JP2003193944A - Fuel feeder of internal combustion engine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel feeder of an internal combustion engine capable of favorably and compatibly suppressing vapor generation in a fuel injection valve and suppressing icing in an air intake passage. <P>SOLUTION: A fuel injection valve 17 to inject liquefied petroleum gas (LPG) in a delivery pipe 23 into an intake port 16a of a cylinder head 16 of the internal combustion engine 10 is fitted to an intake passage part 15 of an intake manifold 14. A phenol resin insulating member 40 is provided between the cylinder head 16 and the intake manifold 14. A fuel injection passage 42 which leads to the intake port 16a from a nozzle 17a of the fuel injection valve 17 successively via the intake manifold 14, the insulating member 40, and the cylinder head 16, and has an opening part 43 in an inner wall surface 16b of the intake port 16a of the cylinder head 16 is formed. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel supply system for an internal combustion engine, and more particularly to liquefied petroleum gas (LP) as a fuel.
G) or liquefied natural gas (LNG) and the like, the present invention relates to a fuel supply device suitable for use in an internal combustion engine that uses liquefied gas fuel.

[0002]

2. Description of the Related Art Conventionally, as a fuel supply device of this type,
For example, those described in JP-A-6-185378 are known.

As described above, in an internal combustion engine that uses LPG as a fuel, the saturated vapor pressure is usually maintained at a saturated vapor pressure determined by the properties and temperature of the LPG, and the LPG is stored in the fuel tank. Then, the LPG in the fuel tank is pressure-fed by the pump to the supply path including the delivery pipe, and is injected and supplied in a liquid state to the internal combustion engine by the fuel injection valve connected to the delivery pipe. The LPG injected from the fuel injection valve in this way is vaporized in the vicinity of the intake port and mixed with the air taken in from the intake passage, and the mixture is supplied to the engine combustion chamber for combustion.

[0004]

By the way, in an internal combustion engine which uses the LPG or the like as fuel, if the fuel injection valve is provided at a high temperature portion such as a cylinder head,
Inside the fuel injection valve, part of the LPG is vaporized and vapor (vaporized fuel) is easily generated. Then, when the fuel injected from the fuel injection valve contains vapor along with the generation of vapor in the fuel injection valve, the fuel density decreases, and it becomes difficult to secure the required fuel amount.

Particularly, after the engine is stopped, the temperature of the fuel injection valve is raised due to the stop of the circulation of the cooling water for cooling the engine, and the circulation of the fuel (LPG) itself is stopped. Therefore, vapor is easily generated in the fuel injection valve. Therefore, if the engine is restarted while the temperature of the engine is high after the engine is stopped, the problem of insufficient fuel amount due to the decrease in fuel density becomes serious.

On the other hand, LPG has a characteristic that the latent heat when vaporizing is large. For this reason, when the fuel injection valve is provided in a portion having a relatively low temperature, such as the intake manifold, the LP injected from the fuel injection valve is
When G vaporizes, it may take a large amount of heat from the intake air, causing freezing or so-called icing at the confluence of the injected fuel (LPG) and the intake air. If such icing occurs, normal injection from the fuel injection valve may be hindered.

In the device described in the above publication,
Although the icing is suppressed by the method of providing the fuel injection valve in the position close to the engine combustion chamber, it is suppressed when the vapor is generated in the previous fuel injection valve. It is not possible.

The present invention has been made in view of the above circumstances, and an object thereof is to achieve both the suppression of vapor generation in the fuel injection valve and the suppression of icing in the intake passage. Another object of the present invention is to provide a fuel supply device for an internal combustion engine.

[0009]

[Means for Solving the Problems] Means for attaining the above-mentioned objects and their effects will be described below. The invention described in claim 1 is an intake port of an internal combustion engine through a fuel injection valve provided in the delivery pipe while pumping liquefied gas fuel stored in a fuel tank in a saturated vapor pressure state to the delivery pipe. In a fuel supply device for an internal combustion engine, the fuel injection device includes: a fuel injection passage communicating with an injection port of the fuel injection valve, reaching an intake port of the internal combustion engine, and being opened at the intake port. The gist of the present invention is that a temperature gradient is set in the passage such that the temperature becomes lower in the vicinity of the communicating portion with the injection port of the fuel injection valve than in the vicinity of the opening of the intake port.

According to the above structure, the temperature in the vicinity of the injection port of the fuel injection valve in the fuel injection passage is lower than that in the vicinity of the opening in the intake port of the internal combustion engine, so that heat from the internal combustion engine is applied to the fuel injection valve. Is difficult to reach. As a result, the temperature rise of the liquefied gas fuel in the fuel injection valve is suppressed, and it is possible to suppress vaporization of a part of the liquefied gas fuel and generation of vapor.

In addition, the temperature around the opening on the intake port side in the fuel injection passage becomes high due to the heat of the internal combustion engine. For this reason, the liquefied gas fuel from the fuel injection valve is injected and supplied from the opening on the intake port side through the fuel injection passage to be vaporized, and at that time, heat is taken from the intake air containing water and the temperature of the intake air is changed. Even if it is lowered, the occurrence of icing can be suitably suppressed.

