WO2013099298A1

WO2013099298A1 - Piezoelectric driving device

Info

Publication number: WO2013099298A1
Application number: PCT/JP2012/052038
Authority: WO
Inventors: 渡辺和久
Original assignee: ワックデータサービス株式会社
Priority date: 2011-12-26
Filing date: 2012-01-30
Publication date: 2013-07-04
Also published as: TW201328162A; JP2013135484A

Abstract

The present invention prevents an excessive current from flowing, and more reliably releases heat generated by the flow of current, thereby more reliably preventing other elements from malfunctioning. A vibrating plate (21) is formed by stacking a piezoelectric element, a plate, and a piezoelectric element, each of which is a substantially rectangular thin film. The stacked piezoelectric element, plate, and piezoelectric element are electrically connected to each other at the adjoining surfaces. A resistor (32) is provided on the outer-side surface of the vibrating plate (21). The resistor (32) has a predetermined electrical resistance value for restricting current. A predetermined voltage is applied to one of the terminals of the resistor (32), and the other terminal of the resistor (32) is electrically connected to the plate.

Description

Piezoelectric drive

The present invention relates to a piezoelectric drive device, and more particularly to a piezoelectric drive device used for a needle selection device of a knitting machine.

In recent years, a needle selection device for transmitting a pattern knitting procedure stored in a storage device to the vertical movement of a knitting needle is used in a knitting machine. In order to meet the demand for lower costs and higher speeds in the textile industry, needle selection devices for knitting machines having sliding or swinging fingers have been developed. Further, as a driving device for a needle selection device for a knitting machine, a piezoelectric driving device using a piezoelectric element having a high response speed and low power consumption has been used.

Conventionally, a plurality of piezoelectric ceramic layers are laminated on one side of a shim material, and the thickness, piezoelectric constant, and applied voltage of the laminated piezoelectric ceramic layers are gradually reduced from the shim material toward the outside. There is also a laminated unimorph type piezoelectric actuator capable of bending displacement using a shim material as a non-polarized piezoelectric inactive layer (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 10-225146

The electrical resistance component of the piezoelectric element used in the piezoelectric drive device inherently has a relatively large electrical resistance value. Due to various factors such as the usage environment and the change in the composition of the piezoelectric element, the electrical resistance value may decrease, and an excessive current may flow through the piezoelectric element. In order to prevent this, a resistor for limiting the current (hereinafter referred to as a current limiting resistor) is provided on the control board.

However, since it is necessary to arrange the control board in the needle selection device, the control board must be made smaller. As a result, current limiting resistors are densely arranged on the control board. When the current flowing through the piezoelectric element increases, heat is generated in the current limiting resistor, and this heat is applied to the current limiting resistor itself, other current limiting resistors, and other elements arranged on the control board. Will cause damage.

The present invention has been made in view of such a situation, and while preventing an excessive current from flowing, the heat generated by the flowing current is more reliably dissipated, and other elements are obstructed. It is possible to prevent more reliably.

A piezoelectric driving device according to one aspect of the present invention is a piezoelectric driving device used in a needle selection device of a knitting machine, a plate formed as a substantially rectangular metal thin film, and a thin film having substantially the same shape as the plate And a second piezoelectric element formed as a thin film having substantially the same shape as the plate and superimposed on the other surface of the plate; The first piezoelectric element is provided on the outer surface, which is the surface facing the plate-side surface, and has a first electric resistance value for limiting current, and one terminal has a first electric resistance value. A first resistor having a voltage applied and the other terminal electrically connected to the plate or the outer surface of the first piezoelectric element, the plate-side surface of the first piezoelectric element, the plate, The surface of the second piezoelectric element on the plate side is electrically It has been continued.

As described above, the first resistor having the first electric resistance value for limiting the current is provided on the outer surface which is the surface of the first piezoelectric element and is the surface facing the surface on the plate side, When a first voltage is applied to one terminal of the first resistor and the other terminal is electrically connected to the outer surface of the plate or the first piezoelectric element, an excessive current flows. The heat generated in the first resistor is conducted to the plate, which is a metal thin film having a relatively high thermal conductivity, through the first piezoelectric element of the thin film, and the heat is conducted to the entire plate. Heat can be dissipated in a wider area. Therefore, heat can be radiated more reliably. Further, since a sufficient distance to other elements such as the control board of the needle selection device can be secured, it is possible to more reliably prevent the other elements from being damaged.

In addition, the other terminal of the first resistor is electrically connected to the outer surface of the first piezoelectric element, and the outer surface is the surface of the second piezoelectric element that faces the surface on the plate side. A second electric resistance value for limiting current, a second voltage is applied to one terminal, and the other terminal is electrically connected to the outer surface of the second piezoelectric element. A second resistor can be further provided.

In this case, since heat generated when an excessive current flows can be distributed to the first resistor and the second resistor, heat concentration can be prevented and heat can be radiated more reliably.

The position where the second resistor is provided can be separated from the position where the first resistor is provided by a predetermined distance. Since it arrange | positions so that a 1st resistor and a 2nd resistor may not oppose, substantial heat concentration can be prevented and it can radiate still more reliably.

A connection point provided on the outer surface of the first piezoelectric element, the connection point for electrically connecting to the outer surface of the first piezoelectric element, and the other terminal of the first resistor are in contact with each other A first resistor can be provided at the position to be. The heat generated in the first resistor can be conducted from the connection point, and the first resistor can be easily fixed by, for example, soldering.

A support portion that is formed so as to sandwich the plate, the first piezoelectric element, and the second piezoelectric element and is supported by the needle selection device may be further provided, and the first resistor may be provided in the vicinity of the support portion. it can. The heat generated in the first resistor can be conducted from the support portion to the needle selection device, and more reliably radiated.

