Pumps and beverage supply devices

Abstract

To provide a pump that can achieve both improved sealing performance of valve elements and suppression of increased size. [Solution] When pistons 71 and 72 move in the direction of increasing the volume of the pump chamber 7, the intake valve 74 opens as the first closing portion 745 of the first valve body 744 moves to a first position where it is separated from the first valve seat 742 of the first valve chamber 741 and does not come into contact with the first tapered surface 743. When pistons 71 and 72 move in the direction of decreasing the volume of the pump chamber 7, the discharge valve 75 opens as the second closing portion 755 of the second valve body 754 moves to a second position where it is separated from the second valve seat 752 of the second valve chamber 751 and does not come into contact with the second tapered surface 753.

Description

Technical Field

[0001] The present disclosure relates to a pump and a beverage supply device.

Background Art

[0002] Conventionally, as a suction valve of a pump chamber, for example, as disclosed in Patent Document 1, it is biased toward the upstream side of the flow path using a coil spring or the like, and is configured to open when the volume of the pump chamber increases and suck fluid into the pump chamber. Similarly, as a discharge valve of the pump chamber, for example, it is biased toward the upstream side of the flow path using a coil spring or the like, and is configured to open when the volume of the pump chamber decreases and discharge fluid from the pump chamber to the downstream side of the flow path.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A suction valve or a discharge valve having the above configuration can improve the sealing performance by increasing the biasing force. However, in order to increase the biasing force, it is necessary to increase the size of the coil spring, etc., and there is room for improvement in terms of increasing the size of the valve element. Such problems are particularly prominent when the pump is applied to a beverage supply device such as an espresso machine and a high-pressure output is required.

[0005] An object of the present disclosure is to provide a pump and a beverage supply device that can achieve both improvement in the sealing performance of the valve element and suppression of an increase in size.

Means for Solving the Problems

[0006] A pump according to one aspect of an embodiment of the present invention comprises a fluid passage through which a fluid flows, a pump chamber provided on the fluid passage, a volume changing member that operates to reduce or increase the volume of the pump chamber, an intake valve provided on the upstream side of the fluid passage in the pump chamber, and a discharge valve provided on the downstream side of the fluid passage in the pump chamber, wherein the intake valve has a frustoconical first valve chamber and a first valve body disposed within the valve chamber, the first valve chamber has a first valve seat on which the first valve body is installed in a portion corresponding to the bottom surface of the frustoconical shape, and the first valve seat communicates with the upstream side of the fluid passage, The first tapered surface, corresponding to the side of the frustoconical shape, decreases in diameter as it proceeds toward the pump chamber, and the portion corresponding to the upper surface of the frustoconical shape is arranged to communicate with the pump chamber. The first valve body is formed to be able to close an opening provided in the first valve seat that communicates with the upstream side of the flow path, and comprises a first closing portion located in the center of the first valve body, an annular first outer edge portion located on the outer circumference of the first closing portion, and a plurality of first connecting portions arranged between the first closing portion and the first outer edge portion with a gap between them, connecting the first closing portion and the first outer edge portion, and formed to be elastically deformable. The discharge valve has a second valve chamber in the shape of a frustoconical pyramid, and a second valve body disposed within the valve chamber, wherein the second valve chamber has a second valve seat on which the second valve body is installed in the portion corresponding to the bottom surface of the frustoconical pyramid, the second valve seat is in communication with the pump chamber, the second tapered surface corresponding to the side surface of the frustoconical pyramid decreases in diameter as it proceeds downstream of the flow path, and the portion corresponding to the top surface of the frustoconical pyramid is in communication with the downstream side of the flow path, the second valve body is formed to be able to close an opening in the second valve seat that communicates with the pump chamber, and is disposed in the center of the second valve body. The valve body has a second closing portion, an annular second outer edge portion arranged on the outer circumference of the second closing portion, and a plurality of second connecting portions arranged between the second closing portion and the second outer edge portion with a gap between them, connecting the second closing portion and the second outer edge portion, and formed to be elastically deformable, and when the volume changing member moves in the direction of increasing the volume of the pump chamber, the first closing portion of the first valve body is attracted toward the pump chamber side and moves away from the first valve seat of the first valve chamber and moves to a first position where it does not contact the first tapered surface of the first valve chamber, thereby opening the intake valve.The fluid is drawn into the pump chamber from the upstream side of the flow path through the gaps of the plurality of first connecting parts of the first valve body, and the second closing part of the second valve body is drawn towards the pump chamber and moves to a position where it contacts the second valve seat of the second valve chamber, thereby closing the communication portion between the pump chamber and the second valve chamber, thereby closing the discharge valve and stopping the discharge of the fluid from the pump chamber to the downstream side of the flow path, and when the volume changing member moves in the direction of reducing the volume of the pump chamber, the second closing part of the second valve body is pressed downstream of the flow path, and the second valve chamber By moving to a second position that is separated from the second valve seat and does not contact the second tapered surface of the second valve chamber, the discharge valve opens, discharging the fluid from the pump chamber through the gaps between the plurality of second connecting portions of the second valve body to the downstream side of the flow path. The first closing portion of the first valve body moves to a position where it is pressed upstream of the flow path and contacts the first valve seat of the first valve chamber, thereby blocking the communication portion between the upstream side of the flow path and the first valve chamber, and the intake valve closes, stopping the intake of the fluid from the upstream side of the flow path to the pump chamber. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a pump and a beverage supply device that can achieve both improved sealing performance of valve elements and suppression of increased size. [Brief explanation of the drawing]

[0008] [Figure 1] Perspective view showing an example of the appearance of the pump according to the embodiment. [Figure 2] Schematic diagram showing the general internal configuration of the pump housing shown in Figure 1. [Figure 3] Perspective view showing the schematic configuration of the resonant actuator. [Figure 4] Figure 3 shows an exploded perspective view of the resonant actuator. [Figure 5] Schematic diagram of the cross-sectional shape of the pump according to the embodiment along the axis of symmetry CA [Figure 6] Schematic diagram of the cross-sectional shape along the axial direction of the fourth flow path of the pump according to the embodiment. [Figure 7] A schematic diagram showing the operation of the pump when the coil is energized. [Figure 8] Schematic diagram showing the area around the first pump room in the state shown in Figure 7. [Figure 9] A schematic diagram showing the operation of the pump when the coil is de-energized. [Figure 10] Schematic diagram showing the area around the first pump room in the state shown in Figure 9. [Figure 11] Schematic diagram of the magnetic field generated in an electromagnet using a flat core as a comparative example. [Figure 12] Plan view of the internal structure of the pump housing, viewed from the positive Z direction. [Figure 13] A schematic diagram showing a magnified view of the area around the first pump room. [Figure 14] TT cross-section in Figure 13 [Figure 15] This diagram shows an example of the operation of the intake valve and discharge valve when the volume of the first pump chamber decreases. [Figure 16] This diagram shows an example of the operation of the intake and discharge valves when the volume of the first pump chamber increases. [Figure 17] A diagram showing an example of the application of the pump according to the embodiment. [Modes for carrying out the invention]

[0009] The embodiments will be described below with reference to the attached drawings. To facilitate understanding of the explanation, the same reference numerals are used for identical components in each drawing whenever possible, and redundant explanations are omitted.

[0010] In the following explanation, the X, Y, and Z directions are perpendicular to each other. The X and Y directions are horizontal, and the Z direction is vertical. The X direction is the longitudinal direction of the housing 2 and the resonant actuator 6. The Y direction is the short-span direction of the housing 2 and the resonant actuator 6. Also, for convenience of explanation, the positive Z direction may be referred to as the upper side, and the negative Z direction as the lower side.

[0011] [Basic pump configuration] Referring to FIGS. 1 to 6, the basic configuration of the pump 1 according to the embodiment will be described.

[0012] FIG. 1 is a perspective view showing an example of the appearance of the pump 1 according to the embodiment. As shown in FIG. 1, the pump 1 includes a housing 2, a suction port 3, and a discharge port 4.

[0013] The housing 2 incorporates elements related to the pump function, such as a flow path 5 and a resonance actuator 6 described later. In the example of FIG. 1, the housing 2 has a pair of rectangular main surfaces 21 and 22, and is formed in a rectangular parallelepiped shape where the dimension between the main surfaces 21 and 22 is relatively thin with respect to each side of the main surface.

[0014] The pair of main surfaces​​​​​​​The intake port 3 draws fluid into the housing 2. The outlet port 4 discharges the fluid pressurized by the pump function inside the housing 2. In the example in Figure 1, the intake port 3 is located on the negative Y-direction side of the side 23 of the housing 2, and the outlet port 4 is located on the positive Y-direction side of the side 24. Both the intake port 3 and the outlet port 4 are in communication in the X-direction, and are positioned so that the direction of fluid intake from the intake port 3 into the housing 2 and the direction of fluid discharge from the housing 2 to the outlet port 4 are the same. Furthermore, the intake port 3 and the outlet port 4 are positioned so as to be point-symmetric when viewed from the Z-direction with respect to the center line CO of the pump 1.

[0017] Figure 2 is a schematic diagram showing the general internal configuration of the housing 2 of the pump 1 shown in Figure 1. Figure 2 is a plan view of the pump 1 as seen from the positive Z direction. In Figure 2, the internal structure of the housing 2 is schematically illustrated, and the external shape of the housing 2 (i.e., the four sides 23-26) is shown by dashed lines. In Figure 2, the axis of symmetry CA, which passes through the center in the Y direction of the main surfaces 21 and 22 of the housing 2 and extends in the X direction, and the axis of symmetry CB, which passes through the center in the X direction and extends in the Y direction, are shown by dashed lines. In Figure 2, the intersection of axis of symmetry CA and axis of symmetry CB is shown as the center line CO.

[0018] As shown in Figure 2, the pump 1 has a passage 5 inside the housing 2 that connects the inlet 3 and the outlet 4. The passage 5 has a first passage 51, a second passage 52, a third passage 53, a fourth passage 54, a fifth passage 55, a sixth passage 56, a seventh passage 57, and an eighth passage 58.

[0019] The first channel 51 is positioned so as to extend in the positive X direction, with its upstream end connected to the downstream end of the intake port 3. The second channel 52 and the third channel 53 branch off, with their upstream ends both connected to the downstream end of the first channel 51, and are positioned so as to extend in the negative X direction and the positive X direction, respectively. The fourth channel 54 is positioned so as to extend in the positive Y direction, with its upstream end connected to the downstream end of the second channel 52. The fifth channel 55 is positioned so as to extend in the positive Y direction, with its upstream end connected to the downstream end of the third channel 53. The sixth channel 56 extends in the positive X direction, with its upstream end connected to the downstream end of the fourth channel 54, and the seventh channel 57 extends in the negative X direction, with its upstream end connected to the downstream end of the fifth channel 55, and the six channels 56 and the seventh channel 57 merging at their downstream ends. The eighth channel 58 is positioned such that its upstream end is connected to the confluence of the sixth channel 56 and the seventh channel 57, extends in the positive X direction, and its downstream end is connected to the upstream end of the discharge port 4. In Figure 2, the flow direction of the fluid flowing inside the intake port 3, channel 5, and discharge port 4 is illustrated with arrows.

