JP2009264141A - Pump unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent gas overflowed from a gas separation chamber from flowing into a pump chamber. <P>SOLUTION: A discharge side check valve mechanism 230 having an outlet side check valve 45, a piston 210 closing the outlet side check valve 45 and a communication path 220 supplying liquid pressure of the gas separation chamber 60 to a cylinder 212 of the piston 210 is provided on an upper part of a flow path 46 of a pump unit. When fluid pressure from the communication path 220 becomes equal to or larger than biasing force of a biasing member 216, the piston 210 in the cylinder 212 is driven downward. With this, the piston 210 moves downward while sliding in the cylinder 212 and brings a tip of a rod 218 extending blow into contact with a valve body 52 of the outlet side check valve 45. Even when a pump 19 is in operation, therefore, if a liquid level in the gas separation chamber 60 rises to a predetermined height or more, the piston 210 close-operates the valve body 52 of the outlet side check valve 45 by the fluid pressure from the gas separation chamber 60. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a pump unit, and more particularly to a pump unit including a gas-liquid separation device that separates a liquid and a gas contained in a fluid in a system for supplying the fluid.

As this type of pump unit, a casing having an inlet and an outlet is provided. In this casing, a pump that sucks fluid from the inlet, and a fluid discharged from the pump are swirled into a liquid and a gas-enriched liquid. A gas-liquid separation device for separation, a gas separation chamber for separating gas from the gas-enriched liquid separated by the gas-liquid separation device, and a filter chamber for filtering the liquid from which gas has been removed in the gas separation chamber are provided. There is one configured to return the liquid filtered in the chamber to the suction port side of the pump (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 8-28442

  However, in the configuration described in Patent Document 1 as described above, for example, the liquid level of the gas separation chamber is a predetermined height in a state where the gas separated in the gas separation chamber is accumulated in the upper space of the gas separation chamber. The float valve opens and discharges the liquid to the pump side to lower the liquid level. For example, troubles on the liquid tank side connected to the inlet of the casing (for example, between the liquid tank and the inlet) A large amount of air may be sucked into the casing.

  In this case, the escape of air through the flow path is insufficient and the casing is filled with air. As a result, the liquid mixed with air leaks from the gas separation chamber to the outlet of the pump, and the outlet The flow meter connected to the pipe measures a fluid containing a large amount of air (a state where bubbles are mixed in liquid fuel), and an error occurs in the measurement of the amount of fuel supplied.

In view of the above circumstances, an object of the present invention is to provide a pump unit that solves the above problems.

  In order to solve the above problems, the present invention has the following means.

  The present invention includes a pump that sucks fluid from the inlet, a gas separation chamber that separates the fluid discharged from the pump into a liquid and a gas-enriched liquid, and the gas in a casing having an inlet and an outlet. A float valve that opens when the liquid level of the liquid separated in the separation chamber rises, and an exhaust that is provided above the gas separation chamber and communicates the gas separation chamber with the outside. When the passage and the liquid level in the gas separation chamber are below a predetermined height, the valve is opened to open the exhaust passage, and the liquid level in the gas separation chamber rises to reach the predetermined height Are provided on the downstream side of the pump, and the flow of the fluid discharged from the pump to the downstream side is allowed. On the contrary, a check valve that blocks the flow in the upstream direction and the reverse valve A movable piston mechanism which is provided at a position facing the valve and which allows a piston provided in the cylinder to move in the same direction as the open / close direction of the check valve; the gas separation chamber; and the cylinder chamber of the movable piston mechanism A communication passage that communicates with the fluid, and when the ejection prevention valve is operated, the piston is moved via the pressure of the fluid in the communication passage to close the check valve, and the fluid Is configured so as not to flow downstream of the check valve, and solves the above-described problems.

  The present invention also includes a pump that sucks a fluid from the inlet into a casing having an inlet and an outlet, a gas separation chamber that separates the fluid discharged from the pump into a liquid and a gas-enriched liquid, A float valve that opens when the liquid level of the liquid separated in the gas separation chamber rises and returns the liquid to the pump and an upper part of the gas separation chamber communicate with the gas separation chamber and the outside. When the exhaust passage and the liquid level in the gas separation chamber are below a predetermined height, the valve is opened to open the exhaust passage, and the liquid level in the gas separation chamber rises to reach the predetermined height. In this case, a pump unit having a jet prevention valve that closes and prevents the ejection of fluid from the exhaust passage, and a detection means that detects that the jet prevention valve has been actuated. The detecting means detects the operation of the ejection prevention valve. By controlling so as to stop the pump, it is to solve the above problems.