As described above, according to one aspect of the present invention, while preventing an excessive current from flowing, the heat generated by the current flowing can be radiated more reliably and other elements can be damaged. Can be prevented more reliably.

1 is a perspective view showing an outline of a needle selection device 1. FIG. 2 is a perspective view illustrating an example of a configuration of a piezoelectric driving device 11. FIG. 2 is a plan view showing an example of the configuration of a piezoelectric driving device 11. FIG. 3 is a bottom view showing an example of the configuration of a piezoelectric driving device 11. FIG. 3 is a perspective view for explaining a piezoelectric element and a plate constituting a diaphragm 21. FIG. 3 is a front view for explaining a piezoelectric element and a plate constituting a vibration plate 21. FIG. 4 is a cross-sectional view showing a configuration of a cross section in the thickness direction of a diaphragm 21. FIG. 2 is a diagram illustrating an example of an equivalent circuit of a piezoelectric driving device 11. FIG. FIG. 6 is a perspective view showing another example of the configuration of the piezoelectric drive device 11. 6 is a plan view showing another example of the configuration of the piezoelectric driving device 11. FIG. FIG. 5 is a bottom view showing another example of the configuration of the piezoelectric drive device 11. FIG. 4 is a diagram illustrating another example of an equivalent circuit of the piezoelectric driving device 11. 6 is a plan view showing still another example of the configuration of the piezoelectric driving device 11. FIG. FIG. 10 is a bottom view showing still another example of the configuration of the piezoelectric driving device 11. 6 is a plan view showing still another example of the configuration of the piezoelectric driving device 11. FIG. FIG. 10 is a bottom view showing still another example of the configuration of the piezoelectric driving device 11.

Hereinafter, a piezoelectric drive device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 12.

FIG. 1 is a perspective view showing an outline of a needle selection device in which a piezoelectric driving device according to an embodiment of the present invention is used. The needle selection device 1 is attached to a knitting machine such as a flat knitting machine or a sock knitting machine. The needle selection device 1 selects the operation of the knitting needle to cause the knitting needle to perform an operation corresponding to the handle.

The needle selection device 1 is configured to include a piezoelectric drive device 11, a frame 12, and a finger 13. The piezoelectric driving device 11 is incorporated in the frame 12 and is charged and bent by a voltage applied from the outside. The end of the piezoelectric driving device 11 that is bent and displaced is inserted into the linear groove of the finger 13 so as to be freely displaceable. The finger 13 is a sliding or swinging type finger. The finger 13 is pivotally fixed to the frame 12 so as to be rotatable. Since the end portion of the piezoelectric driving device 11 is engaged with the finger 13, when the piezoelectric driving device 11 is bent, the finger 13 is displaced about a rotatable shaft. The finger 13 selects the operation of the knitting needle according to the displaced position. That is, the piezoelectric drive device 11 displaces the finger 13 by bending.

Next, an example of the configuration of the piezoelectric drive device 11 according to an embodiment of the present invention will be described. FIG. 2 is a perspective view showing an example of the configuration of the piezoelectric driving device 11. FIG. 3 is a plan view showing an example of the configuration of the piezoelectric driving device 11. FIG. 4 is a bottom view showing an example of the configuration of the piezoelectric drive device 11.

The piezoelectric drive device 11 includes a vibration plate 21, a support portion 22, a support portion 23, a transmission portion 24, a lead wire 25, a lead wire 26, a lead wire 27, a connector 28, a connection point 29, a connection point 30, a connection point 31, and a resistor 32. including. The vibration plate 21 includes a metal plate and piezoelectric elements stacked on both surfaces thereof, and is formed in a substantially rectangular thin plate shape. The diaphragm 21 is charged and bent when a voltage is applied from the outside. That is, the diaphragm 21 bends so that the end portion of the substantially rectangular longitudinal direction is displaced in the thickness direction. Details of the configuration of the diaphragm 21 will be described later.

The support part 22, the support part 23, and the transmission part 24 are formed from resin such as polyolefin, polypropylene, polyacetal, fluororesin, or polycarbonate.

The support portion 22 is formed so as to sandwich one end portion in the longitudinal direction of the diaphragm 21 formed in a substantially rectangular thin plate shape, and when the support portion 22 is incorporated in the frame 12 of the needle selection device 1, the needle selection device 1 (frame 12). The support part 23 intersects the diaphragm 21 in a short direction at a substantially intermediate position in the longitudinal direction of the diaphragm 21 formed in a substantially rectangular thin plate shape, protrudes from both sides of the diaphragm 21 in the longitudinal direction, and It is formed so as to sandwich the diaphragm 21. The support portion 23 is rotatably supported by the needle selection device 1 (the frame 12 thereof) when incorporated in the frame 12 of the needle selection device 1.

The transmission portion 24 is formed so as to sandwich the other end portion in the longitudinal direction of the diaphragm 21 formed in a substantially rectangular thin plate shape. When the transmission portion 24 is incorporated in the needle selection device 1, the linear shape of the finger 13 is formed. Inserted into the groove. Accordingly, when the piezoelectric driving device 11 is bent, the finger 13 is displaced.

The conducting wire 25, the conducting wire 26, and the conducting wire 27 are each a conducting wire for applying a predetermined voltage to the diaphragm 21, and are made of an electric wire with an insulation coating. One ends of the conductive wire 25, the conductive wire 26, and the conductive wire 27 are connected to the connector 28, and are electrically connected to predetermined terminals of the connector 28, respectively. The connector 28 is connected to a control board (not shown). When the connector 28 is connected to the control board, a predetermined voltage is applied to the conductor 25, the conductor 26, and the conductor 27.

