JP2001056064A - Fuel pressure control valve - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel pressure control valve supplying fuel exactly pressure-regulated from a fuel outflow path and having a high pulsation pressure damping effect. SOLUTION: In a valve main body 1, a diaphragm holding flat part 1A is provided on the upper side. At the center, a fuel return boss 1B provided with a valve seat 3 continuous to a fuel return passage 2 is formed by being projected from the diaphragm holding flat part to the upper side. An inner periphery part 1D of the diaphragm holding flat part 1A and an upper end outer peripheral part 1E of the fuel return boss 1B are connected with a connecting part 1F directing an oblique upper side. In the connecting part 1F, a fuel inflow path 4 and a fuel outflow path 5 are opened. A fuel chamber A is formed by a sectioning body 6 and the connecting part 1F.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressurized fuel, wherein a part of the fuel is released through a fuel return passage by the pressure of the fuel, whereby the fuel adjusted to a constant pressure from a fuel outflow passage is released. The present invention relates to a fuel pressure control valve to be supplied, and is used, for example, in a fuel supply device of an internal combustion engine.

[0002]

2. Description of the Related Art A conventional fuel pressure control valve is disclosed in
No. 4718. According to this, a partition body provided with a valve body is sandwiched between the upper end of the valve body and the lower end of the cover, and the partition body forms a fuel chamber on the valve body side and a spring chamber is formed on the cover side. . The fuel chamber has a concave shape that is deeper downward from the upper end of the valve body, and a fuel inflow passage and a fuel outflow passage are opened at or near the bottom of the fuel chamber, and a valve seat that is opened and closed by the valve body. The provided fuel return passage extends from the bottom of the fuel chamber toward the vicinity of the upper end of the valve body. When the fuel pressurized from the fuel inflow passage flows into the fuel chamber, the partition operates according to the pressure in the fuel chamber. When the fuel pressure in the fuel chamber rises above a predetermined pressure, the partition moves to the spring chamber side. And the valve element opens the valve seat to discharge fuel from the fuel return passage. According to the above, the pressure in the fuel chamber is controlled to the predetermined pressure, and the fuel controlled to the predetermined pressure is supplied to the outside from the fuel outflow passage.

[0003]

Such a conventional fuel pressure control valve has the following disadvantages. (1) When fuel is supplied from the fuel inflow passage into the fuel chamber with the fuel pressure control valve being empty, the supply of fuel controlled at a predetermined pressure from the fuel outflow passage to the outside can be immediately performed. This is not preferable because a start delay occurs during the start operation of the engine. This is because the fuel chamber was formed in a concave shape deeper downward from the upper end of the valve body. And that the fuel inflow passage and the fuel outflow passage are opened at the bottom of the fuel chamber. Further, the fuel return passage is provided near the upper end of the valve body from the bottom of the fuel chamber. (2) When fuel is supplied from the fuel inflow passage into the fuel chamber while the fuel pressure control valve is empty, a large amount of air flows out from the fuel outflow passage to the outside to supply accurate fuel to the engine. It is not preferable because it is difficult and hinders the operability of the engine. This is due in particular to the fact that the fuel chamber has a deep concave shape. (3) It is difficult to supply fuel having a high pressure regulation effect from the fuel outflow passage. This is because the fuel inflow passage and the fuel return passage open directly into the fuel chamber with large openings.

[0004] The fuel pressure control valve according to the present invention has been made in view of the above-mentioned problem. In particular, when the fuel chamber of the fuel pressure control valve is supplied with fuel through the fuel inflow passage from an empty state, the fuel is immediately supplied. An object of the present invention is to provide a fuel pressure control valve capable of supplying accurate fuel pressure regulated from an outflow passage and supplying fuel having a small pulsation pressure and a high pressure regulation effect.

