JP4634085B2 - Multi-channel pump, fuel cell and control method thereof - Google Patents

Description

  The present invention relates to a multichannel pump, a fuel cell, and a control method thereof used for a direct methanol fuel cell.

  In the present specification, the “multi-channel pump” refers to a pump having a plurality of outflow passages for discharging fluid.

  As a power source for portable electronic devices that support the information society in recent years, or as a power source for coping with air pollution and global warming, expectations for fuel cells are increasing. Among these fuel cells, direct methanol fuel cells (hereinafter referred to as DMFC) that generate electricity by directly extracting protons from methanol do not require a reformer and have a high volumetric energy density. Therefore, the expectation of application to portable electronic devices is increasing.

  Such a DMFC includes an electromotive device having an electromotive unit (cell), a container for methanol or a methanol aqueous solution (hereinafter referred to as methanol in this specification), and a liquid feed pumping methanol from the container. Various pumps have been proposed (see, for example, Patent Documents 1, 2, and 3).

The cell is disposed between an anode electrode (fuel electrode) having an anode current collector and an anode catalyst layer, a cathode electrode (air electrode) having a cathode current collector and a cathode catalyst layer, and an anode electrode and a cathode electrode. An electrolyte membrane. Methanol is supplied to the anode electrode by a liquid feed pump, and air is supplied to the cathode electrode by an air supply pump.
JP 2004-71262 A JP 2004-127618 A JP 2004-152741 A

  In the anode electrode of the cell which is the electromotive part of the DMFC described above, the activity of methanol oxidation is low and voltage loss occurs. There is also a voltage loss at the cathode electrode. Therefore, the output that can be extracted from one cell is extremely low. Accordingly, in order to obtain a predetermined output, a plurality of cells are used in the DMFC.

  Further, when excessive methanol is supplied to the anode electrode, so-called crossover occurs in which a part of the methanol is unreacted and leaks to the cathode electrode through the electrolyte membrane. This crossover lowers the potential of the cathode electrode, and thus contributes to the above-described voltage loss at the cathode electrode. In addition, unreacted methanol that has reached the cathode electrode reacts with oxygen without generating power and generates heat, so that power generation efficiency in the cell is significantly reduced due to crossover. Therefore, it is preferable not to supply excess methanol to the anode electrode.

  From the above, as a liquid feed pump for supplying methanol to the anode electrode of a cell, a liquid feed pump having characteristics that it can be discharged to a plurality of cells and an appropriate amount of methanol can be discharged with high accuracy is desired. However, no specific proposal has been made regarding a liquid feed pump having such characteristics.

  Accordingly, an object of the present invention is to provide a multi-channel pump, a fuel cell, and a control method therefor that can accurately discharge an appropriate amount of fluid while having a plurality of outflow passages for discharging fluid.

  Another object of the present invention is to provide a multi-channel pump, a fuel cell, and a control method thereof that can be mounted on a small DMFC or the like used for portable electronic devices.

In order to solve the above problems, a multi-channel pump according to the present invention includes a pump chamber, an inflow path connected to the pump chamber, and two or more outflows connected to the pump chamber via an outflow side active valve. And a movable body that changes the volume of the pump chamber. The movable body changes the volume of the pump chamber by a reciprocating motion, and one end side of the inflow path is connected to the end via the inflow side active valve. It is connected to a pump chamber.

In order to solve the above problems, in the present invention, an anode having an anode current collector and an anode catalyst layer, a cathode having a cathode current collector and a cathode catalyst layer, the anode and the cathode A fuel cell having a cell including an electrolyte membrane disposed between electrodes, and having a liquid feed pump for supplying liquid to the anode electrode and an air supply pump for supplying air to the cathode electrode. The liquid feed pump has a pump chamber, an inflow passage connected to the pump chamber, two or more outflow passages connected to the pump chamber via an outflow side active valve, and a volume change in the pump chamber. And a movable body that changes the volume of the pump chamber by a reciprocating motion, and one end side of the inflow path is connected to the pump chamber via an inflow side active valve. You .

In the present invention, the multi-channel pump includes two or more outflow passages connected to the pump chamber via an outflow side active valve. Therefore, while the outflow side active valve is closed, the backflow of fluid can be reliably prevented. Moreover, the discharge destination of the fluid discharged from the outflow path can be controlled by the outflow side active valve. Further, the multi-channel pump includes one movable body that reciprocates to change the volume of the pump chamber . Since the fluid is discharged from each outflow passage by one movable body, the discharge performance becomes uniform, variation in the discharge amount from each outflow passage can be suppressed, and an appropriate amount of fluid can be discharged accurately. Moreover, in this invention, the inflow path is connected to the pump chamber to which the several outflow path was connected. Therefore, the inflow path can be made common to the plurality of outflow paths, and the configuration of the pump can be simplified. Moreover, when there is one movable body, the configuration of the pump can be simplified. Therefore, the pump can be reduced in size, and can be mounted on a small device such as DMFC used for portable electronic devices. In the fuel cell according to the present invention, methanol or an aqueous methanol solution can be used as the liquid.

Further, according to the multi-channel pump and the fuel cell according to the present invention, the one end side of the inflow path is connected to the pump chamber via the inflow side active valve, and therefore, when connected via the passive valve. In comparison, back flow from the pump chamber to the inflow path can be reliably prevented.

  In the multichannel pump and the fuel cell according to the present invention, it is preferable that two or more inflow paths are provided. If comprised in this way, when a fluid storage container is connected for every inflow path, for example, replacement | exchange of a fluid storage container will become easy.

  In the multi-channel pump and the fuel cell according to the present invention, the pump chamber is formed at a substantially center of a base plate in which the two or more inflow passages and the two or more outflow passages are formed, and the two or more inflow passages. The two or more outflow passages may be formed radially from the pump chamber.

