Sandwich type longitudinal-torsional composite vibration power ultrasonic welding transducer and method

Abstract

The invention relates to the technical field of welding devices, in particular to a sandwich type longitudinal-torsional composite vibration power ultrasonic welding transducer and method. The device comprises a connecting rod, a torsional vibration assembly, a longitudinal vibration assembly, a pre-tightening supporting assembly, an amplitude-change pole and a welding head. The external power supply is independently connected with the torsional vibration assembly to generate single torsional vibration; an external power supply is independently connected with the longitudinal vibration assembly to generate single longitudinal vibration; an external power supply adopts two phases of alternating current with the same frequency and the phase difference of 90 degrees, and the torsional vibration assembly and the longitudinal vibration assembly are connected at the same time, so that longitudinal vibration and torsional vibration of the sandwich type longitudinal-torsional composite vibration structure resonate, and the resonance frequency reaches 15KHz. Longitudinal-torsional composite vibration is achieved by improving a sandwich type longitudinal-torsional composite vibration structure, electric energy is efficiently converted into mechanical energy through the piezoelectric effect, vibration energy is amplified at a common node through the amplitude-change pole, and therefore welding efficiency and quality are improved.

Description

Technical Field

[0001] The invention relates to the technical field of welding devices, and in particular to a sandwich-type longitudinal-torsion composite vibration power ultrasonic welding transducer and a method. Background Art

[0002] With the increasing application of hard and brittle composite materials, the difficulty and requirements of their processing are constantly increasing. As the core of ultrasonic welding technology, high-power ultrasonic welding transducers are crucial. However, traditional transducers only support a single vibration mode and are difficult to cope with complex welding requirements. In response to this, technicians have explored, such as the device and method disclosed in Chinese patent CN115971631A. Although there are improvements in welding direction and welding head replacement, it still faces challenges: the efficiency of longitudinal-torsional composite vibration is low and complex; the vibration energy amplification at the common node is limited; the power supply of the torsional and longitudinal vibration components cannot be independently controlled, resulting in inflexible switching of vibration modes; the control accuracy is insufficient, and the switching process is not smooth and stable enough. Summary of the invention

[0003] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a sandwich-type longitudinal-torsional composite vibration power ultrasonic welding transducer and method.

[0004] The technical solution adopted by the present invention is as follows: A sandwich type longitudinal-torsional composite vibration power ultrasonic welding transducer, comprising the following components: The connecting rod is in the shape of a long bar, with a raised middle portion forming a shoulder, and insulating sleeves are sleeved on both sides of the shoulder; The torsional vibration component is in the form of a split ring, which is mounted outside the insulating sleeve on the front side of the shoulder and includes two torsional piezoelectric ceramic sheets for generating axially polarized ultrasonic vibrations; The longitudinal vibration component is in the form of an integrated ring, which is assembled on the outside of the insulating sleeve at the rear side of the shoulder, and includes two longitudinal vibration piezoelectric ceramic sheets for generating tangentially polarized ultrasonic vibrations; The preload support assembly includes a front cover and a rear cover located on both sides of the connecting rod, and a preload nut for locking the rear cover and the connecting rod; the torsional vibration assembly and the longitudinal vibration assembly are clamped on the connecting rod through the preload support assembly to form a sandwich-type longitudinal-torsional composite vibration structure; The horn is cone-shaped, with one end provided with a mounting hole matched with the front end cover, and the other end provided with a threaded hole matched with the welding head; the mounting hole is located at the common node of the longitudinal vibration and the torsional vibration; The welding head is matched with the amplitude transformer through the threaded hole, and its end is in contact with the workpiece.

