Ultrasonic composite vibration device and ultrasonic bonding device

Abstract

Provided is an ultrasonic composite vibration device, and the like, that is configured such that a plurality of oscillating elements are coupled, and improves the stability of the coupling state. In a mid-section of the ultrasonic composite vibration device 1, a first vibration element 11 and an intermediate vibration element 10 are co-axially coupled in one designated coupling location contained in a range within a phase angle of 0.05π based on the antinodes A (M1) of a longitudinal standing wave M1, and contained in a range within a phase angle of 0.22π based on the nodes N (M2) of a torsional standing wave M2. Likewise, in mid-section of the ultrasonic composite vibration device 1, the intermediate vibration element 10 and a second vibration element 12 are co-axially coupled by a mechanical coupling mechanism in another designated coupling location.

Description

Ultrasonic complex vibration device and ultrasonic bonding device using the same

[0001] The present invention relates to an ultrasonic complex vibration device and an ultrasonic bonding device using the same.

[0002] A composite vibration element for an ultrasonic processing machine has been proposed in which the conditions for having common nodal planes and antinodes at the adjacent resonant frequencies of the longitudinal vibration and torsional vibration that make up the composite vibration are determined in advance, and the composite vibration element is supported at the nodal planes (see, for example, Patent Document 1). This reduces vibration loss at the support surfaces while maintaining the high rigidity of the composite vibration element, and improves the positioning accuracy of the tip.

[0003] Patent No. 5036124

[0004] The composite vibration element is composed of two vibration elements connected at a common nodal plane at the resonant frequencies of the longitudinal and torsional vibrations, and therefore a relatively large mechanical load is applied to the connection point of the two vibration elements due to the vibrations, which may cause the connection to become unstable.

[0005] Therefore, an object of the present invention is to provide an ultrasonic complex vibration device or the like that is configured by connecting a plurality of vibration elements and that can improve the stability of the connected state.

[0006] The ultrasonic complex vibration device of the present invention is an ultrasonic complex vibration element that induces complex vibration by combining longitudinal vibration and torsional vibration, and comprises: a first vibration element having an electrostrictive vibrator that generates longitudinal vibration; and a second vibration element having a slit and a frequency adjustment element for converting longitudinal vibration into torsional vibration; the first vibration element and the second vibration element are coaxially connected at a first designated connection point that is within a phase angle range of 0.05π based on an antinode of a standing wave of the longitudinal vibration and within a phase angle range of 0.22π based on a node of a standing wave of the torsional vibration; and the first vibration element or the second vibration element is configured to be supported at a designated support point where a node of at least one of the standing wave of the longitudinal vibration and the standing wave of the torsional vibration is present.

[0007] In the ultrasonic complex vibration device according to claim 1, it is preferable that at least one of the first vibration element and the second vibration element is composed of a plurality of vibration elements, and the plurality of vibration elements are coaxially connected at second designated connection points that are included in a range of a phase angle of 0.05π or less with respect to an antinode of the standing wave of the longitudinal vibration and that are included in a range of a phase angle of 0.22π or less with respect to a node of the standing wave of the torsional vibration.

[0008] In the ultrasonic complex vibration device having the above configuration, it is preferable that the second vibration element has a shape in which a columnar portion and a cylindrical portion are coaxially continuous at a location included in a range of a phase angle of 0.22π or less based on a node of the standing wave of the torsional vibration, and the slit is provided in the columnar portion within a range of a phase angle of 0.20π or less based on a node of the standing wave of the torsional vibration.

[0009] In the ultrasonic complex vibration device having the above configuration, it is preferable that the frequency adjustment element is located rearward of the slit in the second vibration element.

[0010] In the ultrasonic complex vibration device having the above configuration, it is preferable that a node of a standing wave of the torsional vibration exists at the designated support location.

[0011] In the ultrasonic complex vibration device having the above configuration, it is preferable that the first vibration element and the second vibration element are coaxially connected at the first designated connecting point via an intermediate member.

[0012] In the ultrasonic complex vibration device having the above configuration, it is preferable that the plurality of vibration elements are coaxially connected at the second designated connection points via an intermediate member.

