JPS58113573A - Device for injecting fuel heated - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates generally to diesel-type fuel injection systems, and more particularly to a fuel injection system that heats fuel prior to injection.

One of the main objects of the present invention is to inject liquid fuel discharged from an injection nozzle so that it can be accurately metered while simultaneously setting pressure and temperature that immediately transforms it into vapor without the need for additional heat transfer. An object of the present invention is to provide a heating fuel injection device for supplying heating fuel to a container. This improves engine operating efficiency and provides very precise control of fuel flow.

It is a further object of the present invention to provide a heated fuel injection assembly having an injector valve opened by exiting heated fuel and including a servo device that closes and moves the valve away from the valve by fuel discharging from a diesel injection pump. It is about providing.

Another object of the invention is to provide a high pressure fuel sump that is refueled from a main fuel injection pump following the fuel injector opening.

A further object of the present invention is to provide a heater to maintain the discharged fuel at a temperature exceeding the flash point of the steam before injection, the heat source being the combustion products of the engine or during normal operation of the engine. The object of the present invention is to provide a fuel injection device of the above type which is an electric heater for hot exhaust gas and starting.

Other objects, features, and advantages of the invention will become apparent upon reference to the following detailed description and drawings showing the preferred embodiments.

Heating fuel injection devices of the general type described above are well known. For example, U.S. Patent No. 2,747,555
In the fuel distributor shown in the figure, heated fuel is delivered to a piston or servo (Fig. 2), which opens a valve and delivers heated fuel to an injector, which opens a valve. It will be done. An electric heater 50 can be used for starting. U.S. Pat. No. 1,464,253 describes an apparatus that uses an electrical resistor to heat the fuel during starting and heats the fuel during rotational operation by means of hot engine exhaust gas. . Note that the fuel remains in a liquid state until it is discharged from the injector. U.S. Patent No. 5.868.939
The number also uses an electric heating element.

However, the aforementioned prior art includes an injector assembly having a fuel-opening injector controlled by a servo actuated by the discharge pressure of the fuel pump, such that the injected fuel is heated and the opening of the injector valve is heated. There is no indication of an injector of the type provided by the present invention, in which the fuel in the injector is heated prior to discharge from the injector valve, and the fuel in the injector is heated prior to discharge from the injector.

FIG. 1 shows a fuel injection system including a diesel-type fuel injection pump shown schematically at 10. FIG. Details of pump construction and operation are well known and are therefore considered unnecessary to understanding the present invention.

It is omitted here. Here, the pump is of the jerk type, producing an intermittent discharge of fuel into the outlet line 12, and the fuel is pumped between pumping or replenishing strokes, e.g.
0X? Suffice it to say that the pressure is gradually increased to a level exceeding 1700 pat.

The discharged fuel is passed through a suction-back valve of the well-known type shown in 14 which ensures a low residual pressure during the non-pumping period by the valve suction of a predetermined amount back into the valve body in a known manner. pass

The system further includes a fuel injector assembly 16, an electromagnetically operated variable pressure regulator 18, a high pressure check valve 2°, a high pressure fuel reservoir 22, and a fuel heater shown at 24.

Injector assembly 16 includes a hollow casing 30, as shown, divided into upper and lower fuel chambers 32.34 by a pair of spaced apart seal members 36.38. The lower fuel chamber 34 includes a fuel nozzle 40 , and the lower fuel chamber 34 includes a fuel nozzle 40 .
From there, the fuel that has flowed into the engine is discharged into the combustion chamber of one engine (not shown). The nozzle 40 is connected to the stem portion 4
4 to the lower end of the fuel injector 42 connected to the enlarged actuator end 46. The actuator end 46 can be slidably moved within the seal 38 while maintaining a seal. The stem 44 has a spacing from the outer casing and is connected to the chamber 34 by an inlet boat 48 communicating with the high pressure fuel line 5o. Define pipe line 5
o is supplied with fuel via heaters schematically shown in high-pressure fuel reservoirs 22 to 24.

The high-pressure fuel reservoir 22 is supplied with fuel power from the pump 10 through the outlet line 52 and the connecting line 54 and through the ball check valve 2o. In this case, the spring 5 of the check valve 20
6, the pressure inside the pump outlet pipe 52 is approximately 120 kl.
? The valve is set to close until f/cm2 (1700 pa1). This ensures that the fuel reservoir 22 is always maintained at this high pressure. Regulation of the fuel reservoir at this pressure level is ensured by a variable pressure regulator 18. The regulator is approximately 120 kgf/cm under normal environment.
” (1700 psi) while applying voltage to the solenoid to control the activation time of the solenoid as needed to set whatever pressure level is required for injection of fuel into the combustion chamber. Electromagnetically operated pressure regulating valve 6 that can be changed by changing
Consists of 0.

Returning to the injector assembly 16, the upper chamber 32 is provided with a servo arrangement in the form of a piston 62.