[0005] This technical solution improves the sandwich-type longitudinal-torsional composite vibration structure to achieve vibration superposition and amplification, utilizes the piezoelectric effect to generate ultrasonic vibration, and finally transmits the amplified vibration energy to the welding head to complete the welding process of the workpiece. Specifically, the torsional vibration component is composed of two torsional piezoelectric ceramic plates, which will deform and produce axially polarized ultrasonic vibrations when subjected to an electric field. The piezoelectric ceramic plates can convert electrical energy into mechanical energy, that is, when the electric field acts on the ceramic plates, the ceramic plates will undergo a slight deformation along the direction of the electric field, and the deformation will propagate in the form of ultrasonic waves to form torsional vibrations. The longitudinal vibration component is composed of two longitudinal piezoelectric ceramic plates, which produce tangentially polarized ultrasonic vibrations. Unlike torsional vibrations, longitudinal vibrations are propagated along the length direction of the ceramic plates. When the electric field acts on the longitudinal piezoelectric ceramic plates, the ceramic plates will deform along their length direction, thereby producing longitudinal ultrasonic vibrations. The connecting rod plays the role of supporting and transmitting vibrations. The shoulder allows the torsional vibration component and the longitudinal vibration component to be respectively assembled on the front and rear sides of the connecting rod, and are isolated by insulating sleeves to avoid interference between vibrations. The front end cover and the rear end cover clamp the torsional vibration component and the longitudinal vibration component on the connecting rod through pre-tightening nuts to form a stable sandwich structure to ensure the stability of the vibration during transmission. ; When the torsional vibration component and the longitudinal vibration component are simultaneously subjected to the action of the electric field, torsional vibration and longitudinal vibration will be generated respectively; Since the two vibrations are independent of each other on the connecting rod, they are allowed to be superimposed at the same time and in the same space to form a longitudinal-torsional composite vibration; To obtain the best vibration effect, the transducer needs to ensure that its resonant frequency matches the frequency of the external power supply; By adjusting the length of the connecting rod of the transducer and the size of the piezoelectric ceramic sheet, a resonant state is achieved at a specific frequency such as 15KHz, at which time the vibration amplitude is the largest and the energy conversion efficiency is the highest; The amplitude transformer amplifies the vibration inside it and transmits the amplified vibration energy to the welding head; Since the mounting hole is located at the common node of the longitudinal vibration and the torsional vibration, the amplitude transformer receives the energy of the two vibrations at the same time and converts it into a single, amplified vibration output; The welding head is tightly connected to the amplitude transformer through a threaded hole to ensure efficient transmission of vibration energy; The end of the welding head is in contact with the workpiece, and when the vibration energy acts on the workpiece, a high-temperature and high-frequency friction effect is generated, thereby realizing the welding of the workpiece.

[0006] In addition, the sandwich-type longitudinal-torsional composite vibration power ultrasonic welding transducer and method proposed in the present invention also have the following additional technical features: According to one embodiment of the present invention, the torsional vibration piezoelectric ceramic sheets of the torsional vibration component are coaxially spaced; the polarization directions of two adjacent torsional vibration piezoelectric ceramic sheets are oppositely arranged; the same torsional vibration piezoelectric ceramic sheet is a split structure, divided into a number of small sector elements, and the polarization directions of the small sector elements are the same and are arranged along the circumferential direction.

[0007] In the technical solution, the torsional vibration piezoelectric ceramic sheets are arranged around the central axis of the connecting rod to ensure the uniformity of vibration in the circumferential direction, thereby enhancing the effect of torsional vibration; the adjacent torsional vibration piezoelectric ceramic sheets have opposite polarization directions, and under the action of the electric field, the piezoelectric ceramic sheets will deform along their polarization directions; when the adjacent ceramic sheets have opposite polarization directions, they will deform in the opposite direction when subjected to the same electric field, thereby generating a torsional torque in the circumferential direction, thereby enhancing the amplitude and efficiency of torsional vibration; the same torsional vibration piezoelectric ceramic sheet is a split structure, that is, it is divided into several small On the one hand, the sector element more finely controls the vibration behavior of each small sector element, thereby enhancing the controllability and accuracy of the overall vibration; on the other hand, the split structure is used to disperse the vibration stress and improve the durability of the ceramic sheet; each small sector element has the same polarization direction and is arranged along the circumferential direction. When the electric field acts on the entire torsional piezoelectric ceramic sheet, all small sector elements will deform in the same direction; since the small sector elements are arranged along the circumferential direction, the deformation will produce a continuous torsional torque in the circumferential direction, thereby enhancing the continuity of the torsional vibration.

[0008] According to an embodiment of the present invention, the longitudinal vibration piezoelectric ceramic sheets of the longitudinal vibration component are coaxially spaced and are an integrated structure. The polarization directions of two adjacent longitudinal vibration piezoelectric ceramic sheets are the same and are arranged along the tangent direction.

[0009] In the present technical solution, the longitudinal vibration piezoelectric ceramic sheets are arranged in a circular layout around the central axis of the connecting rod to ensure the uniformity of the vibration in the axial direction; the longitudinal vibration piezoelectric ceramic sheets of the longitudinal vibration component are an integrated structure, which is used to reduce energy loss and vibration during the vibration process; the polarization directions of two adjacent longitudinal vibration piezoelectric ceramic sheets are set to be the same because the piezoelectric ceramic sheets will deform along their polarization directions under the action of the electric field; when the polarization directions of adjacent ceramic sheets are the same, the same deformation will occur when subjected to the same electric field, thereby generating continuous longitudinal vibration in the axial direction; the tangential direction refers to the polarization direction of the ceramic sheet, which is a small angle along the axial direction and slightly biased toward the tangential direction; when an external electric field acts on the longitudinal vibration piezoelectric ceramic sheet, the ceramic sheet will deform due to the piezoelectric effect; since all ceramic sheets have the same polarization direction and are designed as an integrated structure with coaxial spacing, the deformation will generate continuous longitudinal vibration in the axial direction.