[0013] The ultrasonic joining device of the present invention includes the ultrasonic complex vibration device, a horn tip attached to the tip of the second vibration element, and an anvil positioned opposite the horn tip and supporting the workpieces to be joined.

[0014] FIG. 1 is a structural diagram of an ultrasonic composite vibration device and an ultrasonic bonding device according to a first embodiment of the present invention. FIG. 2 is a structural diagram of a coupling mode of vibration elements constituting the ultrasonic composite vibration device according to the first embodiment of the present invention. FIG. 3 is a structural diagram of a second vibration element according to the first embodiment. FIG. 4 is a structural diagram of a second vibration element according to another embodiment. FIG. 5 is a structural diagram of a second vibration element according to a first modified embodiment. FIG. 6 is a structural diagram of a second vibration element according to a second modified embodiment. FIG. 7 is a diagram illustrating the relationship between the depth and length of slits in an ultrasonic composite vibration system and the torsional resonance frequency. FIG. 8 is a structural diagram of a coupling mode of vibration elements constituting the ultrasonic composite vibration device according to the second embodiment of the present invention. FIG. 9 is a structural diagram of a coupling mode of vibration elements constituting the ultrasonic composite vibration device according to the third embodiment of the present invention. FIG. 10 is a structural diagram of a coupling mode of vibration elements constituting the ultrasonic composite vibration device according to the fourth embodiment of the present invention. FIG. 11 is a structural diagram of a coupling mode of vibration elements constituting the ultrasonic composite vibration device according to the fifth embodiment of the present invention.

[0015] 1 is a component of an ultrasonic bonding apparatus that bonds workpieces W1 and W2, such as metal plates, using ultrasonic complex vibrations. The ultrasonic bonding apparatus is used, for example, to bond electrodes of lithium-ion batteries and / or semiconductor devices, or to bond metals of the same or different types.

[0016] 1, the ultrasonic complex vibration device 1 includes a substantially cylindrical first vibration element 11, a substantially cylindrical, cylindrical, or bottomed cylindrical intermediate vibration element 10, and a substantially cylindrical or bottomed cylindrical second vibration element 12. The ultrasonic bonding device includes the ultrasonic complex vibration device 1, a horn tip 16, and an anvil 18.

[0017] Fig. 2 shows the configuration of the ultrasonic composite vibration device 1 and the relationship between the longitudinal standing wave M1 and the torsional standing wave M2 generated in the ultrasonic composite vibration device 1. As shown in Fig. 2, the ultrasonic composite vibration device 1 is configured so that antinodes A (M1) of the longitudinal standing wave M1 are present on both the rear end face and the front end face of the ultrasonic composite vibration device 1.

[0018] 2, the first vibration element 11 and the intermediate vibration element 10 are coaxially connected by a mechanical connection mechanism (such as a bolt and / or clamp mechanism) at a designated connection point where one antinode A (M1) of the longitudinal vibration standing wave M1 exists and where one node N (M2) of the torsional vibration standing wave M2 exists, in the middle or intermediate portion of the ultrasonic complex vibration device 1. As shown in FIG. 2, the intermediate vibration element 10 and the second vibration element 12 are coaxially connected by a mechanical connection mechanism at a designated connection point where another antinode A (M1) of the longitudinal vibration standing wave M1 exists and where one node N (M2) of the torsional vibration standing wave M2 exists, in the middle portion of the ultrasonic complex vibration device 1. The designated connection point is defined as any point that exists within a phase angle range of 0.05π based on the antinode A (M1) of the standing wave M1 of the longitudinal vibration, and within a phase angle range of 0.22π based on the node N (M2) of the standing wave M2 of the torsional vibration.

[0019] The intermediate vibration element 10 may be a component of the first vibration element 11. That is, the first vibration element 11 may be composed of two vibration elements. In this case, the first vibration element 11 and the intermediate vibration element 10 may be integrally configured rather than being mechanically connected to each other.

[0020] The intermediate vibration element 10 may be a component of the second vibration element 12. That is, the second vibration element 12 may be composed of two vibration elements. In this case, the second vibration element 12 and the intermediate vibration element 10 may be integrally configured rather than being mechanically connected to each other.

