JP2013223335A - Pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pump device realizing downsizing and high discharge pressure.SOLUTION: A pump device comprises: a tubular flow channel member 83 with elastic force; a pump case 81 including a cylindrical chamber 81H in which the tubular flow channel member 83 is disposed in an arc-shape; an oscillator 40 whose cross section vertical to a central axis is in a rectangle shape, length of short sides and long sides of the rectangle shape are set in prescribed values, and whose elliptic oscillation is excited when longitudinal oscillation telescopic in the central axis direction and torsional oscillation about the central axis as a torsional axis are excited at the same time; a substantially disc-shaped rotor 13 disposed in the cylindrical chamber 81H and rotationally driven by driving source which is the elliptic oscillation of the oscillator 40; a pressure member 85 provided in an outer peripheral portion of the rotor 13 and pressing the tubular flow channel member 83 toward a side wall of the cylindrical chamber 81H; and a pressure mechanism 20 to make an elliptic oscillation generation surface of the oscillator 40 press and contact to the rotor 13. With the aforementioned prescribed value, resonant frequency of the longitudinal oscillation and resonant frequency of the torsional oscillation are almost same.

Description

  The present invention relates to a pump device such as a tube pump.

  2. Description of the Related Art Conventionally, there has been known a tube pump including an elastically deformable tube member arranged in an arc shape and a rotor having a protrusion (see, for example, Patent Document 1). In such a tube pump, in a state where the tube member is locally pressed by the protrusion (in a crushed state), the rotor is rotated to move the position of the press. By this movement of the pressing position, the portion of the tube member that has been crushed by pressing returns to its original shape by the restoring force of the tube member. At that time, since a vacuum state is generated inside the tube member, the next liquid is sucked. By performing the above-mentioned operation continuously, the liquid in the tube member is transported, and the liquid is sucked and discharged by the tube pump.

JP-A-11-62854

  By the way, in the tube pump, a rotary motor is used as a drive source of the rotor. This rotary motor is generally an electromagnetic motor. Here, in order to obtain a high pump discharge pressure, it is necessary to increase the torque of the rotary motor. In order to increase the torque of the rotary motor, for example, it is necessary to increase the size of the rotary motor itself or to provide a multistage reduction gear to reduce the rotational speed. In any case, an increase in the size of the rotary motor is inevitable, and it is difficult to realize a small pump with a high discharge pressure.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a pump device that achieves both downsizing and high discharge pressure.

In order to achieve the above object, a pump device according to one aspect of the present invention comprises:
A channel member which is a tube-type liquid channel having elasticity;
A case member formed with a cylindrical chamber in which the flow path member is disposed in an arc shape;
The cross section perpendicular to the central axis has a rectangular shape, the ratio of the length of the short side to the long side constituting the rectangular shape is set to a predetermined value, and longitudinal vibration that expands and contracts in the direction of the central axis, and the center A vibrator in which elliptical vibration is excited by simultaneous excitation of torsional vibration with the axis being a torsional axis;
A friction contact provided on the surface of the vibrator where the elliptical vibration is excited;
A substantially disk-shaped rotor that is disposed in the cylindrical chamber, abuts against the friction contact, and is rotationally driven using the elliptical vibration of the vibrator as a drive source;
A flow path pressing member provided at an outer peripheral portion of the rotor and pressing the flow path member toward a side wall of the cylindrical chamber;
A pressing mechanism that presses the elliptical vibration generating surface of the vibrator against the rotor;
Comprising
The predetermined value is a value in which a resonance frequency of the longitudinal vibration and a resonance frequency of the torsional vibration substantially coincide with each other.

  ADVANTAGE OF THE INVENTION According to this invention, the pump apparatus which made compatible size reduction and high discharge pressure can be provided.

FIG. 1 is a front view showing a configuration example of a pump device according to an embodiment of the present invention. FIG. 2 is a view of the pump unit of the pump device shown in FIG. 1 as viewed from the upper surface side. FIG. 3 is a diagram illustrating an example of a laminated structure of the vibrator. FIG. 4 is a diagram illustrating an example of an electrode configuration in the vibrator. FIG. 5 is a diagram illustrating an external electrode configuration example of the vibrator (right side surface) viewed from the X1 direction illustrated in FIG. FIG. 6 is a diagram illustrating an external electrode configuration example of the vibrator (left side surface) viewed from the X2 direction illustrated in FIG. FIG. 7 is a perspective view showing the vibration state of the vibrator in the longitudinal primary vibration mode by a broken line. FIG. 8 is a perspective view showing the vibration state of the vibrator in the torsional secondary vibration mode by a broken line. FIG. 9 is a perspective view showing the vibration state of the vibrator with a broken line when the longitudinal primary vibration and the torsional secondary vibration are combined. FIG. 10 is a diagram illustrating an example of a resonance frequency characteristic in each vibration mode of the vibrator.