[0010] According to one embodiment of the present invention, the longitudinal vibration assembly and the preload support assembly are both connected to an external power source via electrode sheets.

[0011] This technical solution controls the intensity and direction of the electric field applied to the piezoelectric ceramic sheet by connecting the electrode sheet to an external power supply, and is used to adjust parameters such as the amplitude, frequency and phase of the longitudinal vibration to meet different welding requirements.

[0012] According to an embodiment of the present invention, the external power supply is independently connected to the torsional vibration component to generate a single torsional vibration; the external power supply is independently connected to the longitudinal vibration component to generate a single longitudinal vibration.

[0013] In this technical solution, since the power supply is independently connected, it is ensured that only a single vibration mode is generated on each component, that is, torsional vibration or longitudinal vibration, which is used to reduce interference between vibration modes and improve the accuracy of vibration.

[0014] According to one embodiment of the present invention, the external power supply uses two-phase alternating current with the same frequency but a phase difference of 90°, and simultaneously connects the torsional vibration component and the longitudinal vibration component to cause the longitudinal vibration and torsional vibration of the sandwich-type longitudinal-torsional composite vibration structure to resonate, and the resonance frequency reaches 15KHz.

[0015] This technical solution uses two-phase alternating current with the same frequency but a phase difference of 90° to achieve coordinated control of the deformation of the piezoelectric ceramic sheet, so that the longitudinal vibration and torsional vibration are carried out at the same time with a specific phase relationship, thereby achieving the generation of composite vibration; when the external power supply is 15 KHz When AC is supplied at a frequency of 100 Hz, the vibrating structure will vibrate with maximum amplitude and efficiency.

[0016] According to one embodiment of the present invention, the front end cover is cylindrical, with a groove matched with the connecting rod provided inside, and a protrusion matched with the amplitude rod provided outside, and the protrusion is located at the common node of the longitudinal vibration and the torsional vibration.

[0017] In the present technical solution, in the vibration system, a node refers to a point where the vibration displacement is zero; the protrusion on the outside of the front end cover is located at the common node of the longitudinal vibration and the torsional vibration, which means that whether it is longitudinal vibration or torsional vibration, its displacement is zero, and the common node realizes efficient conversion of vibration energy.

[0018] According to an embodiment of the present invention, the front end cover, the rear end cover, the amplitude transformer and the connecting rod are all made of high-strength steel material, and the outer surfaces of the front end cover, the rear end cover and the amplitude transformer are all provided with anti-slip surfaces.

[0019] In this technical solution, high-strength steel has high yield strength and tensile strength, and can withstand large loads and stresses, thereby ensuring that the structure can remain stable under harsh working conditions; the anti-slip surface increases the friction with the contact surface to prevent the components from sliding or falling off under vibration or external force.

[0020] To achieve the above-mentioned purpose, the present invention also provides a sandwich-type longitudinal-torsional composite vibration power ultrasonic welding energy conversion method.

[0021] A sandwich type longitudinal-torsion composite vibration power ultrasonic welding energy conversion method, comprising the following steps: S1: Connect the electrode sheet to the external power supply: Connect the electrodes of the torsional vibration component and the longitudinal vibration component to the positive and negative poles of the external power supply through the electrode sheet; select appropriate voltage and current gears. If independent power supply is required, configure two independent power supply channels, corresponding to the torsional vibration component and the longitudinal vibration component respectively; S11: Single vibration mode: S111: Start the torsional vibration mode: switch the external power supply to the channel for powering the torsional vibration component, gradually increase the voltage, and observe the response of the torsional vibration piezoelectric ceramic piece until a stable axial polarized ultrasonic torsional vibration is generated; S112: Start the longitudinal vibration mode: switch the external power supply to the channel for powering the longitudinal vibration component, gradually increase the voltage, and observe the response of the longitudinal vibration piezoelectric ceramic piece until a stable tangential polarization ultrasonic longitudinal vibration is generated; S12: Compound vibration mode: prepare an AC power supply that outputs two phases of the same frequency but with a phase difference of 90°, set the frequency of the power supply to 15KHz, and ensure that it matches the resonance frequency of the sandwich longitudinal-torsional compound vibration structure; connect the two-phase AC to the electrodes of the torsional vibration component and the longitudinal vibration component respectively, and ensure that the voltage and current settings of the two channels are the same to maintain a stable compound vibration mode; S2: Ultrasonic welding transducer: The vibration energy is transmitted to the horn through the front cover, and the horn amplifies the vibration at the common node of the longitudinal vibration and the torsional vibration; the welding head receives and concentrates the amplified vibration energy, and the end of the welding head is in close contact with the workpiece to be welded, allowing the vibration energy to act on the workpiece to complete the welding operation.