[0021] As shown in FIG. 1, the first vibration element 11 is provided with a piezoelectric body 112 whose axial direction is the piezoelectric polarization direction.

[0022] As shown in FIG. 1 , the intermediate vibration element 10 is formed with a substantially annular plate-shaped intermediate flange 100 at a central position in the axial direction, protruding radially along its entire circumference. The intermediate vibration element 10 is configured to be clamped or supported at least at the intermediate flange 100 by a clamping mechanism (not shown) around the entire circumference. If it is ensured that the intermediate vibration element 10 is supported by a mechanical support mechanism, the intermediate flange 100 may be omitted. As shown in FIG. 1 , the intermediate vibration element 10 has a substantially cylindrical shape with a substantially constant outer diameter in the axial direction behind the intermediate flange 100 (leftward in FIG. 1 ). As shown in FIG. 1 , the intermediate vibration element 10 has a substantially cylindrical shape (a shape in which a substantially truncated conical shape and a substantially cylindrical shape are coaxially connected) with a substantially constant outer diameter after continuously tapering partway toward the tip of the intermediate vibration element 10 (rightward in FIG. 1 ).

[0023] 1, the second vibration element 12 is provided with a frequency adjustment element 120 having a generally regular octagonal shape with rounded corners that protrudes radially around the entire circumference at a midpoint in the axial direction of the second vibration element 12. The frequency adjustment element 120 adjusts the resonance frequencies of the longitudinal vibration component and the torsional vibration component of the ultrasonic vibration.

[0024] 1, the second vibration element 12 has a plurality of slits 124 formed on its outer surface behind the frequency adjustment element 120. A plurality of slits 124 may also be formed on the outer surface of the second vibration element 12 ahead of the frequency adjustment element 120. The slits 124 extend obliquely in the second vibration element 12 when viewed from the side, or extend in the axial direction while being displaced in the circumferential direction in phase with each other. N (N=2, 3, ...) slits 124 may be arranged to have N-fold rotational symmetry (e.g., N=8, 12, or 16) around the central axis of the second vibration element 12.

[0025] 3A and 3B, the second vibration element 12 has a shape in which a substantially cylindrical columnar portion 121 on the base end side and a substantially cylindrical columnar portion 122 on the tip side, which has substantially the same diameter as the cylindrical columnar portion, are coaxially connected. In other words, the second vibration element 12 is formed in a substantially cylindrical shape with a substantially cylindrical hole extending axially from the tip side and provided coaxially.

[0026] 3A, the continuous portion (bottom of the hole) of columnar portion 121 and cylindrical portion 122 is located at a position where antinode A(M2) of standing wave M2 of torsional vibration exists. Also, slit 124 is provided in cylindrical portion 122 in a phase angle range of 0.16π to 0.22π with respect to node N(M2) of standing wave M2 of torsional vibration.

[0027] 3B , the continuous portion (bottom of the hole) of columnar portion 121 and cylindrical portion 122 is within a phase angle of 0.22π from node N (M2) of standing wave M2 of torsional vibration. Also, slit 124 is provided in columnar portion 121 within a phase angle of 0.20π from antinode A (M2) of standing wave M2 of torsional vibration.

[0028] In the second vibration element 12, the amplitude amplification factor (U1 / U0), which is the ratio of the amplitude U1 of the torsional vibration at the tip 126 of the second vibration element 12 to the amplitude U0 of the torsional vibration at the tip of the slit 124, is mainly determined by the ratio of the polar moments of area T0 and T1 of the tip of the slit 124 and the tip 126 of the second vibration element 12. Specifically, the smaller T1, the greater the amplitude amplification factor (U1 / U0) of the torsional vibration. The provision of a hole continuing from the tip of the second vibration element 12 (the presence of the cylindrical portion 122) reduces the polar moment of area T1 at the tip of the second vibration element 12. The following relational expression (1) indicates that the continuous portion between the columnar portion 121 and the cylindrical portion 122 in the embodiment shown in FIG. 3B can further increase the amplification factor of the torsional vibration.

[0029] (d 2 θ(x) / dx 2)+{(dT(x) / dx) / T(x)}(dθ(x) / dx) +μ 2 θ(x)=0 (1).

