Ultrasonic junction device, ultrasonic junction method, and ultrasonic junction structure

Abstract

To provide an ultrasonic junction device and the like, which can achieve a junction structure between an inner peripheral part of one workpiece and an outer peripheral part of another workpiece.SOLUTION: A first annular part of a first workpiece W1 and a second annular part of a second workpiece W2 are continuously or discontinuously subjected to ultrasonic junction around the entire perimeter. Since a method different from a swaging method is adopted, downsizing or miniaturization of an ultrasonic junction structure having the first workpiece W1 and the second workpiece W2 is achieved by the unnecessary amount of a swaging margin.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an ultrasonic joining technique for joining a plurality of workpieces made of various materials such as metals by using ultrasonic vibrations. [Background technology]

[0002] 7, a conventional secondary battery C includes a positive electrode plate C1 and a negative electrode plate C2 electrically insulated by a separator C0, a positive electrode current collector C12 electrically connected to the positive electrode plate C1, a negative electrode current collector C22 electrically connected to the negative electrode plate C2, and a generally hollow cylindrical housing H that accommodates and seals these components. The housing H is configured by a generally bottomed, cylindrical stainless steel first housing portion H1 and a generally disk-shaped, stainless steel second housing portion H2 that are crimped together at their respective peripheral edges SH (see, for example, Patent Document 1). The negative electrode terminal of the secondary battery C is configured at the bottom of the first housing portion H1, and the positive electrode terminal of the secondary battery C is configured at the center of the second housing portion H2. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2023-167557 Summary of the Invention [Problem to be solved by the invention]

[0004] 7, however, a crimping margin Δ between the first housing part H1 and the second housing part H2 in the longitudinal direction is required, which increases the distance D1 between the positive electrode current collector C12 and the housing H (the top plate part of the second housing part H2) and therefore the size D of the secondary battery C. From the viewpoint of the volumetric energy density of the secondary battery C, it is preferable to reduce the crimping margin Δ in the longitudinal direction of the secondary battery C, and therefore reduce the distance between the positive electrode current collector C12 and the housing H (the top plate part of the second housing part H2).

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an ultrasonic joining device and the like that can realize a joining structure between the inner peripheral portion of one workpiece and the outer peripheral portion of another workpiece. [Means for solving the problem]

[0006] The ultrasonic bonding device of the present invention comprises: an ultrasonic vibration device configured to generate linear vibrations in a direction parallel to at least the first axis; a rotary drive device configured to drive the ultrasonic vibration device to rotate about the first axis; an ultrasonic bonding tip connected to the ultrasonic vibration device; a translational drive device configured to translate the ultrasonic vibration device in a direction perpendicular to the first axis; and a rotary support member that supports multiple workpieces to be joined at multiple locations together with the ultrasonic bonding tip, and is configured to be rotatable around a second axis in response to the rotation of the multiple workpieces caused by the rotation of the ultrasonic vibration device and the ultrasonic bonding tip around the first axis. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a diagram illustrating the configuration of an ultrasonic bonding device according to an embodiment of the present invention; [Figure 2] FIG. 10 is an explanatory diagram of a first supporting form of the workpiece by the tip and the anvil pulley. [Figure 3] 1 is a flowchart showing the procedure of an ultrasonic bonding method according to an embodiment of the present invention. [Figure 4] 1 is a diagram illustrating the configuration of an ultrasonically bonded structure (secondary battery) according to an embodiment of the present invention. [Figure 5] 1A to 1C are explanatory diagrams illustrating an ultrasonic bonding method according to an embodiment of the present invention. [Figure 6] FIG. 10 is an explanatory diagram of a second supporting form of the workpiece by the tip and the anvil pulley. [Figure 7] FIG. 1 is a diagram illustrating the configuration of a secondary battery manufactured by a conventional technique. DETAILED DESCRIPTION OF THE INVENTION

[0008] (composition) 1, an ultrasonic bonding device according to one embodiment of the present invention includes an ultrasonic vibration device 10 (ultrasonic complex vibration device), a horn tip 140 (ultrasonic bonding tip), a first anvil pulley 141, and a second anvil pulley 142. As shown in FIG. 2, for example, the ultrasonic bonding device is used to continuously or intermittently bond the inner surface of a substantially circular or annular first workpiece W1 (or a joining portion thereof) to the outer surface of a substantially circular or annular second workpiece W2 (or a joining portion thereof) fitted inside the first workpiece W1.

