Ultrasonic complex vibration device and ultrasonic bonding device using same

Abstract

The invention provides an ultrasonic compound vibration device which is formed by connecting a plurality of vibration elements and can improve the stability of the connection state. The first vibration element (11) and the intermediate vibration element (10) are coaxially connected at one specified connection site at the midsection of the ultrasonic compound vibration device (1), the specified connection site is included in a range of a phase angle of 0.05 [pi] or less with respect to an antinode A (M1) of a standing wave (M1) of the longitudinal vibration and a range of a phase angle of 0.22 [pi] or less with respect to a node N (M2) of a standing wave (M2) of the torsional vibration. Similarly, the intermediate vibration element (10) and the second vibration element (12) are coaxially connected by a mechanical connection mechanism at the other designated connection part.

Description

Technical Field

[0001] The present invention relates to an ultrasonic composite vibration device and an ultrasonic bonding device using the ultrasonic composite vibration device. Background Art

[0002] There has been proposed a composite vibration element for an ultrasonic processing machine: Conditions are previously obtained in which the longitudinal vibration and the torsional vibration constituting the composite vibration each have a common nodal plane and antinode plane at approximate resonance frequencies, and the composite vibration element is supported on this nodal plane (for example, refer to Patent Document 1). Thereby, while maintaining the high rigidity of the composite vibration element, vibration loss on its support surface is reduced and the positioning accuracy of the tip is improved.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Patent No. 5036124 Gazette Summary of the Invention

[0006] Problems to be Solved by the Invention

[0007] The composite vibration element is composed of two vibration elements connected by a common nodal plane at the resonance frequencies of the longitudinal vibration and the torsional vibration. Therefore, a relatively large mechanical load is applied to the connecting portion of the two vibration elements due to this vibration, and this connecting state may become unstable.

[0008] Therefore, an object of the present invention is to provide an ultrasonic composite vibration device etc. which is composed of connecting a plurality of vibration elements and can achieve improvement in the stability of this connecting state.

[0009] Means for Solving the Problems

[0010] The ultrasonic composite vibration device of the present invention is an ultrasonic composite vibration element that induces composite vibration by synthesizing longitudinal vibration and torsional vibration, and this ultrasonic composite vibration device is configured to:

[0011] include a first vibration element and a second vibration element, the first vibration element having an electrostrictive vibrator that generates longitudinal vibration, and the second vibration element having a slit and a frequency adjustment element for converting the longitudinal vibration into torsional vibration,

[0012] the first vibration element and the second vibration element are coaxially connected at a first specified connecting portion, where the first specified connecting portion is within a range of a phase angle of 0.05π or less based on the antinode of the standing wave of the longitudinal vibration and within a range of a phase angle of 0.22π or less based on the node of the standing wave of the torsional vibration,

[0013] The first vibration element or the second vibration element is supported at a designated support portion where a node of at least one of the standing waves of the longitudinal vibration and the standing waves of the torsional vibration exists.

[0014] In the ultrasonic composite vibration device described in Technical Solution 1, preferably,

[0015] At least one of the first vibration element and the second vibration element is composed of a plurality of vibration elements,

[0016] The plurality of vibration elements are coaxially connected at a second designated connection portion, where the second designated connection portion is within a range of a phase angle of 0.05π or less based on the antinode of the standing wave of the longitudinal vibration and within a range of a phase angle of 0.22π or less based on the node of the standing wave of the torsional vibration.

[0017] In the ultrasonic composite vibration device having the above structure, preferably,

[0018] The second vibration element has a shape in which a cylindrical portion and a cylindrical tube portion are coaxially continuous at a portion within a range of a phase angle of 0.22π or less based on the node of the standing wave of the torsional vibration.

[0019] The slit is provided within a range of a phase angle of 0.20π or less based on the node of the standing wave of the torsional vibration on the cylindrical portion.

[0020] In the ultrasonic composite vibration device having the above structure, preferably, in the second vibration element, the frequency adjustment element is located at a position behind the slit.

[0021] In the ultrasonic composite vibration device having the above structure, preferably, the node of the standing wave of the torsional vibration is at the designated support portion.