[0020] As explained with reference to Figure 1, the arrangement of the inlet 3 and outlet 4 is such that they are point-symmetrical when viewed from the Z direction with respect to the center line CO of the pump 1. Therefore, it is preferable that the overall shape of the flow path 5 is also arranged in a similar way, so that it is point-symmetrical when viewed from the Z direction with respect to the center line CO of the pump 1. This makes it easier for fluid to flow from the inlet 3 to the outlet 4 through the flow path 5.

[0021] Furthermore, a resonant actuator 6 is installed inside the housing 2 as a drive source for the pump 1. The resonant actuator 6 has an electromagnet 61 and is a device that generates vibration motion by switching the electromagnet 61 on and off. The resonant actuator 6 also causes the movable parts to resonate by setting the frequency of the control signal that switches between on and off (i.e., the switching frequency) to be the same as, or near, the resonant frequency of, the movable parts (a group of components including movable plates 62, 63 and leaf springs 64, 65, etc., which will be described later), which are the vibration elements. As a result, when the electromagnet 61 is on, the resonant actuator 6 can efficiently vibrate the movable parts by utilizing the resonance of the movable parts in addition to the attraction of the movable parts by the electromagnet 61.

[0022] In the example shown in Figure 2, the resonant actuator 6 is positioned such that its longitudinal direction is in the X direction and its short direction is in the Y direction, and is located in the center when viewed in the Z direction. Furthermore, like the housing 2, the resonant actuator 6 is formed to be symmetrical in the Y direction with respect to the symmetry axis CA, and symmetrical in the X direction with respect to the symmetry axis CB. The electromagnet 61 is located in the center of the resonant actuator 6.

[0023] Furthermore, the fourth channel 54 of channel 5 is positioned adjacent to the X-negative side of the electromagnet 61 and is arranged to penetrate the resonant actuator 6 in the Y direction. Similarly, the fifth channel 55 of channel 5 is positioned adjacent to the X-positive side of the electromagnet 61 and is arranged to penetrate the resonant actuator 6 in the Y direction.

[0024] Furthermore, a first pump chamber 7 and a second pump chamber 8 are provided in the portions of the fourth flow path 54 and the fifth flow path 55 that overlap with the resonant actuator 6 in the Z-direction view, respectively. The first pump chamber 7 and the second pump chamber 8 are elements that pressurize and send fluid from the upstream side to the downstream side of the flow path 5 in conjunction with the vibrational motion of the resonant actuator 6. The fluid in the flow path 5 can flow from the inlet 3 to the outlet 4 by the operation of the first pump chamber 7 and the second pump chamber 8. In the example of Figure 2, both the first pump chamber 7 and the second pump chamber 8 are arranged on the axis of symmetry CA of the housing 2 and the resonant actuator 6. Also, as described above, in the example of Figure 2, the shape of the flow path 5 is arranged to be point-symmetric in the Z-direction view with respect to the central axis CO passing through the centers of the pair of main surfaces 21 and 22 of the housing 2. As a result, the first pump chamber 7 and the second pump chamber 8 are positioned approximately midway along the flow path 5, making it possible to make the energy required for the intake of fluid into the first pump chamber 7 and the second pump chamber 8 and the energy required for the discharge of fluid from the first pump chamber 7 and the second pump chamber 8 approximately the same.

[0025] The configuration of the resonant actuator 6 of the pump 1 according to this embodiment will be described with reference to Figures 3 and 4. Figure 3 is a perspective view showing the schematic configuration of the resonant actuator 6. Figure 4 is an exploded perspective view of the resonant actuator 6 shown in Figure 3. The perspective views in Figures 3 and 4 are the same as in Figure 1.

[0026] As shown in Figures 3 and 4, the resonant actuator 6 includes an electromagnet 61, a pair of movable plates 62 and 63, and a pair of leaf springs 64 and 65.

[0027] The electromagnet 61 is positioned in the center of the resonant actuator 6 in the Z direction. As shown in Figure 4, the electromagnet 61 has a core 611 and a coil 612. The core 611 has a winding portion 611A and a pair of widening portions 611B. The winding portion 611A is the central part of the core 611 in the X direction and extends in the X direction. The winding portion 611A has a rectangular cross-sectional shape along the YZ plane, and its outer circumferential surface is formed on four surfaces with the positive Y direction, negative Y direction, positive Z direction, and negative Z direction as normal directions. The coil 612 is wound around the outer circumferential surface of the winding portion 611A. The pair of widening portions 611B are formed at both ends of the winding portion 611A along the X direction, protruding on both sides in the Z direction relative to the winding portion. The widened portion 611B also has a rectangular cross-sectional shape along the YZ plane and has four surfaces with the positive Y direction, negative Y direction, positive Z direction, and negative Z direction as normal directions. In other words, the widened portion 611B has an upper end surface and a lower end surface that protrude by the same amount from the wound portion 611A along the Y direction.

[0028] The electromagnet 61 generates a magnetic field passing through the center of the coil 612 when an electric current flows through the wires that make up the coil 612. The magnetic field generated by the coil 612 is further strengthened by the core 611.

[0029] The pair of movable plates 62 and 63 are plate-shaped members formed from a magnetic material, and consist of a first movable plate 62 and a second movable plate 63. The first movable plate 62 is positioned on the positive Z side of the electromagnet 61, and the second movable plate 63 is positioned on the negative Z side of the electromagnet 61. The first movable plate 62 and the second movable plate 63 are formed to be the same shape and are positioned opposite each other in the Z direction.

[0030] Since the first movable plate 62 and the second movable plate 63 are magnetic materials, they are attracted to the electromagnet 61 by the magnetic field generated when the electromagnet 61 is energized. Furthermore, when the electromagnet 61 is switched from energized to de-energized, the first movable plate 62 and the second movable plate 63 move in the opposite direction to the attractive motion due to the biasing force added by the leaf springs 64 and 65 to which they are attached. In other words, the first movable plate 62 and the second movable plate 63 can perform vibrational motion in the Z direction by switching the energization of the electromagnet 61 between energization and de-energization.

[0031] As shown in Figure 4, the first movable plate 62 has a central portion 621 and a pair of ends 622 and 623. The central portion 621 is the central part of the first movable plate 62 in the X direction and is formed in a rectangular shape with its long sides facing each other in the Y direction and its short sides facing each other in the X direction when viewed in the Z direction. The shape of the central portion 621 is formed to cover the entire outer shape of the electromagnet 61 when viewed from the positive Z direction. The pair of ends 622 and 623 are provided connected to both ends of the central portion 621 along the X direction, i.e., the short sides of the rectangular shape described above. In the example in Figure 4, one end 622 is positioned on the negative X direction side of the central portion 621, and the other end 623 is positioned on the positive X direction side of the central portion 621. The dimensions of the pair of ends 622 and 623 in the Y direction are the same as those of the central portion 621. The dimensions of the pair of ends 622 and 623 in the X direction are approximately the same for both. Furthermore, it is preferable that the thickness dimension of the pair of ends 622 and 623 in the Z direction be formed to be thinner than the central portion 621, as illustrated in Figures 3 and 4.

[0032] A pair of pistons 71 and 81 are installed on the Z-negative side surfaces of the first movable plate 62, at the ends 622 and 623, respectively, extending in the Z-negative direction. The pistons 71 and 81 will be described later.

[0033] The second movable plate 63 has a central portion 631 and a pair of ends 632 and 633. The central portion 631 is the central part of the second movable plate 63 in the X direction and is formed in a rectangular shape with its long sides facing each other in the Y direction and its short sides facing each other in the X direction when viewed in the Z direction. The shape of the central portion 631 is formed to cover the entire outer shape of the electromagnet 61 when viewed from the negative Z direction side. The pair of ends 632 and 633 are provided connected to both ends of the central portion 631 along the X direction, i.e., the short sides of the rectangular shape described above. In the example in Figure 4, one end 632 is positioned on the negative X direction side of the central portion 621, and the other end 633 is positioned on the positive X direction side of the central portion 631. The dimensions of the pair of ends 632 and 633 in the Y direction are the same as those of the central portion 631. The dimensions of the pair of ends 632 and 633 in the X direction are approximately the same for both. Furthermore, it is preferable that the thickness dimension of the pair of end portions 632 and 633 in the Z direction be formed to be thinner than the central portion 631, as illustrated in Figures 3 and 4.

[0034] A pair of pistons 72 and 82 are installed on the Z-positive side of the respective Z-positive surfaces of the second movable plate 63, at the ends 632 and 633, respectively, extending in the Z-positive direction. The pistons 72 and 82 will be described later.

[0035] The pair of leaf springs 64 and 65 are elastic members that bias in the Z direction, and consist of a first leaf spring 64 and a second leaf spring 65. The first leaf spring 64 is positioned on the positive Z side of the first movable plate 62, and the first movable plate 62 is attached to it. The second leaf spring 65 is positioned on the negative Z side of the second movable plate 63, and the second movable plate 63 is attached to it. The first leaf spring 64 and the second leaf spring 65 are formed in the same shape and are positioned opposite each other in the Z direction. In other words, as shown in Figure 3, the first leaf spring 64 and the second leaf spring 65 form the outermost part of the resonant actuator 6 in the Z direction. The first leaf spring 64 biases the first movable plate 62 in the opposite direction (positive Z side) to the attractive movement of the first movable plate 62 to the electromagnet 61. Similarly, the second leaf spring 65 biases the second movable plate 63 in the opposite direction (negative Z direction) to the attraction movement of the second movable plate 63 to the electromagnet 61.

[0036] As shown in Figure 4, the first leaf spring 64 has a central portion 641, a pair of fixed ends 642, and a pair of flexible portions 643. The central portion 641 is the central part of the first leaf spring 64 in the X direction, and is a flat plate-shaped portion formed such that its width dimension in the Y direction is constant and its outer edges on both sides in the Y direction extend along the X direction. The first leaf spring 64 is installed so as to be movable integrally with the first movable plate 62 by attaching the first movable plate 62 to the central portion 641.

[0037] The pair of fixed ends 642 are positioned at both ends of the first leaf spring 64 along the X direction, and are flat plate-shaped portions formed such that their outer edges in the X direction both extend along the Y direction. The pair of fixed ends 642 of the first leaf spring 64 are fixed to a support 9 (see Figure 5, etc.), which is an example of a fixed object installed inside the housing 2, thereby fixing both ends in the X direction.

[0038] The pair of flexible portions 643 are located between the central portion 641 and the pair of fixed ends 642 of the first leaf spring 64, along the X direction. The pair of flexible portions 643 elastically deform and bend so that the relative positional relationship in the Z direction between the central portion 641 to which the first movable plate 62 is attached and the pair of fixed ends 642 fixed to the support 9 changes. The first leaf spring 64 can bias the first movable plate 62 attached to the central portion 641 by the elastic deformation of this pair of flexible portions 643.

