assembly for clamping and fixing the special-shaped workpiece to be processed. The special-shaped workpiece is composed of a workpiece substrate, a welding flux, and cemented carbide;

[0009] A conveying system for continuously conveying the clamped workpiece. The conveying system includes a first conveyor and a second conveyor, and the second conveyor is arranged behind the first conveyor;

[0010] A heating system including a heating furnace for preheating the workpiece and a continuous high-frequency heating device for heating heat-resistant soft particles. The heating furnace is installed on the first conveyor, the continuous high-frequency heating device is arranged above the second conveyor, and a guiding groove for discharging materials is installed on the continuous high-frequency heating device;

[0011] An ultrasonic vibration device is arranged behind the second conveyor. The ultrasonic vibration device is equipped with an ultrasonic welding system for achieving full contact and welding between the flux, the workpiece substrate, and the cemented carbide.

[0012] A transfer system includes a first transfer manipulator, a second transfer manipulator, and a workpiece transfer tray. The first transfer manipulator and the second transfer manipulator are used for transferring workpieces, and the workpiece transfer tray is used for carrying workpieces. Both the first transfer manipulator and the second transfer manipulator are arranged above the second conveyor.

[0013] Further, the material of the fixture assembly is high-temperature resistant alloy steel, and both the first conveyor and the second conveyor are high-temperature resistant chain conveyors.

[0014] Further, the inclination angle of the guiding groove is thirty degrees, and the temperature-resistant soft particles are copper, aluminum, or temperature-resistant engineering hard plastic particles with a diameter of 1 - 3 mm.

[0015] A method of using a continuous processing device for ultrasonic welding of hard and brittle materials on the surface of special-shaped parts includes the following steps:

[0016] S1: First, use the fixture assembly to clamp the workpiece to be processed, the flux, and the cemented carbide. Then place the clamped workpiece on the first conveyor and convey it through the first conveyor into the heating furnace for preheating.

[0017] S2: After heating the workpiece to the specified temperature, the first conveyor conveys the workpiece out of the heating furnace, and then use the first transfer manipulator to transfer and load it into the workpiece transfer tray on the second conveyor.

[0018] S3: Then convey the workpiece transfer tray loaded with workpieces to the specified position, that is, the position below the bottom end of the guiding groove. The temperature-resistant soft particles heated by the continuous high-frequency heating equipment are filled into the workpiece transfer tray at the specified position through the guiding groove until it is full.

[0019] S4: Then use the second transfer manipulator to transfer the full workpiece transfer tray to the ultrasonic vibration device, so that full contact and welding between the flux in the special-shaped workpiece, the workpiece substrate, and the cemented carbide can be achieved. During this process, the temperature of the special-shaped workpiece and the temperature-resistant soft particles always remains above the welding melting temperature.

[0020] S5: After welding, the special-shaped workpiece is slowly cooled to room temperature at a rate of 5 °C / min to avoid cracking caused by residual stress.

[0021] Further, the conveying speeds of the first conveyor and the second conveyor are 0.1 - 0.5 m / min.

[0022] Furthermore, the preheating temperature of the heating furnace is 300 - 400 °C, and the preheating time is 3 - 5 minutes.

[0023] Furthermore, the continuous high-frequency heating device adopts a rotary induction coil design, with a working frequency of 50 - 100 kHz, a power of 5 - 20 kW, and a heating temperature of 800 - 1000 °C.

[0024] Furthermore, the ultrasonic vibration device has a working frequency of 20 kHz, an amplitude of 50 μm, a power of 30 - 50 W, a static pressure controlled at 50 - 100 N, and a welding time of 10 - 15 seconds.

[0025] (III) Beneficial Effects

[0026] Compared with the prior art, the present invention provides a continuous processing device and method for ultrasonic welding of hard and brittle materials on the surface of special-shaped parts, having the following beneficial effects:

[0027] In the present invention, through the synergistic effect of continuous heating and ultrasonic welding, the full contact between the welding flux and the material is ensured, the welding stress is reduced, the fragmentation of cemented carbide is avoided, and the welding quality is improved; the use of temperature-resistant soft particles instead of traditional pressure heads simplifies the equipment structure, reduces the equipment cost and production maintenance cost; the production method of continuous heating and continuous welding significantly improves the production efficiency, reduces the downtime, and is suitable for large-scale production; the harsh working environment of manual flame brazing is avoided, the energy waste and environmental pollution are reduced, and the production safety is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 is a schematic diagram of the fixture assembly structure of the present invention;

[0030] Figure 3 is a schematic diagram of the special-shaped workpiece structure of the present invention.

