JP6585217B2 - Compound bending vibration detection method - Google Patents

Description

In the present invention, the vibration tool is driven by a circular or elliptical vibration locus instead of the conventional one-dimensional linear vibration locus, and two-dimensional vibration stress is applied to a metal or ceramic material to ultrasonic waves such as ultrasonic welding and cutting. The present invention relates to a composite bending vibration detection method of an ultrasonic composite vibration device that performs processing.

  Capacitors, containers such as lithium-ion batteries, electrodes of complicated semiconductor substrates, terminals or the like are welded or processed at deep locations and the periphery is narrow and limited. Electric resistance welding or laser welding is used.

However, in the prior art, if sufficient welding and processing are performed, metal particles are essentially discharged and scattered from the welded and processed parts due to discharge and melting, and adhere to capacitors, lithium ion battery interiors, electrodes, and peripheral parts of the substrate. , Mixed, causing performance degradation and defective products. In addition, lithium ion batteries require simultaneous welding of a plurality of electrodes in order to reduce internal resistance, increasing the difficulty of welding.
In addition, welding must be performed under conditions where performance degradation due to metal particles can be ignored in the actual mass production process, but under these insufficient conditions, stable welding / processing is difficult and many defective products are generated. There is also a problem that troubles occur during use of the product, and there is a strong demand for a solution to this problem.

  In addition, if it becomes possible to use ultrasonic welding where there is no possibility of metal particles being emitted and scattered from the welded / processed part by electric discharge or melting, these problems can be solved, but in conventional ultrasonic welding using linear vibration, Since the required vibration amplitude is large and the required static pressure is also large, deflection during application of vibrations of elongated bending vibration tools of several wavelengths or more, displacement during welding of welded parts, fracture and bending of welded parts It was difficult to realize due to fatigue failure of vibration tools, and practical use was impossible.

  The present invention uses an ultrasonic composite vibration welding apparatus that performs welding by applying a two-dimensional vibration stress to a welded part using an ultrasonic composite bending vibration welding tool whose tip part vibrates in a circular or elliptical locus. The combined vibration detection installed in the composite bending vibration tool takes advantage of the remarkable effect that the vibration amplitude and static pressure required for welding become smaller than when using linear vibration and the damage of the weld is drastically reduced. The objective is to achieve stable welding of multiple weld specimens at narrow and deep positions by using a vibration feedback oscillation device using the output of the vessel and static pressure control and vibration control devices before and after welding and during welding. . In the example of the lithium ion battery, a bending vibration tool having a diameter of about 2.0 mm to 3.0 mm and a length of 75 to 100 mm or more is required.

  In addition, by applying composite bending vibration to the cutting tool for vibration cutting such as milling, the cutting efficiency can be further improved by using ultrasonic vibration in the cutting direction compared to the case of using linear vibration perpendicular to the machining surface. Improvement and reduction of damage to cutting tools can be expected.

  The present invention includes an ultrasonic vibration converter section, an ultrasonic horn section for vibration transmission and vibration speed transformation, a composite vibration converter using longitudinal-torsional vibration conversion by an oblique slit, and a longitudinal vibration source for driving. A thin and long ultrasonic compound bending vibration welding tool is installed at the tip of the ultrasonic compound vibration device to be oscillated in a circular or elliptical locus, and stable welding of narrow and deep parts is performed by two-dimensional vibration (composite vibration) of the tip. It is realized. By using the composite vibration, the necessary vibration amplitude is reduced from a fraction to a tenth, and the required static pressure is also reduced to a fraction. Therefore, welding in a narrow and deep place becomes possible. In addition, the use of a composite vibration that is almost symmetrical at the tip of the circle or ellipse reduces the deformation of the entire tool, dramatically reduces fatigue damage due to misalignment of the welded part and vibration, and realizes stable welding with little sample damage. It becomes possible. Moreover, stable welding can be realized by installing a compound bending vibration detector for detecting only compound bending vibration in the compound bending vibration tool and applying the output voltage to observation or control of the driving device during machining.

