JPH0693933A - Pre-heater of fuel injection part in internal combustion engine - Google Patents

Abstract

PURPOSE:To assist gasification of fuel by transmitting heat on an accumulator to the fuel injection part of an intake pipe and pre-heating it. CONSTITUTION:A pre-heater is a device for pre-heating at the time of starting under a low temperature, being provided with an accumulator 21 for insulating and keeping its waste heat, a preheating flow passage 22 formed on the fuel injection part of an intake port, and a pre-heating circuit 23 for connecting the pre-heating flow passage 22 and the accumulator 21 to each other, and in which a switching valve 25 is interposed between a flow passage 24 for connected the cooling system of the engine and the accumulator 21 to each other and the pre-heating circuit 23. It is thus possible to use the accumulator 21 having a small capacity. And since the pre-heating flow passage 22 is formed on the fuel injection part, it is possible to improve pre-heating efficiency, and improve fuel consumption eliminating necessity for increasing a fuel injection amount at the time of engine starting under cooling condition, and also eliminate incomplete combustion. Furthermore, burden of a battery is reduced, and it is in more useful condition for improving fuel consumption. Since engine waste heat is kept and utilized again in the accumulator 21 as a heating source, energy is saved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a preheating device for a fuel injection part using a heat storage device in an internal combustion engine. More specifically, the present invention relates to a preheating device for assisting vaporization of fuel by transferring heat of a regenerator to preheat it at a fuel injection portion of an intake pipe when the internal combustion engine is started at a low temperature.

[0002]

2. Description of the Related Art As shown in FIG. 6, a fuel injection portion 35 of an internal combustion engine is equipped with an injector 32 for supplying fuel to an intake port 31.
2 injects fuel into the intake port. The injected fuel is mixed with the combustion air introduced through the intake pipe 30, and is introduced into the combustion chamber 34 through the intake valve 33. At this time, if the temperature of the outside air is low and the intake pipe 30 is cold, the injected fuel is condensed and adheres to the pipe wall. This is particularly noticeable in cold weather, which causes engine start-up failure, deteriorates fuel consumption and causes exhaust gas deterioration due to incomplete combustion of fuel, and causes a problem that CO, HC, and NOx in exhaust gas increase.

In order to solve this problem, a method has been attempted in which a small electric heater is provided in the vicinity of the injection port of the injector inside the intake pipe, and the fuel injected into the intake pipe by the electric heater is heated. . According to this method, the evaporation of fuel is assisted by heating, and it is possible to prevent a starting failure during cold weather, but the electric power consumption of the electric heater is large,
The load on the battery increases. Particularly in an internal combustion engine for a vehicle, the capacity of a battery mounted on the vehicle is limited. Therefore, a preheating device with large power consumption is not preferable in practice.

On the other hand, recently, a latent heat accumulator has been studied as a heat source replacing electric energy. This latent heat accumulator adiabatically stores the waste heat of the engine, and uses this heat for heating the interior of the vehicle and preheating fuel as necessary.
The conventional latent heat accumulator is mainly used for heating the interior of the vehicle and is therefore large in size, and is not suitable as a heat source used for temporarily heating the intake system at the time of starting. Further, a conventionally known preheater for an intake system is provided with a latent heat accumulator in the vicinity of a radiator, and a circulation flow path that returns to the heat accumulator via an intake pipe riser portion located immediately below a carburetor causes The preheating circuit is formed, and the heat of the regenerator is guided to the intake pipe riser section by using the cooling water flowing through the preheating circuit as a heat transfer medium.
-115846), this structure does not directly preheat the fuel supply section where the injector is installed, so the preheating effect is small, and since it is a preheating circuit that communicates with the cooling system of the engine and radiator, it is a large heat storage with a large heat capacity. There is a problem that requires a vessel. In addition to this, the conventional latent heat storage device uses barium hydroxide Ba (OH) ₂ .8H ₂ O as a heat storage agent.
However, if it leaks the heat storage agent, the aluminum member of the cooling system will be corroded, and if a preheating circuit is provided directly in the fuel injection part, it is used. The engine may be seriously damaged. SUMMARY OF THE INVENTION It is an object of the present invention to solve the problems of the prior art as described above and to provide a preheating device which is excellent in the preheating effect of the fuel injection portion and therefore can use a small-sized regenerator.