[0005]

In order to achieve the above object, a fuel pressure control valve according to the present invention is divided into a fuel chamber and a spring chamber by a partition sandwiched between a valve body and a cover. The chamber has a fuel inflow passage leading to a pressure source, a fuel outflow passage leading to a consuming portion, and a fuel return passage, and a valve seat formed at an open end of the fuel return passage to the fuel chamber. In a fuel pressure control valve that is controlled to be opened and closed by a valve body that moves synchronously, the valve body has a diaphragm sandwiching flat portion above it, and a fuel return boss provided with a valve seat that is connected to the fuel return passage at the center, The inner peripheral portion of the diaphragm sandwiching flat portion and the outer peripheral portion of the upper end of the fuel return boss are formed so as to protrude upward from the diaphragm sandwiching flat portion, and are connected to each other with a connection portion directed obliquely upward. To, the first feature in that an opening and a fuel inflow path and the fuel outflow passage.

The present invention is characterized in that, in addition to the first feature, a jet is disposed in one of the fuel inflow passage and the fuel return passage.

Further, in the present invention, in addition to the first feature, a third feature is that a jet is disposed in the fuel inflow passage and the fuel return passage.

[0008]

According to the first aspect of the present invention, the fuel chamber is formed by the connecting portion connecting the inner peripheral portion of the diaphragm sandwiching flat portion and the outer peripheral portion of the upper end of the fuel return boss, and the fuel chamber. As the fuel can be minimized and the fuel inflow passage and the fuel outflow passage are opened to the connecting portion of the fuel chamber, the fuel is supplied from the fuel inflow passage to the fuel chamber as soon as the fuel chamber is empty. Fuel can be supplied from the outflow passage, and the amount of air or fuel vapor discharged from the fuel chamber can be greatly reduced.

According to the second feature of the present invention, the pressure fluctuation of the fuel flowing into the fuel chamber from the fuel inflow passage or the pressure fluctuation of the fuel discharged from the fuel chamber via the fuel return passage can be suppressed. Fluctuations in the fuel pressure in the room can be reduced, thereby improving the pressure regulation effect of the fuel discharged from the fuel outflow passage.

Further, according to the third feature of the present invention, the pressure fluctuation of the fuel flowing into the fuel chamber from the fuel inflow passage is suppressed, and the pressure fluctuation of the fuel discharged through the fuel return passage is suppressed. The pressure of the fuel discharged from the fuel outflow passage can be further regulated.

[0011]

FIG. 1 shows an embodiment of a fuel pressure control valve according to the present invention. Reference numeral 1 denotes a valve body, on which an annular diaphragm sandwiching flat portion 1A is formed, and at the center thereof, a fuel return boss 1B protruding above the diaphragm sandwiching flat portion 1A is formed. In this example, the upper end 1C of the fuel return boss 1B is projected upward by H from the diaphragm sandwiching flat portion 1A. A fuel return passage 2 is formed in the fuel return boss 1B, and a valve seat 3 is formed above the fuel return passage 2 and the valve seat 3 opens at an upper end 1C of the fuel return boss 1B. Then, the inner peripheral portion 1D of the diaphragm sandwiching flat portion 1A and the upper peripheral portion 1E of the upper end of the fuel return boss 1B are connected by a connecting portion 1F. The connection portion is formed as an inclined surface that is inclined obliquely upward from the inner peripheral portion 1D of the diaphragm sandwiching flat portion 1A to the upper peripheral portion 1E of the fuel return boss 1B. Further, a fuel inflow path 4 connected to a pressure source (not shown, such as a pump) and a fuel outflow path 5 connected to a consumption section (not shown, such as a fuel injection valve) open toward the connection portion.

