JP2002310025A - Pressure adjusting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To heighten a preset pressure value in a novel pressure adjusting system. SOLUTION: This pressure adjusting system 1 is composed of a pressure passage 2 having a branch passage 20 to which a pressure fluid flows, a first case 30 having a pressure receiving chamber 33 and a pressure release chamber 34 connected to the branch passage 20, and in which the pressure fluid flows, a second case 31 having a back pressure chamber 38 cut off from the pressure receiving chamber 33 and the pressure release chamber 34 by a diaphragm, and an energizing means 37 arranged in the back pressure chamber 38, and energizing the diaphragm 36 in the partition wall direction, and has a pressure regulator 3 for adjusting pressure of the pressure fluid to the preset pressure value, and is characterized by having a pressure aiding system 4 for enhancing the preset pressure value by aiding energizing force of the energizing means 37 by making the fluid adjusted to an aided pressure value flow in the back pressure chamber 38.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure regulating system for suppressing pulsation of a pressure fluid and regulating the fluid pressure to a constant value.

[0002]

2. Description of the Related Art A pressure regulating system is provided in a fuel passage connecting a fuel tank and a fuel injection valve of a fuel supply device of an automobile, for example. The pulsation of the fuel flowing in the fuel passage is adjusted to a predetermined pressure by a pressure regulator. FIG. 4 shows a conventional pressure adjusting system. As shown in the figure, a conventional pressure adjusting system 100 includes a fuel passage 101, a high-pressure pressure regulator 102, a low-pressure pressure regulator 103, and an electromagnetic three-way valve 104.
And

[0003] A fuel passage 101 is provided between a fuel pump 105 and a delivery pipe. The fuel pressurized by the fuel pump 105 is pumped to the delivery pipe.

A high-pressure passage 106 and a low-pressure passage 107 are connected to the fuel passage 101 in a cross-shaped manner.
An electromagnetic three-way valve 104 is provided at the crossroads. That is, the fuel passage 101 and the high pressure passage 106 or the fuel passage 10
1 and the low-pressure passage 107 are connected to each other so as to be switchable in a three-way manner.

The high-pressure passage 106 is connected to the high-pressure pressure regulator 102. The high-pressure pressure regulator 102 has a first case 130 and a second case 140. The first case 130 has a cup shape. And it is arrange | positioned with the opening part upward.
Inside the first case 130, a cylindrical partition 113 is erected. A pressure receiving chamber 108 connected to the high-pressure passage 106 is arranged on the outer peripheral side of the partition 113. On the other hand, a pressure release chamber 109 is arranged on the inner peripheral side of the partition 113. A pressure relief pipe 115 connected to the outside is connected to the lower surface of the pressure relief chamber 109.

[0006] The partition 113 has a cylindrical sheet portion 114 at the upper end on the inner peripheral side. And this seat part 1
Above 14, a diaphragm 111 is provided.
Further, above the diaphragm 111, a cup-shaped second case 140 is installed with the opening facing downward. The back pressure chamber 110 is disposed inside the second case 140. A spring 112 for urging the diaphragm 111 downward is provided on the upper end surface of the back pressure chamber 110. A back pressure pipe 116 connected to the outside is connected to a side surface of the back pressure chamber 110.

On the other hand, the low-pressure passage 107 is connected to the low-pressure pressure regulator 103. The configuration of the low-pressure pressure regulator 103 is the same as that of the high-pressure pressure regulator 102. However, the urging force of the spring is set to be higher in the high-pressure pressure regulator 102 than in the low-pressure pressure regulator 103.

[0008]

In the conventional pressure adjusting system, the back pressure pipe connected to the back pressure chamber of the pressure regulator is connected to the inside of the fuel tank or the inside of the intake manifold. The pressure of the fuel (pressure fluid) is adjusted by the spring (biasing means) alone. For this reason, the set pressure value of the pressure regulator has been determined to be a predetermined value depending on the type of the urging means. For example, when a spring is used as the urging means, the set pressure value of the pressure regulator is determined by the spring constant of the spring. Therefore, in order to increase the set pressure value, it is necessary to replace the urging member or the pressure regulator itself.