[0039] Furthermore, as shown in Figure 4 and other figures, the pair of flexible portions 643 are formed with a relatively small width dimension perpendicular to the direction connecting the central portion 641 and the pair of fixed ends 642, in order to facilitate elastic deformation, and are also formed to curve in an S-shape when viewed in the Z direction. In addition, in order to make the amount of deflection in the Y direction more uniform, the S-shaped curved portions are arranged on both sides in the Y direction with respect to the axis of symmetry CA, and are formed to be symmetric with respect to the axis of symmetry CA. Note that the curved portions may have shapes other than S-shape.

[0040] As shown in Figure 4, the second leaf spring 65 has a central portion 651, a pair of fixed ends 652, and a pair of flexible portions 653. The central portion 651 is the central part of the second leaf spring 65 in the X direction, and is a flat plate-shaped portion formed such that its width dimension in the Y direction is constant and its outer edges on both sides in the Y direction extend along the X direction. The second leaf spring 65 is installed so that it can move integrally with the second movable plate 63 by attaching the second movable plate 63 to the central portion 651.

[0041] The pair of fixed ends 652 are positioned at both ends of the second leaf spring 65 along the X direction, and are flat plate-shaped portions formed such that their outer edges in the X direction both extend along the Y direction. The pair of fixed ends 652 of the second leaf spring 65 are fixed to a support 9 (see Figure 5, etc.), which is an example of a fixed object installed inside the housing 2, thereby fixing both ends in the X direction.

[0042] The pair of flexible portions 653 are located between the central portion 651 and the pair of fixed ends 652 of the second leaf spring 65, along the X direction. The pair of flexible portions 653 elastically deform and bend so that the relative positional relationship in the Z direction between the central portion 651 to which the second movable plate 63 is attached and the pair of fixed ends 652 fixed to the support 9 changes. The second leaf spring 65 can bias the second movable plate 63 attached to the central portion 651 by the elastic deformation of this pair of flexible portions 653.

[0043] Furthermore, as shown in Figure 4 and other figures, the pair of flexible portions 653 are formed with a relatively small width dimension perpendicular to the direction connecting the central portion 651 and the pair of fixed ends 652, in order to facilitate elastic deformation, and are also formed to curve in an S-shape when viewed in the Z direction. In addition, in order to make the amount of deflection in the Y direction more uniform, the S-shaped curved portions are arranged on both sides in the Y direction with respect to the axis of symmetry CA, and are formed to be symmetric with respect to the axis of symmetry CA. Note that the curved portions may have shapes other than S-shape.

[0044] Furthermore, as shown in Figure 4, each element of the resonant actuator 6 is positioned such that the center of its outer shape in the Z-direction view coincides with the center line CO of the pump 1. This allows the center of gravity of the resonant actuator 6 to be located near the center line CO of the pump 1, enabling the resonant actuator 6 to operate in a well-balanced manner.

[0045] In this embodiment, the first leaf spring 64 and the second leaf spring 65 are shown as having a configuration in which the first movable plate 62 and the second movable plate 63 are attached at their central portions 641 and 651, respectively. However, the first movable plate 62 and the second movable plate 63 may be attached at any position other than the central portion in the X direction of the first leaf spring 64 and the second leaf spring 65, respectively. Also, the first leaf spring 64 and the second leaf spring 65 are shown as being fixed to the support 9 at a pair of fixed ends 642 and 652, respectively. However, they may be fixed to the support 9 at any position other than both ends in the X direction.

[0046] Furthermore, in this embodiment, as described above, the first movable plate 62 and the second movable plate 63 are formed with the same shape, and the first leaf spring 64 and the second leaf spring 65 are formed with the same shape. The mounting position of the first movable plate 62 to the first leaf spring 64 and the mounting position of the second movable plate 63 to the second leaf spring 65 are also the same. Therefore, the resonant frequency of the first movable part (the first movable plate 62 and the first leaf spring 64) and the resonant frequency of the second movable part (the second movable plate 63 and the second leaf spring 65) are the same. Consequently, if the switching frequency for switching between the energized and de-energized states of the single electromagnet 61 placed between the first and second movable parts is set to the same frequency as or near the common resonant frequency of the first and second movable parts, both the first and second movable parts can be brought into a resonant state together. As a result, the resonant actuator 6 of this embodiment can vibrate the movable part more efficiently.

[0047] The configurations of the first pump chamber 7 and the second pump chamber 8 of the pump 1 according to this embodiment will be described with reference to Figures 5 and 6. Figure 5 is a schematic diagram of the cross-sectional shape of the pump 1 according to this embodiment along the axis of symmetry CA. Figure 5 omits the illustration of elements of the pump 1 that are outside the resonant actuator 6, including the housing 2.

[0048] As shown in Figure 5, the fourth channel 54 and the fifth channel 55 are holes provided in a support 9, which is an example of a fixed object installed inside the housing 2. The support 9 includes, for example, block-shaped components that are fixedly installed on the inner wall surface of the housing 2. The other channels of the channel 5, other than the fourth channel 54 and the fifth channel 55, are similarly holes provided in the support 9. In the example in Figure 5, the support 9 to which the channel 5 is provided and the support 9 to which the pair of fixed ends 642 of the first leaf spring 64 and the pair of fixed ends 652 of the second leaf spring 65 of the resonant actuator 6 are fixed are shown as an integrated part, but it is also possible to have a configuration in which separate parts are integrally connected. Similarly, the first to eighth channels 51 to 58 that constitute the channel 5 are each provided on separate supports, and these supports are connected to form the channel 5.

[0049] The cross-section in Figure 5 is a cross-section along the axis of symmetry CA of pump 1, and as is clear from Figure 2, it is a cross-section of the portion of the fourth flow path 54 where the first pump chamber 7 is located, and the portion of the fifth flow path 55 where the second pump chamber 8 is located. As shown in Figure 5, the first pump chamber 7 and the second pump chamber 8 are provided with cylinders 73 and 83, respectively, which communicate along the Z direction.

[0050] The cylinder 73 of the first pump chamber 7 is formed with openings on the Z-positive and Z-negative sides of the support 9. Furthermore, in this embodiment, the first piston 71 provided on the first movable plate 62 and the second piston 72 provided on the second movable plate 63 are positioned so that their axial directions coincide with those of the first pump chamber 7, i.e., coincide with the axial direction of the cylinder 73. Therefore, as shown in Figure 5, the first piston 71 is slidably inserted into the cylinder 73 from the opening on the Z-positive side, and the second piston 72 is slidably inserted into the cylinder 73 from the opening on the Z-negative side.

[0051] The cylinder 83 of the second pump chamber 8 is formed with openings on the Z-positive and Z-negative sides of the support 9. Furthermore, in this embodiment, the first piston 81 provided on the first movable plate 62 and the second piston 82 provided on the second movable plate 63 are positioned so that their axial directions coincide with those of the second pump chamber 8, i.e., coincide with the axial direction of the cylinder 83. Therefore, as shown in Figure 5, the first piston 81 is slidably inserted into the cylinder 83 from the opening on the Z-positive side, and the second piston 82 is slidably inserted into the cylinder 83 from the opening on the Z-negative side.

[0052] These first pistons 71, 81 and second pistons 72, 82 are installed in the first movable plate 62 and the second movable plate 63, respectively. Therefore, in conjunction with the vibrational motion of the first movable plate 62 and the second movable plate 63 in the Z direction, controlled by the energization of the electromagnet 61, the first pistons 71, 81 and the second pistons 72, 82 slide within the respective cylinders 73, 83, repeatedly moving closer to and further apart from each other. This allows the volume of the first pump chamber 7 and the second pump chamber 8 to be increased or decreased.

[0053] Figure 6 is a schematic diagram of the axial cross-sectional shape of the fourth passage 54 of the pump 1 according to this embodiment. As shown in Figure 6, an intake valve 74 and a discharge valve 75 are provided on the upstream and downstream sides of the first pump chamber 7 within the fourth passage 54, respectively. When the first piston 71 and the second piston 72 move closer together in the cylinder 73 and the volume of the first pump chamber 7 decreases, the intake valve 74 is configured to close to stop the inflow of fluid from the upstream side of the fourth passage 54 into the first pump chamber 7, and the discharge valve 75 is configured to open to discharge fluid from the first pump chamber 7 to the downstream side of the fourth passage 54. On the other hand, when the first piston 71 and the second piston 72 move further apart in the cylinder 73 and the volume of the first pump chamber 7 increases, the intake valve 74 is configured to open to allow fluid to flow from the upstream side of the fourth passage 54 into the first pump chamber 7, and the discharge valve 75 is configured to close to stop the discharge of fluid from the first pump chamber 7 to the downstream side of the fourth passage 54.

[0054] Figure 6 illustrates a configuration for achieving this effect in which both the intake valve 74 and the exhaust valve 75 have a sphere positioned upstream of the fourth flow path 54 to seal the flow path, and a spring on the downstream side that biases this sphere upstream. However, the configuration of the intake valve 74 and the exhaust valve 75 may be different from the example in Figure 6. The configurations of the intake valve 74 and the exhaust valve 75 shown in Figure 6 and Figures 8 and 10, which will be described later, schematically illustrate the functions of the intake valve 74 and the exhaust valve 75. The specific configuration of the intake valve 74 and the exhaust valve 75 in this embodiment will be described later with reference to Figures 13 to 16.

[0055] In this embodiment, the area between the lower end surface of the first piston 71 and the upper end surface of the second piston 72 within the cylinder 73 constitutes the volume of the first pump chamber 7. This volume increases or decreases in accordance with the vertical movement of the first piston 71 and the second piston 72 within the cylinder 73.

[0056] Although Figure 6 illustrates the cross-section of the fourth flow path 54 and explains the configuration of the first pump chamber 7, the configuration of the second pump chamber 8 in the fifth flow path 55 is similar. That is, the area between the lower end surface of the first piston 81 and the upper end surface of the second piston 82 within the cylinder 83 constitutes the volume of the second pump chamber 8. This volume increases or decreases in accordance with the vertical movement of the first piston 81 and the second piston 82 within the cylinder 83.

[0057] [Pump operation] The operation of the pump 1 according to this embodiment will be explained with reference to Figures 7 to 10.

[0058] Figure 7 is a schematic diagram showing the operation of pump 1 when the coil is energized. Figure 8 is a schematic diagram showing the area around the first pump chamber 7 in the state shown in Figure 7. The outlines of Figures 7 and 8 are the same as those of Figures 5 and 6.

[0059] As shown in Figure 7, when the coil 612 of the electromagnet 61 is energized, a magnetic field M1 is generated passing through the center of the coil 612. The magnetic field M1 generated by the coil 612 is further strengthened by the winding portion 611A of the core 611, which is installed penetrating the center of the coil 612. In the example in Figure 7, a magnetic field M1 directed towards the positive X direction is generated inside the winding portion 611A.