[0009] The first work W1 and the second work W2, either in whole or in part including the joints, may be made of metals such as aluminum alloys, FRPs (fiber reinforced plastics) such as GFRP (glass fiber reinforced plastic), CFRP (carbon fiber reinforced plastic), BFRP (boron fiber reinforced plastic), AFRP / KFRP (aramid fiber reinforced plastic), ZFRP (Zylon fiber reinforced plastic), GMT (long glass fiber reinforced plastic), or synthetic resins such as epoxy resin, vinyl ester resin, polypropylene, and PEEK.

[0010] The first workpiece W1 and the second workpiece W2 may each be partially made of a different material. For example, the first workpiece W1 may be made of a metal (e.g., an aluminum alloy), while the second workpiece W2 may be made of a fiber-reinforced plastic (e.g., GFRP). The first workpiece W1 may be made of a fiber-reinforced plastic (e.g., GFRP), while the second workpiece W2 may be made of a metal (e.g., an aluminum alloy). The first workpiece W1 may be made of a first fiber-reinforced plastic (e.g., GFRP), while the second workpiece W2 may be made of a second fiber-reinforced plastic (e.g., CFRP) having a different type of fiber from the first fiber-reinforced plastic.

[0011] The ultrasonic vibration device 10 includes a substantially cylindrical first vibration element 110, a substantially cylindrical, cylindrical, or bottomed cylindrical intermediate vibration element 100, and a substantially cylindrical or bottomed cylindrical second vibration element 120. The first vibration element 110, the intermediate vibration element 100, and the second vibration element 120 constitute "vibration elements."

[0012] The first vibration element 110 and the intermediate vibration element 100 are coaxially connected by a mechanical connection mechanism (such as a bolt and / or a clamp mechanism) at the middle or intermediate portion of the ultrasonic vibration device 10. The intermediate vibration element 100 and the second vibration element 120 are coaxially connected by a mechanical connection mechanism at the middle portion of the ultrasonic vibration device 10. The first vibration element 110, the intermediate vibration element 100, and the second vibration element 120 may be integrally configured rather than being mechanically connected.

[0013] The intermediate vibration element 100 may be a component of the first vibration element 110. That is, the first vibration element 110 may be composed of two vibration elements. In this case, the first vibration element 110 and the intermediate vibration element 100 may be integrally configured rather than being mechanically connected. The intermediate vibration element 100 may be a component of the second vibration element 120. That is, the second vibration element 120 may be composed of two vibration elements. In this case, the second vibration element 120 and the intermediate vibration element 100 may be integrally configured rather than being mechanically connected.

[0014] As shown in FIG. 1, the first vibration element 110 is provided with a piezoelectric body 112 whose axial direction (parallel to the first axis) is the piezoelectric polarization direction.

[0015] As shown in FIG. 1 , the intermediate vibration element 100 is formed with a substantially annular plate-shaped intermediate flange 102 that protrudes radially around its entire circumference at a central position in the axial direction. The intermediate vibration element 100 is configured to be clamped or supported around its entire circumference by a clamping mechanism (not shown) at least at the intermediate flange 102. If it is ensured that the intermediate vibration element 100 is supported by a mechanical support mechanism, the intermediate flange 102 may be omitted. As shown in FIG. 1 , the intermediate vibration element 100 has a substantially cylindrical shape with a substantially constant outer diameter in the axial direction behind the intermediate flange 102 (leftward in FIG. 1 ). As shown in FIG. 1 , the intermediate vibration element 100 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 100 (rightward in FIG. 1 ).

[0016] 1, the second vibration element 120 is provided with a frequency adjustment element 122 in the shape of a generally regular octagonal plate with rounded corners, which extends radially around the entire circumference at a midpoint in the axial direction of the second vibration element 120. The frequency adjustment element 122 adjusts the resonance frequencies of the longitudinal vibration component and the torsional vibration component of the ultrasonic vibration. The outer shape of the frequency adjustment element 122 may be a generally circular, generally elliptical, or generally regular n-polygonal plate (e.g., n = 4, 6, 8, 12, 16, etc.) plate, columnar, or frustum shape, which shares a common central axis with the second vibration element 120, or any combination thereof.

[0017] As shown in FIG. 1 , the second vibration element 120 has a plurality of slits 124 formed on its outer surface behind the frequency adjustment element 122. A plurality of slits 124 may be formed on the outer surface of the second vibration element 120 ahead of the frequency adjustment element 122. The slits 124 extend obliquely in the second vibration element 120 when viewed from the side, or extend in the axial direction while being displaced in the circumferential direction in phase with each other. The Q (Q=2, 3, ...) slits 124 may be arranged to have Q-fold rotational symmetry (e.g., Q=8, 12, or 16) around the central axis of the second vibration element 120.