  According to the present invention, when the ejection prevention valve is activated, the piston is moved via the pressure of the fluid in the communication passage to close the check valve so that the fluid does not flow downstream from the check valve. Thus, it can be prevented from being supplied into the pump. Thereby, it is possible to prevent a liquid containing a large amount of air from being supplied to the flow meter connected to the outlet of the pump, and it is possible to prevent an error from occurring in the measurement of the oil supply amount.

  Further, when the detection means detects the operation of the ejection prevention valve, the flow of the fluid discharged from the pump is stopped. As a result, it is possible to prevent a liquid containing a large amount of air from being supplied to the flow meter connected to the outlet, and to prevent an error in the measurement of the amount of oil supplied.

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

  FIG. 1 is a longitudinal sectional view showing an embodiment of a pump unit according to the present invention. FIG. 2 shows the structure of the pump unit, and is a cross-sectional view taken along the line II-II in FIG. 3 is a cross-sectional view taken along the line III-III in FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG. FIG. 5 is a sectional view taken along the line VV in FIG. FIG. 6 is a side view showing the pump unit as a partial cross section.

  As shown in FIGS. 1 to 6, the casing 10 of the pump unit has an inlet 11 at the lower part and an outlet 12 at the upper part, and is integrally cast from an aluminum alloy. A suction chamber 13 is formed on the lower side of the casing 10 so as to face the inflow port 11, and a valve assembly 16 including a strainer 14 and a suction-side check valve 15 is disposed in the suction chamber 13. . On the other hand, a pump chamber 18 communicating with the suction chamber 13 via a flow path 17 (see FIG. 4) is formed on the upper side in the casing 10. The pump chamber 18 has a vane pump (rotary pump). ) 19 is provided. The pump 19 includes a bottomed cylindrical main body 20 fitted in the pump chamber 18. The main body 20 has a suction port 21 connected to the flow path 17 and a discharge port connected to another flow path 30 described later. An outlet 22 is provided.

  A rotor 23 is disposed in the main body 20 of the pump 19, and the rotor 23 is fixedly attached to a rotary shaft 24 in which the eccentric position of the main body 20 is extended. The rotating shaft 24 is rotatably supported by a bearing portion 25 formed integrally with the inside of the casing 10 and a bearing portion 26a formed integrally with the lid body 26 covered on the outer wall of the casing 10. The pump chamber 18 and the main body 20 are partitioned as a sealed chamber by closing the opening 10 a of the casing 10 with a lid 26. A plurality of vanes 27 are radially mounted on the rotor 23 so as to be slidable in the radial direction, and each vane 27 is provided at a base end thereof by a ring 28 disposed in a recess 23 a provided on both side surfaces of the rotor 23. Is supported. A pulley 29 that is driven to rotate by a motor (not shown) is attached to one end of the rotating shaft 24 that extends outside the casing 10.

  In the pump 19, when the pulley 29 is rotated by the operation of a motor (not shown), the rotation is transmitted to the rotor 23 via the rotating shaft 24, and each vane 27 is slidably contacted with the inner peripheral surface of the main body 20. Rotate while letting At this time, since the rotor 23 rotates around the eccentric position with respect to the main body 20, the volume of each chamber partitioned by the vane 27 repeatedly expands and contracts, thereby generating a negative pressure on the suction side in the main body 20. Therefore, if the inflow port 11 is connected to the tank, the fluid in the tank is transferred from the inflow port 11 through the strainer 14, the suction side check valve 15, the flow path 17 and the suction port 21 by the rotation of the rotor 23. And is discharged from the discharge port 22 to the flow path 30.

  Further, a gas-liquid separator 31 is disposed on the upper part of the casing 10 and on the opposite side of the pump 19 (see FIG. 1). The gas-liquid separator 31 is composed of a vertical cyclone 32 having an open lower end, and the cyclone 32 extends downward from the upper introduction portion 32a and toward the lower end opening. It is provided with a truncated conical barrel portion 32b and a conical ceiling portion 32c covering the upper side of the introduction portion 32a. The body portion 32b of the cyclone 32 is formed such that a portion corresponding to a substantially half length on the lower side protrudes into a filter chamber 40 described later, and a slit 33 extending in the vertical direction is formed on the peripheral wall of the protruding portion 34a. Is formed.

  In the upper part of the cyclone 32, an opening 30a constituting one end of the flow path 30 is formed. The opening 30a is formed so as to allow the fluid from the pump 19 to flow out in the tangential direction of the cyclone 32, and is provided vertically so as to straddle the introduction portion 32a and the ceiling portion 32c. A plug member 34 having a through hole 34 a is fitted in the center of the ceiling portion 32 c of the cyclone 32. The through hole 34 a of the plug member 34 communicates with a gas separation chamber 60 described later via a flow path 36 in a lid 35 attached to the casing 10.