[0060] The magnetic field M1 generated in this way branches in the positive Z and negative Z directions along the protruding direction of one of the widening sections 611B, which is located on the X-positive side of the winding section 611A of the core 611. Next, it flows through the interior of the first movable plate 62 and the second movable plate 63, which are located opposite each other on the upper and lower end surfaces of the widening section 611B, towards the X-negative side. Then, from the upper and lower end surfaces of the other widening section 611B, which is located on the X-negative side of the winding section 611A, it flows through the interior of this widening section 611B toward the central part in the Z direction, merges, and then flows back into the winding section 611A. In other words, when viewed from the Y-negative side, the magnetic field M1 exemplified in Figure 7 flows clockwise on the first movable plate 62 side and counterclockwise on the second movable plate 63 side.

[0061] As a result of the generation of this magnetic field M1, the first movable plate 62 is attracted to the electromagnet 61 and moves toward the negative Z direction, as shown by arrow A in Figure 7. Similarly, the second movable plate 63 is attracted to the electromagnet 61 and moves toward the positive Z direction, as shown by arrow B.

[0062] As the first movable plate 62 and the second movable plate 63 move toward the side attracted to the electromagnet 61, the first piston 71 slides in the negative Z direction within the cylinder 73, as indicated by arrow C, and the second piston 72 slides in the positive Z direction within the cylinder 73, as indicated by arrow D. As a result, the lower end surface of the first piston 71 and the upper end surface of the second piston 72 move closer to each other, reducing the volume of the first pump chamber 7.

[0063] Similarly, in the second pump chamber 8, the first piston 81 slides within the cylinder 83 in the negative Z direction, as indicated by arrow E. Also, the second piston 82 slides within the cylinder 83 in the positive Z direction, as indicated by arrow F. As a result, the lower end surface of the first piston 81 and the upper end surface of the second piston 82 move closer to each other, reducing the volume of the second pump chamber 8.

[0064] Ideally, the first movable plate 62 and the second movable plate 63 are both moved in the Z direction by the magnetic field M1. Therefore, the amount of sliding movement of the two first pistons 71 and 81 installed on the first movable plate 62 is the same as the amount of sliding movement of the two second pistons 72 and 82 installed on the second movable plate 63. Consequently, the amount of reduction in volume of the first pump chamber 7 and the second pump chamber 8 is also the same.

[0065] Furthermore, as the first movable plate 62 moves toward the side attracted to the electromagnet 61, the central portion 641 of the first leaf spring 64 to which the first movable plate 62 is attached also moves integrally with the first movable plate 62 in the direction of arrow A. At this time, since the fixed end 642 of the first leaf spring 64 is fixedly installed on the support 9, the central portion 641 is displaced toward the negative Z direction relative to the fixed end 642. Figure 7 shows the position of the first leaf spring 64 in the Z direction in the steady state as shown in Figure 5, indicated by the dotted line S1. As a result of this displacement, the deflection portion 643 located between the central portion 641 and the fixed end 642 undergoes elastic deformation toward the negative Z direction, and as a result, a biasing force f1 is generated in the deflection portion 643 to elastically return toward the positive Z direction, as shown by the dotted arrow f1 in Figure 7.

[0066] Similarly, as the second movable plate 63 moves toward the side attracted to the electromagnet 61, the central portion 651 of the second leaf spring 65 to which the second movable plate 63 is attached also moves integrally with the second movable plate 63 in the direction of arrow B. At this time, since the fixed end 652 of the second leaf spring 65 is fixedly installed on the support 9, the central portion 651 is displaced toward the positive Z direction relative to the fixed end 652. Figure 7 shows the position of the second leaf spring 65 in the Z direction in the steady state as shown in Figure 5, indicated by the dotted line S2. As a result of this displacement, the deflection portion 653 located between the central portion 651 and the fixed end 652 elastically deforms toward the positive Z direction, and as a result, a biasing force f2 is generated in the deflection portion 653 to elastically return toward the negative Z direction, as shown by the dotted arrow f2 in Figure 7.

[0067] As shown in Figure 7, when the first pistons 71 and 81 and the second pistons 72 and 82 move closer together, the volumes of the first pump chamber 7 and the second pump chamber 8 decrease. As a result, as shown in Figure 8, in the first pump chamber 7, the spheres of the suction valve 74 and the discharge valve 75 are pressed upstream and downstream of the fourth flow path 54, respectively, by the fluid in the first pump chamber 7. At this time, the sphere of the suction valve 74 blocks the upstream side of the fourth flow path 54, so the suction valve 74 is closed. On the other hand, the sphere of the discharge valve 75 is movable downstream as indicated by arrow G, so the discharge valve 75 is opened. As a result, the fluid in the first pump chamber 7 is pressurized and discharged to the downstream side of the fourth flow path 54.

[0068] As mentioned above, the reduction in volume between the first pump chamber 7 and the second pump chamber 8 is the same. Therefore, in the second pump chamber 8, the fluid is pressurized and discharged downstream of the fifth flow path 55, similar to the operation of the first pump chamber 7 shown in Figure 7.

[0069] Figure 9 is a schematic diagram showing the operation of pump 1 when the coil is switched from energized to de-energized as shown in Figure 7. Figure 10 is a schematic diagram showing the area around the first pump chamber 7 in the state shown in Figure 9. The outlines of Figures 9 and 10 are the same as those of Figures 5 and 6.

[0070] As shown in Figure 9, when the coil 612 of the electromagnet 61 is switched from the energized state shown in Figure 7 to the de-energized state, the magnetic field M1 that was generated around the electromagnet 61 disappears.

[0071] As the magnetic field M1 disappears, the attractive force that the first movable plate 62 and the second movable plate 63 were receiving from the electromagnet 61 also disappears. Therefore, the biasing force f1 generated at the deflected portion 643 of the first leaf spring 64, as shown by the dotted arrow in Figure 7, causes the first leaf spring 64 to return to its elastic state, and in response to this movement, the first movable plate 62 also moves toward the positive Z direction. However, since the attractive force that was balancing the biasing force f1 has disappeared, neither the first movable plate 62 nor the first leaf spring 64 comes to rest at the steady position S1, but moves further toward the positive Z direction. Finally, as shown by the arrow H in Figure 9, they move toward the positive Z direction from the steady position S1 by an amount equal to the amount of movement due to the attraction of the electromagnet 61. Similarly, as indicated by arrow I, the second movable plate 63 and the second leaf spring 65 also move from their steady position S2 toward the negative Z direction due to the biasing force f2 in the negative Z direction that was generated in the deflected portion 653.

[0072] As the first movable plate 62 and the second movable plate 63 move away from the electromagnet 61, the first piston 71 slides in the positive Z direction within the cylinder 73, as indicated by arrow J, and the second piston 72 slides in the negative Z direction within the cylinder 73, as indicated by arrow K. This causes the lower end surface of the first piston 71 and the upper end surface of the second piston 72 to move apart from each other, increasing the volume of the first pump chamber 7.

[0073] Similarly, in the second pump chamber 8, the first piston 81 slides within the cylinder 83 in the positive Z direction, as indicated by arrow L. Also, the second piston 82 slides within the cylinder 83 in the negative Z direction, as indicated by arrow M. As a result, the lower end surface of the first piston 81 and the upper end surface of the second piston 82 are separated from each other, increasing the volume of the second pump chamber 8.

[0074] Ideally, the first movable plate 62 and the second movable plate 63 move parallel to each other in the Z direction due to the biasing forces f1 and f2 of the flexible portions 643 and 653. Therefore, the amount of sliding movement of the two first pistons 71 and 81 installed on the first movable plate 62 is the same as the amount of sliding movement of the two second pistons 72 and 82 installed on the second movable plate 63. Consequently, the increase in volume of the first pump chamber 7 and the second pump chamber 8 is also the same.

[0075] As shown in Figure 9, when the first pistons 71 and 81 and the second pistons 72 and 82 move apart, the volumes of the first pump chamber 7 and the second pump chamber 8 increase. As a result, as shown in Figure 10, in the first pump chamber 7, the spheres of the intake valve 74 and the discharge valve 75 are drawn towards the cylinder 73 by the fluid in the first pump chamber 7. At this time, the sphere of the discharge valve 75 moves to block the upstream side of the fourth passage 54 as indicated by arrow N, so the discharge valve 75 is closed. On the other hand, the sphere of the intake valve 74 can move downstream as indicated by arrow O, so the intake valve 74 is opened. As a result, the fluid on the upstream side of the fourth passage 54 is drawn into the first pump chamber 7.

[0076] As mentioned above, the volume increases of the first pump chamber 7 and the second pump chamber 8 are the same. Therefore, in the second pump chamber 8, the fluid upstream of the fifth flow path 55 is drawn into the second pump chamber 8, similar to the operation of the first pump chamber 7 shown in Figure 10.

[0077] In this embodiment, the pump 1 can be driven by controlling the energization of the electromagnet 61 to the coil 612 so as to repeatedly cycle between the state when the coil is energized (first state) shown in Figures 7 and 8, and the state when the coil is not energized (second state) shown in Figures 9 and 10.

[0078] In this control system, the pressure of the fluid discharged from the pump 1 can be adjusted according to the amount and speed of movement of the first pistons 71, 81 and the second pistons 72, 82. To adjust the pressure, it is necessary to adjust the amount and speed of movement of the first movable plate 62 and the second movable plate 63 on which the first pistons 71, 81 and the second pistons 72, 82 are mounted. To adjust the movement of the movable plates 62, 63, it is necessary to adjust the strength (magnetic flux density, etc.) of the magnetic field M1 generated by the electromagnet 61. To adjust the magnetic field M1, it is necessary to control the magnitude of the current flowing through the coil 612 of the electromagnet 61. In other words, in the pump 1 of this embodiment, the discharge of fluid at a desired pressure can be controlled by controlling the current value flowing through the coil 612 of the resonant actuator 6.

[0079] Alternatively, in the pump 1 of this embodiment, the discharge of fluid at a desired pressure can also be controlled by adjusting various structural elements, such as the number of turns of the wire in the coil 612 of the electromagnet 61, the dimensions of the winding portion 611A of the core 611 in the X and Y directions, the amount of protrusion in the Z direction and the dimensions in the X and Y directions of the widening portion 611B of the core 611, the area and shape of the first movable plate 62 and the second movable plate 63 in the Z direction, and the spring constants of the first leaf spring 64 and the second leaf spring 65.