The pressure adjustment system of the present invention has been completed in view of the above problems. That is, an object of the present invention is to provide a pressure adjustment system capable of increasing a set pressure value without replacing an urging member or a pressure regulator.

[0010]

In order to solve the above-mentioned problems, a pressure regulating system according to the present invention comprises a pressure passage having a branch passage through which a pressure fluid flows, a pressure receiving chamber connected to the branch passage, and a pressure receiving chamber and a partition wall. A first case having a pressure relief chamber defined as a chamber, a second case having a back pressure chamber which is isolated from the pressure receiving chamber and the pressure relief chamber by a diaphragm, and a diaphragm installed in the back pressure chamber in a direction of a partition wall. The lift amount from the partition of the diaphragm is changed by the balance between the urging force of the urging means and the pressure of the pressure fluid in the pressure receiving chamber, and the degree of communication between the pressure receiving chamber and the pressure release chamber is increased. A pressure regulator for adjusting the pressure of the pressurized fluid to a set pressure value by changing the pressure of the pressurized fluid to a set pressure value. And having a pressure grant system to increase the grant set pressure value a biasing force.

That is, the pressure regulating system of the present invention has a pressure assisting system. Then, the fluid pre-regulated by the pressure assisting system is introduced into the back pressure chamber of the pressure regulator to assist the urging force of the urging means.

For example, the urging force of the urging means, that is, the initial set pressure value of the pressure regulator is set to P0, and the assisting pressure value of the fluid regulated by the pressure assisting system is set to P1. In this case, the set pressure value P2 after the assistance is P0 + P1. Thus, according to the pressure regulation system of the present invention,
The set pressure value can be increased without replacing the urging means of the pressure regulator or the pressure regulator itself.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION As a fluid in a pressure assisting system, a gas such as air or an inert gas, or a liquid such as water, gasoline or light oil can be used. As a means for pressurizing the fluid in the pressure assisting system, for example, a pump, a compressor, a blower, or the like can be used.
Further, when the pressure value of the fluid cannot be adjusted to the assisting pressure value by only these pressurizing means, a pressure regulator or the like may be used as the pressure adjusting means. Further, the assistance pressure value of the pressure assistance system may not be a single value. For example, a configuration may be adopted in which a plurality of subsidizing means each including a pressurizing unit and a pressure regulating unit and having different subscribing pressure values are provided, and these subgroups are switched to have a plurality of subscribing pressure values.

Preferably, the pressure assisting system includes an assisting pressure passage connecting the pressure release chamber and the back pressure chamber of the pressure regulator, an assisting branch passage connected to the assisting pressure passage,
A first case having a supporting pressure receiving chamber that is connected to the supporting branch passage and into which the pressure fluid flows in from the pressure releasing chamber, and a supporting pressure releasing chamber that is separated from the supporting pressure receiving chamber by a partition; A second case having an auxiliary back pressure chamber to be shut off, and an urging means installed in the auxiliary back pressure chamber for urging the diaphragm in the direction of the partition wall, the urging force of the urging means and the pressure fluid in the auxiliary pressure receiving chamber. A sub-pressure regulator that adjusts the pressure of the pressurized fluid to a sub-pressure value by changing the lift amount of the diaphragm from the partition wall in balance with the pressure of the diaphragm and changing the degree of communication between the sub-pressure receiving chamber and the sub-pressure release chamber. It is better to have a configuration.

That is, in this configuration, the pressure fluid to be pressure-adjusted flows into the pressure assisting system. Then, the pressure of the pressure fluid is adjusted to a subsidized pressure value by the subsidized pressure regulator, and is sent to the back pressure chamber of the pressure regulator.

According to this configuration, a part of the pressure fluid is used as the fluid for the pressure assist system. Therefore,
Pressurizing means for the pressurized fluid will also be used for the pressure assist system. Therefore, it is not necessary to separately provide a pressurizing means for the pressure assisting system. Note that a coil spring, a U-shaped spring, or the like can be used as the urging means of the subsidy pressure regulator. In this respect, the same applies to the urging means of the pressure regulator.

