JPS5810157A - Fuel injection device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To improve the fuel feeding accuracy of a fuel injection device and to reduce the starting time of an internal-combustion engine, by a mechanism whereby the spring chamber accommodating a spring designed to support the diaphragm which is mounted with a valve and the air-inlet passage are connected through each other. CONSTITUTION:A high-pressure fuel compressed at a fuel pump 7 is pressure- fed through the pipe 9 and the high-pressure joint 35 to fill up the fuel chamber 32 of the fuel pressure adjustor 31. The fuel-pressure acts on the pressure receiving surface, that is, the diaphragm 15. With the fuel pressure rising over the previously-set level, the valve 16 is separated from the valve seat 18 against the compression spring 17 and made open. With the fuel pressure falling below the previously-set level, the valve 16 is pressure-attached to the valve seat 18 to be closed. The fuel pressure in the fuel chamber 32 is adjusted through opening and closing of the valve 16. The spring chamber 20 accommodating the spring 17 that acts on the diaphragm 15 is connected to the air-inlet passage 4 via the through-hole 34.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a fuel injection device for an internal combustion engine, in particular, a fuel injection valve is provided in an intake air passage on the upstream side of a throttle valve, and the fuel injection valve is provided with a fuel injection valve adjusted by a fuel pressure regulator. This invention relates to an improvement in a fuel injection device that supplies fuel to an internal combustion engine.

A conventional fuel injection device for an internal combustion engine will be explained with reference to FIG.

In Figure 1, 1 is a mixer day that mixes intake air and fuel to the engine; the upstream side of the mixer day 1 is connected to an air purifier 2, and the downstream side is connected to the engine (not shown). It is. An intake air passage 4 and a fuel chamber 5 are formed on the upstream side of the throttle valve 3 of the Ka engine in the ζ system goody 1. 6 is the fuel tank, 7 is the fuel 47
The fuel tank 6 is connected to the suction side of the fuel tank f7 by an I-dive 8. 9 is an A4 Eve whose one end is connected to the discharge side of the fuel tank, and this I
The other end of 4 and f9 is connected to the high pressure joint 10 of the fuel chamber 5, and is for pumping the high pressure fuel from fuel f7 to the fuel chamber 5.

11 is a fuel pressure regulator fixed to the outside of the mixing device 1 and communicated with the fuel chamber 5 through a passage 12; 13 is an overflow joint of the fuel pressure regulator 11; The fuel tank 6 is connected to the fuel tank 6 through the /9 engine 14. In the fuel pressure regulator 11, a valve member 16 is integrally attached to a diaphragm 15 which is a fuel pressure receiving surface. 5a is a fuel chamber of the fuel pressure regulator 11, and the fuel chamber 5a is formed on the diaphragm 15.

and the passage 12 from the fuel chamber 5 of which the pumping is D1.
High pressure fuel is introduced.

17 is a compression spring, and this compression spring 17 supports the diaphragm 15 and the valve member 16 fixed thereto.
It is pressed against a valve seat 1B formed between the fuel chamber 5a and the overflow joint 13. 20 is a spring chamber of the fuel pressure regulator 11; this spring 1120 is connected to the diaphragm 15;
A pipe 22 connects a joint 19 that is formed below the housing, houses the compression spring 17, and communicates with the spring chamber 20, and a joint 21 that communicates with the throttle air passage 4 on the upstream side of the throttle valve 3. has been done.

23 is a fuel injection valve fixed to a partition wall 24 that partitions the intake air passage 4 of the D1 and the fuel chamber 5 above it.
A fuel inlet 25 is opened at the bottom, and a spray port 26 for supplying fuel to the engine is formed at the lower end.

27 is a fuel pressure buffer, and this buffer 27 has a diaphragm 28 and a compression spring 29], and the diaphragm 28 is disposed on the lower surface of the fuel chamber 5 so as to receive fuel pressure. A spring chamber 30 houses a compression spring 29. This spring chamber 30 is partitioned from the fuel chamber 5 by a diaphragm 28 and is disposed below this.

Next, the operation of the conventional fuel injection device configured as described above will be explained.

The high-pressure fuel pressurized by the fuel chamber 5
and the fuel pressure regulator 1 via the passage 12.
The fuel pressure is also fed under pressure to the fuel chamber 5a of the fuel pressure regulator 11, which is the pressure receiving surface.
5. When the fuel pressure exceeds the set pressure, the valve member 16 moves away from the valve seat 18 against the compression spring 17 to open the valve, and when the fuel pressure falls below the set pressure, the valve member 16 closes. By opening and closing the valve member 16 in this manner, the fuel chamber 5. ．． The fuel pressure within 5a is regulated.