[0018] The horn tip 140 shown in FIGS. 1 and 2 is formed in a generally circular plate or columnar shape that extends radially beyond the tip of the second vibration element 120 and is connected to the tip of the second vibration element 120. The horn tip 140 may be attached to the middle of the second vibration element 120. The horn tip 140 may be detachably attached to the second vibration element 120. The horn tip 140 may be spherical, spherical band-shaped (shaping a common central axis with the ultrasonic vibration device 10), or spherical truncated. The horn tip 140 may be formed in a generally circular, plate-shaped, or columnar shape having a generally elliptical or regular n-gon cross section to fit the outer shape of the first workpiece W1. The side of the horn tip 140 may have multiple protrusions or an uneven structure.

[0019] Each of the first anvil pulley 141 and the second anvil pulley 142 shown in FIGS. 1 and 2 is formed in a substantially circular plate shape or a substantially cylindrical shape and is disposed so that its side surface faces the side surface of the horn tip 140 in the radial direction. The side surfaces of the first anvil pulley 141 and / or the second anvil pulley 142 may have a plurality of protrusions or a concave-convex structure. The diameters of the first anvil pulley 141 and the second anvil pulley 142 may be the same as, larger than, or smaller than the diameter of the horn tip 140.

[0020] The first anvil pulley 141 and the second anvil pulley 142, either entirely or partially including the contact portion with the first workpiece W1, may be made of metal such as stainless steel, or ceramics, etc. At least a portion of the first anvil pulley 141 and the second anvil pulley 142 may be made of a material harder than the first workpiece W1.

[0021] As shown in FIG. 2, the first workpiece W1 (or its joint portion) with the second workpiece W2 (or its joint portion) fitted inside is supported at three points by the respective side surfaces of the horn tip 140, the first anvil pulley 141, and the second anvil pulley 142. The number of anvil pulleys (rotating support members) may be "1." That is, the first workpiece W1 with the second workpiece W2 fitted inside may be supported at two points (preferably on opposite sides of the center of the first workpiece W1). The number of anvil pulleys (rotating support members) may be more than "2." That is, the first workpiece W1 with the second workpiece W2 inserted or fitted inside may be supported at four or more points.

[0022] The first anvil pulley 141 and / or the second anvil pulley 142 are configured to passively or actively rotate about a second axis (which may be parallel to the first axis or may be inclined relative to the first axis depending on the outer shape of the first workpiece W1, etc.) in response to the rotational force of the horn tip 140 received via the first workpiece W1 and / or the second workpiece W2. The first anvil pulley 141 and / or the second anvil pulley 142 may be configured to passively or actively displace in the radial direction in response to the pressure of the horn tip 140 received via the first workpiece W1 and / or the second workpiece W2.

[0023] As shown in FIG. 1, the ultrasonic bonding apparatus according to one embodiment of the present invention further includes an operating device 20, a control device 22, a rotational driving device 220, a high-frequency power supply device 221, a translational driving device 222, and a status sensor 224.

[0024] The operation device 20 is configured, for example, by a display, and displays or outputs on the display the displacement amount of the pressure block and / or the time series of the pressure according to the output signal of the status sensor 224. The display may be configured by a touch panel display, and may be configured to accept a setting operation for allowing the user to directly or indirectly specify parameters, such as one of a plurality of bonding modes that determine a time series pattern of the target pressure.

[0025] The control device 22 is configured with a microcomputer, an arithmetic processing device (CPU, microprocessor, processor core, etc.), and a storage device (memory such as ROM and RAM). The control device 22 is configured to control the displacement operation of the pressure block by the translation drive device 222 based on a time series of the displacement amount of the pressure block represented by an output signal of a stroke sensor constituting the status sensor 224, for example. The control device 22 is configured to control the power supplied to the piezoelectric body 112 based on the amplitude (corresponding to a specified parameter) of the horn tip 140 represented by an output signal of an amplitude sensor constituting the status sensor 224, and thereby to control the ultrasonic vibration power of the vibration elements (first vibration element 110, intermediate vibration element 100, and second vibration element 120) and the ultrasonic vibration power of the horn tip 140.

[0026] The rotary drive device 220 is configured to rotate the ultrasonic vibration device 10, and ultimately the horn tip 140, around their central axes. The rotary drive device 220 is configured, for example, with an electric motor and a reduction gear or transmission device for transmitting rotational force from the output shaft of the electric motor to the ultrasonic vibration device 10.