  In the control method in the multi-channel pump and the fuel cell having such a configuration, an intake step of opening the inflow side active valve, sucking fluid into the pump chamber by the suction operation of the movable body, and then closing the inflow side active valve; A plurality of discharge steps for sequentially opening predetermined outflow side active valves after the suction step and discharging a predetermined amount of fluid by the discharge operation of the movable body are provided. In such a control method, a fluid necessary for discharging a plurality of times from the outflow passage is sucked in the suction step in the discharge step. Therefore, even if the discharge amount of the fluid discharged from each outflow passage is extremely small, the suction amount can be secured to some extent. Therefore, the capacity of the multi-channel pump can be increased and it becomes easy to provide self-sufficiency performance.

  In this case, the first discharge step among the plurality of discharge steps is to open one outflow side active valve and discharge the fluid from the pump chamber by the discharge operation of the movable body to eliminate the backlash of the pump. The initial discharge step is preferably performed. In such a control method, an initial discharge step for eliminating pump backlash is provided between the suction step and the discharge step. Therefore, in the discharge step, the relationship between the moving amount of the movable body and the discharge amount from the outflow path can be kept linear from the beginning. Therefore, if the amount of movement of the movable body is appropriately controlled, the discharge amount from the outflow passage where the fluid is first discharged in the discharge step can be accurately controlled, and variation in the discharge amount from each outflow passage is reduced. Can be made. Here, `` pump backlash '' refers to a phenomenon in which the moving amount of the movable body and the discharge amount from the outflow path do not have a linear relationship when the movable body shifts from the suction operation to the discharge operation. This is a phenomenon caused by backlash or the like of the mechanism that drives the movable body.

  In the multi-channel pump and the fuel cell according to the present invention, a first flow path having a passive valve that opens toward the inflow direction into the pump chamber on the other end side of the inflow passage, and an outflow direction from the pump chamber It is possible to configure so as to be connected to a second flow path having a passive valve that opens toward the front.

  In the control method of the multi-channel pump and the fuel cell configured as described above, the suction step of opening the inflow side active valve and sucking fluid from the first flow path into the pump chamber by the suction operation of the movable body, And a plurality of discharge steps for sequentially opening predetermined outflow side active valves after the suction step and discharging a predetermined amount of fluid by a discharge operation of the movable body. In such a control method, a fluid necessary for discharging a plurality of times from the outflow passage is sucked in the suction step in the discharge step. Therefore, even if the discharge amount of the fluid discharged from each outflow passage is extremely small, the suction amount can be secured to some extent. Therefore, the capacity of the multi-channel pump can be increased and it becomes easy to provide self-sufficiency performance.

  In this case, the first discharge step among the plurality of discharge steps is to discharge the fluid from the pump chamber by the discharge operation of the movable body to eliminate the pump backlash and then close the inflow side active valve. The initial discharge step is preferable. In such a control method, an initial discharge step for eliminating pump backlash is provided between the suction step and the discharge step. Therefore, in the discharge step, the relationship between the moving amount of the movable body and the discharge amount from the outflow path can be kept linear from the beginning. Therefore, if the amount of movement of the movable body is appropriately controlled, the discharge amount from the outflow passage where the fluid is first discharged in the discharge step can be accurately controlled, and variation in the discharge amount from each outflow passage is reduced. Can be made.

  In the multi-channel pump according to the present invention, the first flow path and the second flow path are connected to a storage container, the first flow path is connected to a lower side of the storage container, and the second flow path is the storage container A configuration connected to the upper side of the container can be adopted. In the multichannel pump and the fuel cell according to the present invention, the first flow path and the second flow path are connected to a storage container that stores methanol or a methanol aqueous solution, and the first flow path is connected to a lower portion of the storage container. In addition, the second flow path may be configured to be connected above the storage container.

  In the multi-channel pump according to the present invention, it is possible to adopt a configuration in which a storage container to which at least one of the two or more inflow paths is connected and a storage container to which the other one inflow path is connected are different. The fuel cell according to the present invention employs a configuration in which a storage container that stores methanol or a methanol aqueous solution to which at least one of the two or more inflow paths is connected is different from a storage container to which the other one inflow path is connected. be able to.

  In the multi-channel pump and the fuel cell according to the present invention, an outlet that is an opening end of the outflow passage, an inlet that is an opening end of the first flow path, and an outlet that is an opening end of the second flow path It is possible to adopt a configuration in which and are formed in the same direction.

  Further, in the multi-channel pump according to the present invention, since the inflow path is connected to the pump chamber to which a plurality of outflow paths are connected, the inflow path can be shared with respect to the plurality of outflow paths. The configuration can be simplified. Further, since there is only one movable body, the configuration of the pump can be simplified. As a result, the pump can be downsized.

In the multichannel pump and the fuel cell according to the present invention, the movable body is preferably a piston that reciprocates in a cylinder connected to the pump chamber. When the movable body is a piston, the movement amount of the piston is relatively easy to control, so that a minute flow rate can be discharged accurately.

In the multi-channel pump and the fuel cell according to the present invention, the piston rod is fixed and the outer periphery is formed with a piston rod, and the female screw that is screwed with the male screw to reciprocate the piston is formed. It is preferable to include a body and a piston drive motor that rotationally drives the rotating body. In this case, since the amount of movement of the piston can be controlled by the pitch of the screw and the amount of rotation of the piston drive motor, a minute flow rate can be accurately discharged with a simple configuration. In the multichannel pump and the fuel cell according to the present invention, the convex portion formed on the piston rod and the concave portion provided on the bracket integrally formed with the drive motor are engaged to prevent the piston from rotating. The structure to comprise can be employ | adopted. In the multi-channel pump and the fuel cell according to the present invention, the piston drive motor is preferably a stepping motor. In this case, the movement amount of the piston can be controlled with higher accuracy.