The other end of the conducting wire 25 is electrically connected to the connection point 29 by, for example, soldering. The other end of the conducting wire 26 is electrically connected to the connection point 30 by, for example, soldering. A resistor 32 is connected to the middle of the conductive wire 26 by, for example, soldering. Details of the resistor 32 will be described later.

The other end of the conductive wire 27 is electrically connected to the connection point 31 by, for example, soldering. The connection point 29 is a connection point for electrically connecting to the outer plane among the planes of one piezoelectric element constituting the diaphragm 21. The connection point 30 is a connection point for electrically connecting to a plate on which piezoelectric elements are superimposed on both sides of the plane. The connection point 31 is a connection point for electrically connecting to the outer plane among the planes of the other piezoelectric element constituting the diaphragm 21.

The resistor 32 has a predetermined electric resistance value that limits the current flowing through the diaphragm 21, and is provided on the surface of the diaphragm 21. For example, the resistor 32 is fixed to the diaphragm 21 with an adhesive. The resistor 32 is connected in the middle of the conductor 26, whereby one terminal of the resistor 32 is electrically connected to the connector 28 side, and the other terminal of the resistor 32 is electrically connected to the connection point 30. Has been. For example, the electrical resistance value of the resistor 32 is 500 to 5000Ω, more preferably 750 to 1500Ω. The resistor 32 is a surface mount package, a so-called chip resistor. The resistor 32 may be of any resistor type or any shape as long as it has a predetermined electric resistance value. For example, a resistor that is a carbon film resistor or a metal film resistor is used. It can be an enameled or molded resistor.

Next, details of the configuration of the diaphragm 21 will be described with reference to FIGS. FIG. 5 is a perspective view for explaining a piezoelectric element and a plate constituting the vibration plate 21. FIG. 6 is a front view for explaining a piezoelectric element and a plate constituting the vibration plate 21. 5 and 6 show a state in which the piezoelectric elements and the plates that originally constitute the diaphragm 21 are separated from each other in the thickness direction. FIG. 7 is a cross-sectional view illustrating a configuration of a cross section in the thickness direction of the vibration plate 21. FIG. 7 also shows electrical connection between the diaphragm 21 and the conducting wire 25, the conducting wire 26, and the conducting wire 27. In the description with reference to FIG. 7, the upper side in FIG. 7 is simply referred to as the upper side, and the lower side in FIG. 7 is simply referred to as the lower side.

The diaphragm 21 includes a piezoelectric element 51-1, a piezoelectric element 51-2, and a plate 52. The piezoelectric element 51-1 and the piezoelectric element 51-2 include PZT (PbZrO ₃ -PbTiO ₃ ) (solid solution of lead zirconate and lead titanate) or PZT with Pb (MG, Nb) O ₃ or Pb (Ni, Nb ) It is formed of a ternary piezoelectric ceramic or other piezoelectric material in which a lead-based composite perovskite compound such as O ₃ is dissolved. The piezoelectric element 51-1 and the piezoelectric element 51-2 are formed as a substantially rectangular thin film. The thickness of the piezoelectric element 51-1 and the piezoelectric element 51-2 is 100 to 300 μm, more preferably 150 to 250 μm.

The plate 52 is made of a metal material having strength and conductivity for supporting the piezoelectric element 51-1 and the piezoelectric element 51-2. Specifically, the plate 52 is made of stainless steel (SUS: Steel Use Stainless) or 42 alloy (42Alloy). The plate 52 is formed as a substantially rectangular thin film having substantially the same shape as that of the piezoelectric elements 51-1 and 51-2. The thickness of the plate 52 is 75 to 150 μm, more preferably 75 to 125 μm.

An electrode film 53-1-1 is formed on the outer surface, which is one surface of the piezoelectric element 51-1, and is formed on the inner surface (the surface in contact with the plate 52), which is the other surface of the piezoelectric element 51-1. The electrode film 53-1-2 is formed. In addition, an electrode film 53-2-1 is formed on the inner surface (the surface in contact with the plate 52) which is one surface of the piezoelectric element 51-2, and the outer surface which is the other surface of the piezoelectric element 51-2. An electrode film 53-2-2 is formed on the side surface. The electrode film 53-1-1, the electrode film 53-1-2, the electrode film 53-2-1, and the electrode film 53-2-2 are formed as a thin film such as gold or silver, and the piezoelectric element 51-1 or By conducting the entire surface of each piezoelectric element 51-2, the piezoelectric element 51-1 or each surface of the piezoelectric element 51-2 is uniformly charged or the electric charge is removed from the entire surface.

The piezoelectric element 51-1 and the piezoelectric element 51-2 are used after being polarized.

As shown in FIG. 7, the piezoelectric element 51-1 is overlaid on the upper surface of the plate 52 (upper surface in FIG. 7), and on the lower surface of the plate 52 (lower surface in FIG. 7). The piezoelectric element 51-2 is overlaid. Accordingly, in the diaphragm 21, the electrode film 53-1-2 and the electrode film 53-2-1 are in contact with the plate 52. Therefore, the surface of the piezoelectric element 51-1 on the plate 52 side, the plate 52, and the piezoelectric element 51- The surface of the two plates 52 is electrically connected. For example, the piezoelectric element 51-1, the piezoelectric element 51-2, and the plate 52 are stacked and fixed with an adhesive such as epoxy resin or polyphenol resin.