[0022] This technical solution ensures that the vibration component works in a preset mode by connecting the electrode sheet to an external power supply; in a single vibration mode, there are two types of starting torsional vibration and longitudinal vibration respectively, by gradually increasing the voltage and observing the response of the piezoelectric ceramic sheet until stable torsional and longitudinal vibrations are generated; in a composite vibration mode, it introduces an AC power supply that outputs two phases of the same frequency but with a phase difference of 90° to achieve simultaneous power supply to the torsional vibration component and the longitudinal vibration component, ensuring that the vibration component vibrates at the same frequency, and also through the control of the phase difference to achieve coordination and superposition of longitudinal vibration and torsional vibration, thereby forming a composite vibration mode; in the ultrasonic welding transduction stage, the vibration energy is transmitted to the amplitude transformer through the front end cover, and is amplified at the common node of the longitudinal vibration and the torsional vibration, the amplified vibration energy is received and concentrated by the welding head, and then acts on the workpiece to be welded, thereby completing the welding operation.

[0023] Compared with the prior art, the present invention has the following beneficial effects: (1) The longitudinal-torsional composite vibration is realized by improving the sandwich longitudinal-torsional composite vibration structure, the piezoelectric effect is used to efficiently convert electrical energy into mechanical energy, and the vibration energy is amplified at the common node through the amplitude rod, thereby improving the welding efficiency and quality; (2) By independently controlling the power supply of the torsional vibration component and the longitudinal vibration component, a single vibration mode and a compound vibration mode can be realized respectively to meet different welding requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a cross-sectional view of the present invention.

[0025] Figure 2 It is a perspective view of the present invention.

[0026] Figure 3 This is a schematic diagram of the electrode structure. Figure 4 It is a schematic diagram of the structure of the torsional vibration component.

[0027] Figure 5 It is a structural schematic diagram of the longitudinal vibration component.

[0028] In the figure: 1. connecting rod; 2. pre-tightening nut; 3. rear end cover; 4. electrode sheet; 5. front end cover; 6. amplitude transformer; 7. welding head; 8. insulating sleeve; 9. torsional vibration piezoelectric ceramic sheet; 10. longitudinal vibration piezoelectric ceramic sheet. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Example 1 like Figures 1 to 5 As shown, this embodiment provides a sandwich-type longitudinal-torsional composite vibration power ultrasonic welding transducer, comprising the following components: The connecting rod 1 is in the shape of a long rod, the middle of which is raised to form a shoulder, and insulating sleeves 8 are sleeved on both sides of the shoulder; The torsional vibration component is in a split ring shape, which is assembled on the outside of the insulating sleeve 8 on the front side of the shoulder, and includes two torsional vibration piezoelectric ceramic sheets 9 for generating axially polarized ultrasonic vibrations; The longitudinal vibration component is in the form of an integrated ring, which is mounted on the outside of the insulating sleeve 8 at the rear side of the shoulder, and includes two longitudinal vibration piezoelectric ceramic sheets for generating tangentially polarized ultrasonic vibrations; The preload support assembly includes a front cover 5 and a rear cover 3 located on both sides of the connecting rod 1, and a preload nut 2 for locking the rear cover 3 and the connecting rod 1; the torsional vibration assembly and the longitudinal vibration assembly are clamped on the connecting rod 1 through the preload support assembly to form a sandwich-type longitudinal-torsional composite vibration structure; The horn 6 is cone-shaped, one end of which is provided with a mounting hole matched with the front end cover 5, and the other end of which is provided with a threaded hole matched with the welding head 7; the mounting hole is located at the common node of the longitudinal vibration and the torsional vibration; The welding head 7 is matched with the amplitude transformer 6 through the threaded hole, and its end is in contact with the workpiece.