The fuel pressure control valve is formed as follows. Reference numeral 6 denotes a partition made of a diaphragm made of rubber or the like. A valve 7 for opening and closing the valve seat 3 is integrally formed at the center of the partition 6. The outer periphery of the partition 6 is the valve body 1
The cover 8 is disposed in contact with the diaphragm holding flat portion 1A, and the outer peripheral portion of the cover 8 is bent and caulked toward the outer periphery of the valve body. According to the above, the outer peripheral portion of the partition body 6 is the diaphragm sandwiching flat portion 1A of the valve body 1.
The fuel chamber A is formed by the lower surface of the partition 6 and the connecting portion 1F of the valve body 1, and the spring chamber S is formed by the upper surface of the partition 6 and the cover 8 separately. You. A fuel return passage 2 is opened in the fuel chamber A through a fuel inflow passage 4, a fuel outflow passage 5, and a valve seat 3. On the other hand, a spring 9 is contracted in the spring chamber S, and the partition 6 is urged by the spring 9 toward the fuel chamber A, and the valve body 7 is moved to the valve seat 3.
Is urged to close.

Next, the operation will be described. The fuel pressurized by the pressurizing source (not shown) flows into the fuel chamber A through the fuel inflow path 4 and is supplied to the consumption unit (not shown) through the fuel outflow path 5 after filling the fuel chamber A. Is done. When the fuel pressure supplied to the fuel chamber A through the fuel inflow passage 4 in the above-described manner rises above a predetermined constant pressure, the partition 6 moves against the spring force of the spring 9 and the spring chamber S
The valve body 7, which is displaced to the side corresponding to the pressure rise and moves synchronously with the partition 6, opens the valve seat 3, thereby releasing the increased pressure to the outside through the fuel return passage 2.
According to the above, the fuel pressure in the fuel chamber A is again controlled to the predetermined fuel pressure, and the fuel adjusted to the predetermined fuel pressure from the fuel outflow passage 5 is supplied to the consuming unit.

According to the fuel pressure control valve of the present invention, the volume of the fuel chamber A can be extremely reduced. This is because the upper end 1C of the fuel return boss 1B is projected slightly above the diaphragm holding flat portion 1A by H, and the inner peripheral portion 1D of the diaphragm holding flat portion 1A and the fuel return boss 1B.
Connecting portion 1 that inclines upwardly with upper end outer peripheral portion 1E of
F, and the fuel chamber A is formed by the connecting portion 1F and the partition 6. As described above, according to the fact that the volume of the fuel chamber A can be extremely reduced, (1) when the fuel is supplied from the fuel inflow passage 4 into the fuel chamber A while the fuel chamber A is empty, The fuel is immediately filled with the fuel, and the fuel can be supplied from the fuel outlet channel 5 to the consuming portion. Accordingly, when such a fuel pressure control valve is used in a fuel supply device of an internal combustion engine, fuel can be supplied to the engine via the fuel pressure control valve without delay with the start of the engine, thereby improving engine start-up responsiveness. it can. (2) When the fuel is supplied from the fuel inflow passage 4 into the fuel chamber A in a state where the fuel chamber A is empty, the air or the fuel vapor in the fuel chamber A is changed to the fuel outflow passage 5 or the fuel And discharged toward the passage 2. At this time, since the volume of the fuel chamber A can be reduced, the amount of air or fuel vapor flowing from the fuel outflow passage 5 to the consuming section can be reduced, so that accurate fuel control can be performed in the consuming section. That is, when a large amount of air or fuel vapor is contained in the fuel directed to the consuming portion, the amount of fuel actually supplied to the engine becomes small.

Further, air or fuel vapor contained in the fuel flowing into the fuel chamber A from the fuel inflow passage 4 is displaced obliquely upward along the inclined connecting portion 1F which goes upward from below. Alternatively, when the valve body 7 opens the valve seat 3, the fuel vapor flows from the upper end 1 C through the valve seat 3 to the fuel return passage 2.
The gas is discharged into the fuel chamber A, and the gas discharge performance in the fuel chamber A can be improved.

J1 is a jet disposed in the fuel inflow passage 4, and the jet J1 regulates the fuel pressure from the fuel inflow passage 4 toward the fuel chamber A. That is, when the pressure of the fuel flowing in the fuel inflow passage 4 forms a large pulsating pressure, the jet J1 suppresses the pressure on the positive pressure side, reduces the fluctuation range of the pulsating pressure, and supplies the fuel to the fuel chamber A. According to the above, the pulsation of the fuel supplied from the fuel outflow passage 5 toward the consuming portion can be reduced, which is suitable for regulating the pressure.