As a result, it is possible to achieve both the suppression of vapor generation in the fuel injection valve and the suppression of icing in the intake passage. The invention according to claim 2 is the invention according to claim 1, further comprising a heat insulating member between a cylinder head of the internal combustion engine in which the intake port is provided and a portion in which the fuel injection valve is provided, The fuel injection passage extends from the injection port of the fuel injection valve to the intake port through the portion where the fuel injection valve is provided, the heat insulating member and the cylinder head in order, and is opened in the cylinder head. And

With the above structure, the temperature gradient in which the temperature becomes lower in the vicinity of the portion communicating with the injection port of the fuel injection valve than in the vicinity of the opening in the intake port of the fuel injection passage is simple and reliable. It becomes possible to set.

According to a third aspect of the present invention, in the first aspect of the invention, a metallic spacer is provided between the cylinder head of the internal combustion engine provided with the intake port and the portion provided with the fuel injection valve. And a heat insulating member, and the fuel injection passage extends from the injection port of the fuel injection valve to the intake port through the portion where the fuel injection valve is provided, the heat insulating member and the metal spacer in order, and The gist is that the spacer is opened.

According to the above construction, the temperature gradient can be set with a simple construction as in the construction according to the second aspect of the invention, and in addition, by the portion where the fuel injection valve is provided, the heat insulating member and the spacer. Since the fuel injection passage is formed, it is not necessary to form a part of the fuel injection passage in the cylinder head. As a result, the engine productivity can be favorably maintained such that the cylinder head can be shared between the internal combustion engine that uses liquefied gas fuel as the fuel and the internal combustion engine that uses gasoline.

According to a fourth aspect of the present invention, in the second or third aspect of the invention, the portion where the fuel injection valve is provided is an intake manifold of an internal combustion engine.

According to the above structure, even if the intake manifold is connected to the cylinder head of the internal combustion engine through a gasket, and heat is particularly easily transferred from the cylinder head, a heat insulating member is provided between the intake manifold and the cylinder head. By interposing it, the temperature rise of the intake manifold can be appropriately suppressed. Therefore, it is possible to follow the normal engine structure such as providing a fuel injection valve in the intake manifold.

According to a fifth aspect of the present invention, in the first aspect of the present invention, the fuel injection valve is provided in a heat insulating member, and the fuel injection passage extends from an injection port of the fuel injection valve to the heat insulating member. The point is to reach the intake port of the internal combustion engine via the.

The invention according to claim 6 is the same as claim 1.
In the invention described in claim 1, the fuel injection valve is provided between the internal combustion engine and at least the heat insulating member, and the fuel injection passage is formed from the injection port of the fuel injection valve through at least the heat insulating member. The point is to reach the intake port of.

With these configurations, the temperature gradient in which the temperature becomes lower in the vicinity of the portion communicating with the injection port of the fuel injection valve than in the vicinity of the opening in the intake port of the fuel injection passage is simple and reliable. Can be set to.

The invention according to claim 7 is the invention according to claim 5 or 6, wherein a metal spacer is provided between the cylinder head of the internal combustion engine provided with the intake port and the intake manifold of the engine. The gist is that the fuel injection passage that is interposed and reaches the intake port is opened in the metal spacer.

Also with the above structure, it is not necessary to form a part of the fuel injection passage in the cylinder head. As a result, the engine productivity can be favorably maintained such that the cylinder head can be shared between the internal combustion engine that uses liquefied gas fuel as the fuel and the internal combustion engine that uses gasoline.

According to an eighth aspect of the present invention, in the first aspect of the present invention, heating means is further provided in the vicinity of the fuel injection passage, and in the fuel injection passage through heating by the heating means. The gist is that a temperature gradient is set such that the temperature becomes lower in the vicinity of a portion communicating with the injection port of the fuel injection valve than in the vicinity of the opening of the intake port.

When the temperature gradient in the fuel injection passage is set by the heat generated during the operation of the internal combustion engine, the heat from the internal combustion engine does not always provide a sufficient temperature gradient. If this temperature gradient is insufficient, icing may occur at the opening of the intake port in the fuel injection passage. In this way, when the temperature gradient becomes insufficient, for example,
When the liquefied gas fuel contains a large amount of components with large latent heat of vaporization (such as propane), when the fuel injection amount by the fuel injection valve is large, when the internal combustion engine is operated in a place where the outside temperature is low, such as in a cold region, It is possible that the engine is cold started.

In this respect, according to the above construction, since the temperature gradient in the fuel injection passage is obtained by heating by the heating means, it is possible to use a heating means capable of heating to a temperature higher than that of the internal combustion engine, or to use the heating means. It is possible to operate it early. Therefore, it is possible to obtain a sufficient temperature gradient in the fuel injection passage regardless of the properties of the liquefied gas fuel used, the operating state and operating environment of the internal combustion engine,
The occurrence of icing can be suppressed more favorably.

