JP2009150333A - Jet pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a jet pump smoothly opening/closing a valve element of a relief valve and certainly preventing generation of abnormal noise such as contact noise. <P>SOLUTION: This jet pump 10 includes: a fluid introducing passage 12 on a return side; a fluid introducing passage 14 on a sub tank side; a nozzle body 11 having the relief valve 20 opening a valve seat opening 13 when fluid pressure in the fluid introducing passage on the return side exceeds a predetermined value; and a diffuser 18 sucking fluid on the sub tank side, introduced into the fluid introducing passage on the sub tank side, and delivering fluid 59A on the return side, injected from a nozzle 12a, and sucked fluid 59B on the sub tank side. In this case, the relief valve is composed of a cylindrical body 21, the valve element 23 sliding in the cylindrical body and opening/closing the valve seat opening, a cover 25 covering the opening of the cylindrical body, and a return spring 27 pressing the valve element in a valve seat opening closing direction. The inner surface 25c of the cover is formed with a guide portion 26c retaining the return spring in a perpendicular direction with respect to the inner surface. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a jet pump suitable for use in, for example, a fuel pump that is mounted in a vertical fuel tank of an automobile and transfers fuel on a sub-tank side to the main tank with fuel returned from a fuel supply device to the main tank.

  An example of this type of jet pump is shown in FIG. 6 (see, for example, Patent Document 1).

  As shown in FIG. 6, the jet pump 1 includes a return-side fluid introduction path 2 that introduces a return-side fuel 9 </ b> A, and a nozzle 3 that injects the return-side fuel 9 </ b> A introduced into the return-side fluid introduction path 2. And the sub tank side fluid introduction path 4 for introducing the sub tank side fuel 9B and the return side fluid introduction path 2, and the fluid pressure of the fuel 9A in the return side fluid introduction path 2 is set to a predetermined value. A nozzle body 5 having a relief valve 6 that opens the valve seat 5a when it exceeds, and attached to the nozzle body 5 and introduced into the sub tank side fluid introduction passage 4 by injection of the return side fuel 9A. A sub-tank side fuel 9B is sucked and a return-side fuel 9A injected from the nozzle 3 and a sub-tank side fuel 9B are discharged.

  When the fluid pressure of the fuel 9A in the return side fluid introduction passage 2 exceeds a predetermined value, the valve seat 5a of the nozzle body 5 is opened by the valve body 6a of the relief valve 6, and the opened nozzle The fuel 9 </ b> A in the return side fluid introduction path 2 is discharged from the valve seat port 5 a of the main body 5 to the relief pipe 8.

Japanese Utility Model Publication No. 7-30361

  However, in the conventional jet pump 1, when the valve body 6a of the relief valve 6 opens the valve seat port 5a of the nozzle body 5, the valve body 6a does not move horizontally with respect to the valve seat port 5a, but obliquely. Because of the movement, the outer peripheral surface of the valve body 6a interferes with the inner peripheral surface or the like of the cylindrical body 6b in which the valve body 6a is slidably accommodated, and a vortex of the fuel 9A is generated, causing abnormal noise. It was.

  Therefore, the present invention has been made to solve the above-described problems, and can smoothly open and close the valve body of the relief valve, and reliably prevent the generation of abnormal noise such as contact noise. An object of the present invention is to provide a jet pump.

  The invention according to claim 1 is a return-side fluid introduction path for introducing a return-side fluid, a nozzle for injecting a return-side fluid introduced into the return-side fluid introduction path, and a sub-tank side for introducing a sub-tank side fluid. Nozzle body having a fluid introduction path and a relief valve that is disposed in the return side fluid introduction path and opens the valve seat when the fluid pressure in the return side fluid introduction path exceeds a predetermined value The sub-tank side fluid that is attached to the nozzle body and is introduced into the sub-tank side fluid introduction path by the return-side fluid ejection, and the return-side fluid ejected from the nozzle and the suctioned fluid. In the jet pump provided with a diffuser for discharging the fluid on the sub tank side, the relief valve protrudes outside the valve seat port of the nozzle body. A cylindrical body, a valve body that slides in the cylindrical body and opens and closes the valve seat opening, a cover that covers the opening of the cylindrical body, and the valve body and the cover in the cylindrical body And a guide spring that holds the return spring in a direction perpendicular to the inner surface of the cover is formed on the inner surface of the cover. It is characterized by.