  In the gas-liquid separator 31, the liquid mixed with gas, which has been pumped from the pump 19 through the flow path 30, flows into the cyclone 32 from the opening 30 a to cause a swiveling motion, and the centrifugal action acting between the liquid and the gas. Due to the different forces, the liquid collects radially outward and the gas collects radially inward. The separated liquid flows down from the lower end opening of the body portion 32b to the filter chamber 40. On the other hand, the gas-enriched liquid containing gas passes through the through-hole 34a of the plug member 34 of the ceiling portion 32c. It passes through the flow path 36 and is discharged to the gas separation chamber 60.

  As shown in FIG. 5, a filter 41 is disposed in the filter chamber 40. The front end of the filter 41 is fitted in a hole 42 a provided in a vertical partition wall 42 in the casing 10 that defines the filter chamber 40. A compression spring 44 having one end abutted against a lid body 43 covered with the casing 10 is disposed behind the filter 41, and the filter 41 is pressed against the vertical partition wall 42 by the compression spring 44. The opening 10b of the casing 10 closed by the lid body 43 has a sufficient size to allow the filter 41 to be taken in and out, so that the filter 41 can be appropriately replaced by removing the lid body 43. It becomes like this.

  As shown in FIGS. 4 and 6, in front of the filter 41, one end of a flow path 46 leading to an outlet side check valve 45 provided on the upper side of the casing 10 and two suction side check valves 15 are provided. One end of a flow path 47 communicating with the flow path 17 on the next side is disposed with a vertical partition wall 48 interposed therebetween. The outlet side check valve 45 includes a valve seat 51 fitted in a through hole 50 formed in the horizontal partition wall 49 of the casing 10, a valve body 52 with a shaft that is attached to and detached from the valve seat 51, and a lid body 53 of the casing 10. And a valve spring 54 that normally urges the valve body 52 in the closing direction by contacting one end of the valve body 52, and the spring force of the valve spring 54 is set to a weak spring force in order to reduce the flow resistance. The valve body 52 closes when the pump 19 is stopped.

  The secondary side of the outlet side check valve 45 is connected to the outlet 12 via a flow path 55. Accordingly, the liquid separated by the gas-liquid separator 31 and flowing down into the filter chamber 40 opens the outlet side check valve 45 from the filter 41 through the flow path 46 and further passes through the outlet 12 from the flow path 55 to the outside. It is pumped to a device (for example, a flow meter) and only allows the flow of oil in the direction leading to the outlet 12.

  As shown in FIG. 4, at the upper part of the flow path 46, the outlet side check valve 45, the piston 210 for closing the outlet side check valve 45, and the cylinder 212 on which the piston 210 slides are separated into gas. A discharge-side check valve mechanism 230 having a communication passage 220 for supplying the hydraulic pressure in the chamber 60 is provided.

  Thus, the vertical partition wall 48 is fitted with a relief valve 56 (see FIG. 5) bolted to the side wall of the casing 10, and the external device is now closed or squeezed while the pump 19 is driven. If this happens, the relief valve 56 is opened, and the liquid is returned from the flow path 47 and the flow path 17 to the suction port 21 of the pump 19. The filter chamber 40 and the flow path 46 form a fluid flow path.

  As shown in FIG. 7, a flow path 36 communicating between the gas-liquid separator 31 and the gas separation chamber 60 is provided on the lower surface of the lid 35 attached to the upper surface of the casing 10 forming the gas separation chamber 60. It has been. A pipe member 62 for supplying the gas-enriched liquid separated by the gas-liquid separator 31 to the gas separation chamber 60 is press-fitted in the vicinity of the left end of the flow path 36 in the drawing. The lower end of the tube member 62 extends to the inside of a small-volume liquid reservoir 64 provided near the lowest liquid level in the gas separation chamber 60. The liquid reservoir 64 is formed in a U-shaped groove shape from a vertical partition wall 63 of the casing 10, a step portion 63a of the partition wall, and a vertical wall 64a parallel to the partition wall 63, and one end thereof is opened as shown in FIG. Yes. As a result, the gas-enriched liquid supplied into the gas separation chamber 60 through the pipe member 62 once accumulates in the liquid reservoir 64 and then flows and accumulates from one end to the bottom side of the gas separation chamber 60. During this time, the gas is separated from the gas-enriched liquid, and this gas is discharged to the outside from the exhaust passage 130 provided on the upper wall of the casing 10.