[0030] Here, "θ(x)" represents the torsion angle of the torsional vibration at the axial position x of the second vibration element 12, "T(x)" represents the polar moment of inertia of the torsional vibration at the axial position x of the second vibration element 12, and "μ" represents μ = ω / c (ω: 2πf, c: the sound speed at which the torsional vibration propagates through metal).

[0031] In a modified embodiment of Fig. 3A, as shown in Fig. 4A, the frequency adjustment element 120 may be provided on the base end side of the slit 124 (provided in the cylindrical portion 122) in the second vibration element 12. In a modified embodiment of Fig. 3B, as shown in Fig. 4B, the frequency adjustment element 120 may be provided on the tip end side of the slit 124 (provided in the cylindrical portion 121) in the second vibration element 12.

[0032] 1, the second vibration element 12 is provided with a tip portion 126 that is approximately regular octagonal in shape with rounded corners and that protrudes radially around the entire circumference at the tip position in the axial direction. Holes 128 (or through holes) are formed in the tip portion 126 at a plurality of locations spaced apart in the circumferential direction. The N (N=2, 3, ...) holes 128 may be arranged to have N-fold rotational symmetry (e.g., N=4) around the central axis of the second vibration element 12. A female thread is provided on the inner surface of the hole 128.

[0033] Horn tip 16 has a substantially truncated cone-shaped base portion and a tip portion that abuts against workpiece W1, which is the uppermost of workpieces W1 and W2. A male thread provided at the base end of horn tip 16 screws into a female thread provided in hole 128 in tip portion 126 of second vibration element 12, thereby removably fixing horn tip 16 to second vibration element 12. Horn tips 16 of various shapes are available, so that horn tips 16 can be appropriately replaced depending on the type of metal to be joined, etc.

[0034] The balancer for adjusting the phase difference between the longitudinal vibration and the torsional vibration at the tip 126 of the second vibration element 12, and thus at the horn tip 16, may be removably fixed to the tip 126 of the second vibration element 12 by screwing the male thread of the balancer into the female thread of the hole 128.

[0035] The anvil 18 is disposed so as to face the front end of the horn tip 16 in the vertical direction. For example, substantially flat workpieces W1 and W2 are placed one on top of the other on the upper surface of the anvil 18. The anvil 18 may be configured to passively or actively displace up and down in response to the pressure of the horn tip 16 that it receives through the workpieces W1 and W2.

[0036] As shown in FIG. 1, the ultrasonic bonding apparatus further includes a control device 20, a high-frequency power supply device 21, a pressure device 22, a stroke sensor 24, and an interface device 26.

[0037] The high-frequency power supply device 21 is configured to apply a high-frequency AC voltage to the piezoelectric element 112 of the first vibration element 11 in response to power supplied from a commercial power source (not shown), thereby exciting the first vibration element 11 in the axial direction. The pressure device 22 includes a pressure block and is configured to apply pressure to the workpieces W1 and W2 from the horn tip 16 by displacing a support mechanism, such as a clamp mechanism, that supports the intermediate vibration element 10 using the pressure block. The stroke sensor 24 outputs a signal corresponding to the displacement of the pressure block constituting the pressure device 22. The interface device 26 is, for example, configured as a display, and displays or outputs a time series of the displacement and / or pressure of the pressure block corresponding to the output signal of the stroke sensor 24 on the display. The display may be configured as a touch panel display and be configured to accept setting operations for allowing a user to directly or indirectly specify parameters, such as a positional joining mode among multiple joining modes that define a time series pattern of a target pressure.

[0038] The control device 20 is composed of a microcomputer, an arithmetic processing device (CPU, microprocessor, processor core, etc.), and a storage device (memory such as ROM and RAM). The control device 20 is configured to control the displacement operation of the pressure block by the pressure device 22, for example, based on a time series of the displacement amount of the pressure block represented by an output signal of the stroke sensor 24. In addition to the stroke sensor 24, a pressure sensor may be provided that outputs a signal corresponding to the pressure acting on the intermediate vibration element 10 from the pressure block of the pressure device 22 (up to the pressure applied by the horn tip 16 to the workpieces W1 and W2), and the control device 20 may control the time series of the pressure to be constant or in a specified manner based on the output signal of the pressure sensor.