[0017] Preferably, the above-mentioned structure is further characterized in that the flow control means is provided downstream of the sub-branch passage in the sub-pressure passage, and one end of the sub-pressure passage is connected to the upstream side of the flow control means and the other end is open to the outside. An upstream open passage provided with a throttle means on the way, and a downstream open passage provided with a throttle means in the middle while the other end is connected to the downstream side of the flow rate control means and the other end is opened to the outside in the auxiliary pressure passage,
It is preferable that the set pressure value is increased by opening the flow control means, and the set pressure value is reduced by closing the flow control means.

That is, in this configuration, the flow rate of the pressure fluid flowing into the back pressure chamber of the pressure regulator is controlled by the flow rate control means. Further, the pressure of the back pressure chamber is maintained by the throttle means provided in the upstream open passage and the downstream open passage.

Again, the initial set pressure value of the pressure regulator is set to P0, and the supporting pressure value of the fluid regulated by the pressure supporting system is set to P1. The final set pressure value is set to P2. Here, when the flow control means is closed, the pressure fluid does not flow into the back pressure chamber. That is, there is no pressure support. Therefore, the set pressure value P2 remains at P0.
On the other hand, when the flow control means is opened, the pressure fluid flows into the back pressure chamber. That is, pressure is assisted. Therefore, the set pressure value P
2 is a value obtained by adding P1 to P0. According to this configuration, the set pressure value of the pressure regulator is changed from P0 to P
You can switch up to two.

By the way, in the conventional fuel supply apparatus, for example, when the vehicle is parked for a short time, if the engine is once stopped and restarted at a high temperature, there is a problem that vapor is generated in the fuel passage. In order to avoid the generation of the vapor, the fuel pressure may be increased when the engine is restarted at a high temperature.

Therefore, as shown in FIG. 4, a pressure adjusting system in which two pressure regulators for low pressure and high pressure are arranged in parallel has been developed. However, in the conventional pressure adjustment system 100, the total amount of fuel is switched between the high-pressure passage 106 and the low-pressure passage 107 by the electromagnetic three-way valve 104. For this reason, when the flow rate of the fuel flowing through the fuel passage 101 is increased, the following problem occurs.

First, when increasing the flow rate of the fuel, it is necessary to increase the valve diameter of the electromagnetic three-way valve 104 and strengthen the magnetic attraction force. Therefore, the electromagnetic three-way valve 104,
As a result, the entire pressure adjusting system 100 is increased in size and cost.

Second, when the flow rate of the fuel is increased, a throttle loss is likely to occur in the electromagnetic three-way valve 104. For this reason, the pressure regulation accuracy of the pressure regulation system 100 is reduced by the throttle loss. Also, due to the decrease in the pressure regulation accuracy, the fuel injection amount to the engine deviates from the control target value. Finally, the exhaust emissions deteriorate.

According to the present configuration, the set pressure value of the pressure regulator can be switched from P0 to P2 with respect to this conventional pressure adjusting system as described above. For this reason, it is not necessary to arrange two pressure regulators for low pressure and high pressure in parallel. That is, there is no need to install the electromagnetic three-way valve 104. Further, since the flow rate control means is for pressure assistance, there is no need to increase the size even if the fuel flow rate is large. Therefore, the entire pressure adjusting system can be downsized. Further, the pressure regulation accuracy can be improved.

Here, the throttle means provided in the upstream open passage and the downstream open passage may be any as long as they have a pressure loss that can maintain the pressure in the back pressure chamber. For example, an orifice, a nozzle, a venturi, or the like can be used.

As the flow control means, a general-purpose gate valve, globe valve, angle valve, or the like can be used. Note that an electromagnetic type, a pneumatic type, a hydraulic type, or the like can be used as a driving method of the flow rate control means.

Preferably, the flow rate control means is a proportional control valve. According to this configuration, the pressure loss ratio of the throttle means provided in the upstream open passage and the downstream open passage can be freely controlled. For this reason, the set pressure value of the pressure regulator can be freely switched in a slope form from P0 to P2.

Preferably, the pressure adjusting system is disposed in a fuel tank of the vehicle, and the pressure passage is a fuel passage connecting the fuel tank and the fuel injection valve. According to this configuration, the pressure adjustment system can be installed separately from the high-temperature engine. Therefore, generation of vapor in the fuel can be more effectively suppressed.

The embodiment of the pressure adjusting system according to the present invention has been described above. However, embodiments are not limited to the above embodiments. It can be performed in various modified applications that can be performed by those skilled in the art.