  The exhaust passage 130 is provided with an overflow prevention valve mechanism 240 that prevents liquid overflowing from the gas separation chamber 60 from flowing out to the outside. The overflow prevention valve mechanism 240 is provided with an ejection prevention valve 242 that rises when the liquid overflowing in the gas separation chamber 60 flows and closes the outlet 241. Normally, since the ejection prevention valve 242 is displaced downward, the gas separated in the gas separation chamber 60 is exhausted from the outlet 241 to the outside.

  Here, a configuration for returning the liquid accumulated in the gas separation chamber 60 to the suction port 21 of the pump 19 will be described. As shown in FIGS. 2 and 3, a float 67 is disposed on the bottom side of the gas separation chamber 60. The float 67 is pivotable in the vertical direction by axially attaching the tip of a shaft portion 67 a extending from one surface thereof to a lid body 68 that closes the side opening of the casing 10. The lid body 68 is provided with a first boss portion 69 projecting from the front and back surfaces thereof, and a shaft hole 70 is formed in the first boss portion 69.

  In addition, an opening 71 is formed at the tip of the boss 69 located in the gas separation chamber 60 so that the shaft hole 70 communicates with the gas separation chamber 60. The periphery of the opening 71 is configured as a valve seat for the return valve 72, and the valve body 74 that is pivotally attached to the shaft portion 67 a of the float 67 is fitted into the opening 71. The return valve 72 moves the valve body 74 upward in response to the rise of the float 67 and opens the opening 71.

  The float 67 and the valve body 74 are integrated with the side cover 68 in advance, and can be taken in and out of the gas separation chamber 60 through the opening 10 c of the casing 10 closed by the cover 68. ing. A plug 75 that closes the shaft hole 70 is screwed to one end of the first boss 69 on the outside of the lid 68.

  On the other hand, as shown in FIGS. 4 and 5, a return flow path 76 that communicates from the side surface of the casing 10 to the secondary flow path 47 of the relief valve 56 is formed in the lower part of the casing 10. The return channel 76 and the shaft hole 70 in the first boss 69 are connected by a communication hole (not shown) in the second boss 77 provided in the casing 10. A check valve (flapper valve) 78 that restricts the backflow of the liquid into the shaft hole 70 in the first boss portion 69 is provided. As a result, when liquid accumulates in the gas separation chamber 60 and the float 67 rises, the valve body 74 of the return valve 72 opens, and the liquid in the gas separation chamber 60 flows into the shaft hole 70 in the first boss portion 69, the first. The suction port of the pump 19 through the communication hole in the boss portion 77 of the two bosses, the return channel 76, the channel 47 on the secondary side of the relief valve 56, and the channel 17 on the secondary side of the suction side check valve 15. 21 is returned.

  In the valve assembly 16, the valve body is opened by the generation of negative pressure in the pump 19, and the fluid flowing in from the strainer 14 flows into the flow path 17 that leads to the suction port 21 of the pump 19.

  On the other hand, in the relief valve 56 arranged in front of the filter 41, when the liquid pressure in the flow path 46 increases more than necessary, the valve body opens to cause the liquid in the flow path 46 to flow. The fluid is returned from the flow path 17 to the suction port 21 of the pump 19.

  Hereinafter, the operation of the pump unit configured as described above will be described. When the rotor 23 of the pump 19 is rotationally driven by a motor (not shown), the suction side check valve 15 opens, and the fluid in the tank passes from the inlet 11 through the strainer 14, the suction side check valve 15 and the flow path 17. Is sucked into the pump 19 and discharged from the discharge port 22 to the flow path 30. Then, the fluid discharged from the pump 19 flows toward the gas-liquid separator 31 and flows into the cyclone 32 from the opening 30a of the flow path 30 to cause a swirling motion. As it collects, gas collects inward in the radius.

  In the present embodiment, since the vertical cyclone 32 is used as the gas-liquid separator 31 in particular, the liquid and the gas are separated in the vertical direction due to the difference in specific gravity, and the gas-liquid separation ability is improved in combination with the centrifugal separation. Further, since the body portion 32b of the cyclone 32 is gradually narrowed toward the lower end opening, the flow velocity of the swirling flow increases as it goes downward, and the gas-liquid separation capability is further improved. Further, since the ceiling portion 32c of the cyclone 32 is formed in a conical shape, not only is it easy to create a downward swirling flow, but also the flow velocity of the swirling flow is increased at the initial stage when the fluid flows into the cyclone 32, and gas-liquid separation is performed. The ability is further improved.