[0027] The high frequency power supply device 221 is configured to apply a high frequency AC voltage to the piezoelectric body 112 of the first vibration element 110 in accordance with power supplied from a commercial power supply (not shown), thereby exciting the first vibration element 110 in the axial direction. Since the ultrasonic vibration device 10 is driven to rotate around its central axis, a slip ring or rotary connector is used to supply power from the high frequency power supply device 221 to the piezoelectric body 112.

[0028] The translational drive device 222 includes a pressure block, and is configured to apply pressure from the horn tip 140 to the first workpiece W1 and the second workpiece W2 by displacing a support mechanism, such as a clamp mechanism, that supports the intermediate vibration element 100 using the pressure block. If necessary, a second translational drive device may be provided to translate the ultrasonic vibration device 10 in a direction parallel to the first axis.

[0029] The status sensor 224 includes a stroke sensor that outputs a signal corresponding to the displacement of the pressure block that constitutes the translational drive device 222, as well as an amplitude sensor that outputs a signal corresponding to the amplitude (corresponding to a specified parameter) of the horn tip 140. The amplitude sensor may be a sensor module composed of an imaging device and a device that calculates the amplitude by analyzing an image captured by the imaging device. As the status sensor 224, a pressure sensor that outputs a signal corresponding to the pressure acting on the intermediate vibration element 100 from the pressure block of the translational drive device 222 (the pressure that the horn tip 140 applies to the first workpiece W1 and the second workpiece W2) may be provided, and the control device 22 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.

[0030] (Ultrasonic bonding method) The procedure of an ultrasonic bonding method according to one embodiment of the present invention using the ultrasonic bonding apparatus 1 will be described with reference to the flowchart of Fig. 3. The objects to be bonded are a first workpiece W1 and a second workpiece W2.

[0031] The index i is set to an initial value of "0" (FIG. 3 / STEP 111). The index "i" is an index representing the progress of the ultrasonic bonding of the first workpiece W1 and the second workpiece W2, or the rotation angle of the first workpiece W1 and the second workpiece W2.

[0032] The ultrasonic vibration device 10 and the horn tip 140 are moved in the radial direction by the translational drive device 222 so as to approach the first workpiece W1 with the second workpiece W2 fitted inside (FIG. 3 / STEP 112).

[0033] Furthermore, it is determined whether the pressure P that horn tip 140 receives from first workpiece W1 (and second workpiece W2) is equal to or greater than first specified pressure P1 (FIG. 3 / STEP 114). The pressure P that horn tip 140 receives from first workpiece W1 is measured based on the output signal of a pressure sensor that constitutes status sensor 224. When the tip of horn tip 140 is separated from first workpiece W1, P=0, and when it comes into contact with first workpiece W1 that is supported by first anvil pulley 141 and second anvil pulley 142, P>0.

[0034] If the determination result is negative (FIG. 3 / STEP 114...NO), the translational drive device 222 moves the ultrasonic vibration device 10 and the horn tip 140 in the radial direction so as to approach the first workpiece W1 with the second workpiece W2 fitted inside (FIG. 3 / connector X1 →STEP 112). As a result, the radial position of the horn tip 140, and therefore the static pressure applied from the horn tip 140 to the first workpiece W1 and the second workpiece W2, is adjusted to be within a specified static pressure range (e.g., 200 N to 800 N).

[0035] If the determination result is affirmative (FIG. 3 / STEP 114...YES), ultrasonic vibrations are generated in the vibration elements (FIG. 3 / STEP 116). Specifically, in response to power being supplied to the high-frequency power supply device 221 from a commercial power source (not shown) via a slip ring or the like, the high-frequency power supply device 221 applies a high-frequency AC voltage to the piezoelectric body 112 of the first vibration element 110. This causes the first vibration element 110 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 110 to the intermediate vibration element 100 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 100 to the second vibration element 120 in its axial direction.

[0036] In this way, a portion of the longitudinal vibration component (axial component of the second vibration element 120) of the ultrasonic vibration transmitted to the second vibration element 120 is converted into a torsional vibration component by the plurality of slits 124 formed on the outer surface of the second vibration element 120. Then, a composite vibration generated by combining the longitudinal vibration component and the torsional vibration component is transmitted to the horn tip 140 fixed to the tip of the second vibration element 120.