Hereinafter, a pump device according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a front view showing a configuration example of a pump device according to an embodiment of the present invention. FIG. 2 is a view of the pump unit of the pump device shown in FIG.
As shown in FIGS. 1 and 2, the pump device according to the present embodiment includes a pump unit 10, a pressing mechanism unit 20, a frame 30, a vibrator 40, and rotation regulating members 51s1 and 51s2. To do.

The pump unit 10 includes a central shaft 11, a bearing 12, a rotor 13, a sliding plate 14, a pump case 81, a tube-type flow path member 83, and a pressurizing member 85.
The pump case 81 is a case member that accommodates the constituent members of the pump unit 10, and a substantially cylindrical storage space (hereinafter referred to as a cylindrical chamber) 81H is provided therein as shown in FIGS. It has been. In the cylindrical chamber 81H, a tube-type flow path member 83, a pressure member 85, a rotor 13, and a sliding plate 14 are disposed. The upper surface of the cylindrical chamber 81H is fixed to a bottom surface portion 32 of the frame 30 described later, and the frame 30 and the pump case 81 are integrated.

  The tube-type flow path member 83 is a tube member formed of an elastically deformable material (for example, silicon rubber), and the hollow portion serves as a liquid flow path. As shown in FIG. 2, the tube-type flow path member 83 is disposed in an arc shape along the circular inner peripheral surface of the cylindrical chamber 81H.

The pressure member 85 is provided on the outer peripheral surface (side surface) of the rotor 13 described later, and is a pressure member for pressing (crushing) the tube-type flow path member 83 toward the inner peripheral surface of the pump case 81. is there.
In this example, three rotatable rollers having a central axis (not shown) fixed to the rotor 13 are provided at equal intervals as pressure members 85 on the outer peripheral portion of the rotor 13 as shown in FIG. ing. These rollers move along the inner peripheral surface of the pump case 81 as the rotor 13 rotates to sequentially press the tube-type flow path member 83 against the inner peripheral surface of the pump case 81, and the rollers The device itself rotates with a central axis (not shown) fixed to the rotor 13 as a rotation axis. By configuring the pressure member 85 itself to rotate in this way, friction between the pressure member 85 and the tube-type flow path member 83 can be suppressed.

  The pressurizing member 85 only needs to have an aspect capable of pressing (crushing) at least the tube-type flow path member 83 toward the inner peripheral surface of the pump case 81, and can be rotated as in this example. It may not be a roller (for example, it may be a simple protruding member).

The central shaft 11 is a shaft member fixed to the pump case 81. Note that the bearing 12, the rotor 13, the sliding plate 14, and the tube-type flow path member 83 are disposed concentrically with respect to the central shaft 11.
The bearing 12 is a bearing member inserted through the central shaft 11.

  The rotor 13 has a substantially disk shape, and is rotatably supported by a bearing 12 at the center of the bottom surface of the pump case 81 via a central shaft 11 provided at the center thereof. The rotor 13 is rotationally driven with a central axis of a vibrator 40 described later as a rotation axis. Further, the outer circumferential surface (side circumferential surface) of the rotor 13 is provided with a pressurizing member 85 for pressing (crushing) the tube-type flow path member 83 toward the inner circumferential surface of the pump case 81 as described above. It has been.

  The sliding plate 14 is a disk-shaped member provided integrally with the upper surface of the rotor 13 and is formed of, for example, zirconia. The sliding plate 14 is in contact (for example, pressure contact) with a friction contact 41 provided on a vibrator 40 that is a vibrating body, and transmits a driving force by the friction contact 41 to the rotor 13.

The pressing mechanism portion 20 includes a pressing spring 21, a pressing member 22, a spring pressing ring 23, and a spring restricting shaft 23a.
The pressing spring 21 is a spring member for pressing the vibrator 40 against the rotor 13. The pressing spring 21 is sandwiched between the pressing member 22 and the spring pressing ring 23 and is held in a state having an urging force. Specifically, the pressing spring 21 is, for example, a leaf spring or a coil spring.