[0022] In the ultrasonic composite vibration device having the above structure, preferably, the first vibration element and the second vibration element are coaxially connected via an intermediate member at the first designated connection portion.

[0023] In the ultrasonic composite vibration device having the above structure, preferably, the plurality of vibration elements are coaxially connected via an intermediate member at the second designated connection portion.

[0024] The ultrasonic bonding device of the present invention includes: the ultrasonic composite vibration device; a welding head mounted on the top end portion of the second vibration element; and an anvil configured to face the welding head and support a workpiece to be bonded.

[0025] Brief Description of the Drawings

[0026] Figure 1 It is a structural explanatory diagram of an ultrasonic composite vibration device and an ultrasonic bonding device according to a first embodiment of the present invention.

[0027] Figure 2 It is an explanatory diagram of a connection method of vibration elements constituting an ultrasonic composite vibration device according to a first embodiment of the present invention.

[0028] Figure 3A It is a structural explanatory diagram of a second vibration element in a first embodiment.

[0029] Figure 3B It is a structural explanatory diagram of a second vibration element in other embodiments.

[0030] Figure 4A It is a structural explanatory diagram of a second vibration element in a first modified embodiment.

[0031] Figure 4B It is a structural explanatory diagram of a second vibration element in a second modified embodiment.

[0032] Figure 5 It is an explanatory diagram of the relationship between the depth and length of a slit and the torsional resonance frequency of an ultrasonic composite vibration system.

[0033] Figure 6 It is an explanatory diagram of a connection method of vibration elements constituting an ultrasonic composite vibration device according to a second embodiment of the present invention.

[0034] Figure 7 It is an explanatory diagram of a connection method of vibration elements constituting an ultrasonic composite vibration device according to a third embodiment of the present invention.

[0035] Figure 8 It is an explanatory diagram of a connection method of vibration elements constituting an ultrasonic composite vibration device according to a fourth embodiment of the present invention.

[0036] Figure 9 It is an explanatory diagram of a connection method of vibration elements constituting an ultrasonic composite vibration device according to a fifth embodiment of the present invention. Specific Embodiments

[0037] (Structure)

[0038] Figure 1 The ultrasonic composite vibration device 1 shown as the first embodiment of the present invention is a component of an ultrasonic bonding device that uses ultrasonic composite vibration bonding described later for workpieces W1 and W2 such as metal plates as bonding objects. The ultrasonic bonding device is used, for example, for bonding electrodes of lithium ion batteries and / or semiconductor elements, and bonding of the same or different metals.

[0039] As Figure 1 shown, the ultrasonic composite vibration device 1 includes a substantially cylindrical first vibration element 11, a substantially cylindrical, substantially cylindrical or substantially bottomed cylindrical intermediate vibration element 10, and a substantially cylindrical or substantially bottomed cylindrical second vibration element 12. The ultrasonic bonding device includes the ultrasonic composite vibration device 1, a sonotrode 16, and an anvil 18.

[0040] Figure 2 The relationship between the structure of the ultrasonic composite vibration device 1 and the standing wave M1 of the longitudinal vibration and the standing wave M2 of the torsional vibration generated in the ultrasonic composite vibration device 1 is shown. As Figure 2 shown, the ultrasonic composite vibration device 1 is configured such that antinodes A(M1) of the standing wave M1 of the longitudinal vibration exist at the rear end face and the top end face of the ultrasonic composite vibration device 1, respectively.

[0041] As Figure 2 shown, one antinode A(M1) of the standing wave M1 of the longitudinal vibration exists in the middle abdomen or the middle part of the ultrasonic composite vibration device 1 for the first vibration element 11 and the intermediate vibration element 10, and they are coaxially connected at a specified connection part that is phase-shifted by a phase angle of 0.05π with respect to one node N(M2) of the standing wave M2 of the torsional vibration through a mechanical connection mechanism (such as bolts and / or clamping mechanisms). Figure 2 shown, another antinode A(M1) of the standing wave M1 of the longitudinal vibration exists in the middle abdomen of the ultrasonic composite vibration device 1 for the intermediate vibration element 10 and the second vibration element 12, and they are coaxially connected at a specified connection part where one node N(M2) of the standing wave M2 of the torsional vibration exists through a mechanical connection mechanism. The specified connection part is defined as any part that exists within a phase angle range of 0.05π or less with respect to the antinode A(M1) of the standing wave M1 of the longitudinal vibration and within a phase angle range of 0.22π or less with respect to the node N(M2) of the standing wave M2 of the torsional vibration.

