JP2008057545A - Fluid pressurization/supply device, and fluid tank unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluid pressurization/supply device capable of saving energy, and of preventing air pollution; and a fluid tank unit equipped with it. <P>SOLUTION: A fuel pump 12 is provided with a piston pump mechanism 33 executing pressurization to DME, and a motor part 30 for driving the piston pump mechanism 33. In a base housing 23, a communication passage 60 capable of making a through-hole 11D communicate with a discharge hole 23D is formed. The discharge hole 23D can communicate with a fuel storage space 110 through the communication passage 60 and the through-hole 11D. In an intermediate part of the communication passage 60, a check valve 61 comprising a ball valve 61A and springs 61B is arranged. The check valve 61 opens the communication passage 60 by the movement of the ball valve 61A against the springs 61B when the pressure on the discharge hole 23D side is smaller to some extent than that on the fuel storage space 110 side. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fluid pressure supply device and a fluid tank unit including the fluid pressure supply device.

As this type of configuration, for example, the configuration disclosed in Patent Document 1 is known.
In this configuration, the excessive pressure relief valve provided in the pump module disposed in the fuel tank is opened when the internal pressure of the fuel tank reaches a threshold value (predetermined pressure). Fuel is discharged out of the tank to limit the maximum pressure in the tank. Thus, the tank internal pressure is limited so as not to be excessive, and damage to the tank due to the excessive pressure is prevented.
JP 2002-115657 A

  However, in the said structure, the fuel discharged | emitted via the said excessive pressure relief valve is discharge | released in air | atmosphere, The said fuel is wasted. Furthermore, there is a possibility that the atmosphere is polluted by the fuel released into the atmosphere.

  An object of the present invention is to provide a fluid pressure supply device capable of saving energy and preventing air pollution, and a fluid tank unit including the fluid pressure supply device.

  In order to solve the above problems, in the invention according to claim 1, a pump unit for pressurizing a fluid that becomes a gas below a saturation pressure, and a motor unit for driving the pump unit A communication path capable of communicating between a fluid storage space of a sealable fluid tank for storing the fluid and a fluid supply side, and a pressure on the fluid supply side Is provided with a differential pressure on-off valve that allows the communication path to communicate with each other when the pressure becomes a predetermined amount smaller than the pressure in the fluid storage space.

  According to this invention, when the fluid in the fluid storage space is heated by heat generated by the pump unit or the motor unit, the pressure in the fluid storage space increases. When the pressure on the fluid supply side becomes a predetermined amount smaller than the pressure in the fluid storage space, the differential pressure on / off valve is opened and the communication path is in a communication state. As a result, the fluid in the fluid storage space is supplied to the fluid supply side via the communication path. Therefore, energy can be saved without wasting the fluid and its pressure, such as discharging the fluid in the fluid storage space to the atmosphere. Moreover, in this structure, there is no possibility of polluting the atmosphere with the fluid.

The “fluid supply side” in the present invention refers to the downstream side including the discharge passage of the pump unit.
In a second aspect of the present invention, a fluid tank unit including a fluid tank having a fluid storage space for storing a fluid that becomes a gas at a saturation pressure or lower, and a fluid pressurizing and supplying device assembled to the fluid tank. And the fluid pressurization supply device according to claim 1 is provided as the fluid pressurization supply device.

  According to the present invention, in the fluid tank unit including the fluid tank and the fluid pressurizing and supplying device assembled to the fluid tank, the effect of the invention described in claim 1 can be obtained.

  According to the first aspect of the present invention, in the fluid pressure supply device, it is possible to save energy and prevent air pollution. Further, according to the invention described in claim 2, in the fluid tank unit including the fluid tank and the fluid pressurizing supply device assembled to the fluid tank, it is possible to save energy and prevent air pollution. become.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 1 and 2.
FIG. 1A shows a fluid fuel supply for supplying dimethyl ether (hereinafter referred to as DME) as a fluid to a fuel injection device F connected to a diesel-type internal combustion engine E which is a driving source of a vehicle. It is a schematic diagram which shows a system. This fluid fuel supply system includes a fuel tank 11 as a fluid tank for storing DME, and a liquid DME in the fuel tank 11 that is assembled to the fuel tank 11 while being in a liquid state with respect to the fuel injection device F. And a fuel pump 12 as a fluid pressurizing pump. The DME has a property of becoming a gas below a saturation pressure. Further, in a state in which the inlet for injecting DME from the outside into the fuel tank 11 is closed, the fuel tank 11 is sealed, and the space inside the fuel tank 11 and the space outside the fuel tank 11 are pressurized. It has become isolated from. The fuel tank 11 and the fuel pump 12 constitute a fuel tank unit (fluid tank unit).