  If a long and thin ultrasonic compound bending vibration welding tool is installed directly on the transducer of an ultrasonic compound vibration device, it will be damaged by tool replacement. It is necessary to use a vibration tool that is joined and integrated with each other. In the case of a non-resonant type holder, the total resonance frequency of the vibration device of 20 to 27 kHz is reduced by several hundred Hz due to the additional mass of the holder, and it is impossible to drive as it is, and readjustment of the power factor in the drive device is indispensable. Moreover, it is difficult to install using a joining screw with a short and small-diameter holder, and it is difficult to install a long vibration tool vertically.

  The invention of [Claim 1] is installed by joining and integrating a multi-wavelength long ultrasonic composite bending vibration welding tool to a resonance type holder having substantially the same frequency as a composite vibration device having a large diameter by shrinking or the like. Further, it is unnecessary to readjust the power factor by eliminating the change in the resonance frequency of the vibration device at the time of removal. The use of a resonating holder of sufficient diameter and length for screw joining facilitates removal and flattening of the joining surface. Moreover, the vibration speed can be increased by making the shape of the holder conical or the like, and the vibration speed can be increased by installing a vibration tool having a small diameter. Since the joint portion and the installation portion of the composite bending vibration welding tool are vibration loops, the vibration stress is minimized and the stability of the joint portion and the installation portion is excellent.

  Applying a relatively high static pressure to suppress deformation of the welded part, etc., applying an optimum welding static pressure in a stable state, applying composite vibration to perform welding, and attaching a sample to the tool tip In this case, a more stable welding process can be realized by using a static pressure control device that applies vibration with a light static pressure. In particular, a large number of electrode plates such as a plurality of welded samples or lithium ion batteries, especially a plurality of terminals having burrs or an electrode plate that has been subjected to a chemical conversion treatment to increase the surface area, the air layer is in a state where the surfaces are not smooth and overlapped. In order to perform welding while the electrode plates are in direct contact with each other, a high static pressure is applied and vibration is applied to the extent that ultrasonic welding is not performed. Therefore, it is necessary to perform welding with the optimum static pressure for ultrasonic composite vibration welding. As a result, it is possible to prevent damage such as breakage due to excessive vibration of the electrode plate due to driving without directivity of the composite vibration and to perform stable welding. This control of the static pressure and vibration amplitude is particularly necessary in complex vibration ultrasonic welding where the static pressure required for welding is small.

  Also, during welding, the static pressure decreases due to the deformation of the sample in a short time due to ultrasonic vibration, but a response using a metal spring or the like to keep the applied static pressure almost constant within the welding process. By using a high-speed actuator, it is possible to realize a more stable welding process. In composite vibration, the deformation of the sample is rapidly performed by applying a two-dimensional vibration stress, so that if the applied static pressure cannot follow and falls, the welding tip slips and the weld tip indentation grows and the sample is damaged. There is a particular need for an actuator with a fast response speed that keeps the pressure constant. The actuator may be incorporated in the upper static pressure applying device 11 or may be separately installed together with the static pressure measuring strain gauge in the lower part of the weld specimen.

  In addition, the welding sample 5 may adhere to the vibration tool tip 4 or the work table 5 during ultrasonic welding, but after welding, vibration can be applied for a short time with a low static pressure to be peeled off.

  Stable welding can be realized by changing the static pressure satisfying the requirement of the above item 3 for each stage and using the static pressure control device 11 provided with an actuator for holding the static pressure constant during welding.

  The ultrasonic vibration device is driven by using a resonance frequency automatic tracking type feedback oscillator and a control device for keeping the vibration speed constant in order to keep the welding process condition constant. By installing the composite vibration detectors 13 and 13 'that directly detect the vibration speed in the ultrasonic vibration tool portion and performing feedback control, vibration control characteristics are improved, and more stable machining can be realized.