The pressing member 22 is a plate-like member provided in the vicinity of the central portion of the bottom surface (the surface facing the pressing mechanism unit 20) of the vibrator 40, and the pressing force of the pressing spring 21 is applied via the pressing member 22. It is transmitted to the vibrator 40.
The spring retaining ring 23 is an annular member that is rotatably provided on a surface (upper surface portion 33 described later) of the frame 30 that faces the upper end surface of the vibrator 40, and is a rod-shaped member that positions the pressing spring 21. The spring restricting shaft 23a is screwed (a thread groove that is screwed to each other is formed on the inner diameter surface of the spring pressing ring 23 and the outer peripheral surface of the spring restricting shaft).

  The spring regulating shaft 23 a is inserted into the hollow portion of the pressing spring 21, one end of which is fixed to the pressing member 22, and the other end is a through-hole formed in the bottom surface of the spring pressing ring 23 and the frame 30. (Not shown). That is, the spring regulating shaft 23a positions the pressing spring 21.

The frame 30 is a frame-shaped member having a frame main body 31, a bottom surface portion 32, and an upper surface portion 33.
The frame main body 31 includes a pair of plate-like members 31a1 and 31a2 facing each other, and the vibrator 40 is inserted between the plate-like members.
The bottom surface portion 32 is a portion that is fixed to the pump case 81 in the frame 30. The bottom surface portion 32 is fixed to the upper surface of the pump case 81, and the frame 30 and the pump case 81 are integrated.
The upper surface portion 33 is a portion of the frame 30 that faces the upper end surface of the vibrator 40. A spring pressing ring 23 that constitutes the pressing mechanism portion 22 is provided on the surface of the upper surface portion 33 that faces the vibrator 40.

The vibrator 40 is a vibrating body in which piezoelectric sheets are laminated, and a friction contact 41 and a pressing member 22 are fixedly provided. The laminated structure of the vibrator 40 will be described later.
The friction contact 41 is provided on the surface of the vibrator 40 that faces the pump unit 10 and is in contact (for example, pressure contact) with the sliding plate 14.

  The rotation restricting members 51 s 1 and 51 s 2 are substantially rod-shaped members provided on the surface of the plate-like members 31 a 1 and 31 a 2 constituting the frame body 31 that face the vibrator 40. Specifically, the positions where the rotation restricting members 51s1 and 51s2 are provided in the plate-like members 31a1 and 31a2 are the torsional vibration node positions of the vibrator 40 (positions that do not hinder the torsional vibration of the vibrator 40). These rotation restricting members 51s1 and 51s2 sandwich the vibrator 40, so that the rotation of the vibrator 40 during driving is restricted.

Hereinafter, an example of the laminated structure of the vibrator 40 will be described. FIG. 3 is a diagram illustrating an example of a laminated structure of the vibrator 40.
As shown in the figure, the vibrator 40 includes a first laminated portion 411, a second laminated portion 412, a third laminated portion 413, a fourth laminated portion 414, a fifth laminated portion 415, and a sixth laminated portion. A portion 416, a seventh laminated portion 417, and an eighth laminated portion 418 are formed.

Specifically, each of these stacking parts (first stacking part 411, second stacking part 412, third stacking part 413, fourth stacking part 414, fifth stacking part 415, sixth stacking part 416, and seventh stacking part 417). The laminated structure of the eighth laminated portion 418) is the following laminated structure. Note that the configurations of the first piezoelectric sheet 401, the second piezoelectric sheet 402, the third piezoelectric sheet 403, the fourth piezoelectric sheet 404, and the fifth piezoelectric sheet 405 constituting each stacked portion will be described later.
<< 1st lamination part 411 >>
The first laminated portion 411 is formed by alternately laminating first piezoelectric sheets 401 and second piezoelectric sheets 402 in the thickness direction.
<< 2nd lamination | stacking site | part 412 >>
The second laminated portion 412 is a portion laminated on the first laminated portion 411 and is composed of at least one third piezoelectric sheet 403 (in the case of being composed of a plurality of third piezoelectric sheets 403, 3 piezoelectric sheets 403 are laminated in the thickness direction).
<< 3rd lamination | stacking site | part 413 >>
The third laminated portion 413 is a portion laminated on the second laminated portion 412, and is formed by alternately laminating the fourth piezoelectric sheet 404 and the fifth piezoelectric sheet 405 in the thickness direction.
<< 4th lamination | stacking site | part 414 >>
The fourth laminated portion 414 is a portion laminated on the third laminated portion 413 and is composed of at least one third piezoelectric sheet 403 (in the case of being composed of a plurality of third piezoelectric sheets 403, 3 piezoelectric sheets 403 are laminated in the thickness direction).
<< 5th lamination | stacking site | part 415 >>
The fifth laminated portion 415 is a portion laminated on the fourth laminated portion 414, and the fourth piezoelectric sheet 404 and the fifth piezoelectric sheet 405 are alternately laminated in the thickness direction.
<< 6th lamination | stacking site | part 416 >>
The sixth laminated portion 416 is a portion laminated on the fifth laminated portion 415 and is composed of at least one third piezoelectric sheet 403 (in the case of being composed of a plurality of third piezoelectric sheets 403, 3 piezoelectric sheets 403 are laminated in the thickness direction).
<< 7th lamination | stacking site | part 417 >>
The seventh laminated portion 417 is a portion laminated on the sixth laminated portion 417, and is formed by alternately laminating the first piezoelectric sheets 401 and the second piezoelectric sheets 402 in the thickness direction.
<< 8th lamination part 418 >>
The eighth laminated portion 418 is a portion laminated on the seventh laminated portion 417 and is composed of at least one third piezoelectric sheet 403 (in the case of being composed of a plurality of third piezoelectric sheets 403, 3 piezoelectric sheets 403 are laminated in the thickness direction).