[0039] (Operation) In response to power being supplied to the high-frequency power supply device 21 from a commercial power source (not shown), the high-frequency power supply device 21 applies a high-frequency AC voltage to the piezoelectric body 112 of the first vibration element 11. This causes the first vibration element 11 to vibrate in its axial direction at, for example, approximately 20 kHz, generating ultrasonic vibrations. The ultrasonic vibrations are transmitted from the first vibration element 11 to the intermediate vibration element 10 in its axial direction, and the amplitude of the ultrasonic vibrations is amplified. Furthermore, the ultrasonic vibrations with amplified amplitude are transmitted from the intermediate vibration element 10 to the second vibration element 12 in its axial direction.

[0040] In this way, a portion of the longitudinal vibration component (axial component of the second vibration element 12) of the ultrasonic vibration transmitted to the second vibration element 12 is converted into a torsional vibration component by the multiple slits 124 formed on the outer surface of the second vibration element 12. Then, a composite vibration generated by combining the longitudinal vibration component and the torsional vibration component is transmitted to the horn tip 16 fixed to the tip 126 of the second vibration element 12.

[0041] In response to this, the front end of the horn tip 16 is displaced or vibrated horizontally in a circular or elliptical orbit, which removes impurities from the contact surface of the workpieces W1 and W2 and promotes plastic deformation of the contact surface of the workpieces W1 and W2.

[0042] When the first vibration element 11, the intermediate vibration element 10 and the second vibration element 12 are moved downward by the pressure device 22 and the workpieces W1 and W2 are pressed vertically by the tip of the horn tip 16, a circular or elliptical vibration is generated that is a combination of vertical and horizontal vibration components.

[0043] At this time, the vertical position of horn tip 16, and therefore the static pressure applied to workpieces W1 and W2 from the tip of horn tip 16, is adjusted by pressure device 22 so that it falls within a specified static pressure range (e.g., 200 N to 800 N). By applying composite vibration to workpieces W1 and W2 while adjusting the amount of pressing of workpieces W1 and W2 by horn tip 16 and / or the static pressure applied to workpieces W1 and W2, workpieces W1 and W2 can be solid-state joined.

[0044] (Effects) The ultrasonic complex vibration device 1 configured as described above is configured such that the multiple vibration elements, i.e., the first vibration element 11, the intermediate vibration element 10, and the second vibration element 12, are mechanically connected at designated connection points that are within a phase angle range of 0.05π with respect to the antinode A (N1) of the longitudinal vibration standing wave M1 as the reference and within a phase angle range of 0.22π with respect to the node N (M2) of the torsional vibration standing wave M2 as the reference (see FIG. 2 ). This improves the stability of the connected state.

[0045] When torsional vibration occurs in an ultrasonic complex vibration system consisting of the first vibration element 11, the intermediate vibration element 10, and the second vibration element 12 (or the first vibration element 11 and the second vibration element 12), the ultrasonic complex vibration system is significantly twisted at the slit 124. This is because the transverse elastic modulus G of the ultrasonic complex vibration system is reduced at the slit 124. The sound velocity c of the torsional vibration is given by c = (G / ρ) using the specific gravity ρ. 1 / 2 Therefore, a decrease in G results in a decrease in the torsional sound velocity c of the slit. The provision of the slit 124 results in a decrease in the torsional sound velocity c, which results in a decrease in the resonant frequency. Furthermore, by making the slit 124 longer and / or deeper, the decrease in the resonant frequency also increases.

[0046] Fig. 5 shows the change (simulation results) in the frequency of the standing wave of torsional vibration (torsional resonance frequency) with respect to the depth and length of the slits 124 in the ultrasonic complex vibration system. The solid line in Fig. 5 shows the dependency of the torsional resonance frequency on the length of the slits 124 in the ultrasonic complex vibration system when the depth of the slits 124 is 2.5 mm. The dashed line in Fig. 5 shows the dependency of the torsional resonance frequency on the length of the slits 124 in the ultrasonic complex vibration system when the depth of the slits 124 is 5.0 mm. The slits 124 are formed to extend parallel to the axial direction of the ultrasonic complex vibration system or the second vibration element 12, and are arranged at equal intervals in the circumferential direction.