[0031] like Figures 1 to 5As shown, the technical solution improves the sandwich-type longitudinal-torsional composite vibration structure to achieve vibration superposition and amplification, utilizes the piezoelectric effect to generate ultrasonic vibration, and finally transmits the amplified vibration energy to the welding head 7 to complete the welding process of the workpiece. Specifically, the torsional vibration component is composed of two torsional piezoelectric ceramic sheets 9, which will deform and produce axially polarized ultrasonic vibrations when subjected to an electric field. The piezoelectric ceramic sheets can convert electrical energy into mechanical energy, that is, when the electric field acts on the ceramic sheets, the ceramic sheets will undergo a slight deformation along the direction of the electric field, and the deformation will propagate in the form of ultrasonic waves to form torsional vibrations. The longitudinal vibration component is composed of two longitudinal piezoelectric ceramic sheets, which produce tangentially polarized ultrasonic vibrations. Unlike torsional vibrations, longitudinal vibrations are propagated along the length direction of the ceramic sheets. When the electric field acts on the longitudinal piezoelectric ceramic sheets, the ceramic sheets will deform along their length direction, thereby producing longitudinal ultrasonic vibrations. The connecting rod 1 plays the role of supporting and transmitting vibrations. The shoulders enable the torsional vibration component and the longitudinal vibration component to be respectively assembled on the front and rear sides of the connecting rod 1, and are isolated by the insulating sleeve 8 to avoid interference between vibrations. The front end cover 5 and the rear end cover 3 clamp the torsional vibration component and the longitudinal vibration component on the connecting rod 1 through the pre-tightening nut 2 to form a stable sandwich structure to ensure the stability of the vibration during the transmission process. ; When the torsional vibration component and the longitudinal vibration component are simultaneously subjected to the action of the electric field, torsional vibration and longitudinal vibration will be generated respectively; since the two vibrations are independent of each other on the connecting rod 1, they are allowed to be superimposed at the same time and in the same space to form a longitudinal-torsional composite vibration; in order to obtain the best vibration effect, the transducer needs to ensure that its resonant frequency matches the frequency of the external power supply; by adjusting the length of the connecting rod 1 of the transducer and the size of the piezoelectric ceramic sheet, a resonant state is reached at a specific frequency such as 15KHz, at which time the vibration amplitude is the largest and the energy conversion efficiency is the highest; the amplitude transformer 6 amplifies the vibration inside it and transmits the amplified vibration energy to the welding head 7; since the mounting hole is located at the common node of the longitudinal vibration and the torsional vibration, the amplitude transformer 6 receives the energy of the two vibrations at the same time and converts it into a single, amplified vibration output; the welding head 7 is tightly connected to the amplitude transformer 6 through a threaded hole to ensure efficient transmission of vibration energy; the end of the welding head 7 is in contact with the workpiece, and when the vibration energy acts on the workpiece, a high-temperature and high-frequency friction effect is generated, thereby realizing the welding of the workpiece.

[0032] In addition, the sandwich-type longitudinal-torsional composite vibration power ultrasonic welding transducer and method proposed in the present invention also have the following additional technical features: According to one embodiment of the present invention, the torsional vibration piezoelectric ceramic sheets 9 of the torsional vibration component are coaxially spaced; the polarization directions of two adjacent torsional vibration piezoelectric ceramic sheets 9 are oppositely arranged; the same torsional vibration piezoelectric ceramic sheet 9 is a split structure, divided into a number of small sector elements, and the polarization directions of the small sector elements are the same and are arranged along the circumferential direction.

[0033] In the present technical solution, the torsional vibration piezoelectric ceramic sheets 9 are arranged around the central axis of the connecting rod 1 to ensure the uniformity of vibration in the circumferential direction, thereby enhancing the effect of torsional vibration; the adjacent torsional vibration piezoelectric ceramic sheets 9 have opposite polarization directions, and under the action of the electric field, the piezoelectric ceramic sheets will deform along their polarization directions; when the adjacent ceramic sheets have opposite polarization directions, they will deform in the opposite direction when subjected to the same electric field, thereby generating a torsional torque in the circumferential direction, thereby enhancing the amplitude and efficiency of torsional vibration; the same torsional vibration piezoelectric ceramic sheet 9 is a split structure, that is, it is divided into several On the one hand, the small sector elements can more finely control the vibration behavior of each small sector element, thereby enhancing the controllability and accuracy of the overall vibration; on the other hand, the split structure is used to disperse the vibration stress and improve the durability of the ceramic sheet; each small sector element has the same polarization direction and is arranged along the circumferential direction. When the electric field acts on the entire torsional piezoelectric ceramic sheet 9, all small sector elements will deform in the same direction; since the small sector elements are arranged along the circumferential direction, the deformation will generate a continuous torsional torque in the circumferential direction, thereby enhancing the continuity of the torsional vibration.