  As a vibration speed detector that directly detects ultrasonic vibration, there is an annular electromagnetic vibration speed detector 14 (註 1) for longitudinal vibration detection, but it vibrates in two dimensions perpendicular to the axis of the vibration tool. The composite bending vibration detectors 13 and 13 ′ using an annular permanent magnet and a detection coil for detecting only a composite vibration of a circular or elliptical locus can be configured. By installing an electromagnetic type composite bending vibration detector that detects only the composite vibration without detecting the linear bending vibration in the ultrasonic vibration tool portion, the detection and recording of the composite vibration condition and the resonance frequency automatic tracking feedback oscillator 15 are performed. By using it for input, more stable vibration machining conditions can be realized.

  Embodiments of the present invention will be described below with reference to the drawings. The overall configuration of the composite vibration device of this embodiment is shown in FIG. FIG. 1 shows an ultrasonic composite bending vibration tool 1 in which a long bending bending vibration rod 1 ′ having five nodes is joined to a bending vibration half-wave resonance holder 1 ″ using an oblique slit that is uniaxially driven by a longitudinal vibration driving source. A fastening screw 2 is installed at the tip of the composite vibration transducer 7 that vibrates in a circular or elliptical locus, and the welded sample 5 that has been superposed is subjected to a large static pressure and a small vibration that does not start welding. Welding is performed by applying pressure and vibration to a stable state with amplitude in advance, and applying composite vibration with vibration amplitude necessary for welding while applying an optimum static pressure by the ultrasonic composite vibration welding tip 4. The slit composite vibration converter 7 is driven by a longitudinal vibration source 8 comprising a stepped horn 8 'and a bolted Langevin type longitudinal vibrator 8 ". The composite vibration device is an ultrasonic wave using the output voltage of the composite vibration detectors 13 and 13 ′ or the longitudinal vibration detector 14 that detects only the vibration velocity of a circular locus installed in a non-contact manner on a resonance type holder or a composite bending vibration bar. It is driven by a feedback oscillator. It is desirable to use a detector output voltage proportional to the vibration speed of the composite vibration tool closer to the welding load for drive control. The applied static pressure applied to the welded specimen before and after the welding process by the composite vibration is optimally controlled using the static applied pressure application control device 11. Static welding pressure during welding is a two-dimensional vibration stress caused by compound vibration, and the deformation of the weld specimen due to vibration application is rapid and the applied static pressure decreases, resulting in poor welding performance. The actuators 11 and 11 'for holding the static pressure constant are particularly necessary. Further, in order to stabilize the welded specimen, it is necessary to make the specimen weld surface directly contact and stabilize using a large static pressure and small vibration amplitude before welding. When the welded sample adheres to the welding tip or workbench after welding, vibration is applied under a small static pressure to separate it.

  FIG. 2 shows a state in which a long and slender composite vibration processing tool 1 in which a composite bending vibration rod is joined to a resonant conical holder by brazing or shrinking is installed by a screw joint 2 on a composite vibration transducer 7 that vibrates in a circular to elliptical locus. Since the holder diameter is large, the welding tool can be installed vertically and can be easily replaced by screw joining. In addition, it is easy to flatten the holder and installation surface because it is installed by screw joint.

  FIG. 3 shows a composite bending made of cemented carbide with a diameter of 3.0 mm and a length of 79 mm, which is integrated by shrink fitting into a conical holder having a base diameter of 15 mm and a tip diameter of 12 mm made of mold steel SKD11 having a bending vibration half wavelength. It is the result of actually measuring the bending vibration distribution at 19.5 kHz along the vibration tool using a laser Doppler vibrometer. The vibration trajectory at the tip is measured using two laser Doppler vibrometers with the same transmission characteristics. The vibration amplitude at the time of measurement is driven with a relatively small vibration amplitude in order to avoid a change in resonance frequency due to a temperature rise. The vibration distribution in the longitudinal vibration direction and the perpendicular direction are almost the same. Although the holder length is slightly shorter than a half wavelength, it is possible to resonate at the same frequency as the driving composite vibration transducer by adjusting the composite bending vibration rod length. It can also be seen that a vibration loop exists on the side of the composite bending vibration bar, and the vibration amplitude increases. As a result, the resonant holder may have a half wavelength and a length that is approximately an integral multiple of the half wavelength, and the entire composite vibrating tool can be resonated in the desired mode only by adjusting the bending vibration rod length.

