JPS6115254Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a fuel supply device for an internal combustion engine (hereinafter also referred to as engine) that injects pressurized fuel into an intake passage by opening and closing a solenoid valve.

Conventionally, in the fuel supply device 1 shown in FIG. 1, fuel pumped from a fuel pump (not shown) is supplied from a fuel introduction passage inlet 2 to a fuel chamber 5 in a valve housing 4 via a fuel introduction passage 3. is,
The fuel passes through the filter 7a of the solenoid valve 6 (see FIG. 2) and enters the inside of the solenoid valve 6 from the inlet 7, and while receiving a valve opening signal, the injection port 8 opens and the intake passage 9
Injected inside. A fuel chamber 5 within the valve housing 4 communicates with a fuel regulator (not shown), and the fuel is regulated at a constant pressure. During this pressure adjustment, excess fuel is removed by a regulating valve (not shown).
is discharged from. When the engine, which has become hot due to long-term operation, is stopped, ventilation of the engine room is also stopped, and the ambient temperature of the fuel supply device 1 increases due to the heat of the engine. Further, the conduction heat of the intake pipe 10 and the heat of the high temperature cooling water of the hot water heating passage 11 heat the fuel supply device 1 . For this reason, the temperature of the lower side wall 12 and upper side wall 13 of the intake passage 9 formed of metal (for example, aluminum die-casting) increases, and the temperature of the fuel introduction passage 3, the fuel chamber 5 in the valve housing 4, the fuel adjustment passage (not shown) and Fuel in the fuel regulator fuel chamber, etc. evaporates. The vaporized fuel has the effect of increasing the fuel pressure due to its volumetric expansion, but the excess fuel is discharged by the adjustment action of the fuel regulator and the pressure is kept constant. As a result, more and more fuel flows out from the regulating valve of the fuel regulator, so that the fuel in the valve housing fuel chamber 5 runs out while the engine is stopped. Therefore, the next time the engine is to be restarted, even if the engine is cranked, there is no fuel around the solenoid valve 6, so the engine cannot be started immediately. This state continues until liquid fuel is pumped out from the fuel pump by continuing cranking for a while. This made it difficult to restart the engine.

This idea solves the problems mentioned above, and allows the area around the solenoid valve to be filled with liquid fuel at any time, and when restarting the engine, the fuel can be injected from the solenoid valve at the same time as cranking. The purpose is to provide a fuel supply device that can restart an engine in a short time.

This invention will be explained based on drawings of embodiments. In FIG. 3, the same numbers as in FIG. 1 indicate components equivalent to the conventional one. That is, 6 is a solenoid valve, 7 is a solenoid valve,
1 is a solenoid valve fuel inlet, 7a is a filter (see FIG. 2), 8 is an injection port, 10 is an intake pipe, 11 is a hot water heating passage, 12 is a lower side wall of the intake passage, and 14 is a throttle valve. The following are the components based on this idea. Reference numeral 21 denotes a fuel supply device according to this invention, in which fuel is fed under pressure from a fuel pump (not shown), enters from a fuel introduction passage entrance 22, passes through a fuel introduction passage 23 having a downward slope, and then passes through the valve housing 2.
Reach 4. A solenoid valve 6 is housed in the valve housing 24, and a space surrounding the solenoid valve fuel inlet 7 forms a fuel chamber 25. The upper part of the fuel chamber 25 is sealed with an O-ring 6a, and the lower part with an O-ring 6b (see FIG. 2). As shown in FIG. 2, the electromagnetic valve 6 has a fuel inlet 7 opened at the bottom, and the fuel in the fuel chamber 25 passes through a filter 7a and enters the fuel inlet 7.
The air enters the electromagnetic valve 6 and is injected from the injection port 8 into the intake passage 29 when the valve element 6c opens.
The upper side wall 33 of the intake passage 29 is the fuel introduction passage 23,
The valve housing 24 and fuel adjustment passage 34 are molded from synthetic resin. Fuel adjustment path 34
exits the fuel chamber 25 of the valve housing 24, has an upward slope, and communicates with a fuel regulator 41 attached to the upper side wall 33. The fuel regulator 41 is divided into a fuel chamber 43 and an air chamber 44 by a diaphragm 42 . Fuel chamber 43
is provided with an outlet 45 that returns to a fuel supply source (not shown), and an outlet pipe 46 that protrudes into the interior of the fuel chamber 43 is attached to this outlet. The free end of the outflow pipe 46 constitutes a valve port 46a, which is opened and closed by a valve 42a provided at the center of the diaphragm 42. A fuel regulator inlet 47 is provided in the upper part of the fuel chamber 43 and communicates with the fuel chamber 25 of the valve housing 24 via the fuel adjustment passage 34 . The negative pressure of the intake passage 29 is introduced into the air chamber 44 through a negative pressure communication port 48 . A compression spring 49 is inserted into the air chamber 44 and constantly pushes the diaphragm 42 toward the fuel chamber 43.

The operation of the fuel supply device 21 configured as described above will be explained with reference to FIG. During engine operation, the fuel supply device 21 operates in the same way as the conventional fuel supply device 1 to supply pressurized fuel from the fuel introduction passage inlet 22 to the intake passage 29 from the injection port 8.
is injected into. The upper main body consisting of the upper side wall 33 of the intake passage 29 according to this invention is made of synthetic resin (phenol resin) and has a heat insulating effect.
Even if hot water at a sufficiently high temperature flows through the hot water heating passage 11 provided in the lower side wall 12 of the intake passage connected to this, the fuel chamber 25 of the valve housing 24
There is no risk of undesirable evaporation of liquid fuel such as fuel being promoted, and the air-fuel mixture in the intake passage 29 is sufficiently heated to achieve atomization of the fuel.