The regulated fuel is guided from the fuel injection valve 25 to the fuel injection valve 23, and by opening the fuel injection valve 23, the fuel is injected into the engine from the spray nozzle 26.

Further, the spring chamber 20 of the fuel pressure regulator 11 is connected to a pipe 22.
communicates with the intake air passage 4 on the upstream side of the throttle valve 3,
When the diaphragm 15 containing the high-pressure fuel Km ruptures, the fuel is compressed and the spring chamber 20 containing the fuel 17 is compressed. Fitting i9+
No arm Eve 22. The air flows into the intake air passage 4 on the upstream side of the throttle valve 3 via the joint 21 and is sucked into one engine.

Furthermore, the fuel pressure buffer 27 alleviates pulsations in the fuel pressure within the fuel chamber s caused by the opening and closing operations of the fuel injection valve 230. That is, when the pulsation pressure of the fuel pressure becomes high, it acts on the pressure receiving surface of the diaphragm 28, and this causes the compression spring -29
deforms downward against the

Absorbs increased pulse pressure.

However, in the conventional fuel injection device described above, the fuel chamber of the construction cylinder and the fuel chamber of the fuel pressure regulator are communicated with each other through a small diameter passage. Pressure fluctuates. This type of fuel injection device controls the amount of fuel supplied to the engine by regulating the opening time of the fuel injection valve.

If the fuel pressure fluctuates as described above, the amount of fuel supplied naturally also fluctuates, which has the drawback of lowering the accuracy of fuel supply to the engine.

Also, since the fuel pressure regulator is fixed to the outside of the mixing device separately, it is far away from the fuel injector, and the fuel injector opens! Recovery from fuel pressure fluctuations caused by valve operation is slow, necessitating a fuel pressure buffer. Since the fuel injection valve and fuel pressure buffer are arranged in parallel, the volume of the fuel chamber is large, and it takes a long time to fully exhaust the air in the fuel chamber during initial operation. However, there are disadvantages in that the starting time becomes longer and air flows into the fuel injection valve at the time of starting, causing misinjection.

Furthermore, since the fuel pressure regulator is installed outside the intake air passage2, there is also the disadvantage that if the diaphragm ruptures, an If valve piping is required to prevent fuel from leaking outside. .

An object of the present invention is to provide a fuel injection device for an internal combustion engine that eliminates the above-mentioned nine drawbacks of the conventional devices.

An embodiment of the present invention will be described below with reference to FIG.

In FIG. 2, 1 is a mixing device, a 2nd company air purifier, 3 is a throttle valve, and 4 is a pilot air passage on the upstream side of the throttle valve 3.

★ 31 is a fuel pressure regulator, which is housed in the intake air passage 4 and has a mixing valve fixed to the D 1, and a valve integrally fixed to the lower surface of the diaphragm 15. A fuel injection valve 23 is integrally mounted in the same direction as the opening/closing direction of the member 16. Diaphragm 15 lower KFi fuel chamber 3 of fuel pressure regulator 31
2 is formed, and a fuel injection valve 23 of this fuel chamber 32 is formed.
The fuel population 33 is located below the valve seat 18 in the fuel chamber J2, and the diaphragm 1 is a fuel pressure receiving surface.
It opens directly below 5. 34 is a communication hole, and the communication hole 34 of j is connected to the diaphragm 15 of the fuel pressure regulator 31.
A spring chamber 20 that accommodates a compression spring 17 that supports the diaphragm 15 and is formed above the diaphragm 15 communicates with the intake air passage 4 on the upstream side of the throttle valve 3. 35 is a high pressure joint that guides high pressure fuel from the fuel pump to the fuel chamber 32;
3 This is the overflow joint of the fuel pressure regulator 31. In addition.

In Figure 2, 6 is a fuel tank, 8, 9, 14a pipe, 2
There are six nozzle nozzles, which are the same as those shown in FIG.

Next, the operation of the fuel injection device according to this embodiment will be explained.

The high-pressure fuel pressurized by the fuel pump 7 is sent under pressure to the fuel chamber 32 of the fuel pressure regulator 31 via the pipe 9 and the high-pressure joint 35, and is filled therein.

