JP2795020B2 - Fuel injection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel injection device,
More specifically, the present invention relates to a cooling structure for fuel injected from an injection nozzle.

[0002]

2. Description of the Related Art A fuel injection system for an automobile engine is provided with an injection nozzle, a so-called injector, which controls an injection state of fuel by opening and closing an injection port by a needle valve driven by a solenoid. There is a structure. As one of the injectors, for example, as shown in FIG. 5, a side in which a fuel supply pipe C is connected to a side of a fuel reservoir of an injector B contained in a delivery pipe A for fuel supply. There is a structure called a feed injector. This injector B
As shown in FIG. 6, a needle valve B1 capable of opening and closing a fuel injection port A1 formed in a housing constituting a delivery pipe A, and sliding the needle valve B1 in a direction in which the fuel injection port A1 is opened. And a solenoid B2. Fuel is stored in a sliding space of the needle valve B1 in the injector B, and a space corresponding to a side portion of the fuel storage portion is formed of a space communicating with a fuel supply pipe C. A fuel storage section A2 is provided. Therefore, the fuel that has reached the fuel reservoir A2 in the housing via the fuel supply pipe C flows into the injector B via the filter A3, and is injected when the tip of the needle valve B1 is drawn into the injector B. It is injected from the mouth A1. In the side feed injector having such a structure, when the temperature of the fuel filled by the injector B is increased by heating from the engine side and evaporation occurs, the space in the injector B is close to the space filled with the fuel. The fuel evaporating gas can be recovered in a short time in the fuel reservoir A2 side of the delivery pipe A communicating with the position, and the heat from the coil of the solenoid B2, which is a heat generating part inside the injector B, is also transmitted to the delivery pipe A.
There is an advantage that the coil can be cooled by being transmitted to the fuel stored in the inside and radiating heat through the fuel in the fuel supply pipe. Therefore, since such a side feed injector can cool the injector and recover steam generated in the injector, for example, when restarting after stopping at a high temperature of the engine, generation of steam in the injector is prevented. Further, it is expected that idle malfunction caused by the incorporation of steam can be prevented.

[0003]

By the way, in the above-described side feed injector, heat generated in the injector and heat transmitted from the engine can be cooled by fuel supplied to the injector. Because the supplied fuel is heated, the temperature rises due to the heating, and especially when this fuel stays in the injector, heat is also transferred to the fuel in the fuel supply pipe, As a result, the evaporation of fuel in the fuel tank is promoted to cause abnormal generation of hydrocarbons, and there is a possibility that the air is polluted. Therefore, conventionally, as a structure for coping with such a situation, for example, a special component such as a charcoal canister is provided to absorb the fuel evaporative gas. However, even in the case of such a special structure, if the amount of heat generated on the injector side is large, the amount of fuel that evaporates increases, and there is a possibility that complete recovery of the evaporated fuel cannot be performed.

An object of the present invention is to provide a fuel injection device having a structure capable of suppressing the evaporation of fuel with a simple structure in the above-mentioned conventional fuel injection device, particularly a side feed injector.

[0005]

SUMMARY OF THE INVENTION To achieve this object, the present invention provides a fuel delivery system having a fuel supply pipe connected to a side of a delivery pipe having a fuel supply passage communicating with a fuel storage space of an enclosed injector. In the fuel injection device having the side feed injector having the above structure, a cooling water passage is formed adjacent to a fuel supply passage in the delivery pipe and the fuel supply pipe.

Further, according to the present invention, the cooling water passage provided in the delivery pipe and the fuel supply pipe is provided separately from the engine cooling water passage, and is circulated through the engine cooling water radiating portion. It is characterized by having a structure to make it.

[0007]

According to the present invention, the fuel supplied from the delivery pipe into the injector is cooled by the cooling water provided at an adjacent position in the pipe. Further, the cooling water which has passed through the injector and has been heated by the heat transfer from the fuel, is radiated by circulating through a passage different from that of the engine cooling water.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of an embodiment of the present invention will be described below with reference to FIGS. FIG. 1 is a schematic view showing a main part of a fuel injection device according to an embodiment of the present invention. The feature of this embodiment is that a cooling water passage is provided adjacent to a fuel supply passage in a delivery pipe containing an injector. Has been established. In FIG. 1, a fuel injection device 1 includes an injector 2, a delivery pipe 3, and a fuel supply pipe 4, which will be described later, as main parts for fuel injection. It should be noted that a fuel pump, a strainer, and a fuel tank for pumping fuel to the delivery pipe 2 are omitted in FIG. As shown in FIG. 2, the injector 2 is disposed in a housing 3A that forms a main part of the delivery pipe 3, and opens and closes a fuel injection port formed in the housing 3A, similarly to this type of injector. A needle valve 2A and a solenoid 2B for controlling the opening and closing of the needle valve 2A are provided. The needle valve 2A is a normally-closed valve normally biased in a direction to close the injection port by a spring (not shown), and is drawn into the housing to open the injection port when the solenoid 2B is excited. It is designed to inject fuel.