  The fuel pump 12 is almost entirely accommodated in the fuel tank 11. The fuel pump 12 is fixed to the bottom of the fuel tank 11. The fuel pump 12 and the fuel injection device F are connected via a supply pipe 13 for supplying DME discharged from the fuel pump 12 to the fuel injection device F. The fuel injection device F and the fuel tank 11 are connected via a return pipe (not shown) for returning the surplus DME supplied from the fuel pump 12 to the fuel injection device F to the fuel tank 11.

  As shown in FIG. 2, the fuel pump 12 includes a center housing 21, a motor housing 22 joined and fixed to the upper end of the center housing 21, and a base housing 23 joined and fixed to the lower end of the center housing 21. Yes. The housings 21, 22, and 23 are joined and fixed by bolts (not shown). Each housing 21, 22, 23 constitutes the entire housing 20 of the fuel pump 12.

  In the fuel pump 12, the base housing 23 is bolted (the bolt is not shown) to the annular mounting base portion 11B fixed to the through hole 11A formed in the fuel tank 11 by welding. It is assembled against. Between the upper surface of the flange portion 23A formed on the outer periphery of the base housing 23 and the mounting base portion 11B, a gasket 15 that seals between the base housing 23 and the mounting base portion 11B is disposed.

  As shown in FIG. 1A, the fuel pump 12 is accommodated in the fuel tank 11 with the lower surface side of the base housing 23 exposed to the outside of the fuel tank 11. Of the internal space of the fuel tank 11, the space outside the entire housing 20 is a fuel storage space 110 (fluid storage space) of the fuel tank 11.

  As shown in FIG. 2, a pump chamber 24 is formed in the center housing 21. A motor chamber 25 is formed in the motor housing 22. The pump chamber 24 and the motor chamber 25 are partitioned by a center block 26 disposed in the center housing 21 and communicated through a communication hole 26 </ b> A formed in the center block 26.

  A drive shaft 27 disposed so as to penetrate the pump chamber 24, the communication hole 26 </ b> A, and the motor chamber 25 is rotatably supported in the entire housing 20. Even when the drive shaft 27 is inserted, there is a gap that allows the pump chamber 24 and the motor chamber 25 to communicate with each other between the drive shaft 27 and the communication hole 26A.

  The upper end portion of the drive shaft 27 is supported by a ball bearing 28 attached to an attachment hole 22 </ b> A formed in the upper portion of the motor chamber 25 in the motor housing 22. The motor chamber 25 communicates with the outside of the entire housing 20 (the fuel storage space 110) via the mounting hole 22A. The lower end portion of the drive shaft 27 is supported by a bearing 29 attached to an attachment recess 23 </ b> B formed in the base housing 23.

  A motor unit 30 is disposed in the motor chamber 25. The motor unit 30 has a stator 31 fixed to the inner peripheral surface of the motor housing 22 in the motor chamber 25. The motor unit 30 includes a rotor 32 that is fixed to the drive shaft 27 in the motor chamber 25 and disposed at a position facing the stator 31. The motor unit 30 is configured to rotationally drive the drive shaft 27 by the rotation of the rotor 32 based on power supplied from the outside (a controller 51 described later) to the stator 31.

  In the pump chamber 24, an axial piston pump mechanism (hereinafter referred to as a piston pump mechanism) 33 as a pump unit is disposed. The piston pump mechanism 33 has a cylinder block 34 that is spline-fitted in the pump chamber 24 so as to be integrally rotatable with the drive shaft 27 and relatively movable in the axial direction thereof. A plurality of cylinder bores 34 </ b> A (only two are shown in the figure) are formed around the drive shaft 27 in the cylinder block 34.