Fuel pressure acts on the diaphragm 15, which is a pressure receiving surface. When the fuel pressure f)E exceeds the set pressure, the valve member 16
When the valve opens by moving away from the valve seat 18 against the compression spring 17, and the fuel pressure falls below the set pressure.

The valve member 16 is pressed against the valve seat 18 to close the valve. By opening and closing the valve member 16 in this manner, the fuel pressure within the fuel chamber 32 is regulated. The regulated fuel is guided from the fuel injection valve 33 to the fuel injection valve 23, and by opening and closing the fuel injection valve 23, the required amount of fuel is injected into each engine.

According to this embodiment, since the fuel injection valve 23 is integrally attached to the fuel pressure regulator 31, almost no pressure loss occurs due to the flow of fuel. The fuel pressure of the cylinder can be applied to the fuel injection valve 23, and the accuracy of fuel supply to the engine can be improved.

Furthermore, since the fuel inlet 33 of the fuel injection valve 23 is provided directly below the diaphragm 15 of the fuel pressure regulator 31,
Since the fuel pressure regulator 31 and the fuel injection valve 23 are close to each other, fluctuations in fuel pressure caused by the opening and closing operations of the fuel injection valve 23 can be recovered quickly.

The pulsation of fuel pressure is controlled by the diaphragm 1 of the fuel pressure regulator 31.
s, the fuel pressure buffer 27 used in conventional fuel injection devices can be eliminated, and the device can be made more compact.

Since the fuel supply 33 to the II fuel injection valve 23 is installed below the valve seat 18, the air in the fuel chamber 32 does not flow into the fuel injection valve 23 during initial startup, and injection can be prevented. In addition, by eliminating the fuel pressure buffer, the volume of the fuel chamber 32 is small, and the air in the fuel chamber 82 can be exhausted in a short time.

Furthermore, the fuel pressure regulator 31 is installed in the intake air passage 4 upstream of the throttle valve 3.

When Meir 79m15, which is in contact with high-pressure fuel, ruptured.

The fuel passes through the spring 1120 housing the compression spring 1.7, flows into the intake air passage 4 from the communication hole 34, and is sucked into the engine. Therefore, it has the advantage of eliminating the need for external pipe piping like the conventional one.

As explained above, the fuel injection device for internal combustion engines of Jin's invention has the fuel inlet to the fuel injection valve opened below the valve seat of the fuel chamber, and the opening and closing directions of the valve member attached to the closing iaphragm are the same. A fuel injection valve is integrally installed in the direction of the throttle valve, a communication hole is formed in the wall of the spring chamber containing the compression spring that supports the closing iaphragm, and a fuel pressure regulator is installed, and this fuel pressure regulator is installed upstream of the throttle valve. Installed in the side intake air passage.

4o in which the spring chamber is communicated with the intake air passage through a communication hole. Therefore, according to this invention, the pressure loss due to the flow of fuel is reduced by 9%, and even if the fuel pressure buffer is abolished, fuel at a constant pressure can always be supplied to the fuel injection valve, and the engine In addition to improving the accuracy of fuel supply to
The starting time can be shortened, and without the need for external arm piping like conventional ones, fuel can be prevented from being released to the outside in the event of a rupture of the closing iaphragm. You can get the effect.

[Brief explanation of the drawing]

1II is a partial cross-sectional structural explanatory diagram showing a conventional fuel injection device, and FIG. 2 is a partial cross-sectional structural explanatory diagram showing a fuel injection device according to an embodiment of the present invention. 1...Mixing is D, 3...Throttle valve. 4... Intake air passage, 5-. 5m, 32...Fuel chamber, 11.31...Fuel pressure regulator, 15...
Maya flammable, 16... Valve member, 18... Valve seat, 2
3...Fuel injection valve, 25.38...Fuel inlet, 34
...Communication hole. Note that the same reference numerals in the figures indicate the same or similar parts. Agent Shin Kuzuno −

Claims (1)

[Claims] A fuel inlet to the fuel injection valve is opened at least below the valve seat of the fuel chamber, and the fuel injection valve is integrally mounted in the same direction as the opening and closing direction of the valve member mounted on the diaphragm,
A fuel pressure regulator is provided with a communication hole formed in the wall of a spring chamber that accommodates a compression spring that supports the diaphragm, and this fuel pressure regulator is installed in the intake air passage upstream of the suittor valve to communicate the spring chamber. A fuel injection device for an internal combustion engine, characterized in that the hole communicates with an intake air passage.