[0080] The pump 1 of this embodiment includes an electromagnet 61, a first movable plate 62 and a second movable plate 63 which are attracted to the electromagnet 61 by the magnetic field M1 generated when the electromagnet 61 is energized, and a first leaf spring 64 which is attached to the first movable plate 62 and the second movable plate 63 respectively, and biases the first movable plate 62 and the second movable plate 63 in the opposite direction to the attraction movement of the first movable plate 62 and the second movable plate 63 to the electromagnet 61. The system includes a second leaf spring 65, a fluid passage 5, a first pump chamber 7 and a second pump chamber 8 provided on the passage 5, and an electromagnet 61 that operates to reduce the volume of the first pump chamber 7 and the second pump chamber 8 in response to the attraction of the first movable plate 62 and the second movable plate 63, and when the electromagnet 61 switches to de-energized after the attraction, the biasing force of the first leaf spring 64 and the second leaf spring 65 causes the electromagnetic forces of the first movable plate 62 and the second movable plate 63 to act. The pumps include, as an example of volume-changing members that operate to increase the volume of the first pump chamber 7 and the second pump chamber 8 in response to a separation operation that moves away from the stone 61, first pistons 71, 81 and second pistons 72, 82, and an intake valve 74 provided on the upstream side of the flow path 5 in the first pump chamber 7 and the second pump chamber 8, which opens when the first pistons 71, 81 and second pistons 72, 82 move in the direction of increasing the volume of the first pump chamber 7 and the second pump chamber 8 to draw fluid into the first pump chamber 7 and the second pump chamber 8 from the upstream side of the flow path 5, and a discharge valve 75 provided on the downstream side of the flow path 5 in the first pump chamber 7 and the second pump chamber 8, which opens when the first pistons 71, 81 and second pistons 72, 82 move in the direction of decreasing the volume of the first pump chamber 7 and the second pump chamber 8 to discharge fluid from the first pump chamber 7 and the second pump chamber 8 to the downstream side of the flow path 5.

[0081] Here, the electromagnet 61 among the above components can also be described as the "fixed part." Furthermore, the first movable plate 62 and the second movable plate 63, and the first leaf spring 64 and the second leaf spring 65 can also be described as "movable parts that are attracted to the fixed part by the magnetic field generated when the electromagnet 61 is energized, and that perform a vibration operation that separates them from the fixed part by the biasing force generated when the electromagnet 61 is not energized."

[0082] With this configuration, the vibration generated in the movable parts (first movable plate 62 and second movable plate 63, first leaf spring 64 and second leaf spring 65) by the fixed part (electromagnet 61) allows the first piston 71 and the second piston 72 installed in the first pump chamber 7 to slide synchronously within a common cylinder 73. In other words, the resonant actuator 6 can be used as the drive source for the pump 1. As a result, the amount of piston movement required to increase or decrease the volume of the first pump chamber 7 and the second pump chamber 8 can be reduced compared to a conventional solenoid-driven metering pump, thereby reducing vibration during pump 1 operation. Furthermore, by setting the switching frequency for switching between the energized and de-energized states of the electromagnet 61 to the same frequency as, or near, the resonant frequency of, the resonant frequency of the movable part, which is the vibration element, the movable part can be made to resonate. As a result, the resonant actuator 6 can efficiently vibrate the movable part by utilizing the resonance of the movable part in addition to the attraction of the movable part by the electromagnet 61 when the electromagnet 61 is energized. As a result, the pump 1 of this embodiment can be made highly efficient.

[0083] Furthermore, in the pump 1 of this embodiment, the first movable plate 62 and the second movable plate 63 are arranged opposite each other with an electromagnet 61 in between. The first movable plate 62 and the second movable plate 63 are attached to the first leaf spring 64 and the second leaf spring 65, respectively. In other words, the first leaf spring 64 and the second leaf spring 65 are also arranged opposite each other with an electromagnet 61 in between. The first pistons 71 and 81 are installed on the first movable plate 62 and move in conjunction with the operation of the first movable plate 62. The second pistons 72 and 82 are installed on the second movable plate 63 and move in conjunction with the operation of the second movable plate 63.

[0084] This configuration allows a single electromagnet 61 to synchronize the vibration of a pair of opposing movable parts (the first movable plate 62 and the first leaf spring 64, and the second movable plate 63 and the second leaf spring 65). Since the pair of movable parts are positioned opposite each other with the electromagnet 61 in between, they are attracted to the electromagnet 61 in opposite directions. Therefore, the vibration directions of the pair of movable parts are in opposite phase. This allows the vibrations generated in the pump 1 by the operation of each movable part to cancel each other out.

[0085] Furthermore, in the pump 1 of this embodiment, the first movable part (first movable plate 62 and first leaf spring 64) and the second movable part (second movable plate 63 and second leaf spring 65) are arranged opposite each other with a fixed part (electromagnet 61) in between. The first pistons 71 and 81 are linked to the operation of the first movable part, and the second pistons 72 and 82 are linked to the operation of the second movable part. The first piston 71 and the second piston 72 are installed in the same first pump chamber 7. Similarly, the first piston 81 and the second piston 82 are installed in the same second pump chamber 8.

[0086] This configuration allows for the sharing of a common pump chamber where a pair of pistons are installed, meaning that only one flow path (fourth flow path 54) and one valve (suction valve 74, discharge valve 75) are needed for the pair of first piston 71 and second piston 72. Similarly, only one flow path (fifth flow path 55) and one valve (suction valve 74, discharge valve 75) are needed for the pair of first piston 81 and second piston 82. This reduces the number of parts and simplifies the structure of pump 1. Furthermore, because the pump chamber is common, the reaction force acting on the pair of pistons installed in this pump chamber is the same, and the misalignment of the operation of the pair of opposing movable parts is reduced. As a result, the number of parts is reduced while increasing the number of pump chambers and improving pump efficiency.

[0087] Here, with reference to Figure 7 and Figure 11, the effect of the core 611 of the electromagnet 61 according to this embodiment will be explained. Figure 11 is a schematic diagram showing the magnetic field M2 generated in an electromagnet 61A using a flat plate-shaped core 611C as a comparative example.

[0088] In the comparative example shown in Figure 11, the electromagnet 61A has a flat core 611C. The core 611C of the comparative example differs from the core 611 of the embodiment in that it does not have the widened portion 611B shown in Figure 7, etc. The core 611C is formed so that the dimensions in the Z direction are uniform throughout the entire X direction. In other words, the core 611C has a shape in which the winding portion 611A of the core 611 of the embodiment extends to the range on both sides of the X direction where the widened portion 611B is located.

[0089] In the case of the core 611C shape shown in Figure 11, when the coil 612 is energized, a magnetic field M2 is generated inside the core 611C in the positive X direction. This magnetic field M2 initially enters the space of the resonant actuator 6 in the positive X direction from the X-positive end of the core 611C. After that, it branches into the positive Z direction and the negative Z direction, curves, reverses direction, and enters the interior from the X-positive ends of the first movable plate 62 and the second movable plate 63, heading towards the negative X direction. Then, from the X-negative ends of the first movable plate 62 and the second movable plate 63, it again enters the space of the resonant actuator 6 in the negative X direction, curves into the negative Z direction and the positive Z direction, reverses direction to the positive X direction, merges, and flows into the X-negative end of the core 611C.

[0090] In other words, the magnetic field M2 of the comparative example illustrated in Figure 11 is similar to the magnetic field M1 of the embodiment shown in Figure 7 in that, when viewed from the negative Y direction side, the flow is clockwise on the first movable plate 62 side and counterclockwise on the second movable plate 63 side. However, the magnetic field M2 of the comparative example tends to increase in magnetic resistance because a larger proportion of it flows within the space of the resonant actuator 6 compared to the magnetic field M1 of the embodiment, meaning the air gap is larger.

[0091] In contrast, in the electromagnet 61 of this embodiment, by providing a widened portion 611B on the core 611, as shown in Figure 7, the air gap in the magnetic field M1 can be limited to the gap between the upper end surface of the widened portion 611B and the first movable plate 62, and the gap between the lower end surface of the widened portion 611B and the second movable plate 63. This reduces the air gap in the magnetic field M1 and decreases magnetic resistance, so that magnetic force can be generated more efficiently than in the comparative example.

[0092] Furthermore, in this embodiment, the core 611 of the electromagnet 61 is formed by stacking multiple electromagnetic steel sheets in the Y direction, as shown in Figures 3 and 4. Since adjacent electromagnetic steel sheets are bonded together with adhesive, this adhesive portion becomes an air gap, which acts as magnetic resistance, making it difficult for magnetic flux to flow. The magnetic flux generated by the coil 612 flows through the core 611 toward the movable plates 62 and 63. Therefore, if the stacking direction is the Y direction as in this embodiment, the air gap is positioned parallel to the flow of magnetic flux, resulting in reduced obstruction to the flow of magnetic flux and improved energy transfer efficiency.

[0093] On the other hand, in a configuration where the stacking direction is 90 degrees different from that of this embodiment, that is, the X direction is the stacking direction, the air gap is placed in a position that obstructs the flow of magnetic flux, resulting in reduced efficiency.

[0094] Next, with reference to Figure 12, the effects of the shapes of the movable plates 62, 63 and the leaf springs 64, 65 in this embodiment will be explained. Figure 12 is a plan view of the internal structure of the housing 2 of the pump 1 as seen from the positive Z direction. Figure 12 shows the inside of the housing 2 as seen from the first leaf spring 64 side, with the main surface portion on the positive Z direction side of the housing 2 removed from the pump 1 shown in Figure 1.

[0095] When the direction perpendicular to the direction (X direction) of the magnetic field M1 generated by the electromagnet 61 (Y direction) is defined as the width direction, as shown in Figure 12, the widthwise dimension W1 of at least the flex portion 643 of the first leaf spring 64 is formed to be larger than the widthwise dimension W2 of the first movable plate 62. Similarly, in Figure 12, the relationship between the second movable plate 63 and the second leaf spring 65, which are hidden in the background of the figure, is also such that the widthwise dimension W1 of at least the flex portion 653 of the second leaf spring 65 is formed to be larger than the widthwise dimension W2 of the second movable plate 63.

[0096] As explained with reference to Figure 7, when the electromagnet 61 is energized during the operation of the resonant actuator 6, the first movable plate 62 and the second movable plate 63 ideally move in parallel in the direction approaching the electromagnet 61 (Z direction) due to the magnetic field M1 generated by the electromagnet 61. However, if a magnetic field M1 with uneven magnetic flux density is generated across the width direction of the movable plates 62 and 63, twisting may occur during operation, such as tilting of the first movable plate 62 or the second movable plate 63 in the X or Y direction. Therefore, as in this embodiment, by making the width dimension W1 of the leaf springs 64 and 65 larger than that of the movable plates 62 and 63, the twisting of the movable plates 62 and 63 during operation can be more easily absorbed by the leaf springs 64 and 65, making it possible to move the first movable plate 62 and the second movable plate 63 in parallel more stably. As a result, the pump 1 of this embodiment can reduce noise and vibration in a configuration in which the resonant actuator 6 is used as the drive source.

[0097] Furthermore, the first pump chamber 7 and the second pump chamber 8 are positioned opposite each other at the locations where a pair of first pistons 71 and 81 are provided at both ends of the first movable plate 62 along the direction of the magnetic field M1 (X direction). Similarly, the second movable plate 63 is positioned opposite each other at the locations where a pair of second pistons 72 and 82 are provided at both ends along the direction of the magnetic field M1 (X direction). In this configuration with two pump chambers, since two pistons are installed on a single movable plate, the relationship between the widthwise dimension W1 of the leaf springs 64 and 65 and the widthwise dimension W2 of the movable plates 62 and 63 allows for stabilization of the sliding of the two pistons on a single movable plate relative to each pump chamber 7 and 8, thus particularly demonstrating the effect of suppressing twisting of the movable plates 62 and 63.