According to a ninth aspect of the present invention, in the invention according to the eighth aspect, a heat insulating member is provided between the cylinder head of the internal combustion engine provided with the intake port and the portion provided with the fuel injection valve. The fuel injection passage includes an opening in the cylinder head that extends from the injection port of the fuel injection valve to the intake port through the portion where the fuel injection valve is provided, the heat insulating member, and the cylinder head. The gist is that the heating means is provided in the cylinder head in the vicinity of the fuel injection passage.

According to the above construction, by providing the heating means on the cylinder head, it is possible to form a sufficient temperature gradient in the fuel injection passage during heating by the heating means.

According to a tenth aspect of the present invention, in the invention according to the eighth aspect, a spacer and a heat insulator are provided between the cylinder head of the internal combustion engine provided with the intake port and the portion provided with the fuel injection valve. A member, the fuel injection passage is opened from the injection port of the fuel injection valve to the intake port through the region where the fuel injection valve is provided, the heat insulating member and the spacer, and is opened in the spacer. The heating means is provided in the vicinity of the fuel injection passage in at least one of the spacer and the cylinder head.

According to the above construction, by providing the heating means on the cylinder head or the spacer, it is possible to form a sufficient temperature gradient in the fuel injection passage during heating by the heating means.

When the heating means is provided on the spacer, the heating means can be provided at a position closer to the fuel injection passage, so that the temperature gradient can be set larger. Further, since the spacer is a small component, it is easier to process the spacer and the like as compared with a case where the spacer is provided on a cylinder head which is a large component, and the productivity can be preferably maintained.

According to an eleventh aspect of the present invention, in the invention according to the tenth aspect, the spacer is a metal spacer, and an insulating layer is provided between the metal spacer and the heating means. That is the summary.

According to the above construction, even if the heating means is driven by heating with an appropriate electric current,
It is possible to prevent the current flowing through the heating means from leaking to the metal spacer. Therefore, the temperature gradient in the fuel injection passage can be reliably formed.

A twelfth aspect of the invention is characterized in that, in the tenth aspect of the invention, the spacer is made of an insulator. According to the above-mentioned configuration, similarly to the above, even when the heating means is driven by heating with an appropriate current, when the heating means is provided in the spacer made of an insulator, the heating means and the spacer There is no need to provide an insulating layer between them. Therefore, when providing the heating means to the spacer, the step of forming the insulating layer can be omitted, and the spacer can be easily formed.

The invention according to claim 13 is the invention according to claim 10
In the invention described in any one of 12 above, the heating means is provided at or near an opening of a through hole communicating with the intake port in the fuel injection passage inside the spacer. To do.

According to the above construction, since the heating means is provided in the opening portion where icing is most likely to occur, the opening portion of the spacer is intensively heated during the heating by the heating means. Therefore, it is possible to efficiently suppress the occurrence of icing with low power consumption.

The invention according to claim 14 is the invention according to claim 10
In the invention described in any one of 12 above, the gist is that the heating means is provided so as to surround a through hole communicating with the intake port of the spacer.

A fifteenth aspect of the present invention is, in the invention according to any one of the tenth to fourteenth aspects, characterized in that the heating means is provided in a plate shape. According to the respective configurations described in claims 14 and 15, the heating area by the heating means can be increased,
During heating by the heating means, the spacer is entirely heated by the heating means provided inside the spacer. As a result, the opening of the through hole communicating with the intake port in the fuel injection passage inside the spacer is maintained at a high temperature because the heat of the opening is less likely to be transmitted to the periphery thereof. Therefore, the heating effect of the heating means can be obtained more reliably.

According to a sixteenth aspect of the present invention, in the invention according to the eighth aspect, the heating means is provided between the injection port of the fuel injection valve and the opening portion of the intake port in the fuel injection passage. The gist is that it is provided so as to surround a part of the fuel injection passage at a position separated from the injection port of the fuel injection valve.

According to the above arrangement, the heating means can be provided at a position closer to the opening in the intake port of the fuel injection passage. Therefore, at the time of heating by the heating means, a sufficient temperature gradient can be formed in the fuel injection passage.

According to a seventeenth aspect of the present invention, in the invention according to the sixteenth aspect, a heat insulating member is provided between the cylinder head of the internal combustion engine provided with the intake port and the portion provided with the fuel injection valve. The fuel injection passage includes an opening in the cylinder head that extends from the injection port of the fuel injection valve to the intake port through the portion where the fuel injection valve is provided, the heat insulating member, and the cylinder head. The fuel injection passage is formed by an inner circumference of a cylindrical insulator at a part separated from the fuel injection valve, and the heating means engages with the cylindrical insulator while The gist is that it is provided so as to surround at least the opening of the injection passage.