[0031] In the figure: 1, workpiece base; 2, welding flux; 3, cemented carbide; 4, special-shaped workpiece; 5, fixture assembly; 10, first conveyor; 20, second conveyor; 30, heating furnace; 40, continuous high-frequency heating device; 41, temperature-resistant soft particle; 50, transfer manipulator one; 60, transfer manipulator two; 70, workpiece transfer disk; 80, guiding groove; 90, ultrasonic vibration device. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] Embodiment

[0034] As Figures 1-3 shown, a continuous processing device for ultrasonic welding hard and brittle materials on the surface of a special-shaped part proposed in an embodiment of the present invention includes:

[0035] A fixture assembly 5 for clamping and fixing the special-shaped workpiece 4 to be processed. The special-shaped workpiece 4 is a hammer head, which is composed of a workpiece base body 1, a welding flux 2, and a cemented carbide 3. The fixture assembly 5 can fix the hammer head to ensure that the special-shaped workpiece 4 does not shift during the welding process. The material of the fixture assembly 5 is high-temperature-resistant alloy steel, such as No. 45 steel, to improve the stability during long-term use.

[0036] A conveying system for continuously conveying the clamped workpiece. The conveying system includes a first conveyor 10 and a second conveyor 20. The second conveyor 20 is arranged behind the first conveyor 10. Both the first conveyor 10 and the second conveyor 20 are high-temperature-resistant chain conveyors.

[0037] A heating system including a heating furnace 30 for preheating the workpiece and a continuous high-frequency heating device 40 for heating the temperature-resistant soft particles 41. The temperature-resistant soft particles 41 are copper, aluminum, or temperature-resistant engineering hard plastic particles with a diameter of 1-3 mm. The heating furnace 30 is installed on the first conveyor 10. The continuous high-frequency heating device 40 is arranged above the second conveyor 20. A guiding groove 80 for discharging materials is installed on the continuous high-frequency heating device 40. The inclination angle of the guiding groove 80 is thirty degrees. The temperature-resistant soft particles 41 are conveyed by vibration assistance to ensure that the materials flow out of the guiding groove 80 conveniently.

[0038] An ultrasonic vibration device 90 is arranged behind the second conveyor 20. The ultrasonic vibration device 90 is equipped with an ultrasonic welding system for realizing the full contact and welding between the welding flux 2 and the workpiece base body 1 and the cemented carbide 3.

[0039] A transfer system includes a first transfer manipulator 50, a second transfer manipulator 60, and a workpiece transfer tray 70. The first transfer manipulator 50 and the second transfer manipulator 60 are used for transferring workpieces. The workpiece transfer tray 70 is used for carrying workpieces. Both the first transfer manipulator 50 and the second transfer manipulator 60 are arranged above the second conveyor 20.

[0040] A method for using a continuous processing device for ultrasonic welding of hard and brittle materials on the surface of a special-shaped part, comprising the following steps:

[0041] S1: First, use the fixture assembly 5 to clamp the special-shaped workpiece 4 to be processed, and then place the clamped workpiece on the first conveyor 10. Through the conveyance of the first conveyor 10, it enters the heating furnace 30 for preheating;

[0042] S2: After the workpiece is heated to the specified temperature, the first conveyor 10 conveys the special-shaped workpiece 4 and the fixture assembly 5 out of the heating furnace 30, and then use the first transfer manipulator 50 to transfer and load them into the workpiece transfer tray 70 on the second conveyor 20;

[0043] S3: Then, through the second conveyor 20, the workpiece transfer tray 70 filled with workpieces is conveyed to the specified position, that is, the position below the bottom end of the guiding groove 80. The temperature-resistant soft particles 41 heated by the continuous high-frequency heating device 40 are filled into the workpiece transfer tray 70 at the specified position through the guiding groove 80 until it is filled up;

[0044] S4: Then use the second transfer manipulator 60 to transfer the filled workpiece transfer tray 70 to the ultrasonic vibration device 90, so that sufficient contact and welding between the welding flux 2, the workpiece substrate 1 and the cemented carbide 3 can be achieved. During this process, the temperature of the special-shaped workpiece 4 and the temperature-resistant soft particles 41 always remains above the welding melting temperature;

[0045] S5: After welding, the special-shaped workpiece 4 is slowly cooled to room temperature at a rate of 5 °C / min to avoid cracking caused by residual stress.

[0046] In this embodiment, the conveying speeds of the first conveyor 10 and the second conveyor 20 are 0.1 - 0.5 m / min to ensure that the workpiece smoothly enters the heating furnace 30; the preheating temperature of the heating furnace 30 is 300 - 400 °C, and the preheating time is 3 - 5 minutes to reduce the energy consumption of subsequent high-frequency heating; the continuous high-frequency heating device 40 adopts a rotary induction coil design, with a working frequency of 50 - 100 kHz, a power of 5 - 20 kW, and a heating temperature of 800 - 1000 °C; the working frequency of the ultrasonic vibration device 90 is 20 kHz, the amplitude is 50 μm, the power is 30 - 50 W to avoid cracking of the cemented carbide 3, the static pressure is controlled at 50 - 100 N, the welding time is 10 - 15 seconds, and after the welding flux 2 (such as silver-based filler metal) melts, it penetrates into the microcracks through ultrasonic cavitation to improve the bonding strength.

[0047] It should be further noted that for the ultrasonic vibration device 90, it needs to stop for 2 hours after every 6 hours of continuous operation to prevent the transducer from overheating; the continuous high-frequency heating device 40 needs to shield electromagnetic radiation, and the operator should wear heat-insulating gloves and goggles; a ventilation and dust removal device should be set up in the temperature-resistant particle 41 filling area of the continuous high-frequency heating device 40 to avoid dust pollution.