Further, a solder resist 71-1 is formed on the outer surface of the piezoelectric element 51-1, that is, on the electrode film 53-1-1 (upper side in FIG. 7). A solder resist 71-2 is formed on the surface, that is, below the electrode film 53-2-2 (the lower side in FIG. 7). The solder resist 71-1 and the solder resist 71-2 are made of a heat-resistant polymer material. For example, the solder resist 71-1 and the solder resist 71-2 are liquid photosensitive resist materials mainly composed of an epoxy resin such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, or novolac type epoxy resin, and urethane. It can be formed of a photosensitive resist material having an acrylate as a main component and excellent folding resistance.

Furthermore, on the outside of the solder resist 71-1 and the solder resist 71-2, an electrical insulating film 72, which is a non-conductive polymer thin film, is formed so as to enclose the entire diaphragm 21.

The solder resist 71-1 and the electrical insulating film 72 are not formed at the connection point 29 and the connection point 30. Further, the solder resist 71-2 and the electric insulating film 72 are not formed at the connection point 31. That is, the connection point 29 is composed of the solder resist 71-1 and the electrode film 53-1-1 exposed from the electrical insulating film 72. The connection point 30 includes a solder resist 71-1 and a plate 52 exposed from the electrical insulating film 72. The connection point 31 is composed of a solder resist 71-2 and an electrode film 53-2-2 exposed from the electrical insulating film 72.

Therefore, as described above, since the end portion of the conducting wire 25 is electrically connected to the connection point 29, the electrode film 53-1-1 is electrically connected to the conducting wire 25 as shown in FIG. Is done. Further, as described above, since the end portion of the conducting wire 26 is electrically connected to the connection point 30, the plate 52 is electrically connected to the conducting wire 26. Furthermore, as described above, since the end portion of the conducting wire 27 is electrically connected to the connection point 31, the electrode film 53-2-2 is electrically connected to the conducting wire 27.

Thus, the plate 52 is formed as a substantially rectangular metal thin film. The piezoelectric element 51-2 is formed as a thin film having substantially the same shape as that of the plate 52, and is superposed on one surface of the plate 52. The piezoelectric element 51-1 is formed as a thin film having substantially the same shape as the plate 52, and is superimposed on the other surface of the plate 52. The surface of the piezoelectric element 51-1 on the plate 52 side, the plate 52, and the surface of the piezoelectric element 51-2 on the plate 52 side are electrically connected. The resistor 32 is provided on the outer surface which is the surface of the piezoelectric element 51-2 and is the surface facing the surface on the plate 52 side.

Further, the support portion 22 is formed so as to sandwich the plate 52, the piezoelectric element 51-2 and the piezoelectric element 51-1, and is supported by the needle selection device 1.

Next, with reference to the equivalent circuit of FIG. 8, the electrical connection of the piezoelectric driving device 11 whose configuration is shown in FIGS. 2 to 4 will be described. A capacitance (capacitance) C _1-1 , an inductance L _1-1 , and an electric resistance R _1-1 in FIG. 8 indicate an equivalent circuit of the piezoelectric element 51-1. That is, the equivalent circuit of the piezoelectric elements 51-1 and to the capacitance C _1-1 and the inductance L _1-1 connected in series, represented by the electrical resistance R _1-1 which are further connected in parallel. Further, a capacitance (capacitance) C _1-2 , an inductance L _1-2 , and an electric resistance R _1-2 in FIG. 8 indicate an equivalent circuit of the piezoelectric element 51-2. That is, the equivalent circuit of the piezoelectric elements 51-2 and to the capacitance C _1-2 and the inductance L _1-2 connected in series, represented by the electrical resistance R _1-2 which are further connected in parallel. When the piezoelectric driving device 11 is normal, the resistance values of the electric resistance _R1-1 and the electric resistance _R1-2 are extremely large values. As a result, as shown in the equivalent circuit, only a minute current flows through the piezoelectric element 51-1 and the piezoelectric element 51-2.

The surface of the piezoelectric element 51-1 on the plate 52 side, the plate 52, and the surface of the piezoelectric element 51-2 on the plate 52 side are electrically connected. Since the element 51-2 is connected in series, the equivalent circuit of the piezoelectric element 51-1 and the equivalent circuit of the piezoelectric element 51-2 are connected in series.

Conductor 26 is electrically connected to the plate 52, since the resistor 32 is connected to the middle of the conductor 26, one terminal of the resistance R ₂ which corresponds to the resistor 32, the plate 52, i.e., the piezoelectric element It is connected to a connection point between the equivalent circuit of 51-1 and the equivalent circuit of the piezoelectric element 51-2. The other terminal of the electrical resistance R ₂ corresponding to the resistor 32 is connected to the connector 28.

When the connector 28 is connected to the control board, the conductor 25, for example, + 48V positive voltage V ₊ is applied, the conductor 27, for example, a negative voltage V of -48V _- is applied, also lead 26 For example, a drive signal having a voltage of + 48V or −48V is applied from the drive signal source 91. For example, when a drive signal having a voltage of + 48V is applied from the drive signal source 91, a voltage of 0V is applied between the electrode film 53-1-1 and the electrode film 53-1-2 of the piezoelectric element 51-1. Is applied, and a voltage of 96 V is applied between the electrode film 53-2-1 and the electrode film 53-2-2 of the piezoelectric element 51-2. As a result, the piezoelectric element 51-2 Bends. On the other hand, when a drive signal having a voltage of −48 V, for example, is applied from the drive signal source 91, the electrode film 53-1-1 and the electrode film 53-1-2 of the piezoelectric element 51-1 are A voltage of 96 V is applied, and a voltage of 0 V is applied between the electrode film 53-2-1 and the electrode film 53-2-2 of the piezoelectric element 51-2. As a result, the piezoelectric element 51-1 bends.