According to an eighteenth aspect of the present invention, in the sixteenth aspect of the present invention, a spacer is provided between the cylinder head of the internal combustion engine provided with the intake port and the portion provided with the fuel injection valve. And a heat insulating member, and the fuel injection passage extends from the injection port of the fuel injection valve to the intake port through the region where the fuel injection valve is provided, the heat insulating member and the spacer, and is opened in the spacer. The fuel injection passage is formed by an inner circumference of a cylindrical insulator at a part separated from the fuel injection valve, and the heating means is provided at a portion corresponding to the cylindrical insulator. The gist is that it is provided so as to surround at least the opening of the fuel injection passage.

According to each of the seventeenth and eighteenth aspects, the heating means is engaged with the cylindrical insulator whose inner circumference forms a part of the fuel injection passage. Therefore, even if the heating means is driven by heating by applying an appropriate current, it can be provided at a position closer to the fuel injection passage. Further, since the heating means is provided so as to surround the opening at the intake port in the fuel injection passage, when heating the heating means, the heating means efficiently and efficiently surrounds the periphery of the opening in the fuel injection passage. It can be heated locally.

According to a nineteenth aspect of the present invention, in the invention according to the eighteenth aspect, the heating means is embedded inside the cylindrical insulator, and the heating means is embedded in the insulation. The gist is that the body is fitted in an engagement hole provided in at least one of the heat insulating member and the spacer.

According to the above construction, the heating means in the tubular insulator can contact the inner surface of the engagement hole of the spacer when the tubular insulator is engaged in the engagement hole of the spacer. Absent. For this reason, even when a metal spacer is used as the spacer and a heating device that is driven to heat by passing an appropriate current is used as the heating device, the current flowing through the heating device when the heating device is heated is It is possible to suppress leakage to the spacers.

According to a twentieth aspect of the invention, in the invention according to the eighteenth aspect, the heating means is provided on the surface of the cylindrical insulator, and the insulator provided with the heating means is The gist is that it is fitted into an engaging hole provided in at least one of the heat insulating member and the spacer.

According to the above construction, even if the heating means is driven by heating by passing an appropriate electric current,
When an insulating spacer is used, even if the spacer is in contact with the heating means, the current flowing through the heating means does not leak to the spacer. This makes it possible to provide the heating means on the outer surface of the cylindrical insulator, for example, and to insert the insulator provided with the heating means into the engagement hole of the spacer. Therefore, it is not necessary to embed the heating means inside the cylindrical insulator, and the heating means is provided by, for example, winding or printing on the surface of the insulator. You can As a result, the manufacturing process of the spacer provided with the heating means can be simplified.

The invention described in claim 21 is the invention according to claim 10
In the invention described in any one of 15 and 18 to 20, the heating means is provided inside the spacer, and between the spacer and the cylinder head, and between the spacer and the heat insulating member. The gist is that a spacer-side heat insulating layer is provided at least between the spacer and the cylinder head.

According to the above structure, heat transfer from the spacer to the portion where the fuel injection valve is provided is suppressed by the heat insulating member, and heat transfer from the spacer to the cylinder head is suppressed by the spacer side heat insulating layer. To be done. Therefore, during heating of the heating means, the opening of the fuel injection passage in the spacer at the intake port can be maintained at a higher temperature.

According to a twenty-second aspect of the invention, in the invention according to the twenty-first aspect, the spacer-side heat insulating layer is one of the facing surfaces of the spacer for the cylinder head or the spacer, or the spacer. Alternatively, the gist is that the heat insulating member is provided by coating one of the facing surfaces.

According to the above construction, it is possible to suppress an increase in the number of parts and to improve the assembling property when assembling the spacer and the like to the internal combustion engine. A twenty-third aspect of the invention is characterized in that, in the invention according to any one of the eighth to twenty-second aspects, the heating means is a heating wire heater.

With the above arrangement, the heating means can be easily realized by means of a versatile means such as a heating wire heater. The invention described in claim 24 is, in the invention described in any one of claims 1 to 23, characterized in that the liquefied gas fuel is liquefied petroleum gas.

According to the above construction, even if the liquefied petroleum gas is liable to be vaporized and has a large latent heat value upon vaporization, the vapor generation in the fuel injection valve and the icing in the intake passage are suppressed. It becomes possible to achieve a suitable compatibility with

[0053]

BEST MODE FOR CARRYING OUT THE INVENTION (First Embodiment) A first embodiment in which the present invention is embodied in a fuel supply device for injecting and supplying liquefied petroleum gas (LPG) as a fuel to an internal combustion engine This will be described with reference to FIGS. In addition, in this embodiment, as shown in FIG. 1, a 4-cylinder internal combustion engine is assumed.

As shown in FIG. 1, this internal combustion engine 10
The air cleaner 12 and the surge tank 1 in the intake passage 11 in order from the upstream side in the flow direction of the intake air.
3, an intake manifold 14 is provided. The intake manifold 14 is branched into intake passage portions 15 corresponding to the cylinders of the internal combustion engine 10, and the intake passage portions 15 are connected to a cylinder head 16 of the internal combustion engine 10. Further, in each intake passage portion 15 of the intake manifold 14, the LPG that is fuel is supplied.
A fuel injection valve 17 for injecting and supplying the fuel to the internal combustion engine 10 is provided.