  The liquid thus separated flows down from the lower end opening of the body portion 32b to the filter chamber 40, while the gas-enriched liquid containing gas is introduced into the lid 35 from the through hole 34a of the plug member 34 of the ceiling portion 32c. To the flow path 36.

  At this time, since the ceiling portion 32c of the cyclone 32 has a conical shape, the gas-enriched liquid can be easily discharged. The gas-enriched liquid discharged above the cyclone 32 passes through the tube member 62 and is discharged into the gas separation chamber 60. As shown in FIG. 3, the gas separation chamber 60 and the flow path 47 communicated with the suction port 21 of the pump 19 are communicated with each other by a communication path 220 made of a bypass pipe. When the liquid level in the separation chamber 60 rises above a predetermined height and the blowout prevention valve 242 of the overflow prevention valve mechanism 240 is closed, the pressure in the gas separation chamber 60 is supplied to the communication passage 220 and the discharge side reverse The piston 210 of the stop valve mechanism 230 is pressed (see FIG. 4).

  The liquid flowing down into the filter chamber 40 passes through the filter 41 and is pushed out into the flow path 46, and the outlet check valve 45 is opened by the pressure of the liquid to be pumped from the flow path 55 to the outlet 12. Here, when a slight amount of gas remains in the liquid separated by the gas-liquid separator 31, the gas is accumulated in the upper part of the filter chamber 40. The accumulated gas remains in the upper part of the filter chamber 40 because the liquid flows during the operation of the pump 19. However, when the pump 19 is stopped, the gas is accumulated in the cyclone 32 from the slit 33 of the trunk portion 32 b. Returning to FIG. 2, the pump 19 is discharged from the ceiling 32c in response to the re-operation. Therefore, the liquid containing gas is not supplied to the outflow port 12. As described above, when the outflow of the liquid from the outflow port 12 is stopped or throttled, the relief valve 56 is opened and the liquid is returned to the suction port 21 of the pump 19.

  On the other hand, the gas-enriched liquid discharged from the cyclone 32 is supplied into the gas separation chamber 60 through the pipe member 62. Gas separation proceeds in the gas separation chamber 60, and the separated gas is discharged to the outside from the exhaust passage 130 above the casing 10. In this way, the liquid from which the gas has been separated accumulates in the gas separation chamber 60, and the liquid level is gradually raised. Then, the float 67 rises, the valve body 74 of the return valve 72 opens, the liquid in the gas separation chamber 60 flows into the return flow path 76, and the secondary flow path 47 of the relief valve 56, the suction side check. It is returned to the suction port 21 of the pump 19 via the flow path 17 on the secondary side of the valve 15.

  Thus, for example, when a large amount of air (including liquid) is sucked into the casing 10 due to a problem on the tank side, the air is discharged to the gas separation chamber 60 through the flow path 36 and the pipe member 62.

  Here, each state of the gas separation chamber 60 will be described with reference to FIGS. 8A and 8B. FIG. 8A is a longitudinal sectional view showing a normal operation state of the gas separation chamber 60 and a state where the liquid A and a large amount of bubbles B flow into the gas separation chamber 60. FIG. 8B is a longitudinal sectional view showing a state in which the gas separation chamber 60 is filled with liquid and the overflow prevention mechanism is activated.

  As shown in FIG. 8A, in the normal state, in the gas separation chamber 60, the fluid A mixed with bubbles gradually flows through the flow path 36 and the pipe member 62, and the liquid level of the fluid A rises. When the predetermined value is exceeded, the valve body 74 of the return valve 72 is opened by the ascending operation of the float 67. As a result, the liquid accumulated at the bottom of the gas separation chamber 60 is returned to the pump chamber 18 via the flow path 30. On the other hand, when a large amount of air bubbles B flows into the gas separation chamber 60 due to piping abnormality or the like, the valve body 74 of the return valve 72 is opened by the ascending operation of the float 67, so that the air bubbles B are mixed. The fluid A is returned to the pump chamber 18. In this case, the bubble B is compressed in the pump chamber 18, so that the inflow of the liquid is inhibited and the pump 19 does not function normally.

  As shown in FIG. 8B, when a large amount of liquid flows into the gas separation chamber 60, the valve body 74 of the return valve 72 opens by the ascending operation of the float 67, but the flow rate that flows out from the return valve 72. Is less than the supply amount, the fluid A cannot be discharged in time, and the liquid level in the gas separation chamber 60 continues to rise. As a result, although the valve element 74 of the return valve 72 is opened, the fluid A overflows from the gas separation chamber 60, and thus the jet of the overflow prevention mechanism 240 that has been discharging gas until then. The prevention valve 242 operates upward to close the exhaust port 241 to prevent the fluid A (including gas and liquid) from flowing out.