  As described above, in the multi-channel pump and the fuel cell according to the present invention, since two or more outflow paths are connected to the pump chamber via the outflow side active valve, the outflow side active valve is closed. Thus, the backflow of the fluid can be reliably prevented, and the discharge destination of the fluid discharged from the outflow path can be controlled by the outflow side active valve. Furthermore, in the multi-channel pump of the present invention, the volume of the pump chamber is changed by one movable body, so that the discharge performance is the same, and variation in the discharge amount from each outflow passage can be suppressed. Therefore, an appropriate amount of fluid can be accurately discharged from each outflow passage. Further, in the multi-channel pump and the fuel cell according to the present invention, since the inflow path is connected to the pump chamber to which the plurality of outflow paths are connected, the inflow path can be shared with the plurality of outflow paths. The configuration of the pump can be simplified. Further, since there is only one movable body, the configuration of the pump can be simplified. As a result, the pump can be downsized. Furthermore, in the control method of the present invention, an initial discharge step for eliminating backlash of the pump is provided between the suction step and the discharge step. Therefore, in the discharge step, the moving amount of the movable body and the outflow path are initially set. The relationship with the discharge amount from can be kept linear. Therefore, the discharge amount from the outflow path from which the fluid is first discharged in the discharge step can be accurately controlled, and variations in the discharge amount from each outflow path can be reduced. As a result, an appropriate amount of fluid can be accurately discharged from each outflow passage.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the drawings.

[Basic configuration of multi-channel pump]
FIG. 1 is a conceptual diagram showing a basic configuration of a multi-channel pump according to an embodiment of the present invention.

  The multi-channel pump 1 (pump 1) of this embodiment is used as a liquid feed pump for feeding methanol under pressure in, for example, a DMFC used for portable electronic equipment, and is connected to the pump chamber 2 and the pump chamber 2 And the two or more outflow passages 4 connected to the pump chamber 2 through the outflow side active valve 6, and one movable body 13 that reciprocates to change the volume of the pump chamber 2. Yes. More specifically, two inflow passages 3a and 3b are connected to one pump chamber 2, and eight outflow passages 4a to 4h are connected to the pump chamber 2 via eight outflow side active valves 6a to 6h. Is connected.

  One end side (the upper end side in the figure) of the inflow passages 3a and 3b is connected to the pump chamber 2 via the inflow side active valves 5a and 5b. In addition, first flow paths 8a and 8b (first flow paths) having passive valves 10a and 10b (passive valves 10) that open toward the flow direction into the pump chamber, respectively, at the other ends of the flow paths 3a and 3b. 8) and second flow paths 9a and 9b (second flow paths 9) each having passive valves 11a and 11b (passive valves 11) that open toward the outflow direction from the pump chamber 2 are connected.

  The first flow path 8 and the second flow path 9 can be connected to a methanol storage container (not shown, hereinafter referred to as a storage container). Specifically, the first flow path 8 can be connected to the lower side of the storage container, and the second flow path 9 can be connected to the upper side of the storage container. The passive valve 10 is a rubber valve, for example, and opens when pressure is generated in the direction of methanol suction toward the pump chamber 2, but does not open even when pressure is generated in the direction of methanol discharge toward the storage container. Yes. On the other hand, the passive valve 11 is also a rubber valve, for example, which opens when pressure is generated in the methanol discharge direction toward the container, but does not open even when pressure is generated in the methanol suction direction toward the pump chamber 2. It has become. Accordingly, methanol is sucked from the storage container into the pump chamber 2 through the first flow path 8 and the inflow path 3, and methanol is sucked from the pump chamber 2 through the inflow path 3 and the second flow path 9. Is discharged. In the present embodiment, the first flow path 8a and the second flow path 9a, and the first flow path 8b and the second flow path 9b are each connected to different storage containers.

  The inflow side active valves 5a and 5b can be individually opened and closed by drive actuators (not shown in FIG. 1).

  Each of the eight outflow paths 4a to 4h can be connected to eight cells (not shown) which are the electromotive parts of the DMFC, and methanol discharged from the outflow paths 4a to 4h can be supplied to the anode electrode of the cell. It has become.

  Similarly to the inflow side active valves 5a and 5b, the outflow side active valves 6a to 6h can be individually opened and closed by a drive actuator (not shown in FIG. 1).

  The movable body 13 in this embodiment is a piston that reciprocates in the cylinder 14 connected to the pump chamber 2 (hereinafter referred to as a piston 13). The piston 13 is fixed to the upper end side of the piston rod 15 in the figure. The piston rod 15 is connected to a drive actuator (not shown in FIG. 1), and is reciprocated in the cylinder 14 by the drive actuator.

  In the pump 1 configured as described above, the piston 13 moves downward in the figure when the outflow side active valves 6a to 6h are closed and at least one of the inflow side active valves 5a and 5b is open. Then, methanol is sucked into the pump chamber 2. Further, when the inflow side active valves 5a and 5b are closed and at least one of the outflow side active valves 6a to 6h is in the open state, the piston 13 moves upward in the figure, and methanol is transferred from the pump chamber 2 to the cell. It is discharged toward. Furthermore, when the outflow side active valves 6a to 6h are in the closed state and at least one of the inflow side active valves 5a and 5b is in the open state, when the piston 13 moves upward in the figure, methanol is discharged into the storage container. . A specific control method of the pump 1 will be described in detail later.

[Specific configuration of multi-channel pump]
A specific configuration of the multi-channel pump 1 having the basic configuration described above will be described below. FIG. 2 is a perspective view showing a specific configuration of the multi-channel pump shown in FIG. 1 from the methanol discharge side. FIG. 3 is a perspective view showing the multi-channel pump shown in FIG. 2 from the X direction. 4 is a perspective view showing a Y cross section of the multi-channel pump shown in FIG. FIG. 5 is an exploded perspective view showing the open / close mechanism of the active valve of the multi-channel pump shown in FIG. FIG. 6 is a plan view showing the configuration of the inflow path and the outflow path of the multichannel pump shown in FIG.