Hereinafter, the first piezoelectric sheet 401, the second piezoelectric sheet 402, the third piezoelectric sheet 403, the fourth piezoelectric sheet 404, the fifth piezoelectric sheet 405, the sixth piezoelectric sheet 406, and the seventh piezoelectric sheet. 407 and the eighth piezoelectric sheet 408 will be described in detail.
The first piezoelectric sheet 401, the second piezoelectric sheet 402, the third piezoelectric sheet 403, the fourth piezoelectric sheet 404, the fifth piezoelectric sheet 405, the sixth piezoelectric sheet 406, the seventh piezoelectric sheet 407, The eighth piezoelectric sheet 408 is a rectangular sheet-like piezoelectric element, and is composed of, for example, a hard lead piezoelectric ceramic element (PZT) of lead zirconate titanate.

Specifically, on the electrode forming surface of the first piezoelectric sheet 401, a + -phase driving internal electrode 401a and a + -phase driving internal electrode 401c are arranged at a substantially central position in the longitudinal direction. They are provided symmetrically with respect to C (a line that bisects the short side).
Similarly, on the electrode forming surface of the second piezoelectric sheet 402, a negative-phase driving internal electrode 402a and a negative-phase driving internal electrode 402c are arranged at the center line C at a substantially central position in the longitudinal direction. They are provided symmetrically with respect to (a line that bisects the short side).

  By the way, between the + phase driving internal electrode 401a and the − phase driving internal electrode 402a, between the + phase driving internal electrode 401c and the − phase driving internal electrode 402c, and for detecting the + phase. A high voltage is applied between the internal electrode 404a and the -phase detection internal electrode 405a, and the piezoelectric material between the electrodes is polarized and piezoelectrically activated (a piezoelectric activation region). ).

Each of the internal electrodes 401a, 401c, 402a, and 402c described above is a silver palladium alloy having a thickness of 4 μm, for example.
The third piezoelectric sheet 403 is a sheet-like member having the same shape as the first piezoelectric sheet 401 and the second piezoelectric sheet 402 and having no internal electrode.

On the electrode formation surface of the fourth piezoelectric sheet 404, + is positioned at a position corresponding to the driving internal electrode 401a on the first piezoelectric sheet 401 and the driving internal electrode 402a on the second piezoelectric sheet when stacked. A phase detection internal electrode 404a is provided.
On the electrode forming surface of the fifth piezoelectric sheet 405, at the position corresponding to the driving internal electrode 401a on the first piezoelectric sheet 401 and the driving internal electrode 402a on the second piezoelectric sheet at the time of lamination, A phase detection internal electrode 405a is provided.

  The + phase driving internal electrode 401a includes an end portion 401ae extending toward one long side of the first piezoelectric sheet 401 having a rectangular shape and exposed. The + phase driving internal electrode 401c includes an end portion 401ce extending toward the other long side of the first piezoelectric sheet 401 having a rectangular shape and exposed.

  The -phase driving internal electrode 402a has one long side of the second piezoelectric sheet 402 having a rectangular shape (side corresponding to the side from which the exposed portion 401ae of the internal electrode 401a is extended (side overlapping when stacked)) ) And an end portion 402ae that extends and is exposed. The negative-phase driving internal electrode 402c includes an end portion 402ce extending toward the other long side of the second piezoelectric sheet 402 having a rectangular shape and exposed.