[0037] In response, the horn tip 140 displaces or vibrates in a circular or elliptical orbit on a plane perpendicular to the contact direction of the first workpiece W1. As a result, the amplitude and ultrasonic vibration power of the horn tip 140 gradually increase from the vibration start time t=t0. During this process, impurities are removed from the contact surfaces of the first workpiece W1 and the second workpiece W2, and plastic deformation of the contact surfaces of the first workpiece W1 and the second workpiece W2 may be promoted. After the rate of increase in the amplitude and ultrasonic vibration power of the horn tip 140 significantly decreases at time t=t1, the amplitude and ultrasonic vibration power of the horn tip 140 gradually increase. This is because the oxide coatings and other metals constituting the joining surfaces of the first workpiece W1 and the second workpiece W2 are removed, revealing clean, activated metal atoms at the joining surfaces. The temperature rise due to frictional heat activates the atomic movement, generating a mutual attraction between the atoms.

[0038] At this time, the amount of pressing of the first workpiece W1 and the second workpiece W2 by the horn tip 140 and / or the static pressure applied to the first workpiece W1 and the second workpiece W2 are adjusted, and a composite vibration is applied to the first workpiece W1 and the second workpiece W2, thereby locally solid-state joining the first workpiece W1 and the second workpiece W2 in the circumferential direction.

[0039] It is determined whether the time derivative δA (= current amplitude A(k) - previous amplitude A(k-1)) of the amplitude A of the horn tip 140 is negative and whether the amplitude A is equal to or less than the reference amplitude A0 (FIG. 3 / STEP 118). An amplitude sensor constituting the state sensor 224 optically measures the amplitude A at a specified location (e.g., a location where the amplitude is relatively large) of the horn tip 140. Instead of this determination process, it may be determined whether the amplitude A has decreased by the reference amplitude A0 (or a reference ratio based on the maximum value) using the maximum value at the time when the amplitude A started to decrease as a reference. For example, the reference amplitude A0, such as one of multiple joining modes for which the reference amplitude A0 is determined, may be directly or indirectly specified via a touch panel display constituting the operation device 20.

[0040] If the determination result is negative (FIG. 3 / STEP 118...NO), ultrasonic vibrations are continuously generated in the vibration element (FIG. 3 / connector X2 →STEP 116). On the other hand, if the determination result is positive (FIG. 3 / STEP 118...YES), the generation of ultrasonic vibrations in the vibration element is stopped (FIG. 3 / STEP 120). For example, after the amplitude of horn tip 140 changes from increasing to decreasing and falls below reference amplitude A0 at time t=t2, the ultrasonic power of horn tip 140 is controlled to become 0 with a slight response delay.

[0041] Furthermore, the index i is incremented by "1" (FIG. 3 / STEP 121).

[0042] The ultrasonic vibration device 10 and the horn tip 140 are moved in the radial direction by the translational drive device 222 so as to move away from the first workpiece W1 with the second workpiece W2 fitted inside (FIG. 3 / STEP 122).

[0043] Furthermore, it is determined whether the pressure P that the horn tip 140 receives from the first workpiece W1 (and the second workpiece W2) has become equal to or less than a second designated pressure P2 (FIG. 3 / STEP 124). The second designated pressure P2 is set to a value smaller than the first designated pressure P1, for example, 0 or a very small value.

[0044] If the determination result is negative (FIG. 3 / STEP 124...NO), the translational drive device 222 moves the ultrasonic vibration device 10 and the horn tip 140 radially away from the first workpiece W1 with the second workpiece W2 fitted inside (FIG. 3 / connector X4 →STEP 122). This adjusts the radial position of the horn tip 140, and therefore the static pressure applied by the horn tip 140 to the first workpiece W1 and the second workpiece W2, so that they decrease.

[0045] If the determination result is affirmative (FIG. 3 / STEP 124...YES), it is determined whether the index i has reached a designated number N (FIG. 3 / STEP 126). The designated number N is set, for example, to N=(360° / δθ) based on the unit rotation amount δθ (e.g., δθ=0.1° to 5°) of the first workpiece W1 and the second workpiece W2 corresponding to the unit rotation amount of the horn tip 140. The designated number N may be greater or less than (360° / δθ). By setting the unit rotation amount δθ to a small value, the inner surface of the first workpiece W1 and the outer surface of the second workpiece W2 are ultrasonically joined continuously or quasi-continuously. On the other hand, by setting the unit rotation amount δθ to a large value, the inner surface of the first workpiece W1 and the outer surface of the second workpiece W2 are ultrasonically joined discontinuously or discretely.

[0046] The joint may extend in an open curve such as an arc rather than in a ring shape such as a circular ring or a closed curve. When the central angle of the arc is Θ (0<Θ<360°), for example, the designated number N may be set to N=(Θ / δθ).