[0034] According to an embodiment of the present invention, the longitudinal vibration piezoelectric ceramic sheets of the longitudinal vibration component are coaxially spaced and are an integrated structure. The polarization directions of two adjacent longitudinal vibration piezoelectric ceramic sheets are the same and are arranged along the tangent direction.

[0035] In the present technical solution, the longitudinal vibration piezoelectric ceramic sheets are arranged in a circular layout around the central axis of the connecting rod 1 to ensure the uniformity of the vibration in the axial direction; the longitudinal vibration piezoelectric ceramic sheets of the longitudinal vibration component are an integrated structure, which is used to reduce energy loss and during the vibration process; the polarization directions of two adjacent longitudinal vibration piezoelectric ceramic sheets are set to be the same because under the action of the electric field, the piezoelectric ceramic sheets will deform along their polarization directions; when the polarization directions of adjacent ceramic sheets are the same, the same deformation will occur when subjected to the same electric field, thereby generating continuous longitudinal vibrations in the axial direction; the tangential direction refers to the polarization direction of the ceramic sheet, which is a small angle along the axial direction and slightly biased toward the tangential direction; when an external electric field acts on the longitudinal vibration piezoelectric ceramic sheet, the ceramic sheet will deform due to the piezoelectric effect; since all ceramic sheets have the same polarization direction and are designed as an integrated structure with coaxial spacing, the deformation will generate continuous longitudinal vibrations in the axial direction.

[0036] like Figure 3 As shown, the longitudinal vibration assembly and the preload support assembly are both connected to an external power source via an electrode sheet 4 .

[0037] This technical solution controls the intensity and direction of the electric field applied to the piezoelectric ceramic sheet by connecting the electrode sheet 4 to an external power source, and is used to adjust parameters such as the amplitude, frequency and phase of the longitudinal vibration to meet different welding requirements.

[0038] According to an embodiment of the present invention, the external power supply is independently connected to the torsional vibration component to generate a single torsional vibration; the external power supply is independently connected to the longitudinal vibration component to generate a single longitudinal vibration.

[0039] In this technical solution, since the power supply is independently connected, it is ensured that only a single vibration mode is generated on each component, that is, torsional vibration or longitudinal vibration, which is used to reduce interference between vibration modes and improve the accuracy of vibration.

[0040] According to one embodiment of the present invention, the external power supply uses two-phase alternating current with the same frequency but a phase difference of 90°, and simultaneously connects the torsional vibration component and the longitudinal vibration component to cause the longitudinal vibration and torsional vibration of the sandwich-type longitudinal-torsional composite vibration structure to resonate, and the resonance frequency reaches 15KHz.

[0041] This technical solution achieves coordinated control of the deformation of the piezoelectric ceramic sheet by using two-phase alternating current with the same frequency but a phase difference of 90°, so that the longitudinal vibration and the torsional vibration occur at the same time with a specific phase relationship, thereby achieving the generation of composite vibration; when the external power supply provides alternating current at a frequency of 15KHz, the vibrating structure will vibrate with the maximum amplitude and efficiency.

[0042] According to one embodiment of the present invention, the front end cover 5 is cylindrical, with a groove matched with the connecting rod 1 inside, and a protrusion matched with the amplitude rod 6 outside, and the protrusion is located at the common node of the longitudinal vibration and the torsional vibration.

[0043] In the present technical solution, in the vibration system, a node refers to a point where the vibration displacement is zero; the protrusion on the outside of the front end cover 5 is located at the common node of the longitudinal vibration and the torsional vibration, which means that whether it is the longitudinal vibration or the torsional vibration, the displacement is zero, and the common node realizes efficient conversion of vibration energy.

[0044] According to one embodiment of the present invention, the front end cover 5, the rear end cover 3, the amplitude transformer 6 and the connecting rod 1 are all made of high-strength steel material, and the outer surfaces of the front end cover 5, the rear end cover 3 and the amplitude transformer 6 are all provided with anti-slip surfaces.

[0045] In this technical solution, high-strength steel has high yield strength and tensile strength, and can withstand large loads and stresses, thereby ensuring that the structure can remain stable under harsh working conditions; the anti-slip surface increases the friction with the contact surface to prevent the components from sliding or falling off under vibration or external force.