The + phase detection internal electrode 404a is one long side of the fourth piezoelectric sheet 404 having a rectangular shape (side corresponding to the side from which the exposed portion 401ae of the internal electrode 401a is extended (side that overlaps when stacked)) ) And an exposed end 404ae.
The -phase detection internal electrode 405a has one long side of the second piezoelectric sheet 402 having a rectangular shape (side corresponding to the side from which the exposed portion 402ae of the internal electrode 402a is extended (side that overlaps when stacked)) ) And an exposed end portion 405ae.

Note that the end portion 401ae and the end portion 402ae are provided so as to be shifted by a predetermined interval so as not to overlap each other during stacking. Similarly, the end portion 404ae and the end portion 405ae are provided so as to be shifted by a predetermined interval so as not to overlap each other during stacking.
As described above, by stacking the first piezoelectric sheet 401, the second piezoelectric sheet 402, the third piezoelectric sheet 403, the fourth piezoelectric sheet 404, and the fifth piezoelectric sheet 405, FIG. 4 can be obtained. FIG. 4 is a diagram illustrating an example of an electrode configuration in the vibrator 40.

In FIG. 4, for convenience of explanation, the drive electrode and the vibration detection electrode (configured by the above-described internal electrodes) existing inside the vibrator 40 are visualized and shown separately for each piezoelectric sheet. Are integrally shown as a vibrator 40.
As shown in FIGS. 3 and 4, in the vibrator 40, the portion where the driving internal electrode 401a and the driving internal electrode 402a are stacked in the first stacked portion 411 is the driving electrode 101B1 (details will be described later). ). A portion of the vibrator 40 in which the driving internal electrode 401c and the driving internal electrode 402c are stacked in the first stacked portion 411 forms a driving electrode 101A2 (details will be described later).

Of the vibrator 40, the portion where the detection internal electrode 404 a and the detection internal electrode 405 a are stacked in the third stacked portion 413 constitutes a vibration detection electrode 101 </ b> D (details will be described later).
In the vibrator 40, a portion in which the detection internal electrode 404a and the detection internal electrode 405a are stacked in the fifth stacked portion 415 constitutes a vibration detection electrode 101C (details will be described later).

  A portion of the vibrator 40 in which the driving internal electrode 401a and the driving internal electrode 402a are stacked in the seventh stacked portion 417 constitutes a driving electrode 101A1 (details will be described later). A portion of the vibrator 40 in which the driving internal electrode 401c and the driving internal electrode 402c are stacked in the seventh stacked portion 417 constitutes a driving electrode 101B2 (details will be described later).

FIG. 5 is a diagram illustrating an external electrode configuration example of the vibrator 40 (right side surface) viewed from the X1 direction illustrated in FIG. FIG. 6 is a diagram illustrating an external electrode configuration example of the vibrator 40 (left side surface) viewed from the X2 direction illustrated in FIG.
On the right side surface of the vibrator 40, as shown in FIGS. 3, 4, and 5, the end portions 401ae of the drive internal electrode 401a constituting the drive electrode (B1 + phase) 101B1 + are short-circuited by the external electrode 113B1 +. . The end portions 402ae of the drive internal electrode 402a constituting the drive electrode (B1-phase) 101B1- are short-circuited by the external electrode 113B1-. The ends 404ae of the detection internal electrode 404a constituting the vibration detection electrode (D + phase) 101D + are short-circuited by the external electrode 113D +. The ends 405ae of the detection internal electrode 405a constituting the vibration detection electrode (D-phase) 101D- are short-circuited by the external electrode 113D-. The ends 404ae of the detection internal electrode 404a constituting the vibration detection electrode (C + phase) 101C + are short-circuited by the external electrode 113C +. The ends 405ae of the detection internal electrode 405a constituting the vibration detection electrode (C-phase) 101C- are short-circuited by the external electrode 113C-. The end portions 401ae of the driving internal electrode 401a constituting the driving electrode (A1 + phase) 101A1 + are short-circuited by the external electrode 113A1 +. The end portions 402ae of the drive internal electrode 402a constituting the drive electrode (A1-phase) 101A1- are short-circuited by the external electrode 113A1-.

  On the left side surface of the vibrator 40, as shown in FIGS. 3, 4, and 6, the end portions 401ce of the drive internal electrode 401c constituting the drive electrode (A2 + phase) 101A2 + are short-circuited by the external electrode 113A2 +. . The end portions 402ce of the driving internal electrode 402c constituting the driving electrode (A2-phase) 101A2- are short-circuited by the external electrode 113A2-. The ends 401ce of the drive internal electrode 401c constituting the drive electrode (B2 + phase) 101B2 + are short-circuited by the external electrode 113B2 +. The ends 402ce of the driving internal electrode 402c constituting the driving electrode (B2-phase) 101B2- are short-circuited by the external electrode 113B2-.

