JP2009174338A - Fuel pressure regulator and fuel supply device using same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel pressure regulator capable of inhibiting generation of decompression boiling noise itself. <P>SOLUTION: This regulator includes; a casing comprising a case including a fuel inlet from a fuel pump, and a housing including a fuel outlet to a fuel tank provided with a fuel pump; a fixed valve unit oscillatably positioned in the casing; a diaphragm partitioning an inside of the casing into a pressure chamber and a back pressure chamber by being fixed when the case and the housing are fastened; a movable valve unit provided with a valve seat provided with a communication hole providing communication between the pressure chamber and the back pressure chamber, and contacting with and separating from the fixed valve unit; and a spring making the movable valve unit contact with the fixed valve unit. The communication hole of the valve seat has different diameter at an opening toward the pressure chamber and at an opening toward the back pressure chamber. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a fuel pressure that adjusts a fuel pressure to a predetermined value among members constituting a fuel supply device that is mounted in a fuel tank of a vehicle or the like and pressurizes and supplies fuel to an injector that injects fuel into an engine. More specifically, the regulator relates to the internal structure of the fuel pressure regulator.

  In order to improve exhaust gas regulations and improve fuel efficiency, it is necessary to supply an appropriate amount of fuel to the injector, and this injector must inject the fuel in a mist form. To this end, the pressure of the fuel supplied to the injector must be kept constant. It is essential to keep. Therefore, it is widely known that a fuel pressure regulator is disposed in the next stage of the fuel filter that filters the fuel pressurized by the fuel pump.

  An example of the structure of this fuel pressure regulator is as follows. The casing is partitioned into a pressure chamber and a back pressure chamber by a diaphragm, and a movable valve having a valve hole that is fixed to the diaphragm and communicates between the two chambers. And a fixed valve body provided on the pressure chamber side, and a spring provided in the back pressure chamber and seating the movable valve body on the fixed valve body. In this case, when the fuel pressurized by the fuel pump flows into the pressure chamber, the diaphragm continuously moves to a position where the force received by the fuel pressure in the pressure chamber and the urging force of the spring balance, in other words, both valves By repeatedly sitting and separating between the bodies, the amount of fuel discharged from the back pressure chamber is adjusted, and the pressure of the fuel supplied from the fuel filter toward the injector is kept constant.

  Further, the pressure chamber is further divided into a fuel inlet side and a diaphragm side by a fixed valve guide that holds the fixed valve body, and the both are made to communicate with each other. It can be accommodated in the fuel tank as one member. For this reason, surplus fuel is heated by the heat of the engine as compared with the case where the fuel discharged from the back chamber, that is, surplus fuel is directly returned into the fuel tank, as compared with the case where it is disposed between the fuel tank and the engine. And generation of fuel vapor and bubbles in the fuel tank can be suppressed.

  Here, when the surplus fuel from the fuel pressure regulator is discharged into the fuel tank, a large flow noise is likely to occur when the pressurized surplus fuel is released from the narrow flow path into the atmospheric pressure. This is because the fuel pressurized to several hundred kilopascals by the fuel pump is lowered to atmospheric pressure at a stretch within a short distance. Therefore, this flow noise, that is, the noise caused by the reduced-pressure boiling sound when surplus fuel is discharged from the fuel pressure regulator is closed up.

  The reason is that due to recent technological innovation, the vibration or noise of the engine is remarkably reduced, and this is largely due to the further improvement of the quietness of the vehicle. In other words, since this quietness greatly affects the sensitivity quality of the vehicle, it is not an exception as the noise at the time of surplus fuel discharge described above, and the sensitivity quality deteriorates due to this noise propagating through the fuel tank, that is, Therefore, it is necessary to avoid a decrease in the comfort and merchantability of the vehicle due to anxiety and discomfort to the driver. Therefore, a maze member that provides a sound insulation effect, that is, a silencer (see, for example, Patent Document 1) and a fixed throttle valve that gradually reduces the fuel pressure to the pressure of the fuel tank (see, for example, Patent Document 2) at the surplus fuel discharge port. In addition, it is disclosed to suppress the generated low-pressure boiling sound.

Japanese Patent No. 3858272 (page 9, line 49 to page 10, line 5, FIG. 12) Japanese Patent No. 3067626 (page 3, left column, lines 12-16), FIG. 2)

  In order to reduce the vacuum boiling noise, members are inevitably added in this way. In particular, in the fuel pressure regulator of Patent Document 1, the regulator itself is increased in size and the layout in the fuel tank is restricted. However, there is a problem that mountability as a fuel supply device deteriorates. In this respect, although the fuel pressure regulator of Patent Document 2 is slightly improved, the amount of adjustment pressure work (spring load adjustment after assembling the regulator) cannot be denied due to the protruding fixed throttle valve. On the other hand, if a fixed throttle valve is added after the adjustment pressure operation, the adjustment pressure increases due to the flow path resistance of the fixed throttle valve.