[0046] Example 2 Based on Example 1, Figures 1 to 5As shown, this embodiment provides a sandwich type longitudinal-torsional composite vibration power ultrasonic welding transducer method, comprising the following steps: S1: Connecting the electrode sheet to the external power supply: Connect the electrodes of the torsional vibration component and the longitudinal vibration component to the positive and negative electrodes of the external power supply through the electrode sheet 4; select appropriate voltage and current gears. If independent power supply is required, configure two independent power supply channels respectively, corresponding to the torsional vibration component and the longitudinal vibration component; S11: Single vibration mode: S111: Start the torsional vibration mode: switch the external power supply to the channel for powering the torsional vibration component, gradually increase the voltage, and observe the response of the torsional vibration piezoelectric ceramic piece 9 until a stable axial polarized ultrasonic torsional vibration is generated; S112: Start the longitudinal vibration mode: switch the external power supply to the channel for powering the longitudinal vibration component, gradually increase the voltage, and observe the response of the longitudinal vibration piezoelectric ceramic piece until a stable tangential polarization ultrasonic longitudinal vibration is generated; S12: Compound vibration mode: prepare an AC power supply that outputs two phases of the same frequency but with a phase difference of 90°, set the frequency of the power supply to 15KHz, and ensure that it matches the resonance frequency of the sandwich longitudinal-torsional compound vibration structure; connect the two-phase AC to the electrodes of the torsional vibration component and the longitudinal vibration component respectively, and ensure that the voltage and current settings of the two channels are the same to maintain a stable compound vibration mode; S2: Ultrasonic welding transduction: The vibration energy is transmitted to the amplitude transformer 6 through the front end cover 5, and the amplitude transformer 6 amplifies the vibration at the common node of the longitudinal vibration and the torsional vibration; the welding head 7 receives and concentrates the amplified vibration energy, and the end of the welding head 7 is in close contact with the workpiece to be welded, so that the vibration energy acts on the workpiece to complete the welding operation.

[0047] The present technical solution ensures that the vibration component works in a preset mode by connecting the electrode sheet 4 to an external power supply; in a single vibration mode, there are two types of starting torsional vibration and longitudinal vibration, respectively. By gradually increasing the voltage and observing the response of the piezoelectric ceramic sheet, stable torsional and longitudinal vibrations are generated; in a composite vibration mode, it simultaneously supplies power to the torsional vibration component and the longitudinal vibration component by introducing an AC power supply that outputs two phases of the same frequency but with a phase difference of 90°, ensuring that the vibration component vibrates at the same frequency, and also realizes the coordination and superposition of longitudinal vibration and torsional vibration by controlling the phase difference, thereby forming a composite vibration mode; in the ultrasonic welding transduction stage, the vibration energy is transmitted to the amplitude transformer 6 through the front end cover 5, and is amplified at the common node of the longitudinal vibration and the torsional vibration. The amplified vibration energy is received and concentrated by the welding head 7, and then acts on the workpiece to be welded, thereby completing the welding operation.

[0048] Although the present invention is described in detail by referring to the accompanying drawings and in combination with the preferred embodiments, the present invention is not limited thereto. Without departing from the spirit and essence of the present invention, a person of ordinary skill in the art may make various equivalent modifications or substitutions to the embodiments of the present invention, and these modifications or substitutions shall be within the scope of the present invention. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, and all of them shall be within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope of protection of the claims.

Claims

1. A sandwich type longitudinal-torsional composite vibration power ultrasonic welding transducer, characterized in that: Includes the following components: The connecting rod (1) is in the shape of a long rod, the middle of which is raised to form a shoulder, and insulating sleeves (8) are sleeved on both sides of the shoulder; The torsional vibration component is in the form of a split ring, which is mounted outside the insulating sleeve (8) on the front side of the shoulder, and includes two torsional vibration piezoelectric ceramic sheets (9) for generating axially polarized ultrasonic vibrations; The longitudinal vibration component is in the form of an integrated ring, which is mounted on the outside of the insulating sleeve (8) at the rear side of the shoulder, and includes two longitudinal vibration piezoelectric ceramic sheets (10) for generating tangentially polarized ultrasonic vibrations; A pre-tightening support assembly comprises a front end cover (5) and a rear end cover (3) located on both sides of a connecting rod (1), and a pre-tightening nut (2) for locking the rear end cover (3) and the connecting rod (1); the torsional vibration assembly and the longitudinal vibration assembly are clamped on the connecting rod (1) through the pre-tightening support assembly to form a sandwich-type longitudinal-torsional composite vibration structure; The horn (6) is in the shape of a cone, one end of which is provided with a mounting hole matched with the front end cover (5), and the other end of which is provided with a threaded hole matched with the welding head (7); the mounting hole is located at the common node of the longitudinal vibration and the torsional vibration; The welding head (7) is matched with the amplitude transformer (6) through the threaded hole, and the end of the welding head (7) is in contact with the workpiece.