[0042] The intermediate vibration element 10 may also be a component of the first vibration element 11. That is, the first vibration element 11 may also be composed of two vibration elements. In this case, the first vibration element 11 and the intermediate vibration element 10 may be integrally formed instead of being mechanically connected.

[0043] The intermediate vibration element 10 may also be a component of the second vibration element 12. That is, the second vibration element 12 may also be composed of two vibration elements. In this case, the second vibration element 12 and the intermediate vibration element 10 may be integrally formed instead of being mechanically connected.

[0044] As Figure 1As shown, a piezoelectric body 112 with its axis direction as the piezoelectric polarization direction is provided on the first vibration element 11.

[0045] As Figure 1 shown, a substantially annular plate-shaped intermediate flange 100 is formed on the intermediate vibration element 10, and the intermediate flange 100 extends radially over the entire circumference at the intermediate position in the axis direction of the intermediate vibration element 10. The intermediate vibration element 10 is configured to be clamped or supported by a clamping mechanism (not shown) over the entire circumference at least at the intermediate flange 100. The intermediate flange 100 can be omitted when ensuring that the intermediate vibration element 10 is supported by a mechanical support mechanism. As Figure 1 shown, the intermediate vibration element 10 is a substantially cylindrical shape with a substantially constant outer diameter in the axis direction at a position behind ( Figure 1 the left direction) the intermediate flange 100. As Figure 1 shown, the intermediate vibration element 10 is formed to have a substantially cylindrical shape with a substantially constant outer diameter after continuously reducing the diameter towards the tip at a position in front of ( Figure 1 the right direction) the intermediate flange 100 (a shape formed by coaxially connecting a substantially conical frustum cylinder shape and a substantially cylindrical shape).

[0046] As Figure 1 shown, on the second vibration element 12, a frequency adjustment element 120 is provided at the intermediate position in its axis direction. The frequency adjustment element 120 extends radially over the entire circumference and has a substantially regular octagonal shape with rounded corners. The longitudinal vibration component and torsional vibration component resonance frequencies of the ultrasonic vibration are adjusted by the frequency adjustment element 120.

[0047] As Figure 1 shown, on the second vibration element 12, a plurality of slits 124 are formed on the outer side surface at a position behind the frequency adjustment element 120. The plurality of slits 124 can also be formed on the outer side surface of the second vibration element 12 at a position in front of the frequency adjustment element 120. When observed from the side, the slits 124 extend obliquely on the second vibration element 12 or extend in the axis direction while being displaced circumferentially with the same phase. The N slits (N = 2, 3,...) 124 can also be arranged to have N-fold rotational symmetry about the central axis of the second vibration element 12 (for example, N = 8, N = 12, or 16).

[0048] As Figure 3A and Figure 3B respectively shown in a simplified manner, the second vibration element 12 has the following shape: a substantially cylindrical portion 121 on the base end side and a substantially cylindrical portion 122 on the tip end side with substantially the same diameter as the cylindrical portion are coaxially continuous. That is, the second vibration element 12 is formed as a substantially cylindrical shape with a substantially cylindrical hole extending in the axis direction from the tip end side coaxially provided.

[0049] In Figure 3A In one embodiment shown, the continuous part (bottom of the hole) of the cylindrical part 121 and the cylindrical part 122 is located at the position where the antinode A(M2) of the standing wave M2 of the torsional vibration exists. In addition, the slit 124 is provided in the cylindrical part 122 within the range of the phase angle of 0.16π to 0.22π with respect to the node N(M2) of the standing wave M2 of the torsional vibration.