  The invention according to claim 2 is the jet pump according to claim 1, wherein the cover is formed in a disk shape, and an annular groove portion is formed on the inner surface of the disk-like cover, and the groove portion The outer peripheral surface is used as the guide portion.

  As described above, according to the first aspect of the present invention, the relief valve has a cylindrical body projecting outward from the valve seat opening of the nozzle body, and slides in the cylindrical body and opens and closes the valve seat opening. The valve body, a cover that covers the opening of the cylindrical body, and a return spring that is interposed between the valve body and the cover in the cylindrical body and biases the valve body in the direction of closing the valve seat opening, By forming a guide part on the inner surface of the valve to hold the return spring in a direction perpendicular to the inner surface, the valve body of the relief valve can be smoothly opened and closed, and abnormal noise such as contact noise is reliably generated. Can be prevented.

  According to the second aspect of the present invention, the cover is formed in a disc shape, and an annular concave groove portion is formed on the inner surface of the disc-shaped cover, and the outer peripheral surface of the concave groove portion is used as a guide portion. When the valve body of the relief valve opens and closes the valve seat opening of the nozzle body, it can be held without tilting the return spring on the outer peripheral surface of the recessed groove portion of the cover. The outer peripheral surface of the valve body does not interfere with the inner peripheral surface of the cylindrical body, and the generation of fluid vortices can be prevented. Thereby, generation | occurrence | production of abnormal noise can be reliably prevented at the time of the action | operation of a relief valve.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  1 is a sectional view showing a jet pump according to an embodiment of the present invention, FIG. 2 is an enlarged sectional view around a relief valve of the jet pump, FIG. 3 is a front view of a cylindrical body of the relief valve, and FIG. Is a sectional view of the cover of the relief valve, FIG. 4B is a bottom view of the cover, and FIG. 5 is a schematic view showing a state in which the jet pump is assembled in the vertical fuel tank.

  As shown in FIGS. 1 and 5, the jet pump 10 includes a synthetic resin nozzle body 11 and a synthetic resin diffuser 18 attached to the lower end of the nozzle body 11 by ultrasonic welding or the like. It is disposed below the main lid 52 of the main tank 51 of the vertical fuel tank 50 that stores the fuel (fluid) 59. As shown in FIG. 5, the vertical fuel tank 50 is separated into a main tank 51 and a sub tank 54 by a separation portion 53 having an inverted U-shaped cross section at the bottom wall portion.

  As shown in FIG. 1, the nozzle body 11 is provided with a return side fluid introduction path 12 for introducing return fuel (return side fluid) 59 </ b> A, and is separated from the return side fluid introduction path 12. A sub tank-side fluid introduction path 14 for introducing fuel (fluid) 59B on the sub tank 54 side is provided.

  As shown in FIG. 1, one fluid introduction portion 17 a of a synthetic resin joint member 17 is fitted into the upper end side of the return side fluid introduction path 12 of the nozzle body 11 via a rubber O-ring 15. . A return fuel pipe (fluid feed pipe) 57 connected to the fuel supply device 56 is coupled to one fluid introduction portion 17 a of the joint member 17. By the operation of the fuel supply device 56, the return fuel 59A is introduced from the return fuel pipe 57 into the return side fluid introduction path 12 as needed.

  Further, as shown in FIG. 1, a nozzle 12a formed in a tapered shape is provided on the lower end side of the return side fluid introduction path 12 of the nozzle body 11, and this nozzle 12a is provided with a return side from a return fuel pipe 57. The return fuel 59A introduced into the fluid introduction path 12 passes therethrough.

  Furthermore, as shown in FIGS. 1 to 3, a circular valve seat 13 is formed at a substantially central position of the return side fluid introduction path 12 of the nozzle body 11. The valve seat 13 is provided with a relief valve 20 that opens the valve seat 13 when the fluid pressure of the return fuel 59A in the return side fluid introduction passage 12 exceeds a predetermined value.