  A piston 35 is accommodated in each cylinder bore 34A so as to be slidable back and forth. A shoe 36 formed on the center block 26 and slidable with respect to a cam surface 26B inclined with respect to the axial direction of the drive shaft 27 is connected to each piston 35 via a spherical joint 37. ing.

  The inner bottom surface of the pump chamber 24 is constituted by a part of the upper surface of the base housing 23. A valve plate 38 is fixed to the inner bottom surface. The upper surface of the valve plate 38 and the lower surface of the cylinder block 34 can be slidably brought into close contact with each other.

  A suction port 38A and a discharge port 38B are formed through the valve plate 38, respectively. Both ports 38A and 38B have openings on the upper and lower surfaces of the valve plate 38, respectively. The suction port 38A communicates with a suction port 11C formed in the mounting base portion 11B via a suction passage 23C formed in the base housing 23. The suction port 11 </ b> C is formed so as to open at substantially the lowest position of the fuel storage space 110. The discharge port 38B communicates with a discharge hole 23D formed in the base housing 23. A discharge passage of the piston pump mechanism 33 is configured by the discharge port 38B and the discharge hole 23D. One end side of the supply pipe 13 is connected to the discharge hole 23D.

  A storage chamber 34 </ b> B is formed at the center of the cylinder block 34. A pressure spring 39 is accommodated in the accommodation chamber 34B so as to surround the drive shaft 27. The spring force of the pressing spring 39 acts on the cylinder block 34 via the spring receiver 40 fixed to the cylinder block 34 and also acts on the shoe retainer 44 via the spring receiver 41, the pin 42 and the pivot 43. ing. The shoe retainer 44 is disposed so as to be engaged with the shoe 36, and the shoe 36 is pressed against the cam surface 26B by the spring force acting on the shoe retainer 44. The cylinder block 34 is pressed against the valve plate 38 by the spring force acting on the spring receiver 40.

  As shown in FIG. 2, the base housing 23 is formed with a communication path 60 through which the through hole 11D formed in the attachment base portion 11B can communicate with the discharge hole 23D. The discharge hole 23D can communicate with the fuel storage space 110 via the communication path 60 and the through hole 11D. In the present embodiment, the fuel pump 12 having the communication path 60 formed in the housing (base housing 23) itself constitutes a fluid pressurizing and supplying device.

  As shown in FIG. 1B, a check valve 61 including a ball valve 61 </ b> A and a spring 61 </ b> B is disposed in the communication path 60. The check valve 61 is configured such that the ball valve 61A closes the communication path 60 by the biasing force of the spring 61B when the pressure on the discharge hole 23D side is greater than the pressure on the fuel storage space 110 side. ing. Further, the check valve 61 has a spring 61B of the ball valve 61A when the pressure on the discharge hole 23D side is somewhat smaller than the pressure on the fuel storage space 110 side (hereinafter referred to as a predetermined amount). The communication path 60 is opened by the movement against the movement.

The fluid pump 12 and the communication path 60 constitute the fluid pressurization supply device of this embodiment.
The controller 51 is connected to a power source (not shown), and performs power feeding to the motor unit 30 and ON / OFF control thereof. Further, the controller 51 can detect the temperature of the fuel storage space 110 by a temperature sensor 52 provided at the bottom of the fuel tank 11. The controller 51 detects the pressure in the fuel storage space 110 based on this detection result. In addition, since the relationship between the temperature and the pressure has a one-to-one correspondence with DME, that is, a fluid that is a gas below the saturation pressure, the pressure can be grasped based on the temperature.

  Based on the detection result of the temperature sensor 52, the controller 51 determines that the pressure in the fuel storage space 110 has reached the upper predetermined pressure from a state below a predetermined pressure (for example, 3.2 MPa, hereinafter referred to as the upper predetermined pressure). Then, power supply is controlled (power supply is stopped) so as to stop the driving of the motor unit 30. As long as the controller 51 determines that the pressure in the fuel storage space 110 is equal to or higher than the upper predetermined pressure, the controller 51 maintains the motor unit 30 in a stopped state.