  Here, with reference to FIG. 9, the flow of the fluid that passes through each device in the casing 10 and is fed to the flow meter will be described. FIG. 9 is a flowchart showing the flow path of the fluid in the pump unit in order.

  As shown in FIG. 9, in the drive state of the pump unit, the fluid (fuel) is first filtered by the strainer 14, then passes through the suction side check valve 15 and flows into the pump chamber 18 of the pump 19. . The pump 19 sucks fluid into the pump chamber 18 from the suction port 21 by the rotation of the rotor 23, and discharges the fluid from the discharge port 22 to the flow path 30. The fluid flows through the flow path 30 in a state where bubbles are mixed in the liquid fuel, and is supplied to the gas separation device 31. In the gas separation device 31, the gas and the liquid are separated by the swirling flow of the cyclone 32. The liquid from which the gas has been removed by the gas separation device 31 is filtered by the filter 41, passes through the outlet check valve 45, is supplied to the flow meter 200, and the flow rate is measured. The flow meter 200 is disposed downstream of the pump unit, and measures the supply amount (flow rate) of the fluid supplied to the oil supply nozzle.

  A relief valve 56 is provided in the flow path 47 that bypasses between the suction port 21 and the discharge port 22 of the pump 19. When the check valve 45 is kept closed while the rotor 23 of the pump 19 is rotating, the fluid discharged from the pump 19 opens the relief valve 56 by the pump pressure and sucks in the pump 19. Returned to mouth 21. Therefore, even if the check valve 45 is closed during operation of the pump 19, no load is applied to the pump 19.

  The gas-enriched liquid containing a large amount of bubbles accumulated in the upper part of the gas separation device 31 is supplied into the gas separation chamber 60 through the flow path 36 and the pipe member 62. The bubbles of the gas-enriched liquid in the gas separation chamber 60 accumulate on the liquid surface of the gas separation chamber 60, and when the liquid from which the bubbles are separated increases and the float 67 rises, the return valve 72 opens and the gas separation is performed. The liquid in the chamber 60 is returned to the suction port 21 of the pump 19.

  Further, as shown in FIG. 4, a piston 210 is provided for closing the outlet side check valve 45 when the pressure of the gas separation device 31 rises to a predetermined value or more. Therefore, as will be described later, when the pressure in the gas separation chamber 60 is transmitted to the piston 210 via the communication path 220, the piston 210 is driven downward to a position where the outlet side check valve 45 is forcibly closed. Moving.

  The gas separated from the gas-enriched liquid in the gas separation chamber 60 is discharged to the outside from the exhaust passage 130 provided on the upper wall in the gas separation chamber 60.

  Here, the discharge side check valve mechanism 230 and the movable piston mechanism constituting the main part of the present invention will be described. FIG. 10 is an enlarged vertical sectional view showing the discharge-side check valve mechanism 230. As shown in FIG. 10, the discharge side check valve mechanism 230 includes a valve seat 51, a valve body 52, and an urging member 54.

  A holding member 190 that holds the biasing member 54 is fitted and fixed to the lower surface of the upper lid 180.

  When the pump 19 is stopped, the valve body 52 is pressed against the valve seat 51 by the urging force of the urging member 54 and is in the closed position. When the fluid is discharged from the pump 19, the discharge pressure of the fluid is increased. When the urging force of the urging member 54 becomes larger, the valve is opened. Thereby, the fluid sent by the pump 19 is supplied from the outlet 12 to the flow meter 200.

  The movable piston mechanism 232 includes a cylinder 212 that communicates with the communication passage 220, a piston 210 that is liquid-tight (sealed) in the cylinder 212, and is movably provided, and a cylinder lid in the cylinder chamber of the cylinder 212. The biasing member 216 is provided between the piston 214 and the piston 210 and biases the piston 210 upward. In this movable piston mechanism 232, the piston 210 is coaxially disposed above the valve body 52 of the discharge-side check valve mechanism 230, and the lower end of the rod 208 extending downward from the piston 210 is the central portion of the valve body 52. Opposite to. In other words, the piston is provided at a position facing the valve body 52 and is movable in the same direction as the opening / closing direction of the check valve 45 so that the lower end of the rod 208 can press the valve body 52 of the check valve 45. It is provided as possible.

  Further, a through hole 192 through which the rod 218 of the piston 210 is inserted is provided on the upper surface of the holding member 190 of the check valve 45, and a spring receiver 194 with which the biasing member 54 abuts is provided on the lower surface of the holding member 190. It has been.