If you stop the engine, which has reached a high temperature due to long-term operation, the ventilation in the engine room will also stop, causing heat to accumulate from the engine, cooling water pipes, exhaust pipes, etc., and the atmospheric temperature of the fuel supply system 21 to rise. Rise. However, the upper body of the intake passage 29 containing the fuel system does not easily absorb heat, so the fuel chamber 2 in the fuel introduction passage 23 and the valve housing 24
5. The temperature rise of liquid fuel in the fuel adjustment path 34 and the like is much smaller than in the past. Heat transmitted by thermal conduction from the intake pipe 10, hot water heating passage 11, etc. is also blocked at the lower end of the upper side wall 33. Therefore, the tendency of the fuel in the fuel chamber 25 to vaporize is much smaller than in the past.

Also, the fuel inlet 7 of the solenoid valve 6 housed in the valve housing 24 and the fuel chamber 25 around it
is located at a lower position than the fuel introduction passage inlet 22 and the fuel regulator inlet 47, so even if some of the fuel in the fuel chamber 25 evaporates, the bubbles will flow through the fuel adjustment passage 34.
The fuel rises and is replaced with fuel in the fuel chamber 43 of the fuel regulator 41.

Thus, the fuel chamber 2 within the valve housing 24
5 is always filled with liquid fuel, and when the engine is restarted, fuel is immediately supplied from the fuel inlet 7 of the electromagnetic valve 6, and fuel injection at the flow rate required by the engine is started.

Figure 4 shows the results after high-load operation at an ambient temperature of 40°C.
3 shows a change in fuel temperature in the fuel introduction passage 23 when the engine is stopped. It becomes difficult to restart at about 60℃. FIG. 5 shows the time it takes for the engine to become difficult to restart after it stops when the ambient temperature is changed. 4 and 5, A is a conventional fuel supply device 1;
B: The material remains the same as before, but the position of the solenoid valve fuel inlet is arranged as in the present application.C: The solenoid valve fuel inlet position remains the same, but the upper body of the intake passage is made of synthetic resin as in the present application. , D is a fuel supply device 21 according to this invention. The time at which it becomes difficult to restart in each case is shown in Figure 5, for example, when the ambient temperature is 40°C.
℃, A after about 5 minutes, B after about 7 minutes, and C after about 5 minutes.
After 12 minutes, D is about 20 minutes later. That is, according to this invention, it is possible to maintain four times the restartability compared to the conventional method.
When the ambient temperature is 35℃ or less, the cooling effect of the engine itself becomes evident after 40 minutes to 1 hour, so when the effect of this invention is added, there is no area where it is difficult to restart in practice, and the engine can be restarted at all times. A quick restart is possible.

This idea is used in a fuel supply system that adjusts pressurized fuel to a constant pressure with a fuel regulator and meters and injects it with a solenoid valve. The solenoid valve is made of synthetic resin, and the solenoid valve fuel inlet is located at a lower position than the fuel introduction passage inlet and fuel regulator inlet.When the engine is stopped after long-term operation, the electromagnetic valve is This prevents the fuel around the valve from evaporating and allows the area around the solenoid valve to be filled with liquid fuel at all times, which has the effect of improving engine restartability.

In addition, this invention fully utilizes the function of the hot water heating passage in the lower side wall of the intake passage, resulting in improved fuel atomization. Therefore, idling stability is improved, the idling speed setting value can be lowered, and the fuel consumption rate is improved. In addition, improved fuel atomization improves the engine's fuel responsiveness during transient times, which has the effect of reducing changes in the air-fuel ratio and improving the feeling.

Furthermore, if we were to obtain the same level of restartability as this invention using conventional materials, we would need a very large fuel chamber for the regulator, but this invention allows for a compact design and is therefore inexpensive. This has the effect of providing a fuel supply device with improved restartability at a lower manufacturing cost.

[Brief explanation of the drawing]

Figure 1 is a vertical cross-sectional view of a conventional fuel supply system, Figure 2
The figure is a partially cutaway detailed view of the solenoid valve shown in Figures 1 and 3, and Figure 3 is a longitudinal sectional view of an embodiment according to this invention.
FIG. 4 and FIG. 5 are action explanatory diagrams. 6... Solenoid valve, 7... Solenoid valve fuel inlet, 11...
...Hot water heating passage, 22...Fuel introduction passage entrance, 23
... Fuel introduction path, 24 ... Valve housing,
25...Fuel chamber, 33...Intake passage upper side wall, 3
4...Fuel adjustment path, 41...Fuel regulator,
47...Fuel regulator inlet.

Claims (1)

[Claims for Utility Model Registration] (1) A solenoid valve that injects pressurized fuel into an intake passage in response to a control signal, a valve housing that holds this solenoid valve, and a valve housing that injects pressurized fuel into an intake passage. It consists of a fuel chamber provided around the inlet, a fuel introduction passage that communicates from the fuel introduction passage entrance on the side wall of the intake passage to the fuel chamber of the valve housing, and a fuel chamber and an air chamber bordered by the diaphragm.The fuel is introduced into the air chamber. A fuel supply device for an internal combustion engine, comprising: a fuel regulator that adjusts fuel pressure to a constant level by negative pressure in an intake passage; and a fuel adjustment path communicating from a fuel chamber of a valve housing to an inlet of the fuel regulator; The fuel inlet of the solenoid valve is provided at a lower position than the fuel introduction passage inlet and the fuel regulator inlet, and the upper body of the intake passage, which consists of an upper side wall, a valve housing, a fuel introduction passage, and a fuel adjustment passage, is made of synthetic resin. Characteristic fuel supply device. (2) The fuel supply device according to claim 1, which has a hot water heating passage in the lower side wall of the intake passage.