Piston 62 is slidably movable within chamber 32 and has a stem actuator 64 slidably and sealingly movable through seal 36 to engage upper end 46 of the fuel injector. The piston 62 is 61f/ctn 106 on the lower surface of the piston 62.
'' (1500 pat) is forced downwardly by the force of the spring 66 which is set to keep the injector closed until a pressure level of 1500 pat. Pressurized fuel is supplied through an inlet port 6B connected to by a conduit TO.

The injector assembly includes a 16% TB chamber that can leak through the piston 62 and the injector top end 46, respectively.
Several fuel return boats T2 for discharging the fuel in
, T4 are also included.

As the last part of the structure, the heater is schematically indicated at 24.

As shown, an enclosure surrounding the conduit 50 is of the known type for heating the conduit 50 by exhaust gas or combustion products from the engine during rotational operation of the engine. Although not shown, an electric heater may be installed to provide the necessary heat when starting the engine.

FIG. 2 schematically shows the change in state of the fuel under conditions of temperature and pressure of the cypress. It can be seen that as long as the relationship between fuel pressure and power lies to the left of line 80, the fuel remains in a liquid state.

In operation, the parts are initially in essentially the state shown. That is, as shown, the force of the spring 66 pushes the piston 62 downward, causing the stem 64 to engage the upper end 46 of the injection valve 42, moving the valve to its closed position. When starting,
The electric heater 24 initially charges the fuel in the conduit 50, e.g.
It is heated to the required temperature of approximately 427°C (800°F). The high pressure fuel reservoir 22 has a pressure of 9 f/cWL" (1700 ps
Once filled with fuel at the pressure level i), the device is now ready for operation.

When the pump is on its refill stroke, the fuel pressure is ramped up to open the suction valve 14 and increase the pressure in line 52, TO 154. The pressure of the fuel in the chamber 32 is, for example,
106 kl? f/cm2 (1500psi)K
Once there, the piston 62 moves upwardly against the force of the spring 66 until it reaches the stop 82. When the piston 620 force is removed from the upper end 66 of the injection valve 42, the line 50
The high pressure heated fuel in the chamber 34 then moves the lower end of the upper end 46 to move the injector 42 upwardly, causing the nozzle 4
Open 0. Therefore, 427°0 (800°'F),
Fuel at a pressure of 10f#f/crn2 (1500 psi) is discharged through the nozzle opening 84. When the pressure of the fuel decreases, the fuel immediately changes from a liquid to a gaseous state without adding the heat necessary for the change of state (Figure 2).
. This results in improved engine operating efficiency.

While the fuel pump 10 continues its refill stroke, the pressure increases to the ball check valve 20 opening pressure level 120 klilf/
It continues to rise in line 54 until cIn2 (1700 psi) is reached. At this stage, the fuel in the line 54 continues to be sent to the fuel reservoir 22 and the electromagnetically operated pressure regulator 1
The pressure level determined by B 120X? f/crI
The fuel in the chamber 34 is thus maintained at a temperature above the flash point of the vapor, as shown in FIG. 2, and is therefore discharged from the nozzle 40. When the pump 10 again performs its suction stroke, the suction valve is seated and the residual pressure in line 52 decays.The spring 66 of the injector assembly 16 then The stem 64 is the injection valve 42
the upper end 46 and move it downward to open the nozzle 4.
0, thereby piston 6 until the end of injection.
Move 2 downward. As previously mentioned, during rotational operation of the engine, hot exhaust gas flows outside the conduit 50 containing fuel from the fuel reservoir 22, thereby maintaining the fuel at a desired temperature of 800'F. be done.

[Brief explanation of the drawing]

Fig. 1 is a diagram schematically showing a fuel injection device embodying the present invention, and Fig. 2 shows the state of the fuel from liquid to gas and from gas to liquid when the fuel temperature If and pressure conditions change. It is a figure which shows a change graphically. 10: Fuel Pump 16: Fuel Injector Assembly 42: Fuel Injector 48: Inlet 68: Outlet

Claims (1)

[Scope of Claims] A fuel pump that intermittently pumps liquid fuel to an outlet to gradually increase the pressure of the fuel to a predetermined pressure level; a fuel injector assembly having a fuel inlet and outlet and a fuel injection valve; heating at a temperature and pressure above the flash point of fuel vapor connected to an inlet of the assembly for acting on the valve to move the injector to an open position and to discharge heated fuel; a source of generated fuel; the injector assembly includes a biasing device for biasing the injector valve to a closed position; the injector assembly includes a biasing device for biasing the injector valve to a closed position; a fuel pressure response device coupled to the fuel pump outlet opposite the biasing device for opening the valve by fuel under pressure from a source; The temperature and pressure of the fuel supplied to the injector are below the flash point of the fuel such that upon discharge from the valve, the pressure level of the fuel drops suddenly and the fuel remains as a liquid until it evaporates. A heating fuel injection device for a diesel engine that is characterized by being kept at a high temperature.