[0050] In Figure 3B In other embodiments shown, the continuous part (bottom of the hole) of the cylindrical part 121 and the cylindrical part 122 is within the range of the phase angle of 0.22π or less with respect to the node N(M2) of the standing wave M2 of the torsional vibration. In addition, the slit 124 is provided in the cylindrical part 121 within the range of the phase angle of 0.20π with respect to the antinode A(M2) of the standing wave M2 of the torsional vibration.

[0051] In the second vibration element 12, the amplitude magnification ratio (U1 / U0) is mainly determined by the ratio of the second moment of area T0 and T1 of the top part of the slit 124 and the top part 126 of the second vibration element 12 respectively, where the amplitude magnification ratio (U1 / U0) is the ratio of the amplitude U1 of the torsional vibration of the top part 126 of the second vibration element 12 to the amplitude U0 of the torsional vibration of the top part of the slit 124. Specifically, the smaller T1 is, the larger the amplitude magnification ratio (U1 / U0) of the torsional vibration is. By providing a hole continuous from the top (with the cylindrical part 122 present) in the second vibration element 12, it is possible to reduce the second moment of area T1 of the top part of the second vibration element 12. According to the following relational expression (1), it can be derived Figure 3B The continuous part of the cylindrical part 121 and the cylindrical part 122 of the embodiment shown can further improve the magnification of the torsional vibration.

[0052] (d 2 θ(x) / dx)+{(dT(x) / dx) / T(x)}(dθ(x) / dx)+μ 2 θ (x) = 0… (1).

[0053] Wherein, "θ(x)" represents the torsional angle of the torsional vibration of the second vibration element 12 at the position x in the axial direction, "T(x)" represents the second moment of area of the torsional vibration of the second vibration element 12 at the position x in the axial direction, and "μ" represents μ = ω / c (ω: 2πf, c: the sound velocity of the torsional vibration transmitted in the metal).

[0054] In Figure 3A the modified embodiment of Figure 4AAs shown, in the second vibration element 12, the frequency adjustment element 120 can also be arranged at a position closer to the proximal end side than the slit 124 (arranged in the cylindrical portion 122). In Figure 3B In a modified embodiment of Figure 4B As shown, in the second vibration element 12, the frequency adjustment element 120 can also be arranged at a position closer to the top end side than the slit 124 (arranged in the cylindrical portion 121).

[0055] As Figure 1 shown, a top end portion 126 is arranged at the top end position in the axial direction on the second vibration element 12. The top end portion 126 extends radially over the entire circumference and has a substantially regular octagonal shape with rounded corners. Holes 128 (or through holes) are respectively formed at a plurality of circumferentially separated portions on the top end portion 126. N holes 128 (N = 2, 3,...) can also be arranged to have N-fold rotational symmetry (for example, N = 4) about the central axis of the second vibration element 12. Internal threads are provided on the inner side surfaces of the holes 128.

[0056] The welding head 16 has a substantially frustoconical base portion and a top end portion, and the top end portion abuts against the workpiece W1 located at the uppermost position among the workpiece W1 and the workpiece W2. By screwing the external threads provided on the base end portion of the welding head 16 with the internal threads of the holes 128 in the top end portion 126 of the second vibration element 12, the welding head 16 is detachably fixed to the second vibration element 12. By preparing welding heads 16 with various shapes, the welding head 16 can be appropriately replaced corresponding to the type of metal to be joined, etc.

[0057] It is also possible to detachably fix the balance member for adjusting the phase difference between the longitudinal vibration and the torsional vibration of the welding head 16 to the top end portion 126 of the second vibration element 12 by screwing the external threads of the top end portion 126 of the second vibration element 12, and further the balance member, with the internal threads of the holes 128.

[0058] The anvil 18 is arranged to face the top end portion of the welding head 16 in the vertical direction. For example, substantially flat workpieces W1 and W2 are overlapped and placed on the upper surface of the anvil 18. The anvil 18 can also be configured to be displaced up and down passively or actively corresponding to the pressure of the welding head 16 received via the workpieces W1 and W2.

[0059] As Figure 1 shown, the ultrasonic bonding device further includes a control device 20, a high-frequency power supply device 21, a pressurizing device 22, a stroke sensor 24, and an interface device 26.