(Schematic configuration of multi-channel pump)
2 to 4, in the pump 1, a base portion 24 and a bracket 31 are connected by screws via four support columns 32 to constitute a main body frame, and a base plate 25 constituting the base portion 24 and The drive mechanism of the piston 13 and the opening / closing mechanisms of the inflow side active valves 5a and 5b and the outflow side active valves 6a to 6h are fixedly held on the bracket 31. An example of the flow of methanol in the pump 1 is indicated by an arrow in FIG.

  The bracket 31 includes a semi-cylindrical extending portion 31a that extends downward in FIG. On the inner peripheral side of the extended portion 31a, concave grooves 31b and 31b constituting the rotation stop of the piston 13 are formed at two positions with a pitch of about 180 ° together with a convex portion 18a of the slide plate 18 described later. .

  The base 24 includes a base plate 25 in which the pump chamber 2, the inflow path 3, the outflow path 4, the first flow path 8 and the second flow path 9 are formed, the inflow side active valve 5, and the outflow side active valve 6. Active valve plate 29 integrally provided, valve pressing plate 26 for pressing active valve plate 29, outlet 40 (40 a to 40 h) serving as the open end of outflow passage 4, and suction serving as the open end of first flow path 8. A port 27 in which a port 80 (80a, 80b) and a discharge port 90 (90a, 90b) serving as an opening end of the second flow path 9 are formed, and a port presser plate 28 for pressing the port 27; The holding plate 26, the active valve plate 29, the base plate 25, the port 27, and the port holding plate 28 are laminated in this order.

(Configuration of piston drive mechanism)
The piston 13 is configured to reciprocate inside the cylindrical cylinder 14 by a piston drive motor 51. The cylinder 14 is formed integrally with the base plate 25 so as to be connected to the pump chamber 2 (see FIG. 4). Hereinafter, the configuration of the drive mechanism of the piston 13 will be described.

  The piston drive motor 51 is specifically a stepping motor, and is fixed to the bracket 31 with screws. In this embodiment, the piston drive motor 51 rotates in both directions. A small gear 53 is fixed to the tip of the output shaft of the piston drive motor 51. The idle gear 19 is rotatably held by a fixed shaft 20 fixed to the bracket 31 so as to mesh with the small gear 53. The gear 17 is rotatably held by a bearing 61 fixed to the outer peripheral portion of the cylinder 14 so as to mesh with the idle gear 19.

  The gear 17 is formed in a substantially bottomed cylindrical shape, and a nut 16 as a rotating body on which a female screw 16a is formed is fixed at the center of the bottom. On the other hand, an external thread 15a is formed on the outer periphery of the piston rod 15 to which the piston 13 is fixed at one end, and the external thread 15a and the internal thread 16a are screwed together. Further, on the other end side of the piston rod 15, a slide plate in which convex portions 18 a and 18 a that engage with a concave groove 31 b formed in the extending portion 31 a of the bracket 31 are formed at two positions at a pitch of approximately 180 °. 18 is fixed (see FIG. 3). These convex portions 18a and the concave grooves 31b constitute a rotation stop of the piston 13.

  Further, seal members (oil seals) 63 and 63 for preventing leakage of methanol sucked into the pump chamber 2 are fixed to the outer peripheral side of the piston 13.

  In the drive mechanism of the piston 13 configured as described above, when the piston drive motor 51 rotates, the drive force is transmitted to the gear 17 via the small gear 53 and the idle gear 19. When the driving force of the piston drive motor 51 is transmitted to the gear 17, the nut 16 rotates together with the gear 17. Here, since the piston 13 is stopped at the other end side of the piston rod 15 formed with the male screw 15a to be screwed with the female screw 16a of the nut 16, the rotational motion of the nut 16 is linearly moved by the piston 13. Converted into movement. The piston 13 reciprocates within the cylinder 14 as the piston drive motor 51 rotates in both directions.

(Configuration of active valve open / close mechanism)
The inflow side active valve 5 and the outflow side active valve 6 can be individually opened and closed by a valve opening / closing drive motor 52. The opening / closing mechanism of the inflow side active valve 5 and the outflow side active valve 6 includes a cam 36 and a leaf spring 37 as main components in addition to the valve opening / closing drive motor 52 (see FIG. 5). Hereinafter, the structure of the opening / closing mechanism of the inflow side active valve 5 and the outflow side active valve 6 will be described.

  The valve opening / closing drive motor 52 is specifically a stepping motor, and is fixed to the bracket 31 with screws. In this embodiment, the valve opening / closing drive motor 52 rotates in one direction (counterclockwise in FIG. 5). A small gear 54 is fixed to the tip of the output shaft of the valve opening / closing drive motor 52. The cam 36 includes a gear 36 a that meshes with the small gear 54, and is rotatably held by a bearing 62 that is fixed to the outer peripheral portion of the cylinder 14. In this embodiment, the cam 36 is rotated clockwise in FIG. 5 by the valve opening / closing drive motor 52. The bearing 61 and the bearing 62 are fixed to the outer periphery of the cylinder 14 so as to overlap in the moving direction of the piston 13, and the cam 36 and the gear 17 are arranged so as to overlap in the moving direction of the piston 13. (See FIG. 4).

  The cam 36 is formed in a cylindrical shape having a flange portion, and the gear 36a is formed on the outer peripheral surface of the flange portion. A pin 38 for opening and closing the inflow side active valve 5 and the outflow side active valve 6 is fixed to the outer peripheral surface of the cam 36 so as to protrude in the radial direction.