On the other hand, a throttle valve 18 is provided upstream of the surge tank 13 in the intake passage 11. The throttle valve 18 is opened / closed in response to an operation of an accelerator pedal (not shown), and depending on its opening,
From the air cleaner 12 to the combustion chamber of the internal combustion engine 10 (each cylinder)
The intake amount of the intake air introduced into is adjusted. Further, each cylinder of the internal combustion engine 10 is provided with an ignition plug (not shown), an igniter (not shown) for generating a high voltage required for ignition of the plug, and the like.

Further, the internal combustion engine 10 is provided with an exhaust passage (exhaust manifold) 19 so as to face the intake passage portion 15. The exhaust passages 19 are connected to the exhaust passage 20. As is well known, an exhaust purification device such as a catalytic converter, a silencer (both not shown), and the like are arranged in the exhaust path 20.

Further, various sensors for detecting the operating state of the internal combustion engine 10 are provided in the internal combustion engine 10, the intake passage 11, and the like. For example, the intake passage 11 is provided with an intake air amount sensor 50 for detecting the amount of intake air flowing through the intake passage 11. Further, the internal combustion engine 10 is provided with a rotation speed sensor 51 for detecting the rotation speed of the engine output shaft, a cooling water temperature sensor 52 for detecting the temperature of the cooling water of the engine 10, and the like. Each of these sensors 50 to 52 is connected to an electronic control unit (ECU) 53 (see FIG. 2) that executes various controls related to the operation of the internal combustion engine 10.

Next, referring to FIG. 2, the internal combustion engine 10 will be described.
The configuration of the fuel supply device for supplying the fuel (LPG) to the vehicle will be described. As shown in FIG. 2, the fuel supply device includes a fuel tank 21 that stores LPG.
The inside of the fuel tank 21 has the LPG stored therein.
It is maintained at a saturated vapor pressure determined by the properties and temperature of.

The fuel tank 21 is connected to the delivery pipe 23 via the fuel supply path 22.
LP in the fuel tank 21 is provided in the middle of the fuel supply path 22.
A fuel pump 24 for pumping G to the delivery pipe 23,
A fuel filter 25 is provided to prevent foreign matter in the fuel tank 21 from flowing into the delivery pipe 23. Further, the delivery pipe 23 is provided with the LPG stored in the delivery pipe 23 so as to correspond to each cylinder of the internal combustion engine 10 (see FIG. 1). The fuel injection valve 17 for injecting the fuel is provided. Further, the delivery pipe 23 is connected to the fuel tank 21 via a return path 26 provided separately from the fuel supply path 22. This return route 2
A pressure regulator 27 is provided in the middle of 6, and the fuel pressure between the fuel pump 24 and the pressure regulator 27 in the fuel supply path 22, the delivery pipe 23, and the return path 26 is kept substantially constant. Here, the injection timing and injection amount of LPG injected from the fuel injection valve 17 are controlled through the electronic control unit 53 based on the detected intake air amount, rotational speed, cooling water temperature, and the like. The injection amount is controlled as an energization time for the electromagnetic valve that opens and closes the injection port of the fuel injection valve 17.

FIG. 3 shows the arrangement of the fuel injection valve 17 in the fuel supply system of this embodiment. As shown in FIG. 3, the fuel injection valve 17 is attached to the intake passage portion 15 of the intake manifold 14. A mounting portion 31 for mounting the fuel injection valve 17 is formed on the flange portion 30 of the intake manifold 14,
A recess 35 is formed in the mounting portion 31. Further, the intake passage portion 15 is formed with a fixing portion 32 for fixing the protruding piece 23a protruding from the delivery pipe 23. The tip of the fuel injection valve 17 is engaged with the recess 35 of the mounting portion 31 of the intake manifold 14 via the seal rubber 33, and the projecting piece 23a of the delivery pipe 23 is fixed to the fixing portion 32 of the intake passage portion 15.
It is fixed by a bolt 34.

Further, the intake manifold 14 to which the fuel injection valve 17 is attached in this way is provided with the heat insulating member 40.
It is fixed to the cylinder head 16 of the internal combustion engine 10 via a bolt (not shown). A gasket (not shown) is interposed between the cylinder head 16 and the heat insulating member 40 and between the heat insulating member 40 and the intake manifold 14. The gasket may be formed integrally with the heat insulating member 40, or may be formed separately.

In this embodiment, the heat insulating member 40 is made of phenol resin. And
The heat insulating member 40 includes an intake passage portion 15 of the intake manifold 14 and an intake port 16 a of the cylinder head 16.
A through hole 41 that communicates with and is formed. In the heat insulating member 40, even if the heat generated by the operation of the internal combustion engine 10 raises the temperature of the cylinder head 16 and the heat is transmitted to the fuel injection valve 17 via the intake manifold 14,
It has adiabatic performance so that the LPG in the fuel injection valve 17 does not rise to a temperature at which it vaporizes. Also,
The heat insulating member 40 has a compressive strength such that the wall thickness of the heat insulating member 40 is reduced by the compressive force generated by bolting the intake manifold 14 and the cylinder head 16 and the above-described heat insulating performance is not lost.