  Further, the controller 51 determines the lower predetermined pressure from a state where the pressure of the fuel storage space 110 is equal to or higher than the lower predetermined pressure (for example, 2.8 MPa) set smaller than the upper predetermined pressure based on the detection result. If it is determined that the state is less than, power supply is controlled (power supply is started) to start driving the motor unit 30. As long as the controller 51 determines that the pressure in the fuel storage space 110 is less than the lower predetermined pressure, the controller 51 maintains the motor unit 30 in the driving state.

  In the present embodiment, the lower predetermined pressure is equal to the amount necessary to open the check valve 61 rather than the minimum amount necessary to supply DME to the fuel injection device F. It is set large.

Next, the operation of the fuel pump 12 and the fuel tank unit configured as described above will be described.
When the cylinder block 34 is rotated integrally with the drive shaft 27, each piston 35 is reciprocated in a stroke defined by the inclination angle of the cam surface 26B. Further, by the rotation of the cylinder block 34, the cylinder bore 34A is alternately communicated with the suction port 38A and the discharge port 38B of the valve plate 38.

  As a result, the DME in the fuel storage space 110 is sucked into the cylinder bore 34A from the suction port 38A via the suction port 11C and the suction passage 23C, and the DME in the cylinder bore 34A is discharged from the discharge port 38B by the pump action. DME discharged from the discharge port 38B is sent to the fuel injection device F through the discharge hole 23D and the supply pipe 13.

  When the piston pump mechanism 33 is driven by the motor unit 30, the DME in the fuel tank 11 is heated by frictional heat from each sliding portion of the piston pump mechanism 33 and heat generated by the motor unit 30. When the DME is vaporized by this heating, the pressure in the fuel storage space 110 increases. The motor unit 30 and the piston pump mechanism 33 are cooled by taking heat away from the DME in the fuel tank 11.

  In the present embodiment, the DME vaporized in the pump chamber 24 and the motor chamber 25 is discharged to the outside of the entire housing 20 (the fuel storage space 110) through the upper communication portion including the clearance of the ball bearing 28 and the mounting hole 22A. Is done.

  When the controller 51 determines that the pressure in the fuel storage space 110 has changed from a state below the upper predetermined pressure to a state equal to or higher than the upper predetermined pressure, the controller 51 stops power supply so as to stop driving the motor unit 30.

  As a result, when the driving of the piston pump mechanism 33 is stopped, the pressure in the supply pipe 13 and the discharge hole 23D decreases with the consumption of DME on the fuel injection device F side. When the pressure on the discharge hole 23D side becomes a predetermined amount smaller than the pressure in the fuel storage space 110 due to the decrease in pressure, the check valve 61 is opened and the communication path 60 is in communication. As a result, the DME in the fuel storage space 110 is supplied to the fuel injection device F through the through hole 11D, the communication path 60, the discharge hole 23D, and the supply pipe 13.

  When the DME supply from the fuel storage space 110 to the fuel injection device F via the communication path 60 and the like is continued, the pressure of the fuel storage space 110 decreases and falls below the lower predetermined pressure. When the controller 51 determines that the pressure in the fuel storage space 110 is less than the lower predetermined pressure, the controller 51 starts power feeding so as to start driving the motor unit 30. Thus, when the driving of the piston pump mechanism 33 is started, the pressure in the discharge hole 23D becomes higher than the pressure in the fuel storage space 110, the check valve 61 is closed, and the communication path 60 is in a non-communication state. . In this state, DME is supplied from the piston pump mechanism 33 to the fuel injection device F.

  As a result, the DME and its pressure can be used for supplying DME to the fuel injection device F without wasting the DME in the fuel storage space 110 into the atmosphere, for example, and energy can be saved. It is possible to prevent the pressure in the space 110 from becoming excessive.

  In this state, since the driving of the motor unit 30 is stopped, heat generation of the piston pump mechanism 33 and the motor unit 30 is suppressed, and further increase in pressure in the fuel storage space 110 is suppressed. .