[0047] If the determination result is negative (FIG. 3 / STEP 126...NO), the rotation drive device 220 rotates the ultrasonic vibration device 10 and the horn tip 140 by the rotation unit amount around the central axis (FIG. 3 / STEP 128). As a result, the first workpiece W1 and the second workpiece W2 are rotated by the rotation unit amount δθ. Then, the translation drive device 222 moves the ultrasonic vibration device 10 and the horn tip 140 in the radial direction so as to approach the first workpiece W1 with the second workpiece W2 fitted inside (FIG. 3 / connector X1→STEP 112). On the other hand, if the determination result is positive (FIG. 3 / STEP 126...YES), the series of processes is stopped.

[0048] In addition, the horn tip 140 may be replaced with another horn tip having a different diameter or shape during the series of processes, in accordance with the outer shape of the first workpiece W1.

[0049] (effect) With the ultrasonic joining device configured as described above, the first annular portion of the first workpiece W1 and the second annular portion of the second workpiece W2 are ultrasonically joined continuously or discontinuously over the entire circumference. Because this is a method different from crimping, a crimping allowance is not required, which allows for a more compact or smaller ultrasonically joined structure including the first workpiece W1 and the second workpiece W2.

[0050] (Example) Using the ultrasonic bonding device configured as described above, for example, a first housing portion H1 and a second housing portion H2 constituting a housing H of a secondary battery C shown in FIG. 4 are ultrasonically bonded. As shown in FIG. 4, the housing H accommodates and seals a positive electrode plate C1 and a negative electrode plate C2 electrically insulated by a separator C0, a positive electrode current collector C12 electrically connected to the positive electrode plate C1, and a negative electrode current collector C22 electrically connected to the negative electrode plate C2. The first housing portion H1 is formed from a stainless steel plate into a generally cylindrical shape with a bottom. The second housing portion H2 is formed from a stainless steel plate into a generally cylindrical shape with a top and a diameter approximately the same as or slightly smaller than the inner diameter of the first housing portion H1.

[0051] The second housing part H2 is fitted inside the upper end or open end (first annular part) of the first housing part H1, and the inner surface of the upper end of the first housing part H1 and the outer surface of the side wall (second annular part) of the second housing part H2 are ultrasonically joined continuously or discontinuously over the entire circumference. That is, the first housing part H1 or its upper end corresponds to the first workpiece W1, and the second housing part H2 or its side wall corresponds to the second workpiece W2 (see FIG. 2). The second housing part H2 may be fitted outside the upper end or open end (first annular part) of the first housing part H1, and the outer surface of the upper end of the first housing part H1 and the inner surface of the side wall (second annular part) of the second housing part H2 may be ultrasonically joined continuously or discontinuously over the entire circumference.

[0052] During ultrasonic bonding of the first housing portion H1 and the second housing portion H2, as shown in FIG. 5, the upper end of the first housing portion H1, into which the second housing portion H2 is fitted, is supported at three points by the horn tip 140, the first anvil pulley 141, and the second anvil pulley 142. Furthermore, as shown in FIG. 5, the upper end of the first housing portion H1 is supported at three points by the auxiliary pulleys 40, 41, and 42. The auxiliary pulleys 40, 41, and 42 may be omitted. Alternatively, the housing H of the secondary battery C may be supported on one or both sides in the longitudinal direction by a support member (not shown) to prevent displacement in the longitudinal direction or axial direction (direction parallel to the first axis). The auxiliary pulleys 40, 41, and 42 may correspond to the horn tip 140, the first anvil pulley 141, and the second anvil pulley 142, respectively. The number of auxiliary pulleys may be two, or may be four or more.

[0053] In this state, the first housing part H1 or its upper end part and the second housing part H2 or its side wall part are ultrasonically joined along the entire periphery according to the procedure shown in Fig. 3, even without the crimping margin Δ (see Fig. 7). As shown in Fig. 4, the absence of the crimping margin Δ (see Fig. 7) allows the distance d1 between the positive electrode current collector C12 and the housing H (the top plate part of the second housing part H2), and therefore the size d of the secondary battery C, to be reduced. This improves the volumetric energy density of the secondary battery C.

[0054] The first housing portion H1 may be constructed by joining an approximately cylindrical member and an approximately bottomed tubular member that is inserted into or inserted into one end of the approximately cylindrical member, all around the circumference, using the ultrasonic joining device of the above configuration in accordance with the procedure shown in Figure 3.