  In the first place, whether it is a silencer or a fixed throttle valve, it is necessary only because the decompression boiling sound occurs. However, the present invention provides a fuel pressure regulator that can suppress the generation of the decompression boiling sound itself. It is for the purpose.

  Through experiments and verifications by the inventors, it has been found that the source of the vacuum boiling sound is directly under the seal surface of the valve seat (the contact surface between the fixed valve body and the movable valve body described above). Therefore, a fuel pressure regulator according to the present invention includes a casing including a case having a fuel inlet from a fuel pump and a housing having a fuel outlet to a fuel tank in which the fuel pump is disposed, and the case. A fixed-side valve unit positioned so as to be able to swing, a diaphragm that is fixed when the case and the housing are fixed, and that defines the inside of the casing into a pressure chamber and a back pressure chamber, and the pressure chamber and the back pressure chamber. A valve seat provided with a communication hole that communicates with the movable valve unit, a movable valve unit that is in contact with and away from the fixed valve unit, and a spring that contacts the movable valve unit with the fixed valve unit. The diameter of the communication hole of the seat is different between the opening toward the pressure chamber and the opening toward the back pressure chamber. It is.

  As described above, the present invention can provide an inexpensive and small fuel pressure regulator that can greatly contribute to the improvement of the sensibility quality of the vehicle, and as a result, a fuel supply device with improved mounting properties in the fuel tank. It becomes possible to provide.

Embodiment 1 FIG.
1 is an external perspective view of a fuel pressure regulator according to Embodiment 1 of the present invention, FIG. 2 is an exploded perspective view of FIG. 1, and FIG. 3 is a sectional view of FIG.

  As shown in FIG. 1, a fuel pressure regulator (hereinafter referred to as a pressure regulator) 101 is composed of a case 1 and a housing 2 in terms of its external appearance. More specifically, a flange 1a (see FIG. 2) is press-inserted into the receiving portion 2a (see FIG. 2) of the housing 2, the tip 2a1 of the receiving portion 2a is bent inward, and the case 1 and the housing 2 are fixed and function as the casing 21. A fuel inlet 1b is formed in the case 1, and a fuel outlet 2b (see FIG. 3) is formed in the housing 2. However, as indicated by the arrows, the fuel flows from the top to the bottom on the paper. become. As is well known, fuel that has been pressurized and filtered by a fuel pump and a fuel filter (both not shown) reaches the fuel inlet 1b and is directed toward an injector (not shown) by the pressure regulator 101. As a result of maintaining the pressure of the supplied fuel at a predetermined value, surplus fuel is discharged from the fuel outlet 2b. At this time, since the fuel supply device in which the pressure regulator 101 is disposed is mounted in a fuel tank (not shown), the above “excess fuel” is directly returned to the fuel tank, and again the fuel pump. Will be sucked and pressurized. Further, in order to connect the pressure regulator 101 to a fuel supply line (for example, a fuel filter case) between the fuel filter and the injector in a liquid-tight manner, the case 1 is provided with an O-ring 3.

  As shown in FIG. 2, the cup 4c of the housing 2 is provided with a spring 4 on the bottom surface of the cup 2c so as not to interfere with the fuel outlet 2b, that is, its inner diameter serves as a fuel flow path. The convex portion 2c1 and a spring guide 5 (see FIG. 3) to be described later are provided for positioning. The spring 4 urges the diaphragm 6 upward on the paper surface via the spring guide 5, but the outer diameter of the diaphragm 6 is substantially the same as that of the flange portion 1a. When the two are fixed, the diaphragm 6 is also fixed, that is, interposed between the flange portion 1a and the receiving portion 2a. However, the casing 21 is divided into two chambers by the diaphragm 6. These two chambers are referred to as a pressure chamber on the paper surface of the diaphragm 6, that is, the case 1 side, and a lower side, that is, the housing 2 side, as a back pressure chamber.

  As shown in FIG. 3, the diaphragm 6 is sandwiched between the spring guide 5 and the armature 7 so that the diaphragm 6 follows the movement of the spring guide 5 due to the urging of the spring 4, and these two members are fixed by caulking or the like. Yes. Here, a valve seat 8 which is a cylindrical member is press-fitted into the armature 7 so as to protrude from the surface of the armature 7. However, the diaphragm 6 is partitioned by the communication hole 8 a of the valve seat 8. The two chambers formed communicate with each other, specifically, the fuel flows from the pressure chamber toward the back pressure chamber. In addition, the integral structure by the spring guide 5, the diaphragm 6, the armature 7, and the valve seat 8, that is, the movable valve body equivalent in Patent Document 1, is referred to as “movable side valve unit 22” herein.