The positive voltage V ₊ , the negative voltage V ₋ , and the voltage of the drive signal source 91 need only be voltages required to drive the piezoelectric driving device 11. For example, a positive voltage V _{+ of +90} V is applied, and the conductor 27 A negative voltage V _{− of} 0V may be applied to the lead wire 26, and a drive signal having a voltage of either + 90V or 0V may be applied to the conductive wire 26 from the drive signal source 91.

Thus, the resistor 32 has a predetermined electrical resistance value that limits the current. A predetermined voltage is applied to one terminal of the resistor 32, and the other terminal of the resistor 32 is electrically connected to the plate 52.

The resistor 32 is provided even if the resistance value of either the electrical resistance R _1-1 or the electrical resistance R _1-2 is reduced due to factors such as a change in the usage environment or the composition of the piezoelectric element. The electric resistance R ₂ can prevent an excessive current from flowing through the piezoelectric element 51-1 or the piezoelectric element 51-2.

A resistor 32 having an electric resistance value for limiting current is provided on the outer surface of the piezoelectric element 51-1, which is the surface facing the surface on the plate 52 side, and is connected to one terminal of the resistor 32. Since a voltage which is a drive signal is applied and the other terminal is electrically connected to the plate 52, the heat generated in the resistor 32 when an excessive current flows flows into the thin film piezoelectric element 51-1. Since the heat is conducted to the whole plate 52 through the plate 52 which is a metal thin film having a relatively high thermal conductivity, heat can be dissipated in a wider area. Therefore, heat can be radiated more reliably. In addition, since a sufficient distance to other elements such as the control board of the needle selection device 1 can be secured, it is possible to more reliably prevent the other elements from being damaged.

It is also possible to provide a resistor having an electric resistance value for limiting the current on the positive voltage V ₊ and negative voltage V ₋ sides. Hereinafter, another example of the configuration of the piezoelectric driving device 11 in this case will be described.

FIG. 9 is a perspective view showing another example of the configuration of the piezoelectric driving device 11. FIG. 10 is a plan view showing another example of the configuration of the piezoelectric driving device 11. FIG. 11 is a bottom view showing another example of the configuration of the piezoelectric driving device 11.

The piezoelectric drive device 11 shown in FIGS. 9 to 11 includes a diaphragm 21, a support portion 22, a support portion 23, a transmission portion 24, a conductive wire 25, a conductive wire 26, a conductive wire 27, a connector 28, a connection point 29, a connection point 30, A connection point 31, a resistor 101, and a resistor 102 are included. The diaphragm 21, the support part 22, the support part 23, the transmission part 24, the conducting wire 25, the conducting wire 26, the conducting wire 27, the connector 28, the connection point 29, the connection point 30, and the connection point 31 are shown in FIGS. Since this is the same as the case, the description thereof is omitted.

In the piezoelectric driving device 11 shown in FIGS. 9 to 11, one end of each of the conductive wire 25, the conductive wire 26, and the conductive wire 27 is connected to the connector 28 and is electrically connected to a predetermined terminal of the connector 28. It is connected. A resistor is not provided in the middle of the conductor 26, and the other end of the conductor 26 is electrically connected to the connection point 30. That is, the conductive wire 26 electrically connects a predetermined terminal of the connector 28 and the connection point 30 directly.

Also, the other end of the conductive wire 25 is electrically connected to one terminal of the resistor 101 by, for example, soldering. The other end of the conducting wire 27 is electrically connected to one terminal of the resistor 102 by, for example, soldering.

The resistor 101 has a predetermined electric resistance value that limits the current flowing through the diaphragm 21, and is provided on the surface of the diaphragm 21. More specifically, the resistor 101 is provided at a position where the other terminal of the resistor 101 contacts the connection point 29. The other terminal of the resistor 101 is electrically connected to the connection point 29 by, for example, soldering. Since the other terminal of the resistor 101 is provided at a position where it comes into contact with the connection point 29, for example, the resistor 101 can be connected to the diaphragm 21 only by soldering the other terminal of the resistor 101 and the connection point 29. Can be fixed easily. Further, the heat generated in the resistor 101 can be conducted from the connection point 29 to the diaphragm 21 (piezoelectric element 51-1, plate 52, and piezoelectric element 51-2).

The resistor 102 has a predetermined electrical resistance value that limits the current flowing through the diaphragm 21, and is provided on the surface of the diaphragm 21. More specifically, the resistor 102 is provided on the surface of the diaphragm 21 that faces the surface on which the resistor 101 is provided. The resistor 102 is provided at a position where the other terminal of the resistor 102 contacts the connection point 31. The other terminal of the resistor 102 is electrically connected to the connection point 31 by, for example, soldering. Since the other terminal of the resistor 102 is provided at a position in contact with the connection point 31, for example, the resistor 102 can be connected to the diaphragm 21 only by soldering the other terminal of the resistor 102 and the connection point 31. Can be fixed easily. Further, the heat generated in the resistor 102 can be conducted from the connection point 31 to the diaphragm 21 (the piezoelectric element 51-2, the plate 52, and the piezoelectric element 51-1).

Further, the resistor 102 is disposed so as not to face the resistor 101. The position where the resistor 102 is provided is preferably separated from the position where the resistor 101 is provided. By doing in this way, substantial heat concentration can be prevented and heat can be radiated more reliably. That is, for example, the resistor 101 is provided at a position where the resistor 102 is provided so that there is no overlap between the region where the resistor 102 is in contact with the diaphragm 21 and the region where the resistor 101 is in contact with the diaphragm 21. It is separated from the position where it is placed by a predetermined distance.