[0098] Next, the effects of the arrangement of the first pump chamber 7 and the second pump chamber 8 will be explained. As shown in Figures 2 and 7, the fourth flow path 54 of the flow path 5 of the pump 1, which includes the first pump chamber 7, is positioned adjacent to the winding portion 611A of the core 611 of the electromagnet 61, on the opposite side (negative X direction side), with the widened portion 611B on the negative X direction side of the core 611, and the flow direction is aligned with the width direction (Y direction). Similarly, the fifth flow path 55 of the flow path 5 of the pump 1, which includes the second pump chamber 8, is positioned adjacent to the winding portion 611A of the core 611 of the electromagnet 61, on the opposite side (positive X direction side), with the widened portion 611B on the positive X direction side of the core 611, and the flow direction is aligned with the width direction (Y direction).

[0099] Therefore, the first piston 71, which is inserted into the first pump chamber 7, is positioned adjacent to the winding portion 611A on the opposite side (negative X direction side) of the widened portion 611B on the X-negative X direction side of the electromagnet 61 of the first movable plate 62. Similarly, the second piston 72, which is inserted into the first pump chamber 7, is positioned adjacent to the winding portion 611A on the opposite side (negative X direction side) of the widened portion 611B on the X-negative X direction side of the second movable plate 63. Likewise, the first piston 81, which is inserted into the second pump chamber 8, is positioned adjacent to the winding portion 611A on the opposite side (positive X direction side) of the widened portion 611B on the X-positive X direction side of the first movable plate 62. Similarly, the second piston 82, which is inserted into the second pump chamber 8, is positioned adjacent to the winding portion 611A of the second movable plate 63, on the opposite side (positive X direction side) from the widened portion 611B on the X-positive side of the electromagnet 61.

[0100] By providing widened portions 611B at both ends in the X direction of the core 611 of the electromagnet 61, a magnetic field M1 is generated such that the magnetic flux concentrates and passes through the upper and lower end surfaces of the widened portions 611B, as shown in Figure 7. In other words, when the electromagnet 61 is energized, the portion of the first movable plate 62 facing the upper end surface of the widened portion 611B receives the strongest attractive force, and the portion of the second movable plate 63 facing the lower end surface of the widened portion 611B receives the strongest attractive force. Therefore, by arranging the first pistons 71, 81 and the second pistons 72, 82 adjacent to the widened portion 611B, each piston can be positioned near the portion of the first movable plate 62 and the second movable plate 63 that receives the strongest attractive force from the electromagnet 61. This makes it possible to efficiently apply sliding external force from the first movable plate 62 and the second movable plate 63 to the first pistons 71 and 81 and the second pistons 72 and 82, thereby improving the operating efficiency of both the first pump chamber 7 and the second pump chamber 8.

[0101] Furthermore, by positioning the first pistons 71, 81 and the second pistons 72, 82 near the point where the first movable plate 62 and the second movable plate 63 receive the strongest attractive force from the electromagnet 61, the attractive force generated when the electromagnet 61 is energized can further suppress the twisting of the direction of movement of the first pistons 71, 81 and the second pistons 72, 82 during the suction operation. As a result, the direction of movement of the first pistons 71, 81 and the second pistons 72, 82 can be aligned with the axial direction (Z direction) of the cylinders 73, 83 of each pump chamber 7, 8, thereby further improving the operating efficiency of the first pump chamber 7 and the second pump chamber 8. As a result, the pump 1 of this embodiment can achieve improved performance and higher efficiency in a configuration that uses the resonant actuator 6 as a drive source.

[0102] Furthermore, the first pump chamber 7 is positioned adjacent to the core 611 of the electromagnet 61 on the opposite side (negative X direction) from the winding portion 611A, with one of the pair of widened portions 611B of the core 611 in between. The second pump chamber 8 is positioned adjacent to the winding portion 611A on the opposite side (positive X direction) from the pair of widened portions 611B, with the other of the pair of widened portions 611B in between. In this configuration with two pump chambers, since two pistons are installed on a single movable plate, by positioning each pump chamber 7 and 8 adjacent to the widened portion 611B, it becomes easier to equalize the external force applied to the two pistons provided on the single movable plate, and it becomes easier to synchronize the sliding of the pistons in each pump chamber 7 and 8. This particularly enhances the operational efficiency of the pump chambers.

[0103] Furthermore, as shown in Figure 2 and other figures, it is preferable that both the first pump chamber 7 and the second pump chamber 8 are positioned on the axis of symmetry CA of the housing 2. As shown in Figure 7 and other figures, the coil 612 of the electromagnet 61 is positioned so that its central axis is the axis of symmetry CA, so the magnetic flux tends to be most concentrated on the axis of symmetry CA on the center side of the coil 612. Therefore, the first movable plate 62 and the second movable plate 63 are most likely to receive the strongest attractive force from the electromagnet 61 on the axis of symmetry CA. For this reason, if the first pump chamber 7 and the second pump chamber 8 are positioned on the axis of symmetry CA, the first pistons 71, 81 and the second pistons 72, 82 are also positioned on the axis of symmetry CA, so it becomes possible to efficiently apply sliding external force from the first movable plate 62 and the second movable plate 63 to the first pistons 71, 81 and the second pistons 72, 82, further improving the operating efficiency of the first pump chamber 7 and the second pump chamber 8.

[0104] [Detailed configuration of intake valve 74 and exhaust valve 75] Referring to Figures 13 and 14, the details of the configuration of the intake valve 74 and discharge valve 75 according to this embodiment will be described. Figure 13 is a schematic diagram showing an enlarged view of the area around the first pump chamber 7. The schematic configuration of Figure 13 corresponds to Figure 6 and is a schematic diagram of the cross-sectional shape along the axial direction of the fourth flow path 54 of the pump 1. Figure 14 is a cross-sectional view of TT in Figure 13. Figure 14 is a view of the intake valve 74 from the downstream side (positive Y direction side) of the fourth flow path 54.

[0105] As shown in Figure 13, the intake valve 74 according to this embodiment has a frustoconical first valve chamber 741 and a first valve body 744 disposed within the first valve chamber 741.

[0106] The first valve chamber 741 has a first valve seat 742 and a first tapered surface 743. The first valve chamber 741 is provided inside a support 9, which is an example of a fixed object installed inside the housing 2, similar to the fourth flow path 54, and is a space formed in the shape of a frustocone by a plurality of inner walls including the first valve seat 742 and the first tapered surface 743.

[0107] The first valve seat 742 is the part corresponding to the base of the frustoconical shape, and the first valve body 744 is installed thereon. The first tapered surface 743 is the part corresponding to the side of the frustoconical shape. The first valve chamber 741 is arranged such that the first valve seat 742 communicates with the upstream side of the fourth flow path 54, and the first tapered surface 743 decreases in diameter as it moves toward the first pump chamber 7 (more specifically, the space between the first piston 71 and the second piston 72), i.e., toward the downstream side of the fourth flow path, and the part corresponding to the top surface of the frustoconical shape communicates with the space in the first pump chamber 7. An upstream communication passage 76 is provided in the part of the first valve chamber 741 corresponding to the top surface of the frustoconical shape, which connects the space in the first pump chamber 7 and the first valve chamber 741.

[0108] In other words, in the first valve chamber 741, the first valve seat 742 is positioned furthest to the negative Y direction, and the portion corresponding to the upper surface of the frustoconical shape having the upstream communication passage 76 is positioned furthest to the positive Y direction. The first valve seat 742 is positioned so that the normal direction of its plane points in the Y direction, that is, parallel to the axial direction of the fourth flow path 54. As shown in Figure 13, the first valve body 744 is a plate-shaped member with a thickness that is approximately uniform in the Y direction, and when not subjected to external forces such as pressure via the fluid flowing in the fourth flow path 54, the entire main surface on the negative Y direction side is in contact with the first valve seat 742, and is installed to block the space between the upstream side of the fourth flow path 54 and the first valve chamber 741. In the following explanation, the arrangement of the first valve body 744 shown in Figure 13 may also be referred to as the "first reference position".

[0109] The first valve body 744 is, for example, a metal plate-shaped member. As shown in Figures 13 and 14, the first valve body 744 has a first closing portion 745, a first outer edge portion 746, and a plurality of first connecting portions 747.

[0110] The first closing portion 745 is formed to be able to close the opening that communicates with the upstream side of the fourth passage 54 provided in the first valve seat 742, and is located in the central part of the first valve body 744. In the example of Figure 14, since the cross-sectional shape of the fourth passage 54 is circular, the shape of the first closing portion 745 is also circular. Furthermore, the circular shape of the first closing portion 745 is arranged concentrically with the circular cross-section of the fourth passage 54 and is formed with a diameter larger than the inner diameter of the fourth passage 54, thereby being configured to close the opening of the fourth passage 54 to the first valve chamber 741.

[0111] The first outer edge portion 746 is an annular portion located on the outer circumference of the first closing portion 745. In the example shown in Figure 14, since the first closing portion 745 is circular in shape, the first outer edge portion 746 is also formed as an annular shape and is arranged concentrically with the first closing portion 745.

[0112] Multiple first connecting portions 747 are arranged between the first closing portion 745 and the first outer edge portion 746 with a gap 748 between them, connecting the first closing portion 745 and the first outer edge portion 746, and are formed to be elastically deformable. In the example of Figure 14, the multiple first connecting portions 747 mainly extend along the circumferential direction of the first valve body 744 and are formed in an arm shape having substantially the same width dimension. The gap 748 connects the main surface on the Y-positive side and the main surface on the Y-negative side of the first valve body 744.

[0113] As shown in Figure 13, the discharge valve 75 according to this embodiment has a frustoconical second valve chamber 751 and a second valve body 754 disposed within the second valve chamber 751.

[0114] The second valve chamber 751 has a second valve seat 752 and a second tapered surface 753. The second valve chamber 751 is provided inside a support 9, which is an example of a fixed object installed inside the housing 2, similar to the fourth flow path 54, and is a space formed in the shape of a frustocone by a plurality of inner walls including the second valve seat 752 and the second tapered surface 753.

[0115] The second valve seat 752 is the part corresponding to the base of the frustoconical shape, and the second valve body 754 is installed thereon. The second tapered surface 753 is the part corresponding to the side of the frustoconical shape. The second valve chamber 751 is arranged such that the second valve seat 752 communicates with the first pump chamber 7 (more specifically, the space between the first piston 71 and the second piston 72), and the second tapered surface 753 decreases in diameter as it moves downstream of the fourth flow path 54, with the part corresponding to the top of the frustoconical shape communicating with the downstream side of the fourth flow path 54. The second valve seat 752 is provided with a downstream communication passage 77 that connects the above space in the first pump chamber 7 to the second valve chamber 751.