The bending vibration tool material has high rigidity, small deflection deformation during welding, small displacement of the weld, and large sound speed, and the length adjustment is possible when the number of nodes is smaller than the required length of the vibration tool. A material that is relatively easy is needed. Further, it is necessary to reduce the wear of the tip part at the time of ultrasonic welding. For this purpose, cemented carbide, tungsten or the like is required. Moreover, since the density is around 13.9 and 18.6, which is larger than that of steel materials, the vibration energy of the vibrating rod becomes large. Further, since the equivalent mass expected from the drive system of the vibration tool becomes large, it is advantageous for vibration feedback oscillation control at the vibration tool resonance frequency.
The measured sound speed of the cemented carbide rod used here is about 6,409 m / s.

  FIG. 4 shows an example in which a composite bending vibration tool in which a composite bending vibration rod is joined to a resonance type holder is installed in an oblique slit composite vibration converter 7 (Japanese Patent Laid-Open No. 2005-288351) having four installation portions at the tip. The composite vibration transducer is driven by a longitudinal vibration source in a uniaxial configuration, performs longitudinal-torsional vibration conversion at an oblique slit, and is designed so that the longitudinal vibration and torsional vibration resonance frequency of the transducer match at the convex portion near the center. ing. The node part of the longitudinal vibration is designed to be present near the center of the convex part, and a pressurized static pressure is applied to this part and the flange of the node part of the longitudinal vibration system for driving.

  FIG. 5 shows a composite using a composite vibration converter driven by a composite vibration conversion pair 19 in which the longitudinal vibration and bending vibration resonance frequencies are matched through a longitudinal-bending vibration converter 18 using metal ring pairs having different sound speeds. It is the schematic of a bending vibration processing apparatus. The transducer tip vibrates from a circular shape to an elliptical locus in a plane having almost no vertical component. The metal ring pair 19 is formed by obliquely cutting and combining metal rings 19 'and 19 "having different sound speeds, and excites bending vibration by being driven by eight longitudinal vibration sources.

  FIG. 6 shows an example in which a plurality of composite bending vibration tools 1 are installed at the tip of the composite vibration converter 18 using the metal ring pair 19 that vibrates with a uniform circular trajectory in the lateral direction.

FIG. 7 shows the temporal change of the static pressure, the welding tip vibration amplitude, and the weld specimen height before, during, and after the ultrasonic welding of the static pressure control device 11.
There is no problem even if the static pressure is discontinuous unless the welding tip and the weld specimen are moved between the static pressure application before welding and the static pressure application during welding.

  FIG. 8 shows a configuration of an electromagnetic composite bending vibration detector 13 that detects only a circular or elliptical vibration velocity. Although a longitudinal vibration type electromagnetic vibration detector 14 that can be directly installed in a vibration system in a non-contact manner is known (非 1), there is a detector that can be directly installed in a non-contact manner that detects only complex vibrations. Not.

  7 and 24 are vibration detection principle diagrams showing a velocity vector V oscillating along a circular locus of the oscillating body, a magnetic field Φ perpendicular to the surface of the oscillating body by an annular magnet orthogonal thereto, and a current I orthogonal thereto. ing. As a result, an eddy current is generated in a direction determined by Lenz's law with respect to a magnetic field perpendicular to the surface of the vibrating body.