  As shown in FIG. 5, the leaf spring 37 includes a ring-shaped center portion 37a, ten arm portions 37b extending spirally from the center portion 37a radially outward, and arm portions 37b. A valve holding portion 37c formed at the tip, and a tip portion 37d formed by bending upward from the radial outer end of the valve holding portion 37c in the figure and then bending toward the center portion 37a. . A sliding contact portion 37d1 that is in sliding contact with the pin 38 and a guide portion 37d2 that is bent obliquely upward in the drawing from the sliding contact portion 37d1 and guides the pin 38 to the sliding contact portion 37d1 are formed at the distal end portion 37d. For convenience, only a part of the arm portion 37b, the valve holding portion 37c, and the tip end portion 37d of the leaf spring 37 are denoted by reference numerals.

  The leaf spring 36 is fixed to the outer peripheral surface of the cylinder 14 at the central portion 37a. In a state where the leaf spring 36 is fixed to the outer peripheral surface of the cylinder 14 and the cam 36 is held by the bearing 62 fixed to the outer peripheral portion of the cylinder 14, the pin 38 is slidably contacted in the vertical direction in FIG. It is located above the lower surface of 37d1 and is located below the upper end of the guide portion 37d2. Therefore, when the cam 36 rotates, the pin 38 is guided to the lower surface of the sliding contact portion 37d1 by the guide portion 37d2, whereby the arm portion 37b is bent, and the valve holding portion 37c and the tip portion 37d are lifted upward in FIG. It has become.

  The active valve plate 29 is made of, for example, rubber, and integrally includes inflow side active valves 5a and 5b and outflow side active valves 6a to 6h that are concentric and formed at an equal angular pitch. The inflow side active valves 5a and 5b and the outflow side active valves 6a to 6h are normally urged to be closed by the elasticity of rubber. Specifically, it is biased downward in FIG. Furthermore, the upper ends of the inflow side active valves 5 a and 5 b and the outflow side active valves 6 a to 6 h are respectively held by the valve holding portions 37 c of the leaf springs 37.

  In the opening / closing mechanism of the inflow side active valve 5 and the outflow side active valve 6 thus configured, the driving force of the valve opening / closing drive motor 52 is transmitted to the gear 36 a via the small gear 54. When the driving force is transmitted to the gear 36a, the cam 36 rotates, and the pin 38 rotates accordingly. The pin 38 is guided to the lower surface of the sliding contact portion 37d1 by the guide portion 37d2, whereby the arm portion 37b is bent and the valve holding portion 37c is lifted upward in FIG. That is, any one of the inflow side active valves 5a and 5b or the outflow side active valves 6a to 6h held by the valve holding portion 37c is lifted upward to be in an open state. Further, when the pin 38 further rotates and the pin 38 is detached from the lower surface of the sliding contact portion 37d1, any of the active valves that are in the open state is closed by the urging force. When the pin 38 further rotates, the next guide portion 37d2 guides the pin 38 to the lower surface of the sliding contact portion 37d1, and any one of the active valves is opened as described above. These operations are repeated, and the inflow side active valves 5a and 5b and the outflow side active valves 6a to 6h respectively held in the valve holding portion 37c sequentially open and close.

(Configuration of inflow and outflow channels)
The pump chamber 2, the inflow path 3, the outflow path 4, the first flow path 8, and the second flow path 9 are formed in the base plate 25 as described above.

  The pump chamber 2 is formed in a substantially central portion of the base plate 25 and includes ten passages extending radially toward the inflow side active valves 5a and 5b and the outflow side active valves 6a to 6h ( (See FIG. 6). The pump chamber 2 may be provided with a detector (not shown) that detects the presence or absence of bubbles.

  The outflow paths 4 a to 4 h are formed so as to go to the outside of the base plate 25 from the outflow side active valves 6 a to 6 h. The inflow passages 3a and 3b are respectively formed between the inflow side active valves 5a and 5b and the passive valves 10a and 11a, 10b and 11b formed in an umbrella shape (see FIGS. 4 and 6). Further, first passages 8a and 8b are formed outside the passive valves 10a and 10b, and first passages 9a and 9b are formed outside the passive valves 11a and 11b, respectively.

[Control method of multi-channel pump]
FIG. 7 is a timing chart for explaining a control method of the multi-channel pump shown in FIG.

  In this embodiment, the pump 1 opens the inflow-side active valve 5, and performs a suction operation of the piston 13 to suck methanol into the pump chamber 2 from the first flow path 8. After the suction step, the piston 13 After discharging methanol from the pump chamber 2 to the second flow path 9 to eliminate the backlash of the pump 1, the initial discharge step S2 for closing the inflow side active valve 5 and the initial discharge step S2, It is controlled by a control method including a discharge step S3 that sequentially opens the predetermined outflow side active valve 6 and discharges a predetermined amount of methanol by the discharge operation of the piston 13. Hereinafter, the control method will be described in detail.

  In FIG. 7, in the timing chart of the piston drive motor 51, the hatched portion from the center line indicates the state of the discharge operation in which the piston 13 operates in the discharge direction (left direction in FIG. 4). The hatched portion on the upper side from the center line indicates the state of the suction operation in which the piston 13 operates in the suction direction (right direction in FIG. 4). Further, in the timing chart of the valve opening / closing drive motor 52, the hatched portion indicates a state where each active valve is open.

  In the initial state, the inflow side active valve 5 and the outflow side active valve 6 are all closed. In this state, first, the valve opening / closing drive motor 52 is driven to open the inflow side active valve 5b. Thereafter, the piston drive motor 51 moves the piston 13 in the methanol discharge direction. The piston 13 is discharged to the top dead center (origin), and the origin of the piston 13 is returned (origin return step S0). At this time, methanol is discharged from the pump chamber 2 to the second flow path 9b through the opened passive valve 11b.

  Subsequently, methanol is sucked into the pump chamber 2 (suction step S1). More specifically, the piston drive motor 51 is driven while the inflow side active valve 5b is opened, and the piston 13 is moved in the methanol suction direction. For example, the suction operation of the piston 13 is performed up to the bottom dead center of the piston 13. Methanol is sucked into the pump chamber 2 from the first flow path 8b through the passive valve 10b opened by the suction operation of the piston 13.