In this embodiment, as shown in FIG. 3, the intake manifold 14 is connected to the heat insulating member 4 as well.
The fuel injection passage 42 is formed by fixing both 0 and the gasket to the cylinder head 16. The fuel injection passage 42 extends from the injection port 17 a of the fuel injection valve 17 to the intake manifold 14 and the heat insulating member 4.
It is provided so as to reach the intake port 16a of the cylinder head 16 through the 0 and the cylinder head 16 in order.
The fuel injection passage 42 opens to the inner wall surface 16b of the intake port 16a. That is, the opening 43 of the fuel injection passage 42 is formed on the inner wall surface 16b of the intake port 16a of the cylinder head 16.

In this embodiment, as described above, the fuel injection passage 42 is formed by interposing the heat insulating member 40 between the intake manifold 14 and the cylinder head 16.
Of the injection port 17 of the fuel injection valve 17 as compared with the vicinity of the opening 43 of
A temperature gradient is set such that the temperature becomes low around the communication part with a. Therefore, the heat of the cylinder head 16 which has become high due to the operation of the internal combustion engine 10 is suppressed from being transmitted to the intake manifold 14, and by extension, the vaporization due to the temperature rise of the LPG in the fuel injection valve 17 is suppressed. Will be able to.

The LPG from the fuel injection valve 17 is injected into the intake port 16a of the cylinder head 16 through the fuel injection passage 42 and joins with the intake air. that time,
The injected LPG is released from the pressurized state around the opening 43 of the fuel injection passage 42, and vaporizes while removing heat from the intake air.

However, the opening 43 of the fuel injection passage 42 has an inner wall surface 16b of the intake port 16a of the cylinder head 16.
Since the opening 43 is formed in the internal combustion engine 1,
The temperature is high during zero operation. Therefore, even if the LPG injected from the fuel injection valve 17 to the intake port 16a merges with the intake air containing water and vaporizes, the heat is taken from the intake air and the temperature of the intake air is lowered, Icing does not occur due to freezing of water in the intake air around the opening 43 of the injection passage 42.

The LPG thus injected into the intake port 16a is vaporized and mixed with the intake air, and this mixture is supplied to the engine combustion chamber. The air-fuel mixture supplied to the combustion chamber of the engine is ignited by the spark plug to explode and burn, and the exhaust gas after combustion flows through the exhaust passage 19 and the exhaust passage 20 and is discharged to the outside.

As described in detail above, according to the fuel supply system of this embodiment, the following excellent effects can be obtained. (1) With a simple configuration, it is possible to reliably achieve both suppression of vapor generation in the fuel injection valve 17 and suppression of icing in the intake port 16a.

(2) Since the heat insulating member 40 is made of phenol resin having good heat insulating properties, the temperature gradient between the periphery of the opening 43 of the fuel injection passage 42 and the periphery of the injection port 17a of the fuel injection valve 17 can be made larger. it can.

(Second Embodiment) Next, the second embodiment of the present invention will be described.
The second embodiment will be described with reference to FIG. 4 focusing on parts different from the first embodiment. In FIG. 4, the same components as those in FIG. 3 are designated by the same reference numerals.

In the second embodiment, as shown in FIG. 4, the fuel injection valve 17 is attached to the intake manifold 14, and the heat insulating member 40 is interposed between the intake manifold 14 and the cylinder head 16. The difference is similar to the first embodiment. However, in the point that the metallic spacer 60 is further interposed between the heat insulating member 40 and the cylinder head 16, the first spacer is used.
Is different from the above embodiment.

The metal spacer 60 is made of, for example, an aluminum alloy and is formed in a plate shape. The spacer 60 has a through hole 6 corresponding to the through hole 41 of the heat insulating member 40 (the intake port 16a of the cylinder head 16).
1 is formed. When the intake manifold 14 is bolted to the cylinder head 16 together with the heat insulating member 40 and the spacer 60, the intake passage portion 15 of the intake manifold 14 and the intake port 16a of the cylinder head 16 are inserted through the through holes 41 and 61. It is designed to communicate. In addition, between the cylinder head 16 and the spacer 60, between the spacer 60 and the heat insulating member 40, and between the heat insulating member 40 and the intake manifold 14,
A gasket (not shown) is interposed in each case. Each gasket may be integrally formed with the spacer 60 and the heat insulating member 40, or may be separately formed.

Further, in the present embodiment, as shown in FIG. 4, the intake manifold 14, the heat insulating member 40, the spacer 60 and the gasket are cylinder head 16 together.
The fuel injection passage 62 is formed by fixing the fuel injection passage 62 to the fuel injection passage 62. The fuel injection passage 62 is provided so as to reach the intake port 16a of the cylinder head 16 from the injection port 17a of the fuel injection valve 17 through the intake manifold 14, the heat insulating member 40, and the spacer 60 in order. The fuel injection passage 62 is connected to the intake port 16
At a, an opening is made on the inner wall surface of the spacer 60. That is, in the present embodiment, the through hole 6 of the spacer 60
An opening portion 63 of the fuel injection passage 62 is formed on the inner wall surface of No. 1.