In the present embodiment, the following effects can be obtained.
(1) When the pressure on the discharge hole 23D side, which is the fluid supply side, is somewhat lower than the pressure in the fuel storage space 110, the check valve 61 is opened and the communication path 60 is in communication. In this communication state, DME in the fuel storage space 110 is introduced to the supply pipe 13 via the communication path 60 and supplied to the fuel injection device F. Therefore, energy can be saved without wasting the DME and its pressure, such as discharging the DME in the fluid storage space into the atmosphere. Further, in this configuration, there is no possibility of polluting the atmosphere with the DME.

  (2) In a state where the pressure of the fuel storage space 110 is equal to or higher than the predetermined pressure (upper predetermined pressure) (a state where the communication path 60 is in an open state), the driving of the motor unit 30, that is, the piston pump mechanism 33 is stopped. . Thereby, heat_generation | fever of the piston pump mechanism 33 and the motor part 30 is suppressed, and the pressure rise of the fuel storage space 110 is suppressed. Therefore, an excessive pressure increase in the fuel storage space 110 is prevented. Further, energy saving can be achieved by stopping the driving of the piston pump mechanism 33.

  (3) The upper predetermined pressure, which is a threshold value when driving the motor unit 30, is stopped, and the lower predetermined pressure, which is a threshold value when starting driving the motor unit 30, is set. The upper predetermined pressure is set to a value larger than the lower predetermined pressure. According to this, chattering for switching the driving state of the motor unit 30 is prevented.

  (4) The pressure in the fuel storage space 110 is detected based on the detection result of the temperature sensor 52. In DME, since the temperature change corresponds to the pressure change, the pressure change can be grasped based on the detection result by the temperature sensor 52. In addition, in pressure detection using a temperature sensor, it is easier to grasp a continuous change in pressure than, for example, pressure detection using a pressure sensor.

  (5) In this embodiment, by using the mechanical check valve 61, the communication state of the communication path 60 and the non-communication state can be switched only by the ON / OFF control of the motor unit 30 by the controller 51.

The embodiment is not limited to the above, and may be, for example, as follows.
In the above embodiment, a through-hole through which the DME of the fuel storage space 110 can be introduced into the entire housing 20 (for example, the pump chamber 24 and the motor chamber 25) is provided in the entire housing 20 of the fuel pump 12 other than the mounting hole 22A. May be. For example, it is assumed that the through hole for communicating the fuel storage space 110 and the pump chamber 24 in the center housing 21 is provided. In this case, the DME introduced into the pump chamber 24 from the fuel storage space 110 via the through hole is caused by the upward flow of DME in the entire housing 20 generated by the heat generated by the piston pump mechanism 33 and the motor unit 30. It is discharged out of the entire housing 20 through the communication hole 26A, the motor chamber 25, and the mounting hole 22A.

  In the above-described embodiment, the fuel pump 12 is configured to be substantially entirely accommodated in the fuel tank 11, but may be configured to be disposed substantially outside the fuel tank. In this case, the DME is introduced into the entire housing 20 by, for example, introducing the DME in the fuel storage space 110 to cool the fuel pump. With this configuration, the pressure in the fuel storage space 110 is increased by heating the DME with the heat generated by the fuel pump.

  In the embodiment, both the piston pump mechanism 33 and the motor unit 30 are cooled using the DME in the fuel storage space 110. However, only one of them may be cooled. In this case, for example, only one of the piston pump mechanism and the motor unit is configured to be disposed inside the fuel tank, and the DME in the fuel storage space 110 is introduced only to the one disposed inside the fuel tank. Configure as follows.

The DME in the fuel storage space 110 may be heated by a heat source different from the fuel pump, and the pressure in the fuel storage space 110 may be increased.
In the above embodiment, the fuel pump 12 is assembled to the fuel tank 11, but it may not be assembled. For example, the fuel pump may be disposed in the vicinity of the fuel tank without contacting the fuel tank. In this case, the DME in the fuel tank is heated by the heat generated by the fuel pump disposed in the vicinity of the fuel tank, so that the pressure in the fuel tank rises. Further, when the fuel pump is arranged in a state not in contact with the fuel tank, the fuel pump is located in the vicinity of the fuel tank when the pressure in the fuel tank can be sufficiently increased by heating by a heat source other than the fuel pump. There is no need to be placed in.