[0116] In other words, the second valve chamber 751 has a second valve seat 752 with a downstream communication passage 77 positioned furthest to the negative Y direction, and the portion corresponding to the top surface of the frustoconical shape positioned furthest to the positive Y direction. The second valve seat 752 is positioned so that the normal direction of its plane is oriented in the Y direction, that is, parallel to the axial direction of the fourth flow path 54. As shown in Figure 13, the second valve body 754 is a plate-shaped member with a substantially uniform thickness in the Y direction, and when not subjected to external forces such as pressure via the fluid flowing through the fourth flow path 54, the entire main surface on the negative Y direction side is in contact with the second valve seat 752, and is installed to block the space between the downstream communication passage 77 and the second valve chamber 751.

[0117] The second valve body 754, like the first valve body 744, is, for example, a metal plate-shaped member. The second valve body 754 is formed in the same shape as the first valve body 744 shown in Figure 14. That is, as shown in Figure 13, the second valve body 754 has a second closing portion 755, a second outer edge portion 756, and a plurality of second connecting portions 757. The second closing portion 755, the second outer edge portion 756, the plurality of second connecting portions 757, and the gap 758 have the same shape and function as the first closing portion 745, the first outer edge portion 746, the plurality of first connecting portions 747, and the gap 748 of the first valve body 744, respectively. The second closing portion 755 is formed to be able to close the opening of the downstream communication passage 77 that communicates with the first pump chamber 7 provided in the second valve seat 752. In the following explanation, the arrangement of the second valve body 754 shown in Figure 13 may also be referred to as the "second reference position."

[0118] The intake valve 74 and exhaust valve 75, configured as shown in Figures 13 and 14, can also behave as if one opens and the other closes, as the volume of the space between the first piston 71 and the second piston 72 increases or decreases in response to the vertical movement of the first piston 71 and the second piston 72 within the cylinder 73.

[0119] Figure 15 shows an example of the operation of the suction valve 74 and discharge valve 75, as illustrated in Figure 13, when the volume of the first pump chamber 7 is reduced. The overview of Figure 15 is the same as that of Figure 8.

[0120] In the example shown in Figure 15, the first piston 71 slides within the cylinder 73 in the negative Z direction, as indicated by arrow C. Also, the second piston 72 slides within the cylinder 73 in the positive Z direction, as indicated by arrow D. As a result, the lower end surface of the first piston 71 and the upper end surface of the second piston 72 move closer together, reducing the volume of the first pump chamber 7.

[0121] As the first piston 71 and the second piston 72 move in the direction of reducing the volume of the first pump chamber 7, the second closing portion 755 of the second valve body 754 is pressed downstream of the fourth passage 54 by the fluid in the first pump chamber 7, as shown by arrow G in Figure 15. As a result, the second closing portion 755 moves to a position (second position) that is separated from the second valve seat 752 of the second valve chamber 751 and does not come into contact with the second tapered surface 753 of the second valve chamber 751, as shown in Figure 15. Consequently, the discharge valve 75 opens, and the fluid in the first pump chamber 7 is discharged downstream of the fourth passage 54 through the gap 758 formed between the multiple second connecting portions 757 of the second valve body 754, as shown by arrow Q in Figure 15. Furthermore, when the discharge valve 75 is open, the second valve body 754 is in the second position and the second connecting portion 757 does not come into contact with the second tapered surface 753. This ensures a reliable space between the second valve body 754 and the second tapered surface 753, preventing the second valve body 754 from obstructing the fluid flow Q.

[0122] At this time, as shown by arrow P in Figure 15, the first closing portion 745 of the first valve body 744 is pressed upstream of the fourth passage 54 by the fluid in the first pump chamber 7. As a result, the first closing portion 745 moves to a position where it contacts the first valve seat 742 of the first valve chamber 741, as shown in Figure 15, blocking the communication between the upstream side of the fourth passage 54 and the first valve chamber 741. Consequently, the suction valve 74 closes, and the suction of fluid from the upstream side of the fourth passage 54 to the first pump chamber 7 is stopped.

[0123] Figure 16 shows an example of the operation of the suction valve 74 and discharge valve 75, as illustrated in Figure 13, when the volume of the first pump chamber 7 increases. The overview of Figure 16 is the same as that of Figure 10.

[0124] In the example shown in Figure 16, the first piston 71 slides within the cylinder 73 in the positive Z direction, as indicated by arrow J. Also, the second piston 72 slides within the cylinder 73 in the negative Z direction, as indicated by arrow K. As a result, the lower end surface of the first piston 71 and the upper end surface of the second piston 72 are separated from each other, increasing the volume of the first pump chamber 7.

[0125] As the first piston 71 and the second piston 72 move in a direction that increases the volume of the first pump chamber 7, the first closing portion 745 of the first valve body 744 is drawn towards the first pump chamber 7 (more specifically, the space between the first piston 71 and the second piston 72) by the fluid in the first pump chamber 7, as shown by arrow O in Figure 16. As a result, the first closing portion 745 moves to a position (first position) that is separated from the first valve seat 742 of the first valve chamber 741 and does not come into contact with the first tapered surface 743 of the first valve chamber 741, as shown in Figure 16. Consequently, the intake valve 74 opens, and as shown by arrow R in Figure 16, fluid is drawn into the first pump chamber 7 from the upstream side of the fourth flow path 54 through the gap 748 formed between the multiple first connecting portions 747 of the first valve body 744. Furthermore, when the intake valve 74 is open, the first valve body 744 is in the first position and the first connecting portion 747 does not come into contact with the first tapered surface 743. This ensures a reliable space between the first valve body 744 and the first tapered surface 743, preventing the first valve body 744 from obstructing the fluid flow R.

[0126] At this time, as shown by arrow N in Figure 16, the second closing portion 755 of the second valve body 754 is drawn towards the first pump chamber 7 by the fluid in the first pump chamber 7. As a result, the second closing portion 755 moves to a position where it contacts the second valve seat 752 of the second valve chamber 751, as shown in Figure 16, and blocks the downstream communication passage 77 that connects the first pump chamber 7 and the second valve chamber 751. As a result, the discharge valve 75 closes, and the discharge of fluid from the first pump chamber 7 to the downstream side of the fourth flow path 54 is stopped.

[0127] As explained with reference to Figures 13 to 16, by forming the first valve body 744 of the intake valve 74 and the second valve body 754 of the discharge valve 75 from plate-shaped members, the stress on the first connecting portion 747 and the second connecting portion 757 can be appropriately adjusted by appropriately adjusting the length and width dimensions in the extending direction of the first connecting portion 747 of the first valve body 744 and the second connecting portion 757 of the second valve body 754 according to the fluid pressure in the first pump chamber 7. As a result, the behavior of the first valve body 744 and the second valve body 754 can be arbitrarily adjusted according to the fluid pressure in the first pump chamber 7, thereby improving the sealing performance of the intake valve 74 and the discharge valve 75 without depending on the pressure output by the pump 1. Furthermore, even if the shape of the first connecting portion 747 and the second connecting portion 757 is adjusted, the plate thickness in the fluid flow direction (Y direction) of the first valve body 744 and the second valve body 754 does not change, and the circular diameter illustrated in Figure 14 does not need to change. This allows the first valve body 744 and the second valve body 754 to be housed in a constant size regardless of the pressure output by the pump 1, thus preventing an increase in the size of the suction valve 74 and the discharge valve 75 even when the output of the pump 1 becomes higher. Furthermore, since the first valve chamber 741 and the second valve chamber 751 are formed in a frustoconical shape that matches the opening and closing operation of the first valve body 744 and the second valve body 754 installed inside them, their volume can be reduced compared to, for example, a cylindrical shape formed with the same diameter in the Y direction, thus contributing to space saving.

[0128] Furthermore, it is preferable that the multiple first connecting portions 747 of the first valve body 744 are formed with stress adjusted so that the first closing portion 745 moves to the first position shown in Figure 16 in accordance with the fluid pressure when the first closing portion 745 is drawn towards the first pump chamber 7. Similarly, it is preferable that the multiple second connecting portions 757 of the second valve body 754 are formed with stress adjusted so that the second closing portion 755 moves to the second position shown in Figure 15 in accordance with the fluid pressure when the second closing portion 755 is pressed downstream of the fourth flow path 54.

[0129] This configuration makes it possible to maintain a constant behavior of the first valve body 744 and the second valve body 754, regardless of the pressure output by the pump 1, thereby stabilizing the pump performance.

[0130] Furthermore, it is preferable that the plurality of first connecting portions 747 of the first valve body 744 are formed to be elastically deformable from a first reference position (shown in Figure 13) where the first closing portion 745 contacts the first valve seat 742 to a first position shown in Figure 16, and that the first closing portion 745 is formed to be elastically returnable from the first position to the first reference position. Similarly, it is preferable that the plurality of second connecting portions 757 of the second valve body 754 are formed to be elastically deformable from a second reference position (shown in Figure 13) where the second closing portion 755 contacts the second valve seat 752 to a second position shown in Figure 15, and that the second closing portion 755 is formed to be elastically returnable from the second position to the second reference position.

[0131] This configuration allows for more reliable stabilization of the movement of the first valve body 744 and the second valve body 754 between the first and second positions and the first and second reference positions by utilizing the elastic deformation and elastic return of the multiple first connecting parts 747 of the first valve body 744 and the multiple second connecting parts 757 of the second valve body 754. As a result, the switching between the open and closed states of the intake valve 74 and the discharge valve 75, and the maintenance of these states, can be made more stable, thereby improving pump performance.

[0132] Furthermore, the plurality of first connecting portions 747 of the first valve body 744 are preferably formed in an arm shape that extends along the circumferential direction of the first valve body 744, as illustrated in Figure 14. Similarly, the plurality of second connecting portions 757 of the second valve body 754 are preferably formed in an arm shape that extends along the circumferential direction of the second valve body 754, similar to the shape of the first connecting portions 747 shown in Figure 14.

[0133] This configuration makes it easy to adjust the length and width dimensions of the arm shape in the longitudinal direction (extension direction), allowing for simpler adjustment of the stress on the first connecting portion 747 and the second connecting portion 757. As a result, the behavior of the first valve body 744 and the second valve body 754 can be more easily adjusted according to the fluid pressure in the first pump chamber 7, thus making it easier to improve the sealing performance of the intake valve 74 and the discharge valve 75 and to suppress an increase in their size.

[0134] Although Figure 13 illustrates the cross-section of the fourth passage 54 and explains the configuration of the first pump chamber 7, the configuration of the second pump chamber 8 in the fifth passage 55 is similar. That is, the area between the lower end surface of the first piston 81 and the upper end surface of the second piston 82 in the cylinder 83 becomes the volume of the second pump chamber 8. This volume increases or decreases in accordance with the vertical movement of the first piston 81 and the second piston 82 within the cylinder 83. The second pump chamber 8 also has an intake valve with a configuration similar to the intake valve 74 shown in Figure 13 on the upstream side of the fifth passage 55, and a discharge valve with a configuration similar to the discharge valve 75 shown in Figure 13 on the downstream side of the fifth passage 55.