[0060] The high-frequency power supply device 21 is configured as follows: A high-frequency AC voltage is applied to the piezoelectric body 112 of the first vibration element 11 according to the power supplied from a commercial power supply (not shown), thereby exciting the first vibration element 11 in the axial direction. The pressing device 22 includes a pressing block and is configured as follows: The supporting mechanism such as the clamping mechanism that supports the intermediate vibration element 10 is displaced by using the pressing block, so that the welding head 16 applies pressure to the workpiece W1 and the workpiece W2. The stroke sensor 24 outputs a signal corresponding to the displacement amount of the pressing block that constitutes the pressing device 22. The interface device 26 is constituted by, for example, a display, and the displacement amount of the pressing block and / or the time series of the pressure corresponding to the output signal of the stroke sensor 24 are displayed or output on the display. The display may also be constituted by a touch panel type display, and is used to accept the following setting operations: parameters such as the bonding mode that directly or indirectly designates the position among a plurality of bonding modes of the time series pattern of the target pressure by the user.

[0061] The control device 20 is constituted by a microcomputer, and further by an arithmetic processing device (CPU, microprocessor, processor core, etc.) and a storage device (ROM, RAM, etc. memories). The control device 20 is configured as follows, for example: Based on the time series of the displacement amount of the pressing block represented by the output signal of the stroke sensor 24, the displacement operation of the pressing block performed by the pressing device 22 is controlled. In addition to providing the stroke sensor 24, a pressure sensor may also be provided to output a signal corresponding to the pressure applied by the pressing block of the pressing device 22 to the intermediate vibration element 10 (the pressure applied by the welding head 16 to the workpiece W1 and the workpiece W2), and the control device 20 performs control based on the output signal of the pressure sensor to control the time series of the pressure to be fixed or a specified form.

[0062] (Function)

[0063] Corresponding to the commercial power supply (not shown) supplying power to the high-frequency power supply device 21, the high-frequency power supply device 21 applies a high-frequency AC voltage to the piezoelectric body 112 of the first vibration element 11. As a result, the first vibration element 11 vibrates in its axial direction at about 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. Moreover, the ultrasonic vibrations with amplified amplitude are transmitted from the intermediate vibration element 10 to the second vibration element 12 in its axial direction.

[0064] Thus, a part of the longitudinal vibration component of the ultrasonic vibration transmitted to the second vibration element 12 (the component in the axial direction of the second vibration element 12) is converted into a torsional vibration component through a plurality of slits 124 formed on the outer side surface of the second vibration element 12. Then, the composite vibration generated by combining the longitudinal vibration component and the torsional vibration component is transmitted to the welding head 16 fixed to the top end portion 126 of the second vibration element 12.

[0065] Correspondingly, the top end portion of the welding head 16 is displaced or vibrated in the horizontal direction in a manner of depicting a circular orbit or an elliptical orbit. At this time, impurities on the contact surfaces of the workpiece W1 and the workpiece W2 are removed, and thus plastic deformation of the contact surfaces of the workpiece W1 and the workpiece W2 can be promoted.

[0066] When the first vibration element 11, the intermediate vibration element 10, and the second vibration element 12 are moved downward by the pressing device 22 and the top end portion of the welding head 16 presses the workpiece W1 and the workpiece W2 in the vertical direction, circular vibration or elliptical vibration formed by combining the longitudinal vibration component and the lateral vibration component is generated.

[0067] At this time, through adjustment by the pressing device 22, the vertical position of the welding head 16, and thus the static pressure applied to the workpiece W1 and the workpiece W2 from the top end portion of the welding head 16, are included within a specified static pressure range (for example, 200 N to 800 N). While adjusting the penetration amount of the welding head 16 into the workpiece W1 and the workpiece W2 and / or the static pressure applied to the workpiece W1 and the workpiece W2, a composite vibration is applied to the workpiece W1 and the workpiece W2, whereby the workpiece W1 and the workpiece W2 can be solid-phase joined.