  In the embodiment, the temperature sensor 52 may not be provided at the bottom of the fuel tank 11. For example, it may be provided at a location spaced upward from the bottom, such as the side of the fuel tank 11.

In the above embodiment, the temperature sensor 52 may not be provided in the fuel tank 11 itself. For example, it may be fixed to the entire housing 20 of the fuel pump 12.
In the embodiment, the controller 51 and the temperature sensor 52 may be provided integrally with the entire housing 20 of the fuel pump 12.

  In the embodiment, the temperature sensor 52 may be provided in the fuel injection device F and the temperature of the DME in the fuel injection device F may be detected. In this case, for example, when the temperature of the DME is low, that is, when the saturation pressure of the DME is low and there is no fear of vaporization in the fuel injection device F, the predetermined value that is a threshold value when the communication path 60 is in the communication state The pressure may be set low. In this case, the power consumption of the motor unit 30 is further reduced.

  In the above-described embodiment, the controller 51 performs ON / OFF control, which is binary control related to the driving of the motor unit 30. However, the number of rotations per unit time of the rotor 32 is not limited to this. You may make it perform control for changing.

  In the above embodiment, when the pressure in the fuel storage space 110 changes from a state below the upper predetermined pressure to a state equal to or higher than the upper predetermined pressure, the motor unit 30 (that is, the piston pump mechanism 33) is stopped from driving. It is comprised so that. On the other hand, when the pressure of the fuel storage space 110 is changed from a state below the upper predetermined pressure to a state equal to or higher than the upper predetermined pressure, the motor unit 30 is maintained in the driving state. Also good. This is realized, for example, in a configuration in which the pressure on the fluid supply side (corresponding to the fuel injection device F side in the embodiment) is kept lower than the lower predetermined pressure even when the piston pump mechanism 33 is driven. It becomes possible. Further, in the configuration in which the motor unit 30 is not stopped when the pressure of the fuel storage space 110 is changed from a state below the upper predetermined pressure (the first upper predetermined pressure) to a state equal to or higher than the upper predetermined pressure. Is configured such that when the pressure of the fuel storage space 110 further exceeds a second upper predetermined pressure that is greater than the first upper predetermined pressure, the motor unit 30 is stopped from driving. Also good. In this case, by setting the magnitude of the second upper predetermined pressure to be equal to or less than the maximum allowable pressure of the fuel tank 11, the fuel tank caused by the pressure increase in the fuel storage space 110 due to the continued driving of the motor unit 30. 11 is prevented from being damaged.

  In the embodiment, the pressure in the fuel storage space 110 is detected based on the detection result using the temperature sensor 52. However, the pressure may be detected using a pressure sensor. In this case, the pressure is directly detected by the pressure sensor without other parameters. Accordingly, the pressure detection result is more accurate than when pressure detection is performed via other parameters. In addition, since the pressure distribution is substantially uniform in the fuel storage space 110, the degree of freedom of installation of the pressure sensor for effective detection is relatively large.

  In the embodiment, the cylinder block 34 may be formed using aluminum, and the piston 35 may be formed using iron. In this case, the clearance between the cylinder block 34 and the piston 35 increases as the temperature increases due to the difference in thermal expansion coefficient between the two. That is, even when the initial setting of the clearance (set dimension at room temperature) is made small, it becomes easy to prevent the seizure of both. In order to obtain good operating efficiency of the piston pump mechanism 33, the clearance is preferably 10 μm or less.

  In the above embodiment, the sliding contact portion between the cylinder block 34 and the valve plate 38, the sliding contact portion between the piston 35 (37) and the shoe 36, and the sliding contact portion between the shoe 36 and the cam surface 26B of the center block 26. Solid lubrication means such as a fluororesin film may be provided. According to this, the image sticking suppression effect of the sliding contact portion is improved. In the piston pump mechanism 33, the sliding resistance at the sliding contact portion is relatively difficult to increase due to the pressure of the liquid film of DME that has entered the sliding contact portion. Is relatively difficult to progress.

In the embodiment, frictional resistance reducing means such as nickel plating or tin plating may be provided at the sliding contact portion between the cylinder block 34 and the piston 35.
In the embodiment, frictional resistance reducing means such as nickel plating or tin plating may be provided on the sliding portions of the bearings 28 and 29.