  Subsequently, in the discharge operation of the piston 13, methanol is discharged from the pump chamber 2 to eliminate the backlash of the pump 1, and then the inflow side active valve 5b is closed (initial discharge step S2). More specifically, the piston 13 is moved in the methanol discharge direction by the piston drive motor 51 until the backlash of the pump 1 is eliminated while the inflow side active valve 5b is kept open. By the discharge operation of the piston 13, methanol is discharged to the second flow path 9 b through the opened passive valve 11 b, and then the inflow side active valve 5 b is closed by the valve opening / closing drive motor 52.

  Subsequently, the predetermined outflow side active valve 6 is sequentially opened, and a predetermined amount of methanol is discharged by the discharge operation of the piston 13 (discharge step S3). More specifically, the outflow side active valve 6f is first opened by the valve opening / closing drive motor 52, and the piston drive motor 51 performs the discharge operation of the piston 13 to discharge a predetermined amount of methanol from the outflow passage 4f. Thereafter, the outflow side active valve 6f is closed and the outflow side active valve 6g is opened by the valve opening / closing drive motor 52, the discharge operation of the piston 13 is performed, and a predetermined amount of methanol is discharged from the outflow passage 4g. In this way, the valve opening / closing drive motor 52 sequentially opens and closes the outflow side active valves 6f, 6g, 6h, 6a, 6b, 6c, 6d, and 6e in this order, and the discharge operation of the piston 13 A predetermined amount of methanol is discharged in this order from 4f, 4g, 4h, 4a, 4b, 4c, 4d, and 4e.

  Here, in the case where a detector for detecting the presence or absence of bubbles is provided in the pump chamber 2, when this detector detects bubbles, for example, the inflow side active valve 5b is opened and the discharge operation of the piston 13 is performed. By doing so, air bubbles can be discharged to the second flow path 9b through the passive valve 11b in the open state. Further, when the pump 1 is started or after replacement of the storage container, it is possible to discharge the bubbles by the same operation.

  When the configuration of the multi-channel pump 1 shown in FIGS. 2 to 6 is employed, the opening / closing operation of the inflow side active valve 5a that is not used in the series of operations described above is also performed by the valve opening / closing drive motor 52. It will be. However, if the piston 13 is not moved when the inflow side active valve 5a is in the open state, the above-described series of operations will not be affected.

[Main effects of this embodiment]
As described above, since the multi-channel pump 1 of this embodiment includes the outflow side active valves 6a to 6h, it is possible to reliably prevent the backflow of methanol from the outflow paths 4a to 4h to the pump chamber 2. it can. Further, the discharge destination of methanol discharged from the outflow paths 4a to 4h can be controlled by the outflow side active valves 6a to 6h. Further, in the multi-channel pump 1, methanol is discharged from each of the outflow paths 4 a to 4 h by the discharge operation of one piston 13. Therefore, compared with the case where a piston is provided for each of the outflow paths 4a to 4h, the discharge performance becomes uniform, and variation in the discharge amount from each of the outflow paths 4a to 4h can be suppressed. Therefore, the multi-channel pump 1 can accurately discharge an appropriate amount of methanol.

  In this embodiment, two inflow passages 3a and 3b are connected to the pump chamber 2 to which the eight outflow passages 4a to 4h are connected. Therefore, the inflow paths 3a and 3b can be used in common for the plurality of outflow paths 4a to 4h, and the configuration of the pump 1 can be simplified. Further, since the number of pistons 13 is one, the configuration of the pump 1 can be simplified. Therefore, the pump 1 can be miniaturized, and can be mounted on a small device such as a DMFC used in a portable electronic device.

  In this embodiment, the drive mechanism of the piston 13 includes a piston rod 15 having a male screw 15a formed on the outer periphery, a nut 16 having a female screw 16a screwed to the male screw 15a, and the nut 16 via a gear 17 or the like. And a piston drive motor 51 that rotates. Therefore, the movement amount of the piston 13 can be controlled by the screw pitch and the rotation amount of the piston drive motor 51. Therefore, a minute flow rate can be discharged from the outflow paths 4a to 4h. In addition, the accuracy of the discharge flow rate can be increased. In particular, in this embodiment, since the piston drive motor 51 is a stepping motor, the movement amount of the piston 13 can be controlled with higher accuracy. For example, in the pump 1 of this embodiment, a minute flow rate of 0.01 cc can be accurately discharged from each outflow passage 4a to 4h. It is also possible to discharge a minute flow rate intermittently.

  In this embodiment, the multi-channel pump 1 includes two inflow passages 3a and 3b. Therefore, when the storage container is connected to each of the inflow passages 3a and 3b, the replacement operation of the storage container becomes easy.

  In this embodiment, one end side of the inflow passages 3a and 3b is connected to the pump chamber 2 through the inflow side active valves 5a and 5b. Therefore, the backflow from the pump chamber 2 to the inflow passages 3a and 3b can be reliably prevented.

  Moreover, in the control method of the multi-channel pump 1 in this embodiment, the initial discharge step S2 for eliminating the backlash of the pump 1 is provided between the suction step S1 and the discharge step S3. Therefore, in the discharge step S3, the relationship between the movement amount of the piston 13 and the discharge amount from the outflow passages 4a to 4h can be kept linear from the beginning. Therefore, if the movement amount of the piston 13 is appropriately controlled, the discharge amount from the outflow passage 4f where the fluid is first discharged in the discharge step S3 can be controlled with high accuracy, and the discharge from the outflow passages 4a to 4h. Variation in the amount can be reduced.

  Furthermore, in the control method of the multi-channel pump 1 in the present embodiment, in the discharge step S3, methanol necessary for discharging a plurality of times from the outflow passages 4a to 4h is sucked in the suction step S1. Therefore, even if the discharge amount of methanol discharged from each of the outflow passages 4a to 4h is extremely small, the suction amount can be secured to some extent. For example, even if each discharge amount from each outflow passage 4a to 4h is 1 (μl), the suction amount can be 8 (μl). Therefore, the capacity | capacitance of the pump 1 can be enlarged and it becomes easy to provide self-sufficiency performance.