As described above, according to the fuel supply device of this embodiment, the above (1) in the first embodiment is used.
In addition to the effects described in (2) and (2), the following excellent effects can be obtained.

(3) Since the fuel injection passage 62 is formed by the intake manifold 14, the heat insulating member 40 and the spacer 60, it is not necessary to form a part of the fuel injection passage 62 in the cylinder head 16. As a result, LP as fuel
The cylinder head can be shared between the internal combustion engine 10 in which G is used and the internal combustion engine in which gasoline is used.

(4) Since the spacer 60 is formed of an aluminum alloy having good thermal conductivity, the temperature around the opening 63 of the fuel injection passage 62 can be kept high by the heat of the internal combustion engine 10.

(Third Embodiment) Next, the third embodiment of the present invention will be described.
The embodiment will be described with reference to FIGS. 5 to 7 focusing on the part different from the second embodiment. 5 to 7, the same components as those in FIG. 3 are designated by the same reference numerals.

In the third embodiment, as shown in FIG. 5, the fuel injection valve 17 is attached to the intake manifold 14, and the heat insulating member 40 and the metal spacer 60 are provided between the intake manifold 14 and the cylinder head 16.
Is the same as that of the second embodiment in that However, in the present embodiment, a heating means is provided for the metal spacer 60, and the communication portion with the injection port 17a of the fuel injection valve 17 is provided through heating by the heating means as compared with the vicinity of the opening 63 in the fuel injection passage 62. This is different from the second embodiment in that a temperature gradient is set so that the temperature becomes lower in the periphery.

In this embodiment, a heating wire heater is used as the heating means. Further, as the heating wire heater, a wire rod made of various high resistance materials having high exothermic properties such as Ni-Cr (nickel-chromium) alloy, tungsten, silicon carbide, and ceramics, which are generally used as heating wire heaters, is used. .

Further, in this embodiment, as shown in FIG. 5, the heating wire heater 70 includes a metallic spacer 60.
Is provided in the vicinity of the opening 63 of the fuel injection passage 62.

Further, as shown in FIG. 6, the metal spacer 60 provided with the heating wire heater 70 has a side surface 60a on the side facing the cylinder head 16 (see FIG. 5).
In, a concave groove 65 having an opening is provided near the through hole 61. The concave groove 65 is formed in the fuel injection passage 6
It is formed with a depth that does not allow communication with 2.

In the concave groove 65 of the metallic spacer 60, there is provided a heating wire heater 70 disposed on the bottom side of the concave groove 65 so as to approach the opening 63 of the fuel injection passage 62.
An insulating layer 66 that covers the heating wire heater 70 is provided. Here, the heating wire heater 70 is provided so as not to contact the inner surface of the groove 65.

Further, as shown in FIG. 7, each heating wire heater 70 has a coil shape, and the heating wire heaters 70 having the coil shape are connected in series by a wire 71. The wiring 71 is a wire made of a low-resistance material such as Al (aluminum) whose resistance value per unit length is smaller than that of the heating wire heater 70. In addition, each wiring 71
Is the same as the heating wire heater 70.
It is accommodated in the concave groove 65 of 0 in a state of being covered with an insulating layer 66 so as not to contact the inner surface of the concave groove 65.

Further, one end of the heating wire heater 70 and the wiring 71 connected in series in this manner is connected to an energization device 72 for energizing / stopping energization of the heating wire heater 70 and the wiring 71. Heating wire heater 70 and wiring 7
The other end of 1 is connected to the ground (ground).

In the above structure, when the heating wire heater 70 and the wiring 71 are energized by the operation of the energization device 72, the opening 63 of the metal spacer 60 and its part are mainly generated by the heating wire heater 70. The neighborhood is heated. Due to the heating by the heating wire heater 70, a temperature gradient is formed in which the temperature becomes lower in the periphery of the communication portion with the injection port 17a of the fuel injection valve 17 than in the periphery of the opening portion 63 of the fuel injection passage 62.

As described above, according to the fuel supply device of this embodiment, the above (1) in the first embodiment is used.
Further, in addition to the effects described in (2) and (3) and (4) in the second embodiment, the following excellent effects can be obtained.

(5) In this embodiment, the metal spacer 6 is used.
No. 0 is provided with a heating wire heater 70 in the groove 65,
Through the heating by the heating wire heater 70, the fuel injection valve 1 is compared with the vicinity of the opening 63 in the fuel injection passage 62.
A temperature gradient is set such that the temperature becomes low around the area where the No. 7 and the nozzle hole 17a communicate with each other.