[0005]

In view of the above problems, the inventor of the present invention forms a preheating circuit in a fuel supply portion provided with an injector to directly heat a strong fuel portion independently of a cooling system of an engine or a radiator. This makes it possible to use a small heat storage device by enhancing the preheating effect, and as an embodiment thereof, the use of a weakly alkaline heat storage agent with low corrosiveness makes it possible to improve the reliability of the preheating device formed in the fuel injection portion. It is the one that enhances sex. That is, the present invention provides (1)
A device for preheating a fuel injection part of an internal combustion engine at the time of starting at a low temperature, a regenerator connected to a cooling system of the engine and adiabatically storing the waste heat of the engine, and a preheating flow formed in the fuel injection part of the intake port. And a preheating circuit connecting the preheat passage and the regenerator, and a switching valve is provided between the passage connecting the engine cooling system and the regenerator and the preheating circuit. (2) The preheating device for the fuel injection portion, (2) the preheating device according to (1), wherein the preheating passage is formed on the engine head side outer periphery of the fuel injection portion of the intake pipe, and (3) the preheating passage. The jacket is formed by a jacket surrounding the outer circumference of the intake pipe. The jacket is formed by a hollow member through which a heat transfer medium flows, and a port liner that is inserted into the intake port is integrally formed. Extends to the fuel injection part And has preheating apparatus of (1),
(4) As a heat storage agent sealed in the heat storage device, Mg (N
O ₃₎ is a pre-heating device of the above (1) using _{2 · 6H 2 O / LiNO 3} .

The present invention will be described below with reference to the embodiments shown in the drawings. FIG. 1 is a layout view of a preheating device of the present invention,
2 is a schematic cross-sectional view of an intake pipe fuel injection portion in which a preheating passage is formed in an engine head portion according to an embodiment of the present invention,
3 and 4 relate to another embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of an intake pipe fuel injection portion having a preheating passage formed by using a jacket and a port liner, and FIG. 4 is a jacket and a liner. Fig. 5 is a schematic perspective view, and Fig. 5 is a partial cutaway schematic perspective view showing an example of the heat storage device.

As shown in FIG. 1, a vehicle water-cooled internal combustion engine includes a radiator 11 for cooling an engine 10 and an engine 1.
A heater 12 that guides the heat of 0 into the vehicle is provided. These are connected by a pipe 13 through which cooling water of a heat transfer medium flows, and a cooling circuit 1 that circulates between an engine 10 and a radiator 11.
4, heat dissipation circuit 1 circulating through engine 10 and heater 12
5 is formed. Cooling water circulates in the circuit by a pump 16 provided in a pipe near the inlet of the engine. Further, a fan 17 and a blower 18 are provided behind the radiator 11 and the heater 12 in order to enhance thermal efficiency. In the illustrated embodiment, the cooling circuit and the heat radiation circuit are formed by a common pipe in the vicinity of the inlet and the outlet of the engine 10, but they can be formed separately as necessary. The preheater 20 of the present invention includes a regenerator 21 for adiabatically storing waste heat of the engine 10, a preheat passage 22 formed in the fuel injection portion 21 of the engine 10, and a preheat connecting the regenerator 21 and the preheat passage 22. A circuit 23 is provided, and the preheating circuit 23 is connected to a cooling system of the engine through a passage 24 and a heat radiation circuit 15.
Further, the switching valve 2 is provided at the branch portion of the preheating circuit 23 and the flow path 24.
5, and a pump 26 is provided in the flow path 24.

In FIG. 1, when the engine 10 is in operation, a switching valve 25 is used to move the heat storage device 21 to the preheating passage 22.
Is closed, the cooling water heated by the residual heat of the engine 10 is guided to the heater 12 through the heat dissipation circuit 15, and a part of the cooling water is introduced into the heat storage device 21 through the flow path 24, and the inside of the heat storage device 21 is Heat is exchanged with the heat storage agent while circulating and flowing, and after radiating heat, it flows out from the heat storage device 21 and returns to the engine 10 through the flow path 24. The heat storage agent is heated to a temperature equal to or higher than the melting point by the heat exchange, is transformed from the solid phase to the liquid phase, and is adiabatically stored as latent heat accompanying the phase transformation. When the engine is started in a low temperature environment, the switching valve 25 closes the flow path 24 connecting the engine cooling system and the heat storage unit 21, and the preheating circuit 25 is opened to connect the heat storage unit 21 and the preheating flow path of the fuel injection portion. Cooling water (heat transfer medium) flows in between, and the cooling water is heated by the latent heat generated when the heat storage agent is transferred from the liquid phase to the solid phase, and this flows through the preheating flow path to preheat the fuel injection part and reheat storage. Return to vessel 21.