[0055] (Another embodiment of the present invention) In the above embodiment, ultrasonic complex vibration is generated by forming slit 124 in ultrasonic vibration device 10 (second vibration element 120), but slit 124 may be omitted from ultrasonic vibration device 10 (second vibration element 120) to generate ultrasonic linear vibration.

[0056] In the above embodiment, the first workpiece W1 and the second workpiece W2 are supported with the horn tip 140, the first anvil pulley 141, and the second anvil pulley 142 each abutting against the outer surface of the first workpiece W1 (see FIG. 2). In other embodiments, the first workpiece W1 and the second workpiece W2 may be supported with the horn tip 140 abutting against the outer surface of the first workpiece W1 while one or more anvil pulleys abut against the inner surface of the second workpiece W2. For example, as shown in FIG. 6, the first workpiece W1 and the second workpiece W2 may be supported with the horn tip 140 abutting against the outer surface of the first workpiece W1 while the first anvil pulley 141 abutting against the inner surface of the second workpiece W2. Similarly, the first workpiece W1 and the second workpiece W2 may be supported with the horn tip 140 abutting the inner surface of the second workpiece W2 while one or more anvil pulleys abutting the outer surface of the first workpiece W1.

[0057] In the above embodiment, the first workpiece W1 (or its joint portion) and the second workpiece W2 (or its joint portion) were each approximately circular, but they may also be plate-shaped, columnar, or frustum-shaped in cross section, the entirety of which is surrounded by a convex curve, such as an approximately elliptical plate, or may be plate-shaped, columnar, or frustum-shaped in cross section, the entirety of which is composed of a convex curve in part.

[0058] Instead of executing the process of separating the horn tip 140 (decompression process) after the process of stopping the ultrasonic vibrations (see FIG. 3 / STEP 120 → ... → STEP 122 → ...), the process of stopping the ultrasonic vibrations may be executed after the process of separating the horn tip 140. That is, the process of STEP 120 after the determination process of STEP 118 may be omitted, and if the determination process of STEP 124 is positive, the process of STEP 120 may be executed.

[0059] Rather than repeatedly executing the ultrasonic vibration generation and stop processes in conjunction with the sequential rotational drive process of the horn tip 140 (see FIG. 3 / STEP 116 → STEP 120 → STEP 116 → STEP 120 → ), the ultrasonic vibration stop process may be executed only when it is determined that the joining process at all joining locations has been completed. That is, the process of STEP 120 after the determination process of STEP 118 may be omitted, and the process of STEP 120 may be executed if the determination process of STEP 126 is affirmative. In this case, the ultrasonic vibration is continuously generated without being stopped until joining at all joining locations or joining regions of the first workpiece W1 and the second workpiece W2 is completed.

[0060] Instead of intermittently executing the approaching operation process (pressurizing operation process) and the separating operation process (depressurizing operation process) of horn tip 140 in conjunction with the intermittent rotational drive process of horn tip 140 (see FIG. 3 / STEP 112 → STEP 122 → STEP 112 → STEP 122 → ), the separating operation process of horn tip 140 may be executed only when it is determined that the joining process has been completed at all joining locations. That is, the process of STEP 122 after the process of STEP 121 may be omitted, and the process of STEP 122 may be executed if the determination process of STEP 126 is affirmative. In this case, pressing force is continuously applied from horn tip 140 to first workpiece W1 and / or second workpiece W2 until joining is completed at all joining locations or joining regions of first workpiece W1 and second workpiece W2. Furthermore, when the ultrasonic vibration stopping process is executed on the condition that it has been determined that the joining process has been completed at all joining points as described above, a pressing force is continuously applied from the horn tip 140 to the first workpiece W1 and / or the second workpiece W2 until joining at all joining points or joining areas of the first workpiece W1 and the second workpiece W2 is completed, and the ultrasonic vibration is continuously generated without being stopped.

[0061] The joining completion determination process (see FIG. 3 / STEP 118) for each or all of the multiple joining points of the first workpiece W1 and the second workpiece W2 may be omitted. In this case, instead of the joining completion determination process, it may be determined whether the cumulative time of application of ultrasonic vibrations to each of the multiple joining points has reached a specified time.