[Other embodiments]
The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention.

  For example, the multi-channel pump 1 having the above-described configuration is a piston-type pump using the piston 13 as a movable body, but is not limited to the piston-type pump, and is a diaphragm-type pump including only one movable body. It may be. Moreover, the pump which employ | adopted another system may be sufficient.

  In the above-described embodiment, the inflow side active valve 5 and the outflow side active valve 6 are opened / closed by the valve opening / closing drive motor 52 which is a common drive actuator. However, a drive actuator is provided for each active valve. Alternatively, a plurality of drive actuators for opening and closing several active valves may be provided.

  Furthermore, the piston drive motor 51 is not limited to a stepping motor, and other motors can be used. The drive actuator for the piston 13 is not limited to a motor, and various drive actuators can be used.

  Furthermore, in the embodiment described above, the two inflow paths 3a and 3b are provided, but the number of inflow paths may be one. Conversely, three or more inflow paths may be provided.

  Moreover, the control method of the multichannel pump 1 is not limited to the control method described above. For example, the inflow side active valve 5 is opened, methanol is sucked into the pump chamber 2 by the suction operation of the piston 13, and then the inflow side active valve 5 is closed. , The initial discharge step for discharging methanol from the pump chamber 2 by the discharge operation of the piston 13 to eliminate the backlash of the pump 1, and after the initial discharge step, the predetermined outflow side active valve 6 is sequentially opened, The pump 1 may be controlled by a control method including a discharge step of discharging a predetermined amount of methanol by the discharge operation of the piston 13.

  Also in this case, an initial discharge step for eliminating the backlash of the pump 1 is provided between the suction step and the discharge step. Therefore, in the discharge step, the movement amount of the piston 13 and the outflow passage 4 from the beginning are provided. The relationship with the discharge amount can be kept linear, and variations in the discharge amount from each outflow passage 4 can be reduced. Since the methanol required for discharging from the outflow passage 4 a plurality of times in the discharge step is sucked in the inhalation step, even if the discharge amount of methanol discharged from each outflow passage 4 is extremely small, the inhalation amount Can be secured to some extent. Therefore, the capacity | capacitance of the pump 1 can be enlarged and it becomes easy to provide self-sufficiency performance.

  Furthermore, the fluid used is not limited to methanol or an aqueous methanol solution, but may be ethanol (ethyl alcohol) or an aqueous solution thereof, or other liquid.

  Also, the use is not limited to the fuel cell. For example, in the field of chemical substance analyzers, it may be used as a substitute for a plurality of syringe pumps used in a trace reagent dropping device.

It is a conceptual diagram which shows the basic composition of the multichannel pump concerning embodiment of this invention. FIG. 2 is a perspective view showing a specific configuration of the multi-channel pump shown in FIG. 1 from the methanol discharge side. FIG. 3 is a perspective view showing the multi-channel pump shown in FIG. 2 from the X direction. FIG. 3 is a perspective view showing a Y cross section of the multi-channel pump shown in FIG. 2. FIG. 3 is an exploded perspective view showing an open / close mechanism of an active valve of the multi-channel pump shown in FIG. 2. It is a top view which shows the structure of the inflow path and outflow path of the multichannel pump shown in FIG. It is a timing chart explaining the control method of the multi-channel pump shown in FIG.

1 Multi-channel pump 2 Pump chamber 3 (3a, 3b) Inflow passage 4 (4a-4h) Outflow passage 5 (5a, 5b) Inflow side active valve 6 (6a-6h) Outflow side active valve 8 (8a, 8b) 1 flow path 9 (9a, 9b) 2nd flow path 10 (10a, 10b), 11 (11a, 11b) Passive valve 13 Piston (movable body)
14 Cylinder 15 Piston rod 15a Male thread 16 Nut (Rotating body)
16a female screw 51 piston drive motor S1 suction step S2 initial discharge step S3 discharge step

Claims (33)