On the other hand, a sliding space of the needle valve 2A in the injector 2 is a storage space 2C filled with fuel, and a housing 3 corresponding to a side portion of the storage space 2C.
At a position on the side A, a fuel storage passage 3B is provided which is a fuel supply passage from the fuel tank. And fuel storage channel 3
In B, a cooling water passage 3C composed of a space is formed at a position adjacent to the cooling water via a partition wall. In the case of this embodiment,
The partition separating the fuel storage passage 3B and the cooling water passage 3C is as follows:
In order to widen the range of heat transfer from the fuel, it is made into a bent shape. As shown in FIG. 1, the cooling water passage 3 </ b> C is also provided in a part of an extension of the fuel supply pipe 4 connected to the injectors 2. As shown in FIG. 3, it is constituted by a space 4B formed at a position adjacent to the fuel supply path 4A. Further, the fuel supply pipe 4 having the cooling water passage 4B has a portion corresponding to the cooling water passage branched in the middle, and the branched cooling water passage portion is connected to the cooling water circulation passage of the engine. Separately, a circulation path having a water pump 5 is formed. As shown in FIG. 1, a part of the circulation path is connected to a radiator 6 serving as a heat radiating portion of engine cooling water, and is pressure-fed from the injector 2. Cooling water can be radiated.

Since the present embodiment has the above configuration,
When the cooling water is pumped toward the cooling water passage 3C in the delivery pipe 3 by the pressure from the water pump 5, the heat from the fuel filling the space adjacent to the cooling water passage 3C passes through the partition wall. It is transmitted to the cooling water, which cools the fuel. On the other hand, the cooling water whose temperature has risen due to the heat transfer through the partition wall reaches the radiator 6 after flowing through a part of the fuel supply pipe 4, where the temperature is lowered by the heat radiation in this part, and the inside of the fuel supply pipe 4 Reaches the inside of the delivery pipe 3 together with the fuel supply passage 4B, and flows toward the cooling water passage 3C in the delivery pipe 3 to circulate through the cooling water passage. According to the present embodiment, the radiating portion of the engine cooling water can be used only by providing the cooling water passage to the fuel supply path of the injector 2. No parts are required.

In the above-described embodiment, the radiator, which is one of the heat radiation structures of the engine side cooling water, is also used for the heat radiation of the cooling water to the fuel. As an example, the structure shown in FIG. 4 can be adopted. That is, in the structure shown in FIG. 4, the pipe 4 shown in FIG. 1 is connected together with the radiator 6 to a cooling water circulation path of a water-cooled intercooler 7, which may be provided in an intake system of the engine. . The use of such a structure is possible because the amount of heat generated on the cooling water side of the fuel is smaller than the amount of heat generated on the water-cooled intercooler 7 side. In the case of a vehicle that requires high output, such as a vehicle equipped with a turbocharger 8, which often uses the fuel cell 7, it is known that the temperature rise on the injector side becomes significant and the generation of fuel vapor becomes remarkable. By using the heat dissipation structure of the above, it is helpful to prevent it.

[0012]

As described above, according to the present invention, since the cooling water passage is provided adjacent to the fuel supply passage in the delivery pipe containing the injector, the generation of the fuel vapor due to the temperature rise of the injector is provided. Can be suppressed.

Further, according to the present invention, as a radiating mechanism for radiating the fuel cooling water, a circulating path separate from the engine cooling water is provided, and an existing radiating section is disposed in the circulating path. This makes it possible to suppress fuel evaporation with a simple structure without providing a special fuel cooling radiator.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a main part of a fuel injection device according to an embodiment of the present invention.

FIG. 2 is a schematic cross-sectional view of FIG.

FIG. 3 is a schematic barn finger men's in a direction indicated by a reference numeral in FIG.

FIG. 4 is a schematic diagram for explaining a modified example of a main part of the present invention.

FIG. 5 is a schematic view showing a main part of a conventional fuel injection device.

FIG. 6 is a schematic cross-sectional view taken along a line indicated by a reference numeral in FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Fuel injection device 2 Injector 2A Needle valve 2C Fuel storage space 3 Delivery pipe 3A Housing 3B Fuel storage channel 3C Cooling water passage 4 Fuel supply pipe 4B Cooling water passage 6 Radiator 7 Intercooler

Claims (2)

(57) [Claims] 1. A fuel injection device comprising a side feed injector having a structure in which a fuel supply pipe is connected to a side of a delivery pipe having a fuel supply passage communicating with a fuel storage space of an included injector. A fuel injection device, wherein a cooling water passage is formed adjacent to a fuel supply passage in the delivery pipe and the fuel supply pipe. 2. The fuel injection device according to claim 1, wherein a cooling water passage provided in the delivery pipe and the fuel supply pipe is provided separately from the engine cooling water passage, and the engine cooling water passage is provided. A fuel injection device having a structure for circulating through a radiator.