FIG. 2 shows an example of the preheating passage in the preheating device of the present invention. In the embodiment shown in FIG. 2, the intake pipe 30
Fuel injection portion 35 from the engine to the intake port 31 of the engine
Is equipped with an injector 32 for fuel injection,
The tip of the injector 32 projects into the intake port 31, and the fuel vaporized from the tip of the injector is injected toward the intake valve 33. The combustion air is introduced into the intake port 31 through the intake pipe 30, mixed with the fuel injected in the fuel injection portion 35, and then introduced into the combustion chamber 34 through the intake valve 33. The preheating channel 2
2 is formed on the engine head side outer peripheral portion located immediately below the fuel injection portion of the intake port 31. The preheating channel 2
The inflow port (not shown) and the outflow port (not shown) of 2 are connected to the preheat circuit 23, and the cooling water circulates between the regenerator 21 and the preheat passage 22 through the preheat circuit 23. . In the present embodiment, since the preheating flow passage is formed immediately below the fuel injection portion of the intake port, the inner wall of the fuel injection portion is directly heated by the heated cooling water flowing through the preheating passage, and thus the preheating effect. This part can be preheated with a small amount of heat.

Another example of the preheating channel is shown in FIG. Figure 3
In this embodiment, the preheating flow passage 22 is formed by the jacket 40 surrounding the outer circumference of the intake pipe 30. The jacket 40 is made of a material having good thermal conductivity such as copper or aluminum and is formed by a hollow member through which cooling water flows, and the intake pipe 30 surrounds the intake pipe 30.
And the intake port 31. In order to enhance the heat transfer effect to the fuel injection portion 35, the jacket 40
Is a cylindrical port liner 4 that is inserted into the intake port 31.
1 is integrally formed, the liner 41 is provided with an injector hole 42 into which the injector 32 is inserted, and the liner tip 43 extends to the fuel injection portion. The jacket 40 has its liner portion 41 inserted into the intake port 31, and is connected to the inlet of the intake port of the engine 10 by a suitable connecting means, and the intake pipe 30 is connected to the inlet pipe 30 by a suitable connecting means.
Connected to. In this embodiment, heat is radiated through a jacket and a port liner made of a material having good thermal conductivity,
Moreover, since the tip of the port liner extends to the fuel injection portion, the heat transfer effect to this portion is excellent, and as in the embodiment of FIG. 2, a sufficient preheating effect can be obtained with a small amount of heat. In addition, a jacket is provided between the intake pipe and the intake port, and a port liner is inserted into the intake port to form a preheating flow path, so it can be installed without requiring major changes to the engine, and it can be easily assembled and removed. Yes, maintenance work is easy.

In the embodiment shown in FIGS. 2 and 3, the heat storage unit 21 may have the structure shown in FIG. 5 as an example. In FIG. 5, the heat storage unit 21 includes a heat storage core 40 and an outer casing 4 that houses the heat storage core 40.
1, and a heat insulating region 42 is provided between the heat storage core 40 and the outer casing 41 for adiabatically storing the waste heat guided to the heat storage core. The heat insulating region 42 is kept in a vacuum, but it may be filled with a high heat insulating material and kept in a low vacuum. Inside the heat storage core 40, a large number of heat transfer medium passages 43 and the passages 4 are provided.
A heat storage material storage portion 44 sandwiched between 3 and a storage portion 45 that communicates the heat transfer medium flow passage 43 with each other are provided, and the flow passage 43 and the heat storage material storage portion 44 improve heat exchange efficiency. Is divided into a number of narrow grooves. Accumulating Mg (NO ₃₎ as a heat storage material in the thermal material housing portion 44 ₂ · 6H ₂ O / L
iNO ₃ is filled. This material is weakly alkaline, and even if it leaks to the cooling system, it is weakly corrosive, so the damage to the engine is small, and the human body and environment are also less affected.

[0012]

In the preheating device of the present invention, the preheating system of the fuel injection portion is formed independently of the engine cooling system by the switching valve, and it is dedicated to preheating this portion, so the capacity is small and the weight is light. A small heat storage device can be used. In addition, since the preheating flow path is formed in the fuel injection part, it has an excellent preheating effect, and it is not necessary to increase the fuel injection amount at the time of engine start in cold weather, which improves fuel efficiency and eliminates incomplete combustion of fuel. CO, HC and NOx in exhaust gas are reduced. Further, since an electric heater is not used as a heating source, the burden on the battery is small and it is more advantageous for improving fuel consumption. Since the heat storage of the heating source stores and reuses engine waste heat, resource saving and energy saving can be achieved.