2. The sandwich type longitudinal-torsional composite vibration power ultrasonic welding transducer according to claim 1, characterized in that: The torsional vibration piezoelectric ceramic sheets (9) of the torsional vibration component are coaxially spaced and arranged; the polarization directions of two adjacent torsional vibration piezoelectric ceramic sheets (9) are arranged in opposite directions; the same torsional vibration piezoelectric ceramic sheet (9) is a split structure, divided into a plurality of small sector elements, and the polarization directions of the small sector elements are the same and arranged along the circumferential direction.

3. The sandwich type longitudinal-torsional composite vibration power ultrasonic welding transducer according to claim 1, characterized in that: The longitudinal vibration piezoelectric ceramic sheets (10) of the longitudinal vibration component are coaxially arranged at intervals, the longitudinal vibration piezoelectric ceramic sheets (10) are an integrated structure, and the polarization directions of two adjacent longitudinal vibration piezoelectric ceramic sheets (10) are the same and are arranged along the tangent direction.

4. The sandwich type longitudinal-torsional composite vibration power ultrasonic welding transducer according to claim 1, characterized in that: The longitudinal vibration component and the pre-tightening support component are both connected to an external power source via an electrode sheet (4).

5. The sandwich type longitudinal-torsional composite vibration power ultrasonic welding transducer as claimed in claim 4, characterized in that: The external power source is independently connected to the torsional vibration component to generate a single torsional vibration; the external power source is independently connected to the longitudinal vibration component to generate a single longitudinal vibration.

6. The sandwich type longitudinal-torsional composite vibration power ultrasonic welding transducer as claimed in claim 4, characterized in that: The external power supply uses two-phase alternating current with the same frequency but a phase difference of 90°, and simultaneously connects the torsional vibration component and the longitudinal vibration component, so that the longitudinal vibration and torsional vibration of the sandwich-type longitudinal-torsional composite vibration structure resonate, and the resonance frequency reaches 15KHz.

7. The sandwich type longitudinal-torsional composite vibration power ultrasonic welding transducer according to claim 1, characterized in that: The front end cover (5) is cylindrical, with a groove inside thereof matching with the connecting rod (1), and a protrusion outside thereof matching with the amplitude transformer (6), the protrusion being located at a common node of the longitudinal vibration and the torsional vibration.

8. The sandwich type longitudinal-torsional composite vibration power ultrasonic welding transducer according to claim 1, characterized in that: The front end cover (5), the rear end cover (3), the amplitude change rod (6) and the connecting rod (1) are all made of high-strength steel material, and the outer surfaces of the front end cover (5), the rear end cover (3) and the amplitude change rod (6) are all provided with anti-slip surfaces.

9. A sandwich type longitudinal-torsion composite vibration power ultrasonic welding transducer method, using the sandwich type longitudinal-torsion composite vibration power ultrasonic welding transducer as claimed in any one of claims 1 to 8, characterized in that: The steps include: S1: connecting the electrode sheet to the external power supply: connecting the electrodes of the torsional vibration component and the longitudinal vibration component to the positive and negative electrodes of the external power supply via the electrode sheet (4); selecting appropriate voltage and current gears; if independent power supply is required, configuring two independent power supply channels, corresponding to the torsional vibration component and the longitudinal vibration component respectively; S11: Single vibration mode: S111: Start the torsional vibration mode: switch the external power supply to the channel for powering the torsional vibration component, gradually increase the voltage, and observe the response of the torsional vibration piezoelectric ceramic piece (9) until a stable axial polarized ultrasonic torsional vibration is generated; S112: starting the longitudinal vibration mode: switching the external power supply to the channel for powering the longitudinal vibration component, gradually increasing the voltage, and observing the response of the longitudinal vibration piezoelectric ceramic piece (10) until a stable tangential polarization ultrasonic longitudinal vibration is generated; S12: Compound vibration mode: prepare an AC power supply that outputs two phases of the same frequency but with a phase difference of 90°, set the frequency of the power supply to 15KHz, and ensure that it matches the resonance frequency of the sandwich longitudinal-torsional compound vibration structure; connect the two-phase AC to the electrodes of the torsional vibration component and the longitudinal vibration component respectively, and ensure that the voltage and current settings of the two channels are the same to maintain a stable compound vibration mode; S2: Ultrasonic welding energy conversion: The vibration energy is transmitted to the amplitude transformer (6) through the front end cover (5), and the amplitude transformer (6) amplifies the vibration at the common node of the longitudinal vibration and the torsional vibration; the welding head (7) receives and concentrates the amplified vibration energy, and the end of the welding head (7) is in close contact with the workpiece to be welded, so that the vibration energy acts on the workpiece to complete the welding operation.

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