  7 and 25 show the configuration of the composite vibration detector. An annular magnet 29 having a non-contact NS polarity in the thickness direction is installed in the composite bending vibration system, and two detection annular coils 31 are arranged on both sides to constitute a detector. Since the direction 29 'of the magnetic flux is opposite on both sides of the annular magnet, the direction of the magnetic flux and the eddy current 30 generated at the vibration speed 28 is opposite in polarity. Also, in the normal bending vibration of the linear vibration locus, the direction of the eddy current generated on both sides of the vibration direction has a reverse polarity, so that it is canceled and no vibration is detected.

  7 and 26 show a connection diagram of the detector and an equivalent circuit of the parallel resonance capacitor. Since the voltages 34E1 and E2 induced in the eddy current detection annular coils 31 of the same polarity on both sides have opposite polarities, the detection coils are connected to opposite polarities. By inserting a resonance capacitor 33 having the same value as the resonance frequency of the vibration system in parallel with both connected detection coils in consideration of the capacitance of the output cable, the output voltage 35 is increased and the frequency selectivity is increased. Is obtained.

  The two detection coils 31 in the previous section have the same shape and the same inductance and are connected to opposite polarities, so that disturbance can be canceled and a stable output can be obtained. Further, the entire detector is an electrostatic shield 36, and the vibration is insulated by a closed cell sponge or the like and installed on the vibrating body. The influence of the vibration detector installation on the vibration device is very small and can be ignored. The linearity of the electromagnetic vibration speed detector is good.

  By combining the functions of the above items, it is possible to realize an ultrasonic composite vibration processing apparatus that can perform ultrasonic welding in a narrow and deep place with high strength of a stable welded portion and less damage to a welded sample.

  This ultrasonic composite vibration device can be effectively applied not only to ultrasonic welding but also to cutting, micro milling, and the like.

FIG. 1 is an elongate ultrasonic composite bending vibration tool 1 in which a composite bending vibration rod is joined to a resonance type holder of the present invention, a welded specimen 5, a schematic diagram of a bending vibration distribution of the vibration tool, and a composite vibration conversion using an oblique slit. Block diagram of the ultrasonic feedback oscillator 15 using the generator 7, the longitudinal vibration drive device 8, the composite vibration detectors 13 and 13 'and the longitudinal vibration detector output voltage, and the static pressure application controller 11 before and after welding by the composite vibration It is a block diagram of the ultrasonic complex vibration processing apparatus using the. FIG. 2 shows that a long and slender composite vibration processing tool 1 in which a composite bending vibration rod 1 ′ is joined to a resonance type holder 1 ″ by brazing or shrinking or the like is installed by screw joint 2 on a composite vibration transducer 7 that vibrates from a circular shape to an elliptical locus. The state is shown and can be easily replaced. FIG. 3 shows a composite bending vibration made of a cemented carbide alloy having a diameter of 3.0 mm and a length of 79 mm, which is installed by shrink fitting on a conical holder having a base diameter of 15 mm and a tip diameter of 12 mm made of mold steel SKD11 having a half-wave bending vibration. It is the result of actually measuring the bending vibration distribution at 19.5 kHz along the tool and the vibration trajectory of the welding tip using a laser Doppler vibrometer. FIG. 4 shows the configuration of a vibration system for composite bending vibration machining in which the composite bending vibration tool 1 using a resonance type holder is installed in an oblique slit composite vibration converter 7 having four installation positions at the tip. FIG. 5 shows the structure of a vibration system for composite vibration processing in which the composite bending vibration tool 1 using a resonance type holder is installed at the tip of a metal ring pair composite vibration converter 18 in which longitudinal and bending vibrations are combined. FIG. 6 shows the configuration of a vibration system for complex vibration machining in which a composite bending vibration tool 1 using a plurality of resonance type holders is installed at the tip of a wide metal ring pair composite vibration transducer 18 in which longitudinal and bending vibrations are combined. Indicates. FIG. 7 shows temporal changes of the static pressure control apparatus 11 before, during, and after ultrasonic welding, static pressure, composite vibration amplitude, welding tip vibration amplitude, and weld specimen height. FIG. 8 shows a principle of vibration detection in a compound bending vibration detector that detects only a circular or elliptical vibration velocity. FIG. 8 shows an arrangement of a ring magnet and two detection annular coils arranged in a non-contact manner in a bending vibration system. The connection diagram of FIG. 2 and the equivalent circuit 26 of the capacitor for parallel resonance are shown.