[0068] (Effect)

[0069] The ultrasonic composite vibration device 1 having the above structure is configured as follows: at a specified connection portion within a range of a phase angle of 0.05π or less with respect to the antinode A (N1) of the standing wave M1 of the longitudinal vibration and within a range of a phase angle of 0.22π or less with respect to the node N (M2) of the standing wave M2 of the torsional vibration, a plurality of vibration elements, namely the first vibration element 11, the intermediate vibration element 10, and the second vibration element 12, are mechanically connected (refer to Figure 2 ). Thereby, the stability of this connection state is improved.

[0070] In the ultrasonic composite vibration system composed 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), when torsional vibration is generated, the ultrasonic composite vibration system is greatly twisted at the portion of the slit 124. This is because the lateral elastic coefficient G of the ultrasonic composite vibration system decreases at the portion of the slit 124. The sound velocity c of the torsional vibration can be expressed as c = (G / ρ) using the specific gravity ρ. 1 / 2, therefore, due to the decrease in G, the torsional sound velocity c of the slit decreases. By providing the slit 124, the torsional sound velocity c decreases, resulting in a decrease in the resonance frequency. Moreover, by making the slit 124 longer and / or deeper, the magnitude of the decrease in the resonance frequency also increases.

[0071] In Figure 5 shows the manner of change (simulation results) of the frequency of the standing wave of torsional vibration (torsional resonance frequency) with respect to the depth and length of the slit 124 in the ultrasonic composite vibration system. Figure 5 The solid line in Figure 5 represents the dependence of the torsional resonance frequency in the ultrasonic composite vibration system on the length of the slit 124 when the depth of the slit 124 is 2.5 mm.

[0072] As Figure 5 shown, the lengths of the solid line and the dashed line are the values at 0 mm, that is, the torsional resonance frequency of this ultrasonic composite vibration system without the slit 124 provided is approximately 12.7 kHz. As Figure 5 shown by the solid line in Figure 5 , as the length of the slit 124 with a depth of 2.5 mm increases to 12 mm → 16 mm → 20 mm, the torsional resonance frequency of the ultrasonic composite vibration system decreases to approximately 12.42 kHz → approximately 12.35 kHz → approximately 12.3 kHz. As

[0073] shown by the dashed line in

[0074] (Second Embodiment)

[0075] Figure 6 The ultrasonic composite vibration device 1 shown as the second embodiment of the present invention and Figure 1The ultrasonic composite vibration device 1 shown as the first embodiment of the present invention also has a first vibration element 11, an intermediate vibration element 10, and a second vibration element 12. In the intermediate vibration element 10, a plurality of slits 104 are formed in a substantially cylindrical front portion in front of the intermediate flange 100. The plurality of slits 104 extend linearly 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. Regarding other structures, the ultrasonic composite vibration device 1 of the second embodiment is the same as or substantially the same as the ultrasonic composite vibration device 1 of the first embodiment. Therefore, the same reference numerals are assigned to the same structures, and the description thereof is omitted.

[0076] In Figure 6 shows the relationship between the structure of the ultrasonic composite vibration device 1 and the standing wave M2 of the torsional vibration generated in the ultrasonic composite vibration device 1. As Figure 6 shown, a node N(M2) of the standing wave M2 of the torsional vibration coincides with or overlaps the intermediate flange 100 of the intermediate vibration element 10. This is achieved by adjusting the respective shapes, dimensions (length, width, and / or depth (wall thickness of the front portion of the intermediate vibration element 10)) and / or the number in the circumferential direction or the circumferential interval of the plurality of slits 104 on the intermediate vibration element 10. The respective shapes and dimensions of the plurality of slits 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 the shape and / or dimension, and the first slits constituting the first slit group and the second slits constituting the second slit group are alternately arranged in the circumferential direction.

[0077] (Third Embodiment)

[0078] Figure 7 The ultrasonic composite vibration device 1 shown as the third embodiment of the present invention has the same first vibration element 11, intermediate vibration element 10, and second vibration element 12 as Figure 6 the ultrasonic composite vibration device 1 shown as the second embodiment of the present invention. On the intermediate vibration element 10, a plurality of slits 104 are formed in a substantially cylindrical front portion in front of the intermediate flange 100. In addition, a plurality of slits 102 are formed in a substantially cylindrical rear portion behind the intermediate flange 100 on the intermediate vibration element 10. The plurality of slits 102 and 104 extend linearly 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. Regarding other structures, the ultrasonic composite vibration device 1 of the third embodiment is the same as or substantially the same as the ultrasonic composite vibration device 1 of the second embodiment. Therefore, the same reference numerals are assigned to the same structures, and the description thereof is omitted.