[0047] As shown in Figure 5, when the solid and dashed lines are 0 mm long, i.e., when the slit 124 is not provided, the torsional resonance frequency of the ultrasonic complex vibration system is approximately 12.7 kHz. As shown by the solid line in Figure 5, as the length of the 2.5 mm deep slit 124 increases from 12 mm to 16 mm to 20 mm, the torsional resonance frequency of the ultrasonic complex vibration system decreases from approximately 12.42 kHz to approximately 12.35 kHz to approximately 12.3 kHz. As shown by the dashed line in Figure 5, as the length of the 5.0 mm deep slit 124 increases from 12 mm to 16 mm to 20 mm, the torsional resonance frequency of the ultrasonic complex vibration system decreases from approximately 11.68 kHz to approximately 11.4 kHz to approximately 11.2 kHz. The deeper the slit 124, the greater the decrease in torsional resonance frequency as the slit 124 lengthens.

[0048] In this way, by adjusting the depth and length (and further the width, opening shape, number and / or circumferential spacing) of each of the multiple slits 124, the position of the node N (M2) of the standing wave M2 of the torsional vibration in the ultrasonic complex vibration system is adjusted, and ultimately the position of the designated connecting point is adjusted so that it falls within a range of a phase angle of 0.22π based on that position.

[0049] Second Embodiment An ultrasonic composite vibration device 1 according to a second embodiment of the present invention, shown in Fig. 6, includes a first vibration element 11, an intermediate vibration element 10, and a second vibration element 12, similar to the ultrasonic composite vibration device 1 according to the first embodiment of the present invention shown in Fig. 1. The intermediate vibration element 10 has a plurality of slits 104 formed in a substantially cylindrical front portion thereof forward of the intermediate flange 100. The slits 104 extend linearly in parallel to the central axis of the intermediate vibration element 10 and are arranged at equal intervals in the circumferential direction of the intermediate vibration element 10. Other configurations of the ultrasonic composite vibration device 1 according to the second embodiment are common or substantially similar to those of the ultrasonic composite vibration device 1 according to the first embodiment. Therefore, the common configurations are denoted by the same reference numerals and will not be described again.

[0050] FIG. 6 shows the relationship between the configuration of the ultrasonic complex vibration device 1 and the standing wave M2 of torsional vibration generated in the ultrasonic complex vibration device 1. As shown in FIG. 6, one node N (M2) of the standing wave M2 of torsional vibration coincides with or overlaps the intermediate flange 100 of the intermediate vibration element 10. This is achieved by adjusting the shape, size (length, width, and / or depth (wall thickness of the front portion of the intermediate vibration element 10)) and / or the number or spacing of the slits 104 in the circumferential direction of the intermediate vibration element 10. The shapes and sizes of the slits 104 may be the same or different from each other. In the latter case, for example, the slits 104 may be classified into first and second slit groups based on their shapes and / or sizes, and the first slits constituting the first slit group and the second slits constituting the second slit group may be arranged alternately in the circumferential direction.

[0051] Third Embodiment An ultrasonic composite vibration device 1 according to a third embodiment of the present invention, shown in Fig. 7, includes a first vibration element 11, an intermediate vibration element 10, and a second vibration element 12, similar to the ultrasonic composite vibration device 1 according to the second embodiment of the present invention, shown in Fig. 6. The intermediate vibration element 10 has a plurality of slits 104 formed in a substantially cylindrical front portion thereof forward of the intermediate flange 100. In addition, the intermediate vibration element 10 has a plurality of slits 102 formed in a substantially cylindrical rear portion thereof rearward of the intermediate flange 100. The slits 102, 104 extend linearly parallel to the central axis of the intermediate vibration element 10 and are arranged at equal intervals around the circumference of the intermediate vibration element 10. Other configurations of the ultrasonic composite vibration device 1 according to the third embodiment are common or substantially similar to those of the ultrasonic composite vibration device 1 according to the second embodiment. Therefore, the common configurations are denoted by the same reference numerals and will not be described again.