Hereinafter, the vibration mode of the vibrator 40 configured as described above will be described in detail.
FIG. 7 is a perspective view showing the vibration state of the vibrator 40 in the vertical primary vibration mode by a broken line. FIG. 8 is a perspective view showing the vibration state of the vibrator 40 in the torsional secondary vibration mode by a broken line. FIG. 9 is a perspective view showing the vibration state of the vibrator 40 by a broken line when the longitudinal primary vibration and the torsional secondary vibration are combined. 7 to 9, the state (shape) of the vibrator 40 before vibration is indicated by a solid line, and the state (shape) of the vibrator 40 during vibration in each vibration mode is indicated by a broken line.

Here, as shown in FIGS. 4 and 7 to 9, the short side constituting a cross section orthogonal to the central axis of the substantially rectangular parallelepiped transducer 40 (the axis denoted by reference numeral 100 c in FIGS. 7 to 9). The length (the thickness of the vibrator 40) is T, the length of the long side (the width of the vibrator 40) is W, and the height along the central axis 100c is H. However, the size relationship between the short side T, the long side W, and the height H is
T <W <H
Suppose that In the following description, the height H direction is the vibration direction of the longitudinal primary vibration mode and the torsional axial direction of the torsional vibration.

In the pump device according to this embodiment, by appropriately setting the values of the dimensions of the short side T, the long side W, and the height H of the vibrator 40, the resonance frequency and the twist of the longitudinal primary vibration mode are set. The resonance frequency of the secondary vibration mode is substantially matched.
In FIGS. 7 to 9, p1 and p2 indicate directions of torsional vibration, q indicates a direction of longitudinal vibration, and N indicates a vibration node.

In the longitudinal primary vibration shown in FIG. 7, one node N exists at the center position in the height H direction of the vibrator 40. Further, in the torsional secondary vibration shown in FIG. 8, the node N exists at two places in two positions in the height H direction.
Here, assuming that the height c is constant, the value of (thickness (short side) T / width (long side) W) is taken on the horizontal axis, and the value of the resonance frequency in each vibration mode is taken on the vertical axis. The following characteristics can be obtained. Specifically, the following characteristics are obtained. That is,
The value of the resonance frequency in the longitudinal primary vibration mode does not depend on the value of (T / W) and takes a substantially constant value corresponding to the height c.
The value of the resonance frequency in the torsional primary vibration mode, the torsional secondary vibration mode, and the torsional tertiary vibration mode increases as the value of (T / W) increases.
The resonance frequency in the torsional primary vibration mode does not coincide with the resonance frequency in the longitudinal primary vibration mode regardless of the value of (T / W).
The resonance frequency in the torsional secondary vibration mode coincides with the resonance frequency in the longitudinal primary vibration mode in the vicinity where the value of (T / W) is 0.6.
The resonance frequency in the torsional tertiary vibration mode coincides with the resonance frequency in the longitudinal primary vibration mode in the vicinity where the value of (T / W) is 0.3.

Because of the characteristics mentioned above,
When using the longitudinal primary vibration mode and the torsional tertiary vibration mode, the short side T and the long side W of the vibrator 40 are set so that the value of (T / W) is 0.25 to 0.35. Set the length.
When the longitudinal primary vibration mode and the torsional secondary vibration mode are used, the short side T and the long side W of the vibrator 40 are set so that the value of (T / W) is 0.55 to 0.65. Set the length.

  In the pump device according to the present embodiment, since the torsional secondary vibration is used as the torsional vibration, the (T / W) value is designed to be approximately 0.6. Thereby, the resonance frequency in the longitudinal primary vibration mode and the resonance frequency in the torsional secondary vibration mode are substantially matched.

By the way, as shown in FIGS. 3 to 9, each of the internal electrodes 401a, 401c, 402a, 402c, 404a, and 405a described above is a node portion of longitudinal primary vibration excited by the vibrator 40 and twisted secondary. It is provided at a position corresponding to the abdomen of vibration.
Hereinafter, the operation of the pump device according to the present embodiment having the above-described configuration will be described in detail. In addition, in order to avoid duplication of description, the A1 phase and the A2 phase of the drive electrode are collectively referred to as the An phase, and the B1 phase and the B2 phase are collectively referred to as the Bn phase.