The resistor 101 and the resistor 102 are provided closer to the support portion 22 than the resistor 32. By doing in this way, the heat which generate | occur | produced in the resistor 101 and the resistor 102 can be conducted from the support part 22 to the needle selection apparatus 1 (frame 12), and also can be radiated more reliably.

For example, the electrical resistance value of the resistor 101 or the resistor 102 is 500 to 5000Ω, more preferably 750 to 1500Ω. Note that the electrical resistance value of the resistor 101 and the electrical resistance value of the resistor 102 may be the same value or different values.

The resistor 101 or the resistor 102 is a surface mount package, a so-called chip resistor. The resistor 101 or the resistor 102 may have any resistor type or any shape as long as it has a predetermined electric resistance value. For example, the resistor 101 is a carbon film resistor or a metal film resistor. It can be an enamel-type or mold-type resistor employing a body.

Next, with reference to the equivalent circuit of FIG. 12, the electrical connection of the piezoelectric driving device 11 whose configuration is shown in FIGS. 9 to 11 will be described. Capacitance (capacitance) C _1-1 , inductance L _1-1 , and electrical resistance R _{1-1 and} capacitance (capacitance) C _1-2 , inductance L _1-2 , and electrical resistance R _1-2 Since it is the same as that shown in FIG.

Since the conductive wire 26 is electrically connected directly to the plate 52, the drive signal from the drive signal source 91 is directly connected to the connection point between the equivalent circuit of the piezoelectric element 51-1 and the equivalent circuit of the piezoelectric element 51-2. Applied. Since one terminal of the resistor 101 is electrically connected to the conductive wire 25 and the other terminal of the resistor 101 is electrically connected to the connection point 29, the electrical resistance R ₂₁ corresponding to the resistor 101 is obtained. the one terminal of the positive voltage V ₊ is applied, the other terminal of the resistance R ₂₁ corresponding to the resistor 101, among the terminals of the equivalent circuit of the piezoelectric elements 51-1, which corresponds to the connection point 29 Connected to the terminal.

Since one terminal of the resistor 102 is electrically connected to the conducting wire 27 and the other terminal of the resistor 102 is electrically connected to the connection point 31, an electrical resistance R ₂₂ corresponding to the resistor 102 is obtained. The negative voltage V ₋ is applied to one of the terminals, and the other terminal of the electrical resistance R ₂₂ corresponding to the resistor 102 corresponds to the connection point 31 among the terminals of the equivalent circuit of the piezoelectric element 51-2. Connected to the terminal.

When the connector 28 is connected to the control board, the positive voltage V ₊ is applied to the conductive wire 25, the negative voltage V ₋ is applied to the conductive wire 27, and the conductive wire 26, as in the case shown in FIG. Since a drive signal is applied from the drive signal source 91, a detailed description thereof is omitted.

Depending on factors such as the usage environment and changes in the composition of the piezoelectric element, either the electrical resistance R _1-1 or the electrical resistance R _1-2 , or both the electrical resistance R _1-1 and the electrical resistance R _1-2 even it becomes small, since the resistor 101 and resistor 102 is provided by the electrical resistance R ₂₁ and resistance R _22, an excessive current to the piezoelectric elements 51-1 or piezoelectric elements 51-2 flows Can be prevented.

Thus, the resistor 101 has a predetermined electrical resistance value that limits the current. A predetermined voltage is applied to one terminal of the resistor 101, and the other terminal of the resistor 101 is electrically connected to the outer surface of the piezoelectric element 51-1. The resistor 102 has a predetermined electrical resistance value that limits the current. A predetermined voltage is applied to one terminal of the resistor 102, and the other terminal of the resistor 102 is electrically connected to the outer surface of the piezoelectric element 51-2.

Note that the resistor 32, the resistor 101, or the resistor 102 may be connected to the conductor 25, the conductor 26, or the conductor 27. More specifically, the resistor 32, the resistor 101, or the resistor 102 is connected to the conductor 25, the conductor 26, or the conductor 27 other than on the diaphragm 21, for example, the conductor 25, the conductor 26, or the conductor 27 may be provided at an intermediate position of 27 or on the connector 28 side.

A resistor 101 having an electric resistance value for limiting the current is provided on the outer surface which is the surface of the piezoelectric element 51-1 and faces the surface on the plate 52 side, and is connected to one terminal of the resistor 101. A resistor 102 having an electric resistance value that limits the current is applied to the surface of the piezoelectric element 51-2 by applying a positive voltage V ₊ and electrically connecting the other terminal to the outer surface of the piezoelectric element 51-1. The negative voltage V ₋ is applied to one terminal of the resistor 102, and the other terminal is electrically connected to the outer surface of the piezoelectric element 51-2. Therefore, the heat generated when an excessive current flows can be distributed to the resistor 101 and the resistor 102. Therefore, heat concentration can be prevented and heat can be radiated more reliably.

Here, the configuration of the piezoelectric driving device 11 provided with a resistor in the middle of the conductive wire 25, the conductive wire 26, or the conductive wire 27 will be described in more detail.

FIG. 13 is a plan view showing an example of the configuration of the piezoelectric driving device 11 in which a resistor is provided in the middle of the conducting wire 26. FIG. 14 is a bottom view showing an example of the configuration of the piezoelectric driving device 11 in which a resistor is provided in the middle of the conducting wire 26.

The piezoelectric drive device 11 shown in FIGS. 13 and 14 includes a diaphragm 21, a support portion 22, a support portion 23, a transmission portion 24, a conductive wire 25, a conductive wire 26, a conductive wire 27, a connector 28, a connection point 29, a connection point 30, A connection point 31 and a resistor 121 are included. The diaphragm 21, the support part 22, the support part 23, the transmission part 24, the conducting wire 25, the conducting wire 26, the conducting wire 27, the connector 28, the connection point 29, the connection point 30, and the connection point 31 are shown in FIGS. Since this is the same as the case, the description thereof is omitted.