  As shown in FIGS. 8A and 8B described above, when a large amount of liquid flows into the gas separation chamber 60 (when the liquid level in the gas separation chamber 60 rises above a predetermined height), the float 67 rises. Although the valve body 74 of the return valve 72 is opened by the operation, the flow rate flowing out from the return valve 72 is smaller than the supply amount, and thus the pressure in the gas separation chamber 60 may increase to a predetermined pressure or more. In this case, as shown in FIG. 11, when the fluid pressure from the communication passage 220 becomes equal to or greater than the urging force of the urging member 216, the piston 210 in the cylinder 212 is driven downward.

  As a result, the piston 210 slides on the cylinder 212 and moves downward, and the tip of the rod 218 extending downward is brought into contact with the valve body 52 of the outlet check valve 45. Therefore, even when the pump 19 is in operation, when the liquid level in the gas separation chamber 60 rises to a predetermined height or more (see FIGS. 8A and 8B), the piston 210 exits due to the fluid pressure from the gas separation chamber 60. The valve body 52 of the side check valve 45 is closed, and the valve body 52 is brought into close contact with the valve seat 51. Thus, the fluid (bubbles and liquid) overflowing from the gas separation chamber 60 is prevented from flowing into the pump chamber 18 of the pump 19, and the liquid discharged from the pump 19 is not supplied to the flow meter 200.

  Further, a sub valve 260 for closing the small-diameter through hole 250 from the lower side is provided at the center of the upper surface of the valve body 52. The auxiliary valve 260 is normally urged upward (in the valve closing direction) by the urging force of the urging member 270, and the pressure in the gas separation chamber 60 is maintained even after the valve body 52 contacts the valve seat 51. When raised, the piston 210 is further driven downward to open the auxiliary valve 260. As a result, the fluid in the channel 46 flows out little by little to reduce the pressure in the pump chamber 18 and the gas separation chamber 60.

  When the pump 19 is stopped, the pressure in the flow path 46 and the pressure in the gas separation chamber 60 become the same pressure, so that the piston 210 returns upward by the biasing force of the biasing member 216. At the same time, when the pump 19 is stopped, when the discharge pressure is applied to the valve body 52, the valve body 52 is also moved downward by the urging force of the urging member 54 to close the valve seat 51.

  As described above, in this embodiment, the piston 210 is driven by the pressure increase in the gas separation chamber 60 and the valve body 52 of the outlet check valve 45 is closed, so that an electric component such as a motor is not used. In the case of supplying fuel, it is advantageous in terms of safety.

Here, a modified example will be described.
[Modification 1]
FIG. 12 is a longitudinal sectional view showing a first modification. As shown in FIG. 12, in the case of a liquid type (oil type) with less foaming in the gas separation chamber 60, the positions of the exhaust passage 130 and the overflow prevention mechanism 240 are not on the upper part of the casing 10 but on the side surface of the casing 10. It can also be provided. Even in this case, the piston 210 is operated when the pressure of the gas separation chamber 60 reaches a predetermined pressure by setting the pressure required to close the valve body 52 of the outlet side check valve 45 to a low value. The discharge of the fluid from the pump 190 can be stopped to prevent bubbles in the gas separation chamber 60 from flowing into the pump 18.
[Modification 2]
FIG. 13 is a longitudinal sectional view showing a second modification. As shown in FIG. 13, the overflow prevention mechanism 240 is provided with a detection unit 300 that detects that the ejection prevention valve 242 is operated upward to close the exhaust port 241. As the detection means 300, a magnetic sensor or a microswitch is used.

  As shown in FIG. 14, the discharge side check valve mechanism 230 </ b> A has an actuator 310 attached to the upper lid 180 instead of the piston 210. As the actuator 310, a driving means including a motor or a solenoid is used.

  As shown in FIG. 15, when a detection signal that detects that the ejection prevention valve 242 is closed by the detection unit 300 is output to the control unit 320, the actuator 310 of the discharge-side check valve mechanism 230 </ b> A is driven. A drive signal for output is output to the actuator 310.

  As shown in FIG. 16, the valve body 52 of the outlet side check valve 45 is thereby driven to close, and the valve body 52 comes into close contact with the valve seat 51. Therefore, the fluid (bubbles and liquid) overflowing from the gas separation chamber 60 is prevented from flowing into the pump chamber 18 of the pump 19, and the liquid discharged from the pump 19 is not supplied to the flow meter 200.

  The control unit 320 stops the pump motor that rotationally drives the rotor 23 of the pump 19 when the detection unit 300 outputs a detection signal that detects that the ejection prevention valve 242 is closed. May be.