J2 is a jet disposed in the fuel return passage 2, and the jet J2 is located in the fuel return passage 2.
Control the fuel pressure from the air to the atmosphere. That is, when the valve element 7 opens the valve seat 3, the fuel pressure in the fuel chamber A is released from the fuel return passage 2 at once, and the pressure in the fuel chamber A is greatly reduced. Since the fuel pressure in the fuel chamber A is limited and opened by the jet J2, the pressure in the fuel chamber A is not greatly reduced.
As a result, the pulsation of the fuel supplied from the fuel outflow passage 5 toward the consuming portion can be reduced. In addition, since the jet J1 is disposed in the fuel inflow passage 4 and the jet J2 is disposed in the fuel return passage 2, a positive pressure portion from the fuel inflow passage 4 toward the fuel chamber A can be reduced, and the fuel return passage 2 Since the pressure reduction portion in the fuel chamber A due to the opening of the valve seat can be reduced, the pulsation of the fuel pressure supplied from the fuel outflow passage 5 can be further reduced.

[0018]

As described above, according to the fuel pressure control valve according to the present invention, the valve body has the fuel return boss having the diaphragm sandwiching flat portion above it and the valve seat at the center connected to the fuel return passage. The inner peripheral portion of the diaphragm sandwiching flat portion and the outer peripheral portion of the upper end of the fuel return boss are connected to each other with a connecting portion directed obliquely upward, and fuel flows into the connecting portion. Since the passage and the fuel outflow passage are opened, the volume of the fuel chamber can be made extremely small, whereby the responsiveness of fuel supply from the fuel outflow passage when the fuel control valve is empty can be improved, and This has improved controllability. Further, the fuel inflow passage, the fuel retarder,
According to the arrangement of the jet in one of the flow passages, the pulsation pressure in the fuel chamber can be reduced, and the pulsation pressure of the fuel supplied from the fuel outflow passage can be reduced. Further, according to the arrangement of the jets in the fuel inflow passage and the fuel return passage, the pulsating pressure of the fuel supplied from the fuel outflow passage can be reduced more effectively.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing one embodiment of a fuel pressure control valve of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Valve main body 1A Diaphragm clamping flat part 1B Fuel return boss 1F Connection part 2 Fuel return passage 3 Valve seat 4 Fuel inflow passage 5 Fuel outflow passage

Continued on the front page (51) Int.Cl. ⁷ identification code FI theme coat II (reference) F16K 7/17 F16K 7/17 C

Claims (3)

[Claims] 1. A fuel chamber and a spring chamber are divided by a partition body sandwiched between a valve body and a cover. The fuel chamber has a fuel inflow passage connected to a pressure source and a fuel outflow passage connected to a consumption unit. A fuel return control valve, which is opened and closed and a valve seat formed at an open end of the fuel return passage to the fuel chamber is opened and closed by a valve body that moves synchronously with the partition body; The main body 1 has a diaphragm holding flat portion 1A above it, and a fuel return passage 2 at the center.
A fuel return boss 1B provided with a valve seat 3 is formed so as to protrude above the diaphragm sandwiching flat portion, and an inner peripheral portion 1D of the diaphragm sandwiching flat portion 1A and an upper peripheral portion 1E of the fuel return boss 1B are inclined. A fuel pressure control valve connected with an upwardly connecting portion 1F, wherein a fuel inflow passage 4 and a fuel outflow passage 5 are opened in the connection portion. 2. The fuel pressure control valve according to claim 1, wherein a jet J is disposed in one of the fuel inflow path and the fuel return path. 3. The fuel pressure control valve according to claim 1, wherein a jet J is disposed in the fuel inflow passage and the fuel return passage.