A pump room,
An inflow channel connected to the pump chamber;
Two or more outflow passages connected to the pump chamber via an outflow side active valve;
A movable body for changing the volume of the pump chamber ,
The movable body changes the volume of the pump chamber by a reciprocating motion,
One end side of the inflow path is connected to the pump chamber via an inflow side active valve. The multichannel pump according to claim 1, comprising two or more inflow paths. The pump chamber is formed at a substantially center of a base plate in which the two or more inflow passages and the two or more outflow passages are formed, and the two or more inflow passages and the two or more outflow passages are formed from the pump chamber. The multi-channel pump according to claim 2, wherein the multi-channel pump is formed in a radial shape. On the other end side of the inflow path, a first flow path having a passive valve that opens toward the inflow direction to the pump chamber and a second flow path having a passive valve that opens toward the outflow direction from the pump chamber. The multi-channel pump according to claim 1, wherein the multi-channel pump is connected to the multi-channel pump. The first channel and the second channel are connected to a storage container,
The first flow path is connected to the lower side of the container;
The multi-channel pump according to claim 4, wherein the second flow path is connected above the container. 6. The multichannel pump according to claim 5, wherein a storage container to which at least one of the two or more inflow paths is connected is different from a storage container to which the other one inflow path is connected. An outlet that is an open end of the outflow passage, an inlet that is an open end of the first flow path, and a discharge port that is the open end of the second flow path are formed in the same direction. The multi-channel pump according to claim 4 or 5. The multi-channel pump according to any one of claims 1 to 7, wherein the movable body is a piston that reciprocates in a cylinder connected to the pump chamber. A piston rod in which the piston is fixed and a male screw is formed on the outer periphery thereof, a rotating body in which a female screw is formed to be screwed with the male screw to reciprocate the piston, and a piston drive that rotationally drives the rotating body The multichannel pump according to claim 8, further comprising a motor. The convex part formed in the said piston rod and the recessed part provided in the bracket comprised integrally with the said drive motor engage, and comprise the rotation prevention of the said piston. Multi-channel pump. The multi-channel pump according to claim 9, wherein the piston drive motor is a stepping motor. The multi-channel pump according to any one of claims 1 to 11, further comprising a detector that uses liquid as a fluid and detects the presence or absence of bubbles in the pump chamber. A control method for a multi-channel pump according to claim 1,
An inhalation step of opening the inflow side active valve, inhaling fluid into the pump chamber by the inhalation operation of the movable body, and then closing the inflow side active valve;
A control method for a multi-channel pump, comprising a plurality of discharge steps for sequentially opening a predetermined outflow side active valve after the suction step and discharging a predetermined amount of fluid by a discharge operation of the movable body. The first discharge step among the plurality of discharge steps is an initial discharge in which one outflow side active valve is opened and fluid is discharged from the pump chamber by the discharge operation of the movable body to eliminate pump backlash. The method of controlling a multi-channel pump according to claim 13, wherein the method is a step. A control method for a multi-channel pump according to claim 4,
A suction step of opening the inflow side active valve and sucking fluid from the first flow path into the pump chamber by the suction operation of the movable body;
A control method for a multi-channel pump, comprising: a plurality of discharge steps for sequentially opening a predetermined outflow side active valve after the suction step and discharging a predetermined amount of fluid by a discharge operation of the movable body. Of the plurality of discharge steps, the first discharge step is an initial discharge step of closing the inflow side active valve after discharging the fluid from the pump chamber by the discharge operation of the movable body to eliminate pump backlash. The method for controlling a multi-channel pump according to claim 15, wherein: A cell comprising an anode electrode having an anode current collector and an anode catalyst layer, a cathode electrode having a cathode current collector and a cathode catalyst layer, and an electrolyte membrane disposed between the anode electrode and the cathode electrode Have
A fuel cell comprising a liquid feed pump for supplying a liquid to the anode electrode and an air supply pump for supplying air to the cathode electrode,
The liquid feed pump includes a pump chamber, an inflow passage connected to the pump chamber, two or more outflow passages connected to the pump chamber via an outflow side active valve, and a movable chamber that changes the volume of the pump chamber. With body,
The movable body changes the volume of the pump chamber by a reciprocating motion,
One end side of the inflow path is connected to the pump chamber via an inflow side active valve. The fuel cell according to claim 17, comprising two or more inflow paths. The pump chamber is formed at a substantially center of a base plate in which the two or more inflow passages and the two or more outflow passages are formed, and the two or more inflow passages and the two or more outflow passages are formed from the pump chamber. The fuel cell according to claim 18, wherein the fuel cell is formed radially. On the other end side of the inflow path, a first flow path having a passive valve that opens toward the inflow direction to the pump chamber and a second flow path having a passive valve that opens toward the outflow direction from the pump chamber. The fuel cell according to any one of claims 17 to 19, characterized by being connected to each other. The liquid is methanol or an aqueous methanol solution,
The first flow path and the second flow path are connected to a storage container that stores methanol or an aqueous methanol solution,
The first flow path is connected to the lower side of the container;
21. The fuel cell according to claim 20, wherein the second flow path is connected above the container. The fuel according to claim 21, wherein a storage container for storing methanol or a methanol aqueous solution to which at least one of the two or more inflow paths is connected is different from a storage container to which the other one inflow path is connected. battery. An outlet that is an open end of the outflow passage, an inlet that is an open end of the first flow path, and a discharge port that is the open end of the second flow path are formed in the same direction. The fuel cell according to claim 20 or 21. The fuel cell according to any one of claims 17 to 20, wherein the liquid is methanol or an aqueous methanol solution. The fuel cell according to any one of claims 17 to 24, wherein the movable body is a piston that reciprocates in a cylinder connected to the pump chamber. A piston rod on which the piston is fixed and a male screw is formed on the outer periphery, a rotating body formed with a female screw that is screwed with the male screw to reciprocate the piston, and a piston drive that rotationally drives the rotating body 26. The fuel cell according to claim 25, further comprising a motor. 27. The rotation prevention of the piston according to claim 26, wherein a convex portion formed on the piston rod and a concave portion provided in a bracket integrally formed with the drive motor are engaged to constitute a detent of the piston. Fuel cell. 28. The fuel cell according to claim 27, wherein the piston drive motor is a stepping motor. The fuel cell according to any one of claims 17 to 28, further comprising a detector that uses a liquid as a fluid and detects the presence or absence of bubbles in the pump chamber. A fuel cell control method according to claim 17,
An inhalation step of opening the inflow side active valve, inhaling fluid into the pump chamber by the inhalation operation of the movable body, and then closing the inflow side active valve;
A fuel cell control method comprising a plurality of discharge steps for sequentially opening a predetermined outflow side active valve after the suction step and discharging a predetermined amount of fluid by a discharge operation of the movable body. The first discharge step among the plurality of discharge steps is an initial discharge in which one outflow side active valve is opened and fluid is discharged from the pump chamber by the discharge operation of the movable body to eliminate pump backlash. 31. The method of controlling a fuel cell according to claim 30, wherein the method is a step. The method for controlling a fuel cell according to claim 20,
A suction step of opening the inflow side active valve and sucking fluid from the first flow path into the pump chamber by the suction operation of the movable body;
A fuel cell control method comprising: a plurality of discharge steps for sequentially opening predetermined outflow side active valves after the suction step and discharging a predetermined amount of fluid by a discharge operation of the movable body. Of the plurality of discharge steps, the first discharge step is an initial discharge step of closing the inflow side active valve after discharging the fluid from the pump chamber by the discharge operation of the movable body to eliminate pump backlash. The fuel cell control method according to claim 32, wherein:

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