[Brief description of drawings]

FIG. 1 is a layout view of a preheating device of the present invention.

FIG. 2 is a schematic cross-sectional view of an intake pipe fuel injection portion in which a preheating passage is formed in an engine head portion according to an embodiment of the present invention.

FIG. 3 is a schematic cross-sectional view of an intake pipe fuel injection portion having a preheat passage formed by using a jacket and a port liner according to an embodiment of the present invention.

FIG. 4 is a schematic perspective view of the jacket and liner.

FIG. 5 is a partially cutaway schematic perspective view showing an example of a heat accumulator used in the preheating device of the present invention.

FIG. 6 is a schematic sectional view of a conventional fuel injection portion.

[Explanation of symbols]

10-engine, 11-radiator, 12-heater, 1
3-Piping, 14-Cooling circuit, 15-Radiation circuit, 16-Pump, 17-Fan, 18-Blower, 20-Preheating device,
21-heat accumulator, 22-preheating passage, 23-preheating circuit, 24
-Flow path, 25-switching valve, 26-pump, 30-intake pipe,
31-intake port, 32-injector, 33-intake valve, 34-combustion chamber, 35-fuel injection part, 40-jacket, 41-port liner, 42-injector hole, 43-liner tip

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[Procedure amendment]

[Submission date] December 25, 1992

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0005

[Correction method] Change

[Correction content]

[0005]

In view of the above-mentioned problems, the inventor of the present invention forms a preheating circuit in a fuel supply section provided with an injector, and supplies the fuel independently of the cooling system of the engine or the radiator.
By directly heating the supply part , the preheating effect is enhanced so that a small heat storage device can be used, and as an embodiment thereof, by using a weakly alkaline heat storage agent with low corrosiveness, the fuel injection part is This improves the reliability of the formed preheating device. That is, the present invention is
(1) A device for preheating a fuel injection portion of an internal combustion engine at the time of starting at a low temperature, which is connected to a cooling system of the engine and is formed in a heat accumulator for adiabatically storing the waste heat of the engine and the fuel injection portion of an intake port. And a preheating circuit connecting the preheating flow path and the regenerator, and a switching valve is interposed between the flow path connecting the engine cooling system and the regenerator and the preheating circuit. (2) The preheating device for a fuel injection portion, (2) the preheating device according to (1), wherein the preheating passage is formed on an outer peripheral portion of the fuel injection portion of the intake pipe on the engine head side, and (3) the preheating device. The flow path is formed by a jacket that surrounds the outer periphery of the intake pipe, and the jacket is formed by a hollow member through which the heat transfer medium flows and a port liner that is inserted into the intake port is integrally formed. The liner tip is the fuel injection part Preheating device, of the above (1) to extend as a heat storage agent encapsulated (4) above the heat accumulator, Mg
_{(NO 3)} it is a pre-heating device of the above (1) using _{2 · 6H 2 O / LiNO 3} . Tetrachlorogermanium (GeCl ₄ ) is used, but chlorine is generated at the same time when the SiO ₂ film is formed, so that there is a problem that a chlorine treatment process is required.

Claims (4)

[Claims] 1. A device for preheating a fuel injection portion of an internal combustion engine at the time of starting at a low temperature, which is connected to a cooling system of the engine and adiabaticly stores waste heat of the engine, and the fuel injection portion of the intake port. And a preheating circuit connecting the preheating flow path and the regenerator, and a switching valve is provided between the flow path connecting the engine cooling system and the regenerator and the preheating circuit. A preheating device for a fuel injection part, which is characterized in that 2. The preheating flow path is formed in the engine head side outer peripheral portion of the fuel injection portion of the intake port.
Preheating device. 3. The preheating flow passage is formed by a jacket surrounding the outer periphery of the intake pipe, and the jacket is formed by a hollow member through which a heat transfer medium flows and a port liner inserted into the intake port is formed. The preheating device according to claim 1, wherein the preheating device is integrally formed and the liner tip extends to the fuel injection portion. 4. The heat storage agent sealed in the heat storage device,
Mg (NO ₃₎ preheating device according to claim 1 using a _{2 · 6H 2 O / LiNO 3} .