In the piezoelectric driving device 11 whose configuration is shown in FIGS. 13 and 14, one end of each of the conductive wire 25, the conductive wire 26, and the conductive wire 27 is connected to the connector 28, and is electrically connected to a predetermined terminal of the connector 28. It is connected. The other end of the conducting wire 25 is electrically connected to the connection point 29 by, for example, soldering. A resistor 121 is provided in the middle of the conducting wire 26, and the other end of the conducting wire 26 is electrically connected to the connection point 30. The other end of the conducting wire 27 is electrically connected to the connection point 31 by, for example, soldering.

The resistor 121 has a predetermined electric resistance value that limits the current flowing through the diaphragm 21, is electrically connected to the middle of the conductive wire 26, and is fixed to the conductive wire 26. The resistor 121 is connected to the conductive wire 26 by, for example, soldering. That is, the resistor 121 is connected in the middle of the conducting wire 26, whereby one terminal of the resistor 121 is electrically connected to the connector 28 side, and the other terminal of the resistor 121 is electrically connected to the connection point 30. It is connected to the. For example, the electrical resistance value of the resistor 121 is 500 to 5000Ω, more preferably 750 to 1500Ω. The resistor 121 is a surface mount package, a so-called chip resistor. The resistor 121 may have any resistor type or any shape as long as it has a predetermined electric resistance value. For example, the resistor 121 is a carbon film resistor or a metal film resistor. It can be an enameled or molded resistor.

The equivalent circuit of the piezoelectric drive device 11 whose configuration is shown in FIGS. 13 and 14 is the same as the equivalent circuit shown in FIG. In this case, the electrical resistance R ₂ corresponds to the resistance of the resistor 121.

Since the resistor 121 having an electric resistance value for limiting the current is provided in the middle of the conductor 26 so as to be electrically connected, heat generated in the resistor 121 when an excessive current flows is conducted to the conductor 121. 26 and to the conductor 25 and the conductor 27 adjacent to the conductor 26. Since the conducting wire 25, the conducting wire 26, and the conducting wire 27 come out of the frame 12 shown in FIG. 1, heat is not trapped inside the frame 12, and can be cooled by outside air, more efficiently and wider. Heat can be dissipated in the area. Therefore, heat can be radiated more reliably. In addition, since a sufficient distance to other elements such as the control board of the needle selection device 1 can be secured, it is possible to more reliably prevent the other elements from being damaged.

The resistor 121 may be provided at an intermediate position of the conducting wire 26 (a central position from both ends of the conducting wire 26), may be provided at a side closer to the connector 28, or provided at a side closer to the diaphragm 21. May be.

Next, the configuration of the piezoelectric driving device 11 in which a resistor is provided in the middle of each of the conducting wire 25 and the conducting wire 27 will be described in more detail. FIG. 15 is a plan view showing an example of the configuration of the piezoelectric driving device 11 in which a resistor is provided in the middle of each of the conducting wire 25 and the conducting wire 27. FIG. 16 is a bottom view illustrating an example of the configuration of the piezoelectric driving device 11 in which a resistor is provided in the middle of each of the conducting wire 25 and the conducting wire 27.

15 and 16 includes a diaphragm 21, a support portion 22, a support portion 23, a transmission portion 24, a conductive wire 25, a conductive wire 26, a conductive wire 27, a connector 28, a connection point 29, a connection point 30, A connection point 31, a resistor 141, and a resistor 142 are included. The diaphragm 21, the support part 22, the support part 23, the transmission part 24, the conducting wire 25, the conducting wire 26, the conducting wire 27, the connector 28, the connection point 29, the connection point 30, and the connection point 31 are shown in FIGS. Since this is the same as the case, the description thereof is omitted.

In the piezoelectric drive device 11 whose configuration is shown in FIGS. 15 and 16, one end of each of the conductive wire 25, the conductive wire 26, and the conductive wire 27 is connected to the connector 28, and is electrically connected to a predetermined terminal of the connector 28. It is connected. A resistor 141 is provided in the middle of the conductor 25, and the other end of the conductor 25 is electrically connected to the connection point 29. The other end of the conducting wire 26 is electrically connected to the connection point 30 by, for example, soldering. A resistor 142 is provided in the middle of the conducting wire 27, and the other end of the conducting wire 27 is electrically connected to the connection point 31.

The resistor 141 has a predetermined electric resistance value that limits the current flowing through the diaphragm 21, and is electrically connected to the middle of the conductive wire 25 and fixed to the conductive wire 25. The resistor 141 is connected to the conductive wire 25 by, for example, soldering. That is, the resistor 141 is connected in the middle of the conductive wire 25, whereby one terminal of the resistor 141 is electrically connected to the connector 28 side, and the other terminal of the resistor 141 is electrically connected to the connection point 29. It is connected to the. For example, the electrical resistance value of the resistor 141 is 500 to 5000Ω, more preferably 750 to 1500Ω. The resistor 141 is a surface mount package, a so-called chip resistor.

The resistor 142 has a predetermined electrical resistance value that limits the current flowing through the diaphragm 21, and is electrically connected to the middle of the conducting wire 27 and fixed to the conducting wire 27. The resistor 142 is connected to the conducting wire 27 by, for example, soldering. That is, the resistor 142 is connected in the middle of the conductive wire 27, whereby one terminal of the resistor 142 is electrically connected to the connector 28 side, and the other terminal of the resistor 142 is electrically connected to the connection point 31. It is connected to the. For example, the electric resistance value of the resistor 142 is 500 to 5000Ω, and more preferably 750 to 1500Ω. The resistor 142 is a surface mount package, a so-called chip resistor.