[0030]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a pressure adjusting system according to the present invention will be specifically described with reference to embodiments. The pressure adjusting system according to the present embodiment is disposed in a fuel passage connecting a fuel tank of an automobile fuel supply device and a fuel injection valve.

(1) First, the configuration of the pressure adjusting system of this embodiment will be described. FIG. 1 shows a schematic diagram of the pressure adjustment system of the present embodiment. As shown in the figure, the pressure adjustment system 1 of the present embodiment is installed above a fuel tank 200. The pressure adjusting system 1 has a fuel passage 2, a pressure regulator 3, and a pressure assisting system 4.

The fuel passage 2 is provided between the fuel pump 300 and the delivery pipe. Also, the fuel passage 2
There is a branch passage 20 that branches off from the fuel passage 2 in a three-way manner.

The pressure regulator 3 is connected to the branch passage 20. The pressure regulator 3 has a first case 30 and a second case 31. The first case 30 has a cup shape that opens upward.
Inside the first case 30, a cylindrical partition wall 32 extends upward and stands upright. A cylindrical pressure receiving chamber 33 connected to the branch passage 20 is arranged on the outer peripheral side of the partition wall 32. On the other hand, on the inner peripheral side of the partition wall 32, a cylindrical pressure release chamber 34 is arranged. In addition, the partition wall 32 includes a similarly cylindrical sheet portion 320 at the upper end on the inner peripheral side.

Above the first case 30, a cup-shaped second case 31 that opens downward is provided. Further, a thin-film disk-shaped diaphragm 36 is disposed so that the periphery thereof is sandwiched between the opening of the first case 30 and the opening of the second case 31. A valve portion 360 is disposed below the center of the diaphragm 36. On the other hand, a spring receiver 361 is disposed above the center of the diaphragm 36. Note that the diaphragm 36, the valve portion 360, and the spring receiver 361 move up and down integrally.

A back pressure chamber 38 is arranged inside the second case 31. A spring 37 is interposed between the upper surface of the back pressure chamber 38 and the spring receiver 361. The diaphragm 36 is urged downward by the spring 37.

The pressure assistance system 4 includes an assistance pressure passage 40
And a sub-branch passage 41 and a sub-pressure regulator 5. Further, an electromagnetic cutoff valve 43, an upstream open passage 44, and a downstream open passage 45
And are arranged.

The auxiliary pressure passage 40 connects the pressure release chamber 34 and the back pressure chamber 38 of the pressure regulator 3. From the pressure release chamber 34 side, that is, from the upstream side, an upstream opening passage 44 and a subsidizing branch passage 41
The electromagnetic cutoff valve 43 and the downstream open passage 45 are connected. That is, the upstream opening passage 44 and the sub-branch passage 41 are branched from the sub-pressure passage 40 in a cross-shaped manner. An orifice 46 is provided in the upstream opening passage 44 which branches off from the auxiliary pressure passage 40 in a three-forked manner. The end of the upstream opening passage 44 on the side opposite to the auxiliary pressure passage 40 side is opened into the fuel tank 200.

Similarly, an orifice 47 is also provided in the downstream opening passage 45. Further, the end of the downstream opening passage 45 on the side opposite to the auxiliary pressure passage 40 side is also connected to the fuel tank 20.
It is open to 0.

The sub-pressure regulator 5 is connected to the sub-branch passage 41. The configuration of the further pressure regulator 5 is the same as the configuration of the pressure regulator 3 described above. Briefly, the subsidy pressure regulator 5 has a first case 50 and a second case 51. A partition 52 is erected inside the first case 50. A sub-pressure receiving chamber 53 connected to the sub-branch passage 41 is arranged on the outer peripheral side of the partition wall 52. On the other hand, partition 5
A sub-pressure release chamber 54 is arranged on the inner peripheral side of 2. The partition wall 52 has a sheet portion 520 at the upper end on the inner peripheral side.
Above the first case 50, a second case 51 is installed. Further, a diaphragm 56 is provided between the first case 50 and the second case 51. A valve section 560 is disposed below the center of the diaphragm 56. Further, a spring receiver 561 is arranged above. An auxiliary back pressure chamber 58 is disposed inside the second case 51. The upper surface of the back pressure chamber 58 and the spring receiver 561 are also provided.
And a spring 57 is interposed between them. The diaphragm 56 is urged downward by the spring 57. The pressure release passage 59 connected below the sub-pressure release chamber 54 is connected to the lower open passage 45 and is opened into the fuel tank 200.