[0135] Therefore, the suction valve and discharge valve of the second pump chamber 8 can achieve the same effect as the suction valve 74 and discharge valve 75 of the first pump chamber 7.

[0136] [Examples of applications for Pump 1] Figure 17 shows an example of the application of the pump 1 according to this embodiment. As shown in Figure 17, the pump 1 according to this embodiment can be applied to a beverage supply device such as an espresso machine 100.

[0137] The espresso machine 100 comprises a tank 101, a heater 102, a damper 103, and an extraction unit 104.

[0138] Tank 101 stores the water used for espresso. The tank 101 and pump 1, the pump 1 and heater 102, and the heater 102 and extraction unit 104 are connected by a water channel 107 that transports the water supplied from tank 101.

[0139] Pump 1 pressurizes the water transported from tank 101 and sends it to heater 102. In the case of an espresso machine 100, it is preferable for pump 1 to pressurize the water to, for example, 9 atmospheres.

[0140] The heater 102 heats the pressurized water transported from the tank 101 and sends it to the extraction unit 104.

[0141] The extraction unit 104 has powdered coffee beans 105 packed into the bottom and is pressed downwards by a damper 103. Hot water heated and pressurized by a heater 102 is supplied to the pressed coffee bean powder 105, and coffee is extracted from the extraction hole 106 at the bottom end of the extraction unit 104.

[0142] Espresso machines require a high-pressure pump to extract coffee under high pressure. Therefore, conventional espresso machines often utilize solenoid-driven metering pumps. However, solenoid-driven metering pumps have drawbacks such as high vibration and poor efficiency.

[0143] In contrast, the pump 1 of this embodiment uses a resonant actuator 6 as a drive source, thus solving the problems of the conventional solenoid-driven metering pump described above and providing a more convenient espresso machine 100.

[0144] Furthermore, pump 1 can be applied to any beverage supply device that requires pressure boosting, not just the espresso machine 100. Such a beverage supply device only needs to include at least a tank for storing beverages, a pump 1 according to the embodiment that sucks the beverage from the tank and discharges it at a predetermined pressure, and a discharge unit (corresponding to the extraction unit 104 in the example of Figure 17) that discharges the beverage discharged from pump 1.

[0145] Furthermore, pump 1 can be applied to any device other than beverage supply equipment that requires pressure boosting. Examples of such devices include industrial manufacturing equipment (such as semiconductor manufacturing equipment), medical equipment, household equipment (such as toilets, washbasins, and bathtubs), and agricultural equipment.

[0146] The embodiments have been described above with reference to specific examples. However, this disclosure is not limited to these specific examples. Modifications made to these specific examples by those skilled in the art are also included within the scope of this disclosure, as long as they retain the features of this disclosure. The elements, their arrangement, conditions, shapes, etc., of each of the aforementioned specific examples are not limited to those illustrated and can be modified as appropriate. The elements of each of the aforementioned specific examples can be combined in different ways as appropriate, as long as no technical inconsistencies arise.

[0147] The pump 1 according to this embodiment only needs to be capable of dispensing fluid in the flow path 5, and the structure of the pump 1 may be other than the configuration described above. For example, in the above embodiment, a configuration in which the intake port 3 is located on the side surface 23 of the housing 2 and the discharge port 4 is located on the side surface 24 was illustrated, but the arrangement of the intake port 3 and the discharge port 4 may be changed as desired.

[0148] Furthermore, although the above embodiment illustrates a configuration in which both the first pump chamber 7 and the second pump chamber 8 are arranged on the axis of symmetry CA, the arrangement of the first pump chamber 7 and the second pump chamber 8 is limited to at least the fourth flow path 54 and the fifth flow path 55, and may be at positions other than the axis of symmetry CA.

[0149] Furthermore, although the above embodiment illustrates a configuration in which two pistons, first pistons 71, 81 and second pistons 72, 82, are arranged in each pump chamber 7, 8, a configuration in which only a single piston is installed in one pump chamber is also acceptable.

[0150] Furthermore, although the above embodiment illustrates a configuration in which two pump chambers 7 and 8 are provided within the flow path 5, a configuration in which only a single pump chamber is provided within the flow path 5 is also acceptable.

[0151] Furthermore, in the above embodiment, a configuration was illustrated in which two movable parts, a first movable part (first movable plate 62 and first leaf spring 64) and a second movable part (second movable plate 63 and second leaf spring 65), are provided with a single fixed part including the electromagnet 61 in between. However, a configuration in which only one of the pair of movable parts is provided is also acceptable.

[0152] In the above embodiment, a configuration using first pistons 71, 81 and second pistons 72, 82 was illustrated as an example of a "volume changing member that operates to reduce or increase the volume of pump chambers 7, 8," but elements other than pistons may also be used. Examples of elements other than pistons for the volume changing member include diaphragms and bellows. [Explanation of symbols]

[0153] 1 pump 5 channels 54 Fourth channel 55 Fifth channel 6. Resonant Actuator 61 Electromagnet (fixed part) 62 First movable plate (movable part) 63. Second movable plate (movable part) 64. First leaf spring (movable part) 65. Second leaf spring (movable part) 7. Pump Room 1 71 First piston (volume changing member) 72. Second piston (volume changing member) 74 Inhalation valve 741 1st valve chamber 742 First valve seat 743 First tapered surface 744 First valve body 745 1st closing section 746 First outer edge 747 1st connection part 748 Gap 75 Discharge valve 751 2nd valve chamber 752 Second valve seat 753 Second tapered surface 754 Second valve body 755 Second closing part 756 Second outer edge 757 2nd connection part 758 Gap 8. Pump Room No. 2 81. First piston (volume changing member) 82. Second piston (volume changing member) 9 Support (fixed object) 100 Espresso Machines (Beverage Dispensing Devices) 101 Tank 104 Extraction unit (dispensing section)

Claims

1. A fluid channel and A pump chamber provided on the aforementioned flow path, A volume changing member that operates to reduce or increase the volume of the pump chamber, A suction valve is provided on the upstream side of the flow path in the pump chamber, A discharge valve provided on the downstream side of the flow path in the pump chamber, Equipped with, The intake valve has a first valve chamber shaped like a frustoconical pyramidal structure and a first valve body disposed within the first valve chamber. The first valve chamber has a first valve seat on which the first valve body is installed in the portion corresponding to the bottom surface of the frustoconical shape, the first valve seat is in communication with the upstream side of the flow path, the first tapered surface corresponding to the side surface of the frustoconical shape decreases in diameter as it proceeds toward the pump chamber, and the portion corresponding to the top surface of the frustoconical shape is in communication with the pump chamber. The first valve body is A first closing portion is formed to be able to close an opening in the first valve seat that communicates with the upstream side of the flow path, and is positioned in the central part of the first valve body, An annular first outer edge portion is arranged on the outer circumferential side of the first closing portion, It has a plurality of first connecting portions that are arranged with a gap between them and the first outer edge portion, connecting the first closing portion and the first outer edge portion, and are formed to be elastically deformable, The discharge valve has a frustoconical second valve chamber and a second valve body disposed within the second valve chamber. The second valve chamber has a second valve seat on which the second valve body is installed in the portion corresponding to the bottom surface of the frustoconical shape, the second valve seat is in communication with the pump chamber, the second tapered surface corresponding to the side surface of the frustoconical shape decreases in diameter as it proceeds downstream of the flow path, and the portion corresponding to the top surface of the frustoconical shape is in communication with the downstream side of the flow path. The second valve body is A second closing portion is formed to be able to close the opening in the second valve seat that communicates with the pump chamber, and is located in the center of the second valve body, The annular second outer edge portion is arranged on the outer circumferential side of the second closing portion, It has a plurality of second connecting portions that are arranged with gaps between them and the second outer edge portion, connecting the second closing portion and the second outer edge portion, and are formed to be elastically deformable, When the volume changing member moves in the direction of increasing the volume of the pump chamber, The first closing portion of the first valve body is drawn towards the pump chamber and moves to a first position where it is separated from the first valve seat of the first valve chamber and does not contact the first tapered surface of the first valve chamber, thereby opening the intake valve and drawing the fluid into the pump chamber from the upstream side of the flow path through the gaps between the plurality of first connecting portions of the first valve body. The second closing portion of the second valve body is drawn towards the pump chamber and moves to a position where it contacts the second valve seat of the second valve chamber, thereby blocking the communication portion between the pump chamber and the second valve chamber, and the discharge valve closes, stopping the discharge of the fluid from the pump chamber to the downstream side of the flow path. When the volume changing member moves in the direction of reducing the volume of the pump chamber, The second closing portion of the second valve body is pressed downstream of the flow path and moves to a second position where it is separated from the second valve seat of the second valve chamber and does not contact the second tapered surface of the second valve chamber, thereby opening the discharge valve and discharging the fluid from the pump chamber to the downstream side of the flow path through the gaps between the plurality of second connecting portions of the second valve body. The first closing portion of the first valve body is pressed upstream of the flow path and moves to a position where it contacts the first valve seat of the first valve chamber, thereby blocking the communication between the upstream side of the flow path and the first valve chamber, and the suction valve closes, stopping the suction of the fluid from the upstream side of the flow path into the pump chamber. pump.

2. The plurality of first connecting portions of the first valve body are formed such that the stress is adjusted so that the first closing portion moves to a first position in accordance with the pressure of the fluid when the first closing portion is drawn towards the pump chamber side. The plurality of second connecting portions of the second valve body are formed such that the stress is adjusted so that the second closing portion moves to the second position in response to the fluid pressure when the second closing portion is pressed downstream of the flow path. The pump according to claim 1.

3. The plurality of first connecting portions of the first valve body are formed to be elastically deformable from a first reference position in which the first closing portion contacts the first valve seat to the first position, and the first closing portion is formed to be elastically return from the first position to the first reference position. The plurality of second connecting portions of the second valve body are formed to be elastically deformable from a second reference position in which the second closing portion contacts the second valve seat to the second position, and the second closing portion is formed to be elastically return from the second position to the second reference position. The pump according to claim 1.

4. The plurality of first connecting portions of the first valve body are formed in an arm shape that extends along the circumferential direction of the first valve body, The plurality of second connecting portions of the second valve body are formed in an arm shape that extends along the circumferential direction of the second valve body. The pump according to claim 1.

5. The volume changing member is a piston. The pump in question is, The fixed part on which the electromagnet is installed, A movable part is attracted to the fixed part by the magnetic field generated when the electromagnet is energized, and vibrates to move away from the fixed part by the biasing force generated when the electromagnet is not energized. Equipped with, The piston operates to reduce the volume of the pump chamber in response to the movement of the movable part being attracted to the fixed part, and operates to increase the volume of the pump chamber in response to the movement of the movable part moving away from the fixed part. The pump according to claim 1.

6. A tank for storing beverages, A pump according to any one of claims 1 to 4, which sucks the beverage in the tank and discharges it at a predetermined pressure, A discharge unit for discharging the beverage discharged from the pump, A beverage dispensing device equipped with the following features.

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