  As shown in FIG. 1, the other fluid introduction portion 17 b of the synthetic resin joint member 17 is fitted into the upper end side of the sub tank side fluid introduction path 14 of the nozzle body 11 via a rubber O ring 16. . A sub tank-side fuel pipe (fluid feed pipe) 58 fixed to the sub lid 55 of the sub tank 54 and connected in communication with the sub tank 54 is coupled to the other fluid introduction portion 17 b of the joint member 17. Further, the lower end side of the sub tank side fluid introduction path 14 of the nozzle body 11 communicates with the diffuser 18.

  The diffuser 18 is disposed on the lower side of the nozzle body 11. In the substantially central portion of the diffuser 18, a constricted portion 18 b formed by constricting the inner diameter toward the fluid discharge portion 18 a provided in the lower end portion is provided. The fluid discharge part 18a and the throttle part 18b communicate with the return side fluid introduction path 12 of the nozzle body 11 via the nozzle 12a and also communicate with the sub tank side fluid introduction path 14. In addition, the fluid discharge portion 18 a of the diffuser 18 communicates with the main tank 51.

  The diffuser 18 causes the return fuel 59A introduced into the return side fluid introduction path 12 to be injected from the nozzle 12a of the return side fluid introduction path 12, thereby generating a negative pressure in the throttle portion 18b. The fuel 59B on the sub tank 54 side introduced into the sub tank side fluid introduction passage 14 is sucked. That is, the return fuel 59A injected from the nozzle 12a of the return side fluid introduction path 12 and the sucked fuel 59B on the sub tank 54 side are discharged into the main tank 51 from the fluid discharge portion 18a of the diffuser 18. .

  As shown in FIGS. 1 and 2, the relief valve 20 includes a cylindrical body 21 that is integrally protruded outside the valve seat 13 of the nozzle body 11 made of synthetic resin, and slides in the cylindrical body 21. A synthetic resin valve body 23 for opening and closing the valve seat 13, a synthetic resin cover 25 covering the opening 21 a of the cylindrical body 21, and the valve body 23 and the cover 25 in the cylindrical body 21 are interposed. The valve body 23 is composed of a return spring 27 made of metal and coiled to bias the valve body 23 in the direction of closing the valve seat 13.

  As shown in FIGS. 1 to 3, a plurality of ribs 22 having a circular arc cross section are formed on the inner peripheral surface 21 b of the cylindrical body 21 so as to extend in the axial direction at equal intervals. The outer peripheral surface 23 b of the valve body 23 slides on the plurality of ribs 22.

  As shown in FIGS. 1 and 2, the valve body 23 is formed in a disc shape, and the upper surface thereof serves as a contact surface 23 a that opens and closes the valve seat surface 13 a of the valve seat port 13. An annular recess 24 is formed in the center of the lower surface 23 d of the disc-like valve body 23, and one end 27 a of the return spring 27 is held in the annular recess 24.

  As shown in FIGS. 1, 2, 4A, and 4B, the cover 25 is formed in a disc shape. Then, as shown in FIGS. 4A and 4B, the outer peripheral surface 25a of the disc-like cover 25 is formed with a cutout portion 25b cut out in an arc shape. Further, an annular concave groove portion 26 is formed at the center of the lower surface (inner surface) 25c of the disc-like cover 25, and a return spring 27 is returned to the step portion 26b of the inner peripheral surface 26a of the annular concave groove portion 26. The other end portion 27b is held. Further, the outer peripheral surface 26c of the annular concave groove portion 26 serves as a guide portion for holding the return spring 27 in a direction perpendicular to the lower surface 25c.

  As shown in FIG. 1, the cylindrical body 21 of the relief valve 20 is fitted with a lower portion 31a of a synthetic resin cylindrical portion 31 of a silencer 30 for reducing the artery of the return fuel 59A generated by the jet pump 10. Between the upper portion 31b of the cylindrical portion 31 and the synthetic resin cover 32, a sponge member 33 for silencing is incorporated.