[0079] Figure 7 shows the relationship between the structure of the ultrasonic composite vibration device 1 and the standing wave M2 of the torsional vibration generated in the ultrasonic composite vibration device 1. As Figure 7 shown, a node N(M2) of the standing wave M2 of the torsional vibration coincides with or overlaps the intermediate flange 100 of the intermediate vibration element 10. This is achieved by adjusting the respective shapes, dimensions (length, width, and / or depth (wall thickness of the substantially cylindrical portion of the intermediate vibration element 10)), and / or the number or circumferential intervals in the circumferential direction of the plurality of slits 104 in the front portion of the intermediate vibration element 10, and / or the respective shapes, dimensions (length, width, and / or depth (wall thickness of the substantially cylindrical portion of the intermediate vibration element 10)), and / or the number or circumferential intervals in the circumferential direction of the plurality of slits 102 in the rear portion of the intermediate vibration element 10. The shapes and dimensions of the plurality of slits 102 and 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 the shape and / or dimension, and the first slit constituting the first slit group and the second slit constituting the second slit group may be alternately arranged in the circumferential direction. Alternatively or in addition to the above arrangement, the plurality of slits 102 may be classified into a first slit group and a second slit group according to the shape and / or dimension, and the first slit constituting the first slit group and the second slit constituting the second slit group may be alternately arranged in the circumferential direction.

[0080] (Fourth Embodiment)

[0081] Figure 8 The ultrasonic composite vibration device 1 shown as the fourth embodiment of the present invention has the first vibration element 11, the intermediate vibration element 10, and the second vibration element 12 in the same manner as Figure 1 the ultrasonic composite vibration device 1 shown as the first embodiment of the present invention. In the intermediate vibration element 10, the front portion located in front of the intermediate flange 100 is formed to have a continuously reduced diameter (substantially frustoconical) toward the front end portion. Regarding other structures, the ultrasonic composite vibration device 1 of the fourth embodiment is the same as or substantially the same as the ultrasonic composite vibration device 1 of the first embodiment. Therefore, the same reference numerals are assigned to the same structures, and the description thereof is omitted.

[0082] In Figure 8 shows the relationship between the structure of the ultrasonic composite vibration device 1 and the standing wave M2 of the torsional vibration generated in the ultrasonic composite vibration device 1. As Figure 8As shown, a 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 change manner of the diameter of the substantially frustum-shaped front portion of the intermediate vibration element 10 with respect to the position in the axial direction. The side surface of the substantially frustum-shaped front portion of the intermediate vibration element 10 may also be formed by a convex surface or a concave surface, or a combination of a convex surface and a concave surface.

[0083] (Fifth Embodiment)

[0084] Figure 9 The ultrasonic composite vibration device 1 shown as the fifth embodiment of the present invention is the same as Figure 1 the ultrasonic composite vibration device 1 shown as the first embodiment of the present invention, and has a first vibration element 11, an intermediate vibration element 10, and a second vibration element 12. The first vibration element 11 and the intermediate vibration element 10 are connected via a substantially disk-shaped or substantially ring-shaped first intermediate member 141 having substantially the same diameter. The second vibration element 12 and the intermediate vibration element 10 are connected via a substantially disk-shaped or substantially ring-shaped second intermediate member 142 having substantially the same diameter. Regarding other structures, the ultrasonic composite vibration device 1 of the fifth embodiment is the same as or substantially the same as the ultrasonic composite vibration device 1 of the first embodiment. Therefore, the same reference numerals are assigned to the same structures, and the description thereof is omitted.