  An An-phase and Bn-phase drive electrode is driven by applying an AC voltage having substantially the same phase and the same phase as the resonance frequency of the longitudinal primary vibration and torsional secondary vibration of the vibrator 40. The piezoelectric activation region corresponding to the electrode and the piezoelectric activation region corresponding to the Bn phase drive electrode vibrate in the same phase. As a result, the vibrator 40 vibrates longitudinally. At this time, potentials having the same amplitude and the same phase are generated in the piezoelectric activation region corresponding to the C-phase vibration detection electrode and the piezoelectric activation region corresponding to the D-phase vibration detection electrode.

  On the other hand, an AC voltage having a frequency substantially coincident with the resonance frequency of the longitudinal primary vibration and the torsional secondary vibration of the vibrator 40 and opposite phases (180 ° phase difference) is applied to the An-phase and Bn-phase drive electrodes. As a result, the piezoelectric activation region corresponding to the An phase drive electrode and the piezoelectric activation region corresponding to the Bn phase drive electrode vibrate in opposite phases. As a result, the vibrator 40 performs torsional vibration. At this time, the piezoelectric activation region corresponding to the C-phase vibration detection electrode and the piezoelectric activation region corresponding to the D-phase vibration detection electrode have the same amplitude and opposite phase (reverse polarity) potentials. Occur.

  By applying alternating voltages having different phases (for example, a phase difference of 90 degrees) to the An-phase drive electrode and the Bn-phase drive electrode of the vibrator 40 acting in this way, As shown in FIG. 9, the longitudinal primary vibration and the torsional secondary vibration are simultaneously excited, and elliptical vibration is formed on the end face of the vibrator 40.

  At this time, the sliding plate 14 in pressure contact with the friction contact 41 as described above rotates by friction drive by the friction contact 41 using the elliptical vibration of the vibrator 40 as a drive source. As the sliding plate 14 rotates, the rotor 13 fixed integrally with the sliding plate 14 also rotates. At this time, the pressurizing member 85 provided in the rotor 13 moves circularly along the inner peripheral surface of the cylindrical chamber 81H, and in this process, the tube-type flow path member 83 is sequentially pressed in one direction. By this action, the liquid in the tube type flow path member 83 is conveyed in the rotation direction of the rotor 13 (pump operation is performed).

Note that the rotational direction of the elliptical vibration generated in the vibrator 40 can be reversed by reversing the phase difference of the AC voltage applied to the An-phase drive electrode and the Bn-phase drive electrode. By utilizing this, the rotation direction of the rotor 13 can be controlled.
By the way, when the longitudinal primary vibration and the torsional secondary vibration are simultaneously excited in the vibrator 40, the potential related to the longitudinal primary vibration and the torsional secondary vibration is present in the piezoelectric activation region corresponding to the C phase and the D phase. (Vibration detection signal) is excited simultaneously. At this time, by calculating the difference between the potential generated in the piezoelectric activation region corresponding to the C phase and the potential generated in the piezoelectric activation region corresponding to the D phase, the longitudinal primary vibration in the vibration detection signal is calculated. Such components are canceled out, and only the components related to the torsional secondary vibration can be detected.

This is because the C phase and the D phase generate potentials having the same amplitude and the same phase in the longitudinal primary vibration mode as described above, and generate potentials having the same amplitude and the opposite phase in the torsional secondary vibration mode. .
Specifically, the external electrode 101C− and the external electrode 101D− are electrically connected, the external electrode 101C + and the external electrode 101D + are electrically connected, and the external electrode 101C + and the external electrode 101D + are electrically connected. By extracting (detecting) the potential difference between them, only the torsional secondary vibration component can be extracted (detected) as the vibration detection signal.

  In addition, by calculating the sum of the potential generated in the piezoelectric activation region corresponding to the C phase and the potential generated in the piezoelectric activation region corresponding to the D phase, it relates to the torsional secondary vibration of the vibration detection signal. The components are canceled out, and only the component related to the longitudinal primary vibration can be detected. Specifically, the vibration detection signal is obtained by electrically connecting the external electrode 101C− and the external electrode 101D + and extracting (detecting) a potential difference between the external electrode 101C + and the external electrode 101D−. Only the longitudinal primary vibration component can be extracted (detected). If necessary, this longitudinal primary vibration component may be used as a vibration detection signal.

  It is known that the phase difference between the vibration detection signal acquired in this way and the AC voltage applied to the drive electrode is a predetermined phase difference during resonance vibration. In general, the resonance frequency of an ultrasonic motor fluctuates due to temperature rise due to heat generated by the motor itself, temperature fluctuations in the surrounding environment, and load fluctuations. By controlling the drive frequency so that this phase difference is kept at a predetermined value, Since driving can be performed near the resonance frequency, efficient and stable driving is possible. Since the technology itself related to frequency tracking based on the vibration detection signal is not a characteristic part of the present invention, a detailed description of the technology related to frequency tracking is omitted.