  On the other hand, in the case 1, a fixed side valve unit 23, which is obtained by welding the rigid ball 9 and the valve 10, for example, corresponding to the fixed valve body in Patent Document 1, is urged downward on the paper by the valve spring 11. It is prepared to be. That is, both the movable side and fixed side valve units 22 and 23 are arranged so as to oppose each other. Specifically, in the casing 21, the valve seat 8 and the valve 10 are positioned so that their surfaces face each other. . Therefore, as in Patent Document 1, as the engine starts, the fuel flows into the pressure chamber, and the diaphragm 6 constantly moves to a position where the force received by the fuel pressure in the pressure chamber and the biasing force of the spring 4 in the back pressure chamber are balanced. As a result, the valve seat 8 that has been seated (closed) on the valve 10 is separated (opened), and when this valve is opened, fuel flows into the back pressure chamber through the valve seat 8 and surplus from the fuel outlet 2b. By discharging as fuel, the pressure of the fuel supplied toward the injector is kept constant.

  Hereinafter, the valve seat 8 which is a main part of the present invention will be described. The communication between the pressure chamber and the back pressure chamber through the communication hole 8a of the valve seat 8 is as described above, and this is the same as in Patent Document 1, but in the present invention, the communication hole 8a The shape has been devised. That is, the diameter is not constant, and the diameter of the opening toward the pressure chamber, that is, the sealing surface with the valve 10 is made larger than the diameter of the opening toward the back pressure chamber, that is, the outlet toward the fuel outlet 2b. Yes. In other words, a throttle function is added to the valve seat 8 itself, and the distance to reach the atmospheric pressure is shortened. By doing so, the back pressure is applied to the front side (on the paper surface, the upper side) from the diameter reducing portion 8a1 and the pressure is increased as a whole, and the pressure distribution region below the fuel saturation vapor pressure is increased, thereby reducing the pressure. The region where boiling occurs is reduced, and the generation of the vacuum boiling sound itself can be suppressed.

  In this way, the reduced pressure boiling sound is not reduced by the fixed throttle valve (Patent Document 2) over a long distance, but as described above, the reduced pressure boiling sound is generated just below the sealing surface with the valve. In particular, we succeeded in suppressing the vacuum boiling sound itself. As a result, as with Patent Document 2, when viewed as a small and fuel supply device, the pressure regulator can be dramatically improved while being a pressure regulator with excellent mountability, thereby reducing the cost of the product itself. Can be expected.

  Further, it is preferable that the diameter reduced portion 8a1 is formed in an edge shape because the suppression effect is higher. As described above, since the throttle function is added to the valve seat 8, the outlet of the valve seat 8 is closer to the fuel outlet 2b. Therefore, the outer diameter of the valve seat 8 is formed so as to become smaller toward the discharge port. By doing so, even if the movable side valve unit 22 is lifted obliquely, the valve seat 8 and the spring 4 do not interfere with each other, and stable pressure regulation performance can be obtained.

It is an external appearance perspective view of the pressure regulator in Embodiment 1 of this invention. It is a disassembled perspective view in FIG. It is sectional drawing in FIG.

Explanation of symbols

1 case, 1b fuel inlet, 2 housing, 2b fuel outlet,
4 Spring, 6 Diaphragm, 8 Valve seat, 8a Communication hole,
8a1 diameter reduction part, 10 valve, 21 casing,
22 movable side valve unit, 23 fixed side valve unit,
101 Fuel pressure regulator (pressure regulator).

Claims (3)

A casing comprising a case having a fuel inlet from a fuel pump and a housing having a fuel outlet to a fuel tank in which the fuel pump is disposed, a fixed-side valve unit positioned in a swingable manner in the case, A valve seat provided with a diaphragm that partitions the inside of the casing into a pressure chamber and a back pressure chamber by being fixed when the case and the housing are fixed, and a communication hole that communicates between the pressure chamber and the back pressure chamber. A fuel pressure regulator comprising: a movable valve unit that contacts and separates from the fixed valve unit; and a spring that brings the movable valve unit into contact with the fixed valve unit.
The fuel pressure regulator according to claim 1, wherein the communication hole of the valve seat has different diameters between an opening toward the pressure chamber and an opening toward the back pressure chamber. The diameter of the opening toward the pressure chamber is larger than the diameter of the opening toward the back pressure chamber, and the diameter of the opening toward the back pressure chamber from the diameter of the opening toward the pressure chamber in the communication hole of the valve seat 2. The fuel pressure regulator according to claim 1, wherein the throttle portion is formed in an edge shape. A fuel pump that pumps fuel in the fuel tank to an engine injector through a discharge pipe, a fuel filter that filters the fuel discharged from the fuel pump, and a pressure of the fuel discharged from the fuel pump to a predetermined pressure A fuel supply device comprising the fuel pressure regulator according to claim 1 or 2 that adjusts to

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