[0052] FIG. 7 shows the relationship between the configuration of the ultrasonic composite vibration device 1 and the torsional standing wave M2 generated in the ultrasonic composite vibration device 1. As shown in FIG. 7 , one node N (M2) of the torsional standing wave M2 coincides with or overlaps the intermediate flange 100 of the intermediate vibration element 10. This is achieved by adjusting the shape, size (length, width, and / or depth (wall thickness of the substantially cylindrical portion of the intermediate vibration element 10)) and / or the circumferential number or circumferential spacing of each of the multiple slits 104 in the front portion of the intermediate vibration element 10, and / or the shape, size (length, width, and / or depth (wall thickness of the substantially cylindrical portion of the intermediate vibration element 10)) and / or the circumferential number or circumferential spacing of each of the multiple slits 102 in the rear portion of the intermediate vibration element 10. The shapes and sizes of the multiple slits 102, 104 may be the same or different from each other. In the latter case, for example, the plurality of slits 104 may be classified into a first slit group and a second slit group according to their shapes and / or sizes, and the first slits constituting the first slit group and the second slits constituting the second slit group may be arranged alternately in the circumferential direction. Alternatively or in addition, the plurality of slits 102 may be classified into a first slit group and a second slit group according to their shapes and / or sizes, and the first slits constituting the first slit group and the second slits constituting the second slit group may be arranged alternately in the circumferential direction.

[0053] (Fourth embodiment) An ultrasonic composite vibration device 1 according to a fourth embodiment of the present invention, shown in Fig. 8, includes a first vibration element 11, an intermediate vibration element 10, and a second vibration element 12, similar to the ultrasonic composite vibration device 1 according to the first embodiment of the present invention, shown in Fig. 1. The front portion of the intermediate vibration element 10, located in front of the intermediate flange 100, is formed so as to have a continuously decreasing diameter (approximately a truncated cone shape) toward the front end. Other configurations of the ultrasonic composite vibration device 1 according to the fourth embodiment are common or substantially similar to those of the ultrasonic composite vibration device 1 according to the first embodiment, and therefore, the common configurations are denoted by the same reference numerals and will not be described again.

[0054] Fig. 8 shows the relationship between the configuration of the ultrasonic composite vibration device 1 and the standing wave M2 of torsional vibration generated in the ultrasonic composite vibration device 1. As shown in Fig. 8, one node N (M2) of the standing wave M2 of torsional vibration coincides with or overlaps with the intermediate flange 100 of the intermediate vibration element 10. This is achieved by adjusting the change in diameter with respect to the axial position of the substantially truncated cone-shaped front portion of the intermediate vibration element 10. The side surface of the substantially truncated cone-shaped front portion of the intermediate vibration element 10 may be formed as a convex curved surface, a concave curved surface, or a combination of convex and concave curved surfaces.

[0055] Fifth Embodiment An ultrasonic composite vibration device 1 according to a fifth embodiment of the present invention, shown in Fig. 9, includes a first vibration element 11, an intermediate vibration element 10, and a second vibration element 12, similar to the ultrasonic composite vibration device 1 according to the first embodiment of the present invention shown in Fig. 1. The first vibration element 11 and the intermediate vibration element 10 are connected via a first intermediate member 141 having a substantially circular or annular plate shape and substantially the same diameter. The second vibration element 12 and the intermediate vibration element 10 are connected via a second intermediate member 142 having a substantially circular or annular plate shape and substantially the same diameter. Other configurations of the ultrasonic composite vibration device 1 according to the fifth embodiment are common or substantially similar to those of the ultrasonic composite vibration device 1 according to the first embodiment. Therefore, the common configurations are denoted by the same reference numerals and will not be described again.

[0056] Fig. 9 shows the relationship between the configuration of the ultrasonic composite vibration device 1 and the standing waves M2 of torsional vibration generated in the ultrasonic composite vibration device 1. As shown in Fig. 9, the standing waves M2 of torsional vibration are attenuated behind the slits 124 of the second vibration element 12. This is achieved by adjusting the sizes (inner diameter, outer diameter, and thickness) of the first intermediate member 141 and the second intermediate member 142. One of the first intermediate member 141 and the second intermediate member 142 may be omitted.