(2) Next, the pressure adjusting system 1 of the present embodiment.
The case where the set pressure value is set to a high pressure value will be described. For convenience of explanation, an initial set pressure value of only the spring 37 of the pressure regulator 3 is set to P0. Further, the assistance pressure value of the assistance pressure regulator 5 is set to P1. Further, a final set pressure value of the pressure regulator 3, that is, a high pressure value is set to P2.

When the set pressure value is set to the high pressure value P2, the electromagnetic cutoff valve is opened by a control signal from an electronic control unit (not shown). FIG. 2 shows an equivalent circuit diagram when the electromagnetic cutoff valve is opened. Members corresponding to those in FIG. 1 are indicated by the same symbols. As shown in FIG. 2, a spring 37 is installed in the back pressure chamber 38 of the pressure regulator 3. The initial set pressure value of the pressure regulator 3 determined by the spring 37 is P0. When the electromagnetic cutoff valve is opened, the pressure release chamber 34 of the pressure regulator 3 and the back pressure chamber 38 are connected by the auxiliary pressure passage 40. Then, the fuel flowing out of the pressure release chamber 34 flows into the pressure receiving chamber 53 of the sub-pressure regulator 5. Here, the assistance pressure value of the assistance pressure regulator 42 is P1
It is. Therefore, the pressure value of the fuel also becomes P1.

The auxiliary pressure passage 40 is connected to an upstream open passage 44 and a downstream open passage 45 which open into the fuel tank. However, the inside of the fuel tank is almost at atmospheric pressure. For this reason, the pressure value P1 of the fuel may decrease. Therefore, in order to suppress the pressure drop, the upstream opening passage 44 and the downstream opening passage 45 are provided with orifices 46 and 47, respectively. Thus, the fuel pressure value is maintained at P1.

When the fuel having the pressure value P1 flows into the back pressure chamber 38, the initial set pressure value P0 is promoted and the set pressure value becomes the high pressure value P2. That is, the high pressure value P2 is the sum of the initial set pressure value P0 and the assisting pressure value P1.

(3) Next, the pressure adjusting system 1 of the present embodiment.
The case where the set pressure value is set to a low pressure value will be described. For convenience of explanation, a set pressure value of only the spring 37 of the pressure regulator 3 is set to P0. Further, a final set pressure value of the pressure regulator 3, that is, a low pressure value is set to P3.

When the set pressure value is set to the low pressure value P3, the electromagnetic cutoff valve is closed by a control signal from an electronic control unit (not shown). FIG. 3 shows an equivalent circuit diagram when the electromagnetic cutoff valve is closed. Members corresponding to those in FIG. 1 are indicated by the same symbols. As shown in FIG. 3, when the electromagnetic cutoff valve is closed, the pressure release chamber 3 of the pressure regulator 3 is closed.
4 and the back pressure chamber 38 are shut off. Therefore, the pressure assistance by the assistance pressure regulator 5 cannot be received.
The pressure release chamber 34 is connected to the inside of the fuel tank via the upstream open passage 44. The back pressure chamber 38 also has a downstream open passage 45.
Connected to the fuel tank via the Therefore, the low pressure value P3 of the pressure regulator 3 is equal to the initial set pressure value P
It becomes 0.

(4) As described above, according to the present embodiment, the fuel pressure can be switched in two stages, the high pressure value P2 and the low pressure value P3. In the present embodiment, the upstream opening passage 44 and the sub-branch passage 41 are arranged in a cross-shaped manner, but one may be arranged on the upstream side and the other may be arranged on the downstream side. However, both need to be arranged on the upstream side of the electromagnetic cutoff valve 43.

[0047]

According to the pressure adjusting system of the present invention, it is possible to provide a pressure adjusting system capable of increasing the set pressure value.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a pressure adjustment system according to an embodiment.

FIG. 2 is an equivalent circuit diagram when a set pressure value is a high pressure value.