  In the above embodiment, a piston pump mechanism (for example, a radial piston pump mechanism) other than the axial piston pump mechanism 33, a gear pump mechanism, a centrifugal pump mechanism, a screw pump mechanism, a roots pump mechanism, or the like may be applied as the pump unit. Good.

In the embodiment, the fuel pump 12 that pressurizes fluid fuel is applied as the fluid pressurizing pump. However, a pump that pressurizes fluid other than fluid fuel may be applied.
In the above embodiment, chlorofluorocarbon, propane, or the like may be applied in addition to DME as a fluid that becomes a gas at a saturation pressure or lower.

The technical idea that can be grasped from the embodiment described above will be described below.
<1> The pressure on the fluid supply side is lowered by stopping the driving of the motor unit from the state where the motor unit is driven, and when the pressure becomes a predetermined amount smaller than the pressure of the fluid storage space. The fluid pressure supply device according to claim 1, wherein the differential pressure on-off valve is opened.

  When the driving of the motor unit is stopped, the driving of the pump unit is stopped and the fluid supply to the fluid supply side is stopped. Accordingly, when the pressure on the fluid supply side decreases and the pressure on the fluid supply side becomes a predetermined amount lower than the pressure in the fluid storage space due to the decrease in the pressure, the communication path is in a communication state. As a result, the fluid in the fluid storage space is supplied to the fluid supply side via the communication path.

  <2> A temperature sensor for detecting the temperature of the fluid storage space, and a controller for controlling power supply to the motor unit, the controller storing the fuel storage space based on a detection result of the temperature sensor. The fluid pressure supply device according to <1>, wherein the controller stops driving the motor unit when the detected pressure is equal to or higher than a predetermined pressure.

  In the fluid, since the temperature change corresponds to the pressure change, according to the present invention, the pressure change can be grasped based on the detection result by the temperature sensor. In addition, in pressure detection using a temperature sensor, it is easier to grasp a continuous change in pressure than, for example, pressure detection using a pressure sensor.

  <3> A pressure sensor for detecting the pressure in the fluid storage space, and a controller for controlling power supply to the motor unit, wherein the controller detects a pressure detected by the pressure sensor equal to or higher than a predetermined pressure. In the fluid pressurizing and supplying apparatus according to <1>, the controller stops driving the motor unit.

  The pressure of the fluid storage space is directly detected by a pressure sensor without passing through other parameters. Accordingly, the pressure detection result is more accurate than when pressure detection is performed via other parameters. In addition, since the pressure distribution is substantially uniform in the fluid storage space, the degree of freedom of the installation location of the pressure sensor for effective detection is relatively large.

1 shows an embodiment, and (a) is a schematic diagram showing a fluid fuel supply system. FIG. (B) is the elements on larger scale which show a communication path. The schematic cross section which shows the outline | summary of a fuel pump.

Explanation of symbols

  11: A fuel tank as a fluid tank constituting the fluid tank unit. 12. A fuel pump that constitutes a fluid pressurizing and supplying apparatus and a fluid tank unit. 23D: Discharge hole on the fluid supply side. 30 ... Motor part. 33 ... Axial piston pump mechanism as a pump part. 38B: Discharge port on the fluid supply side. 52 ... Temperature sensor. 60: Communication route.

Claims (2)

A fluid pressurizing and supplying apparatus including a pump unit for pressurizing a fluid that is a gas below a saturation pressure, and a motor unit for driving the pump unit,
A communication path capable of communicating between a fluid storage space of a sealable fluid tank for storing the fluid and a fluid supply side;
A fluid pressurizing and supplying apparatus comprising: a differential pressure on / off valve that communicates the communication path when a pressure on the fluid supply side becomes a predetermined amount smaller than a pressure in the fluid storage space.   A fluid tank unit comprising a fluid tank having a fluid storage space for storing a fluid that becomes a gas below a saturation pressure, and a fluid pressurization supply device assembled to the fluid tank, the fluid pressurization supply A fluid tank unit provided with the fluid pressure supply device according to claim 1 as an apparatus.

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