[0057] In each of the second to fourth embodiments, the first vibration element 11 and the intermediate vibration element 10 may be coaxially connected at a location other than the designated connection location. Additionally or alternatively, in each of the second to fourth embodiments, the intermediate vibration element 10 and the second vibration element 12 may be coaxially connected by a mechanical connection mechanism at a location other than the designated connection location.

[0058] In the fifth embodiment, the first vibration element 11 and the first intermediate member 141, or the first intermediate member 141 and the intermediate vibration element 10, may be coaxially coupled at a location other than the designated coupling location. Additionally or alternatively, in the fifth embodiment, the intermediate vibration element 10 and the second intermediate member 142, or the second intermediate member 142 and the second vibration element 12, may be coaxially coupled by a mechanical coupling mechanism at a location other than the designated coupling location.

[0059] DESCRIPTION OF SYMBOLS 1: Ultrasonic complex vibration device 10: Intermediate vibration element 100: Intermediate flange 11: First vibration element 112: Piezoelectric body 12: Second vibration element 120: Frequency adjustment element 121: Cylindrical portion 122: Cylindrical portion 124: Slit 126: Tip portion 128: Hole 16: Horn tip 18: Anvil 20: Control device 21: High frequency power supply device 22: Pressure device 24: Stroke sensor 26: Interface device

Claims

1. An ultrasonic complex vibration element that induces complex vibration by combining longitudinal vibration and torsional vibration, a first vibration element having an electrostrictive vibrator that generates longitudinal vibration, and a second vibration element having a slit and a frequency adjustment element for converting the longitudinal vibration into torsional vibration; the first vibration element and the second vibration element are coaxially connected at a first designated connection point that is included in a range of a phase angle of 0.05π or less with respect to an antinode of a standing wave of the longitudinal vibration and is included in a range of a phase angle of 0.22π or less with respect to a node of a standing wave of the torsional vibration, The first vibration element or the second vibration element is configured to be supported at a designated support point where a node of at least one of the standing wave of the longitudinal vibration and the standing wave of the torsional vibration exists. Ultrasonic complex vibration device.

2. The ultrasonic complex vibration device according to claim 1, At least one of the first vibration element and the second vibration element is composed of a plurality of vibration elements, The plurality of vibration elements are coaxially connected at second designated connection points that are included in a range of a phase angle of 0.05π or less with respect to an antinode of the standing wave of the longitudinal vibration and that are included in a range of a phase angle of 0.22π or less with respect to a node of the standing wave of the torsional vibration. Ultrasonic complex vibration device.

3. The ultrasonic complex vibration device according to claim 1, The second vibration element has a shape in which a columnar portion and a cylindrical portion are coaxially continuous at a location included in a range of a phase angle of 0.22π or less based on a node of a standing wave of the torsional vibration, and the slit is provided in the columnar portion within a range of a phase angle of 0.20π or less based on a node of the standing wave of the torsional vibration. Ultrasonic complex vibration device.

4. The ultrasonic complex vibration device according to claim 3, The frequency adjustment element is located behind the slit in the second vibration element. Ultrasonic complex vibration device.

5. The ultrasonic complex vibration device according to claim 1, A node of the standing wave of the torsional vibration exists at the specified support point. Ultrasonic complex vibration device.

6. The ultrasonic complex vibration device according to claim 1, The first vibration element and the second vibration element are coaxially connected via an intermediate member at the first designated connection point. Ultrasonic complex vibration device.

7. The ultrasonic complex vibration device according to claim 2, The plurality of vibration elements are coaxially connected at the second designated connection points via an intermediate member. Ultrasonic complex vibration device.

8. The ultrasonic complex vibration device according to claim 1 , a horn tip attached to a tip end of the second vibration element; an anvil disposed opposite the horn tip and supporting a workpiece to be joined; Equipped with Ultrasonic bonding equipment.

9. The ultrasonic complex vibration device according to claim 1, The first vibration element or the second vibration element is configured to be supported at the designated support point that is axially offset from the first designated connection point. Ultrasonic complex vibration device.

10. The ultrasonic complex vibration device according to claim 2, The first vibration element or the second vibration element is configured to be supported at the designated support point that is axially offset from the second designated connection point. Ultrasonic complex vibration device.