  According to the jet pump 10 of the above embodiment, the return fuel 59A introduced into the return side fluid introduction path 12 of the nozzle body 11 by the operation of the fuel supply device 56 is caused by the nozzle 12a of the return side fluid introduction path 12. Since the return fuel 59A injected into the diffuser 18 and introduced into the return side fluid introduction path 12 is injected from the nozzle 12a of the return side fluid introduction path 12, a negative pressure is generated in the throttle portion 18b. The fuel 59B on the sub tank 54 side introduced into the sub tank side fluid introduction path 14 is sucked by the negative pressure, and the return fuel 59A injected from the nozzle 12a of the return side fluid introduction path 12 and the sucked fuel 59B on the sub tank 54 side are The fluid is discharged from the fluid discharge portion 18 a of the diffuser 18 into the main tank 51. At this time, when the fluid pressure of the return fuel 59 </ b> A in the return side fluid introduction passage 12 exceeds a predetermined value, the valve body 23 of the relief valve 20 resists the urging force of the return spring 27 and causes the return spring 27 to move. The valve seat 13 of the return side fluid introduction path 12 is opened by sliding in the compression direction.

  When the valve body 23 of the relief valve 20 opens the valve seat port 13 of the return side fluid introduction passage 12, the return spring 27 is formed on the outer peripheral surface 26c of the annular groove 26 formed on the lower surface 25c of the cover 25. Since the tilt can be reliably prevented, the outer peripheral surface 23b of the valve body 23 does not interfere with the plurality of ribs 22 of the inner peripheral surface 21b of the cylindrical body 21 in which the valve body 23 is slidably accommodated. The body 23 can be smoothly slid. As a result, it is possible to prevent the vortex of the return fuel 59A from being generated, and to reliably prevent the generation of abnormal noise when the relief valve 20 is operated.

  In addition, according to the said embodiment, although the case where the jet pump was used for the vertical fuel tank (fuel tank) of the motor vehicle was demonstrated, of course, the said embodiment is applicable to tanks other than a fuel tank. Further, the cylindrical body of the relief valve is integrally formed on the nozzle body, but a separate body from the nozzle body may be used. In addition, the outer peripheral surface of the annular concave groove formed on the lower surface of the cover is a guide portion that holds the return spring in a direction perpendicular to the lower surface, but an annular concave portion is formed on the lower surface of the cover. A cylindrical body separately formed in the annular recess may be fitted to serve as a guide portion for the return spring.

It is sectional drawing which shows the jet pump of one Embodiment of this invention. It is an expanded sectional view around the relief valve of the jet pump. It is a front view of the cylindrical body of the relief valve. (A) is sectional drawing of the cover of the said relief valve, (b) is a bottom view of the cover. It is a schematic diagram which shows the state which assembled | attached the said jet pump in the vertical fuel tank. It is sectional drawing of the conventional jet pump.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Jet pump 11 Nozzle main body 12 Return side fluid introduction path 12a Nozzle 13 Valve seat port 14 Sub tank side fluid introduction path 18 Diffuser 20 Relief valve 21 Cylindrical body 21a Opening part 23 Valve body 23b Outer peripheral surface 25 Cover 25c Lower surface (Inner surface)
26 Concave groove part 26 Outer peripheral surface (guide part)
27 Return spring 59A Return side fuel (return side fluid)
59B Subtank side fuel (Subtank side fluid)

Claims (2)

A return side fluid introduction path for introducing a return side fluid, a nozzle for injecting a return side fluid introduced into the return side fluid introduction path, a sub tank side fluid introduction path for introducing a sub tank side fluid, and the return A nozzle body having a relief valve that is disposed in the side fluid introduction path and opens the valve seat when the fluid pressure in the return side fluid introduction path exceeds a predetermined value, and is attached to the nozzle body The sub-tank side fluid introduced into the sub-tank side fluid introduction path is sucked by the return-side fluid jet, and the return-side fluid jetted from the nozzle and the sucked sub-tank side fluid are discharged. In a jet pump with a diffuser that
A cylindrical body projecting outwardly from the valve seat opening of the nozzle body, a valve body that slides inside the cylindrical body and opens and closes the valve seat opening, and covers an opening of the cylindrical body. A cover and a return spring that is interposed between the valve body and the cover in the cylindrical body and biases the valve body in a direction to close the valve seat opening; A jet pump characterized in that a guide portion for holding the return spring is formed in the vertical direction. The jet pump according to claim 1,
A jet pump characterized in that the cover is formed in a disc shape, an annular concave groove portion is formed on the inner surface of the disc-shaped cover, and the outer peripheral surface of the concave groove portion is used as the guide portion.

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