FIG. 3 is an equivalent circuit diagram when a set pressure value is set to a low pressure value.

FIG. 4 is a schematic diagram of a conventional pressure adjustment system.

[Explanation of symbols]

1: pressure adjustment system 2: fuel passage 20: branch passage 3: pressure regulator 30: first case 3
1: second case 32: partition wall 320: sheet part 33: pressure receiving chamber 34:
Pressure relief chamber 36: Diaphragm 360: Valve portion 361: Spring receiver 37: Spring 38: Back pressure chamber 4: Pressure assist system 40: Support pressure passage 41: Support branch passage 43: Electromagnetic cutoff valve 44: Upstream open passage 45 : Downstream open passage 46: Orifice 47: Orifice 5: Subsidy pressure regulator
50: first case 51: second case 52: partition wall 53: subsidy pressure receiving chamber 5
4: Subsidized pressure release chamber 520: Seat section 56: Diaphragm 560: Valve section 561: Spring receiver 57: Spring 58: Subsidiary back pressure chamber 59: Pressure release passage 200: Fuel tank 300: Fuel pump

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16K 17/06 F16K 17/06 B G05D 16/06 G05D 16/06 SF Term (Reference) 3G066 AA01 AB02 BA37 BA51 BA67 CB07 CB11 CB15 CB16 CE34 CE35 3H059 AA05 BB05 CD05 CD12 CE05 EE01 EE13 FF13 FF16 5H316 AA09 BB09 CC01 EE02 EE10 EE14 JJ07 JJ09 JJ14 KK01

Claims (5)

[Claims] A first case having a pressure passage provided with a branch passage through which a pressure fluid flows, a pressure receiving chamber connected to the branch passage and into which the pressure fluid flows, and a pressure release chamber divided by the partition wall from the pressure receiving chamber; A second case having a back pressure chamber that is isolated from the pressure receiving chamber and the pressure relief chamber by a diaphragm, and a biasing unit that is installed in the back pressure chamber and biases the diaphragm toward the partition wall.
The lift amount of the diaphragm from the partition is changed by balancing the urging force of the urging means and the pressure of the pressure fluid in the pressure receiving chamber, and the degree of communication between the pressure receiving chamber and the pressure release chamber is changed. A pressure regulator for adjusting the pressure of the pressurized fluid to a set pressure value by changing the pressure of the pressurized fluid to a set pressure value. A pressure assisting system for assisting the urging force of (1) and increasing the set pressure value. 2. The pressure subsidy system includes: a subsidy pressure passage connecting the pressure release chamber and the back pressure chamber of the pressure regulator; a subsidy branch passage connected to the subsidy pressure passage; And a first case having a sub-pressure receiving chamber into which the pressure fluid flows from the pressure-release chamber and a sub-pressure releasing chamber partitioned from the sub-pressure receiving chamber by a partition, and the sub-pressure receiving chamber and the sub-pressure releasing by a diaphragm. A second case having an auxiliary back pressure chamber that is isolated from the chamber, and urging means installed in the auxiliary back pressure chamber and urging the diaphragm in the direction of the partition wall, the urging force of the urging means The amount of lift of the diaphragm from the partition is changed by balancing with the pressure of the pressure fluid in the sub-pressure receiving chamber, and the pressure of the pressure fluid is changed by changing the degree of communication between the sub-pressure receiving chamber and the sub-pressure release chamber. The above subsidy pressure value Pressure control system according to claim 1 having a grant pressure regulator to adjust, the. 3. A flow control means provided downstream of the sub-branch passage in the sub-pressure passage, one end of the sub-pressure passage being connected to the upstream side of the flow control means and the other end being opened to the outside and An upstream open passage having a throttle means, and a downstream open passage having one end connected to the downstream side of the flow rate control means and the other end opened to the outside and having a throttle means in the middle of the auxiliary pressure passage, The pressure adjustment system according to claim 2, wherein the set pressure value is increased by opening the flow control means, and the set pressure value is decreased by closing the flow control means. 4. The pressure adjusting system according to claim 3, wherein said flow control means is a proportional control valve. 5. The pressure regulation system according to claim 1, wherein the pressure passage is disposed in a fuel tank of the vehicle, and the pressure passage is a fuel passage connecting the fuel tank and a fuel injection valve.