[0048] Finally, it should be noted that the above are only the preferred embodiments of the present invention and are not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A continuous processing device for ultrasonic welding of hard and brittle materials on the surface of special-shaped parts, characterized in that ,include: A fixture assembly (5), the fixture assembly (5) is used to clamp and fix a special-shaped workpiece (4) to be processed, the special-shaped workpiece (4) is composed of a workpiece substrate (1), a flux (2) and a hard alloy (3); A conveying system, the conveying system is used for continuously conveying clamped workpieces, the conveying system comprises a first conveyor (10) and a second conveyor (20), wherein the second conveyor (20) is arranged behind the first conveyor (10); A heating system, the heating system comprising a heating furnace (30) for preheating a workpiece and a continuous high-frequency heating device (40) for heating temperature-resistant soft particles (41), the heating furnace (30) being installed on a first conveyor (10), the continuous high-frequency heating device (40) being arranged above a second conveyor (20), and a guide trough (80) for discharging materials being installed on the continuous high-frequency heating device (40); An ultrasonic vibration device (90), the ultrasonic vibration device (90) being arranged behind the second conveyor (20), and the ultrasonic vibration device (90) being equipped with an ultrasonic welding system for achieving full contact and welding between the flux (2) and the workpiece substrate (1) and the cemented carbide (3); The transfer system comprises a first transfer robot (50), a second transfer robot (60) and a workpiece transfer tray (70), wherein the first transfer robot (50) and the second transfer robot (60) are used for transferring workpieces, and the workpiece transfer tray (70) is used for carrying workpieces, and the first transfer robot (50) and the second transfer robot (60) are both arranged above the second conveyor (20).

2. The continuous processing device for ultrasonic welding hard and brittle materials on the surface of special-shaped parts according to claim 1 is characterized in that: The material of the clamp assembly (5) is high temperature resistant alloy steel, and the first conveyor (10) and the second conveyor (20) are both high temperature resistant chain conveyors.

3. The continuous processing device for ultrasonic welding hard and brittle materials on the surface of special-shaped parts according to claim 1 is characterized in that: The inclination angle of the guide groove (80) is thirty degrees, and the temperature-resistant soft particles (41) are copper, aluminum or temperature-resistant engineering hard plastic particles with a diameter of 1-3 mm.

4. The method for using the continuous processing device for ultrasonic welding hard and brittle materials on the surface of a special-shaped part according to any one of claims 1 to 3, characterized in that: The steps include: S1: First, a clamp assembly (5) is used to clamp a special-shaped workpiece (4) to be processed, and then the clamped workpiece is placed on a first conveyor (10), and is transported by the first conveyor (10) to a heating furnace (30) for preheating; S2: After the workpiece is heated to a specified temperature, the first conveyor (10) conveys the irregular-shaped workpiece (4) and the fixture assembly (5) out of the heating furnace (30), and then uses the first transfer robot (50) to transfer and load them into the workpiece transfer tray (70) on the second conveyor (20); S3: Then, the workpiece transfer tray (70) loaded with the workpieces is conveyed to a designated position, i.e., a position below the bottom end of the guide groove (80) by the second conveyor (20), and the temperature-resistant soft particles (41) heated by the continuous high-frequency heating device (40) are filled into the workpiece transfer tray (70) at the designated position through the guide groove (80) until it is full; S4: Then, the second transfer manipulator (60) is used to transfer the filled workpiece transfer tray (70) to the ultrasonic vibration device (90), so that the flux (2) in the special-shaped workpiece (4) can be fully contacted and welded with the workpiece substrate (1) and the hard alloy (3). During this process, the temperature of the special-shaped workpiece (4) and the temperature-resistant soft particles (41) is always kept above the welding melting temperature; S5: After welding, the special-shaped workpiece (4) is slowly cooled to room temperature at a rate of 5°C / min to avoid cracking caused by residual stress.

5. The method for using the continuous processing device for ultrasonic welding hard and brittle materials on the surface of special-shaped parts according to claim 4 is characterized in that: The conveying speed of the first conveyor (10) and the second conveyor (20) is 0.1-0.5 m / min.

6. The method for using the continuous processing device for ultrasonic welding hard and brittle materials on the surface of special-shaped parts according to claim 4 is characterized in that: The preheating temperature of the heating furnace (30) is 300-400°C, and the preheating time is 3-5 minutes.

7. The method for using the continuous processing device for ultrasonic welding hard and brittle materials on the surface of special-shaped parts according to claim 4 is characterized in that: The continuous high-frequency heating device (40) adopts a rotary induction coil design, with an operating frequency of 50-100 kHz, a power of 5-20 kW, and a heating temperature of 800-1000°C.

8. The method for using the continuous processing device for ultrasonic welding hard and brittle materials on the surface of special-shaped parts according to claim 4 is characterized in that: The ultrasonic vibration device (90) has an operating frequency of 20 kHz, an amplitude of 50 μm, a power of 30-50 W, a static pressure controlled at 50-100 N, and a welding time of 10-15 seconds.

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