1 Complex bending vibration tool 1 'using a resonance type holder 1' Long and complex bending vibration rod 1 "whose length is several wavelengths Resonance type vibration rod holder (half wavelength)
2 Fastening screw for composite vibration tool installation 3 Bending vibration distribution along composite bending vibration tool 4 Composite bending vibration welding tip (vibration tool)
5 Welding samples (processed samples)
6 Metal block work table 7 Compound vibration converter 7 'using slant slit 7' Slant slit part 7 "Frequency adjusting convex part 8 having longitudinal vibration node part Longitudinal vibration source 8 'for driving composite vibration converter For fixing node part Stepped horn with flange 8 "bolted Langevin PZT longitudinal vibrator (BLT)
9 Longitudinal vibration distribution 9 'Torsional vibration distribution 10 Node part retainer 11 Static pressure control device 11' Welding static pressure constant holding lower actuator 12 Welding base lower part 13 Composite bending vibration detector (installed on vibration bar)
13 'Composite bending vibration detector (installed in the holder)
14 Electromagnetic annular longitudinal vibration detector 15 Ultrasonic vibration feedback oscillator (input switching)
16 Input for vibrator drive 17 Fastening screw hole 18 for installing composite vibration tool Vertical-bending composite vibration transducer 19 Metal ring pair vibration transducer 19 'with different sound speeds Metal ring A cut obliquely
19 "slant cut metal ring B
20 Driving longitudinal vibration source 21 Composite longitudinal-bending vibration transducer 22 equipped with a plurality of composite bending vibration tools 22 Time variation of applied static pressure of a static pressure control device 22 ′ welding tip composite vibration amplitude 22 ”welding sample height change 23 Peeling process 24 of welded specimen 24 Principle of composite vibration detection 25 Composition of composite vibration detector 26 Equivalent circuit 27 of composite vibration detector Composite bending vibration round bar 28 Circular trajectory vibration speed 29 Annular magnet 29 'on composite bending vibration round bar surface Vertical magnetic flux Φ
30 Eddy current on the surface of composite bending vibration round bar 31 Annular detection coils L1, L2
32 Parallel resonant capacitor 33 Electrostatic shield 34 Eddy current detection voltage E1, E2
35 Compound bending vibration detector output voltage E = E1 + E2

Claims (4)

Compound bending vibration that detects only the circular or elliptical locus component of a compound bending vibration tool that is installed at the tip of a compound vibration transducer that uses longitudinal-torsional vibration conversion and has a compound bending vibration bar that vibrates in a circular or elliptical locus. A detection method,
An annular magnet, the annular two complex bending electromagnetic type Ru comprising a detection toroid vibration detector which is provided on both sides in the thickness direction of the magnet, the magnetic field direction and the composite bending vibrating rod of the annular magnet The composite bending vibration detecting method , wherein the composite bending vibration detecting means is installed on the composite bending vibration bar so that velocity vectors of circular or elliptical locus components are orthogonal to each other . The composite bending vibration test method according to claim 1, wherein the annular magnet is installed in a non-contact manner on the composite bending vibration rod . The electromagnetic composite flexural vibration detector, characterized in that said installed in composite flexural vibrating rod via a closed cell sponge to insulate the vibrations of the composite bending vibrating rod, composite bend according to claim 1 or 2, wherein Vibration detection method . 4. The composite bending vibration detection method according to claim 1, wherein the electromagnetic composite bending vibration detector further includes a resonance capacitor in parallel with the two detection annular coils.