  In the above embodiment, the pump unit is disposed in the system path for supplying the oil liquid, but the present invention can of course be applied to the case where the pump unit is disposed in the system path for supplying fluid other than the oil liquid.

It is a longitudinal cross-sectional view which shows one Example of the pump unit by this invention. The structure of this pump unit is shown, and it is sectional drawing which follows the II-II arrow line of FIG. It is sectional drawing which follows the III-III arrow line of FIG. It is sectional drawing which follows the IV-IV arrow line of FIG. It is sectional drawing which follows the VV arrow line of FIG. It is a side view which shows this pump unit as a partial cross section. 3 is a longitudinal sectional view showing the structure of a cyclone 32, a gas separation chamber 60, and an ejection prevention valve 242. FIG. 4 is a longitudinal sectional view showing a normal operation state of the gas separation chamber 60 and a state where a liquid and a large amount of bubbles flow into the gas separation chamber 60. FIG. It is a longitudinal cross-sectional view which shows the state with which the gas separation chamber 60 was filled with the liquid, and the overflow prevention mechanism act | operated. It is a flowchart which shows the path | route through which the fluid in a pump unit flows. It is a longitudinal cross-sectional view which expands and shows the discharge side non-return valve mechanism 230. FIG. 5 is a longitudinal sectional view showing the operation of the discharge side check valve mechanism 230. FIG. It is a longitudinal cross-sectional view which shows the modification 1. 6 is a longitudinal sectional view showing Example 2. FIG. 10 is an enlarged longitudinal sectional view showing a discharge-side check valve mechanism 230 according to Modification 2. FIG. FIG. 10 is a control block diagram showing a control system of a second modification. FIG. 10 is a longitudinal sectional view showing the operation of the discharge side check valve mechanism 230 of Modification 2.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Casing 11 Inlet 12 Outlet 15 Suction-side check valve 18 Pump chamber 19 Pump 21 Pump suction port 22 Pump discharge port 23 Rotor 31 Gas-liquid separation device 32 Cyclone 35 Cover body 36 Channel 40 Filter chamber 41 Filter 45 Outlet check valve 51 Valve seat 52 Valve body 54 Energizing member 60 Gas separation chamber 62 Pipe member 67 Float 72 Return valve 130 Exhaust passage 200 Flow meter 210 Piston 212 Cylinder 214 Cylinder lid 216 Energizing member 218 Rod 220 Communication passage 230 , 230A Discharge-side check valve mechanism 232 Movable piston mechanism 240 Overflow prevention mechanism 241 Exhaust port 242 Blowout prevention valve 260 Sub valve 300 Detection means 310 Actuator 320 Control unit

Claims (2)

A pump for sucking fluid from the inlet into a casing having an inlet and an outlet;
A gas separation chamber for separating the fluid discharged from the pump into a liquid and a gas-enriched liquid;
A float valve that opens and returns the liquid to the pump when the liquid level of the liquid separated in the gas separation chamber rises;
An exhaust passage provided at an upper portion of the gas separation chamber and communicating the gas separation chamber with the outside;
When the liquid level in the gas separation chamber is below a predetermined height, the valve is opened to open the exhaust passage, and when the liquid level in the gas separation chamber rises to reach the predetermined height, An ejection preventing valve that is closed to prevent ejection of fluid from the exhaust passage;
A check valve provided downstream of the pump, allowing a flow of fluid discharged from the pump to the downstream, and conversely blocking a flow in the upstream direction;
A movable piston mechanism that is provided at a position facing the check valve, and that allows the piston provided in the cylinder to move in the same direction as the check valve opening and closing direction;
A communication path communicating between the gas separation chamber and the cylinder chamber of the movable piston mechanism;
With
When the ejection prevention valve is activated, the piston is moved through the pressure of the fluid in the communication path to close the check valve so that the fluid does not flow downstream from the check valve. A pump unit characterized by comprising. A pump for sucking fluid from the inlet into a casing having an inlet and an outlet;
A gas separation chamber for separating the fluid discharged from the pump into a liquid and a gas-enriched liquid;
A float valve that opens and returns the liquid to the pump when the liquid level of the liquid separated in the gas separation chamber rises;
An exhaust passage provided at an upper portion of the gas separation chamber and communicating the gas separation chamber with the outside;
When the liquid level in the gas separation chamber is below a predetermined height, the valve is opened to open the exhaust passage, and when the liquid level in the gas separation chamber rises to reach the predetermined height, An ejection preventing valve that is closed to prevent ejection of fluid from the exhaust passage;
Detecting means for detecting that the ejection preventing valve is activated;
A pump unit having
A pump unit that controls to stop the pump when the detecting means detects the operation of the ejection prevention valve.

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