[0062] In the above embodiment, the amplitude A of the horn tip 140 was measured as a specified parameter that changes depending on the progress of joining the first workpiece W1 and the second workpiece W2, but in other embodiments, the axial displacement amount, displacement speed and / or displacement acceleration of the vibration element (e.g., the second vibration element 120) may be measured as a specified parameter. [Explanation of symbols]

[0063] 10. Ultrasonic vibration device 100...Intermediate vibration element 102...Intermediate flange 110...First vibration element 112. Piezoelectric material 120...Second vibration element 122...Frequency adjustment element 124. Slit 140...Horn tip (Ultrasonic bonding tip) 141...First anvil pulley (rotating support member) 142... Second anvil pulley (rotating support member) 20‥Operation device 22. Control device 220 Rotational drive device 221‥High frequency power supply equipment 222...Translation drive device 224...Status sensor C‥Secondary battery H...Housing H1: First housing part (first work) H2: Second housing part (second work) W1: First work W2: Second work.

Claims

1. an ultrasonic vibration device configured to generate linear vibrations in a direction parallel to at least the first axis; a rotary drive device configured to drive the ultrasonic vibration device to rotate about the first axis; an ultrasonic bonding tip connected to the ultrasonic vibration device; a translational drive device configured to translate the ultrasonic vibration device in a direction perpendicular to the first axis; a rotation support member configured to support a plurality of workpieces to be joined at a plurality of locations together with the ultrasonic bonding tip, and to be rotatable about a second axis in response to rotation of the plurality of workpieces by rotation of the ultrasonic vibration device and the ultrasonic bonding tip about the first axis. Ultrasonic bonding equipment.

2. 2. The ultrasonic bonding apparatus according to claim 1, The ultrasonic vibration device is configured to generate a composite vibration of the linear vibration and a torsional vibration around an axis. Ultrasonic bonding equipment.

3. 3. The ultrasonic bonding apparatus according to claim 1, A protrusion or a concave-convex structure is formed at least partially at the support points of the ultrasonic bonding tip for supporting the plurality of workpieces. Ultrasonic bonding equipment.

4. 3. The ultrasonic bonding apparatus according to claim 1, The ultrasonic bonding tip and the rotary support member are each configured to abut against one of the plurality of workpieces in a state where the workpieces are positioned relative to one another, so that the plurality of workpieces are supported by the ultrasonic bonding tip and the rotary support member. Ultrasonic bonding equipment.

5. 3. The ultrasonic bonding apparatus according to claim 1, The ultrasonic bonding tip is configured to contact one of the plurality of workpieces, while the rotary support member is configured to contact another of the plurality of workpieces, so that the plurality of workpieces are supported by the ultrasonic bonding tip and the rotary support member. Ultrasonic bonding equipment.

6. 3. The ultrasonic bonding apparatus according to claim 1, a state sensor that outputs a signal according to a parameter corresponding to the joining state of the plurality of workpieces; a control device configured to control the operation of each of the ultrasonic vibration device, the rotation drive device, and the translation drive device in response to an output signal from the state sensor. Ultrasonic bonding equipment.

7. A program for causing a computer to execute a method for joining a plurality of workpieces using the ultrasonic joining device according to any one of claims 1 to 6, The method includes a step of supporting the plurality of workpieces on the ultrasonic bonding tip and the rotary support member by causing the translation drive device to translate the ultrasonic bonding tip in a direction perpendicular to the first axis; generating vibrations in the ultrasonic vibration device; and causing the rotary drive device to rotate the ultrasonic vibration device. Ultrasonic welding program.

8. The method includes: providing a first workpiece having a first annular portion; and providing a second workpiece having a second annular portion that is ultrasonically welded or solid-state welded to the first annular portion of the first workpiece while being inserted or extrapolated thereto. Ultrasonic bonded structure.

9. 9. The ultrasonically bonded structure according to claim 8, An annular trace of ultrasonic bonding is present on at least one of the first annular portion of the first workpiece and the second annular portion of the second workpiece. Ultrasonic bonded structure.

10. 9. The ultrasonically bonded structure according to claim 8, The first workpiece is a cylindrical first workpiece having a bottom and an open end as the first annular portion, the second workpiece is a cylindrical second workpiece having a second annular portion that is ultrasonically welded to the first annular portion of the first workpiece while being inserted or extrapolated thereto, and a structure accommodated in an internal space of the first workpiece and the second workpiece. Ultrasonic bonded structure.

11. The ultrasonically bonded structure according to claim 10, a secondary battery including a positive electrode plate material, a negative electrode plate material, a separator that electrically insulates the positive electrode plate material and the negative electrode plate material, a positive electrode current collector electrically connected to the positive electrode plate material, and a negative electrode current collector electrically connected to the negative electrode plate material, as the structure accommodated in the internal space of a housing formed by the first workpiece and the second workpiece; Ultrasonic bonded structure.

Images