  As described above, according to the present embodiment, it is possible to provide a pump device that achieves both miniaturization and high discharge pressure. That is, in the pump device according to the present embodiment, the pump operation is realized by rotating the rotor 13 of the pump unit 10 using the vibration of the vibrator 40 excited using the piezoelectric lateral effect as a drive source.

  In other words, since the pump device according to the present embodiment uses an ultrasonic motor having a low speed and high torque characteristics as a drive source as compared with the electromagnetic motor, a reduction gear for increasing the torque is not required, and the electromagnetic motor Compared with the case of using the above, a small and high discharge pressure pump device can be realized.

  Further, in the pump device according to the present embodiment, the friction contact 41 provided in the vibrator 40 is brought into pressure contact with the sliding plate 14 fixed to the rotor 13 disposed in the pump case 81 and directly driven. Therefore, further downsizing can be realized because the member that functions as the rotor of the pump device and the member that functions as the rotor of the ultrasonic motor are configured as the same member (rotor 13).

  Further, the above-described embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent requirements are deleted from all the constituent requirements shown in the embodiment, the problem described in the column of the problem to be solved by the invention can be solved, and the effect described in the column of the effect of the invention can be achieved. In the case of being obtained, a configuration from which this configuration requirement is deleted can also be extracted as an invention.

    DESCRIPTION OF SYMBOLS 10 ... Pump part, 11 ... Center axis, 13 ... Rotor, 14 ... Sliding plate, 20 ... Pressing mechanism part, 21 ... Pressing spring, 22 ... Pressing member, 23 ... Ring, 23a ... Spring control shaft, 30 ... Frame, DESCRIPTION OF SYMBOLS 31 ... Frame main body, 31a1, 31a2 ... Plate-like member, 32 ... Bottom surface part, 33 ... Upper surface part, 40 ... Vibrator, 41 ... Friction contact, 51s1, 51s2 ... Rotation restriction member, 81 ... Pump case, 81H ... Cylindrical 83, tube-type flow path member, 85 ... pressure member, 101A1, 101A2, 101B1, 101B2, drive electrode, 101C, 101D, vibration detection electrode, 113A1, 113A2, 113B1, 113B2, 113C, 113D, external electrode, 401a, 401c, 402a, 402c ... driving internal electrodes, 404a, 405a ... Outgoing internal electrode, 401ae, 401ce, 402ae, 402ce, 404ae, 405ae ... end, 401 ... first piezoelectric sheet, 402 ... second piezoelectric sheet, 403 ... third piezoelectric sheet, 404 ... fourth piezoelectric Sheet, 405 ... 5th piezoelectric sheet, 406 ... 6th piezoelectric sheet, 407 ... 7th piezoelectric sheet, 408 ... 8th piezoelectric sheet, 411 ... 1st lamination part, 412 ... 2nd lamination part, 413 ... 3rd lamination site, 414 ... 4th lamination site, 415 ... 5th lamination site, 416 ... 6th lamination site, 417 ... 7th lamination site, 418 ... 8th lamination site.

Claims (2)

A channel member which is a tube-type liquid channel having elasticity;
A case member formed with a cylindrical chamber in which the flow path member is disposed in an arc shape;
The cross section perpendicular to the central axis has a rectangular shape, the ratio of the length of the short side to the long side constituting the rectangular shape is set to a predetermined value, and longitudinal vibration that expands and contracts in the direction of the central axis, and the center A vibrator in which elliptical vibration is excited by simultaneous excitation of torsional vibration with the axis being a torsional axis;
A friction contact provided on the surface of the vibrator where the elliptical vibration is excited;
A substantially disk-shaped rotor that is disposed in the cylindrical chamber, abuts against the friction contact, and is rotationally driven using the elliptical vibration of the vibrator as a drive source;
A flow path pressing member provided at an outer peripheral portion of the rotor and pressing the flow path member toward a side wall of the cylindrical chamber;
A pressing mechanism that presses the elliptical vibration generating surface of the vibrator against the rotor;
Comprising
The pump device according to claim 1, wherein the predetermined value is a value in which a resonance frequency of the longitudinal vibration and a resonance frequency of the torsional vibration substantially coincide with each other. The pump device according to claim 1, wherein the rotor is driven to rotate about the central axis of the vibrator.

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