The resistor 141 or the resistor 142 may be of any resistor type or any shape as long as it has a predetermined electric resistance value. For example, the resistor 141 or the resistor is a metal film resistor. It can be an enamel-type or mold-type resistor employing a body.

The equivalent circuit of the piezoelectric drive device 11 whose configuration is shown in FIGS. 15 and 16 is the same as the equivalent circuit shown in FIG. In this case, the electrical resistance R ₂₁ corresponds to the resistance of the resistor 141, and the electrical resistance R ₂₂ corresponds to the resistance of the resistor 142.

Since the resistor 141 and the resistor 142 each having an electric resistance value for limiting the current are provided in the middle of each of the conducting wire 25 and the conducting wire 27 and are electrically connected to each other, an excessive current is generated. The heat generated in the resistor 141 and the resistor 142 when it flows is transmitted to the conductor 25 and the conductor 27, and is also transmitted to the conductor 25 adjacent to the conductor 25 and the conductor 27. Since the conducting wire 25, the conducting wire 26, and the conducting wire 27 come out of the frame 12 shown in FIG. 1, heat is not trapped inside the frame 12, and can be cooled by outside air, more efficiently and wider. Heat can be dissipated in the area. Therefore, heat can be radiated more reliably. In addition, since a sufficient distance to other elements such as the control board of the needle selection device 1 can be secured, it is possible to more reliably prevent the other elements from being damaged.

Note that the resistor 141 or the resistor 142 may be provided at an intermediate position of the conductive wire 25 or the conductive wire 27 (a central position from both ends of the conductive wire 25 or the conductive wire 27), or may be provided closer to the connector 28. Alternatively, it may be provided on the side closer to the diaphragm 21.

Thus, a piezoelectric drive device used for a needle selection device of a knitting machine, which is formed as a thin film of a substantially rectangular metal thin film, and a thin film of substantially the same shape as the plate, A first piezoelectric element superimposed on the surface of the first piezoelectric element, a second piezoelectric element formed as a thin film having substantially the same shape as the plate, and superimposed on the other surface of the plate; A first electric resistance value for limiting current, a first voltage is applied to one terminal, and the other is provided on an outer surface that is a surface facing the plate side surface. A first resistor electrically connected to the outer surface of the plate or the first piezoelectric element; a plate-side surface of the first piezoelectric element; the plate; and the second piezoelectric element. When the plate side surface is electrically connected The heat generated in the first resistor when an excessive current flows is conducted to the plate, which is a metal thin film having a relatively high thermal conductivity, through the first piezoelectric element of the thin film, Since heat is conducted to the entire plate, heat can be dissipated over a wider area. Therefore, heat can be radiated more reliably. Further, since a sufficient distance to other elements such as the control board of the needle selection device can be secured, it is possible to more reliably prevent the other elements from being damaged.

The embodiments of the present invention are not limited to the above-described embodiments, and various modifications can be made without departing from the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Needle selector, 11 Piezoelectric drive device, 12 Frame, 13 Finger, 21 Diaphragm, 22 Support part, 23 Support part, 24 Transmission part, 25 Conductor, 26 Conductor, 27 Conductor, 28 Connector, 29 Connection point, 30 Connection Point, 31 connection point, 32 resistor, 51-1 and 51-2 piezoelectric element, 52 plate, 53-1-1 to 53-2-2 electrode film, 71-1 and 71-2 solder resist, 72 electrical insulation Membrane, 101 Resistor, 102 Resistor, 121 Resistor, 141 Resistor, 142 Resistor

Claims

In the piezoelectric drive device used in the needle selection device of the knitting machine,
A plate formed as a substantially rectangular metal thin film;
A first piezoelectric element formed as a thin film having substantially the same shape as the plate, and being superimposed on one surface of the plate;
A second piezoelectric element formed as a thin film having substantially the same shape as the shape of the plate and superimposed on the other surface of the plate;
A surface of the first piezoelectric element, which is provided on an outer surface which is a surface facing the plate side surface, has a first electric resistance value for limiting current, and has a first terminal at one terminal. A first resistor having the other terminal electrically connected to the plate or the outer surface of the first piezoelectric element,
The piezoelectric driving device, wherein the plate-side surface of the first piezoelectric element, the plate, and the plate-side surface of the second piezoelectric element are electrically connected.
The piezoelectric drive device according to claim 1,
The other terminal of the first resistor is electrically connected to the outer surface of the first piezoelectric element;
A surface of the second piezoelectric element, which is provided on an outer surface which is a surface facing the plate-side surface, has a second electric resistance value for limiting current, and has a second terminal at one terminal. The piezoelectric drive device further includes a second resistor to which the voltage of 2 is applied and the other terminal is electrically connected to the outer surface of the second piezoelectric element.
The piezoelectric drive device according to claim 2,
The position where the second resistor is provided is a predetermined distance away from the position where the first resistor is provided.
The piezoelectric drive device according to claim 1,
A connection point provided on the outer surface of the first piezoelectric element, the connection point for electrically connecting to the outer surface of the first piezoelectric element, and the other terminal of the first resistor A piezoelectric driving device in which the first resistor is provided at a position where the first and second resistors come into contact with each other.
The piezoelectric drive device according to claim 1,
The plate, the first piezoelectric element, and the second piezoelectric element are formed so as to sandwich the plate, and further includes a support portion supported by the needle selection device,
The first resistor is provided close to the support portion. Piezoelectric drive device.