[0085] In Figure 9 is shown the relationship between the structure of the ultrasonic composite vibration device 1 and the standing wave M2 of torsional vibration generated in the ultrasonic composite vibration device 1. As Figure 9 shown, at a position behind the slit 124 of the second vibration element 12, attenuation of the standing wave M2 of torsional vibration is achieved. This is achieved by adjusting the respective dimensions (inner diameter, outer diameter, 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 also be omitted.

[0086] In each of the second to fourth embodiments, the first vibration element 11 and the intermediate vibration element 10 may also be coaxially connected at a position different from the specified connection portion. On the basis of or instead of this connection manner, in each of the second to fourth embodiments, the intermediate vibration element 10 and the second vibration element 12 may also be coaxially connected at a position different from the specified connection portion by a mechanical connection mechanism.

[0087] In the fifth embodiment, the first vibration element 11 and the first intermediate member 141 may be coaxially connected at a position different from the specified connection position, or the first intermediate member 141 and the intermediate vibration element 10 may be coaxially connected. On the basis of or instead of this connection method, in the fifth embodiment, the intermediate vibration element 10 and the second intermediate member 142 may be coaxially connected at a position different from the specified connection position by a mechanical connection mechanism, or the second intermediate member 142 and the second vibration element 12 may be coaxially connected.

[0088] Reference Signs

[0089] 1…Ultrasonic composite vibration device

[0090] 10…Intermediate vibration element

[0091] 100…Intermediate flange

[0092] 11…First vibration element

[0093] 112…Piezoelectric body

[0094] 12…Second vibration element

[0095] 120…Frequency adjustment element

[0096] 121…Cylindrical portion

[0097] 122…Cylindrical portion

[0098] 124…Slit

[0099] 126…Tip portion

[0100] 128…Hole

[0101] 16…Welding head

[0102] 18…Anvil

[0103] 20…Control device

[0104] 21…High-frequency power supply device

[0105] 22…Pressing device

[0106] 24…Stroke sensor

[0107] 26…Interface device.

Claims

1. An ultrasonic composite vibration device, which is an ultrasonic composite vibration element that generates composite vibration by synthesizing longitudinal vibration and torsional vibration. The ultrasonic composite vibration device is characterized in that it is configured as follows: It includes a first vibration element and a second vibration element. The first vibration element has an electrostrictive vibrator that generates longitudinal vibration, and the second vibration element has 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 specified connection portion, wherein, The first specified connection part is within a range of a phase angle of 0.05π or less with respect to the antinode of the standing wave of the longitudinal vibration and within a range of a phase angle of 0.22π or less with respect to the node of the standing wave of the torsional vibration. The first vibration element or the second vibration element is supported at a specified support part where at least one of the standing waves of the longitudinal vibration and the torsional vibration has a node.

2. The ultrasonic composite vibration device according to claim 1, wherein: 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 a second specified connection part, where the second specified connection part is within a range of a phase angle of 0.05π or less with respect to the antinode of the standing wave of the longitudinal vibration and within a range of a phase angle of 0.22π or less with respect to the node of the standing wave of the torsional vibration.

3. The ultrasonic composite vibration device according to claim 1, wherein: The second vibration element has a shape in which a cylindrical part and a cylindrical tube part are coaxially continuous at a part within a range of a phase angle of 0.22π or less with respect to the node of the standing wave of the torsional vibration. The slit is provided within a range of a phase angle of 0.20π or less with respect to the node of the standing wave of the torsional vibration on the cylindrical part.

4. The ultrasonic composite vibration device according to claim 3, characterized in that, In the second vibration element, the frequency adjustment element is located behind the slit.

5. The ultrasonic composite vibration device according to claim 1, characterized in that, The node of the standing wave of the torsional vibration is at the specified support part.

6. The ultrasonic composite vibration device according to claim 1, wherein: The first vibration element and the second vibration element are coaxially connected via an intermediate member at the first specified connection part.

7. The ultrasonic composite vibration device according to claim 2, wherein The plurality of vibration elements are coaxially connected via an intermediate member at the second specified connection part.

8. An ultrasonic bonding device, characterized in that, It includes: The ultrasonic composite vibration device according to claim 1; A sonotrode, which is mounted on the top end of the second vibration element; and An anvil, which is arranged to face the sonotrode and supports a workpiece to be joined.

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