When the temperature gradient in the fuel injection passage 62 is set by the heat generated during the operation of the internal combustion engine 10 as in the above-described first and second embodiments, the heat from the internal combustion engine 10 is set. Then, a sufficient temperature gradient is not always obtained. If this temperature gradient is insufficient, icing may occur at the opening 63 of the fuel injection passage 62. As described above, when the temperature gradient becomes insufficient, for example, when the liquefied gas fuel contains a large amount of components with large latent heat of vaporization (for example, propane), when the fuel injection amount by the fuel injection valve 17 is large, When the engine 10 is operated in a place where the outside temperature is low, such as in a cold region, the internal combustion engine 10 may be cold-started.

On the other hand, in this embodiment, since the temperature gradient in the fuel injection passage 62 is obtained by heating by the heating wire heater 70, the heating wire heater 70 capable of heating to a temperature higher than that of the internal combustion engine 10 is used. It is possible to operate the heating wire heater 70 at an early stage. Therefore, a sufficient temperature gradient can be obtained in the fuel injection passage 62 regardless of the property of the liquefied gas fuel used, the operating state and the operating environment of the internal combustion engine 10, and the occurrence of icing can be suppressed more preferably. You can

Further, since the heating wire heater 70 is excellent in versatility, the heating means can be easily realized. (6) Further, in the present embodiment, the heating wire heater 70 includes the side surface 60 a of the metal spacer 60 on the cylinder head 16 side.
Is provided in the concave groove 65 near the through hole 61. Therefore, the heating wire heater 70 can be provided at a position closer to the fuel injection passage 62, and the fuel injection passage 6 can be provided.
The temperature gradient in 2 can be set larger. Moreover, since the metal spacer 60 is a small component,
As compared with the case where the cylinder head 16 or the like, which is a large component, is provided, the metal spacer 60 can be easily processed, and the productivity can be preferably maintained.

(7) In this embodiment, the metal spacer 6 is used.
In the groove 0, the insulating layer 6 is provided between the inner surface of the groove 65 and the outer surfaces of the heating wire heater 70 and the wiring 71.
6 is provided. Therefore, it is possible to prevent the current flowing through the heating wire heater 70 and the wiring 71 from leaking to the metallic spacer 60, and thus it is possible to reliably form the temperature gradient in the fuel injection passage 62.

(8) In the present embodiment, the heating wire heater 70
Is provided in the vicinity of the opening 63 of the fuel injection passage 62 in the metal spacer 60. Here, the opening 63 of the fuel injection passage 62 is a portion where icing is most likely to occur. As a result, at the time of heating by the heating wire heater 70, the opening 63 of the fuel injection passage 62 of the metallic spacer 60 is intensively heated, so that the occurrence of icing is efficiently suppressed with low power consumption. can do.

(9) In this embodiment, each heating wire heater 7
0 is a wiring 71 having a resistance value per unit length lower than the resistance value per unit length of the heating wire heater 70.
Are connected to each other by. Therefore, the metal spacer 6
The opening 63 of the fuel injection passage 62 at 0 can be locally heated by the heating wire heater 70, and a sufficient temperature gradient in the fuel injection passage 62 can be efficiently obtained with low power consumption.

The present embodiment can be modified as appropriate, for example, as follows. In the third embodiment, the plate-shaped heating wire heater 70 may be used in the mode shown in FIG. 8, for example. However, this plate-shaped heating wire heater 70
In the case of using, it is desirable to use a film-shaped material having a small cross-sectional area in order to increase the resistance value per unit length. When such a film-shaped heating wire heater 70 is used, a plurality of heating wire heaters 70 may be stacked and used.

When the wire heating wire heater 70 is used, the heating wire heater 70 may be folded back at a plurality of locations or bent at a plurality of locations in the manner shown in FIG. 9, for example. It may be formed in a plane.

In such a case, for example, as shown in FIG.
In the embodiment shown in FIG.
Heating wire heater 70 so as to occupy most of the area above 1.
The heating area of the heating wire heater 70 with respect to the metal spacer 60 can be increased. As a result, when heating by the heating wire heater 70, the metallic spacer 60 can be entirely heated, and the heat of the opening 63 of the fuel injection passage 62 in the metallic spacer 60 is less likely to be transmitted to its peripheral portion or the outside air. can do. Therefore, the opening 63 is maintained in a high temperature state, the heating effect of the heating wire heater 70 can be more reliably obtained, and the fuel injection valve 62 is provided in the fuel injection passage 62 as compared with the vicinity of the opening 63. It is possible to more reliably obtain the temperature gradient in which the temperature around the communication portion 17 (see FIG. 5) with the injection port 17a decreases.

In the third embodiment, the heating wire heater 70 may be provided so as to surround the opening 63 of the metal spacer 60, for example. (Fourth Embodiment) Next, a fourth embodiment of the present invention will be described with reference to FIG. 11 focusing on parts different from the third embodiment. In addition, in FIG.
The same components as those of the above are denoted by the same reference numerals.

In the fourth embodiment, as shown in FIG. 11, the heating wire heater 7 in the metal spacer 60 is used.
The arrangement mode of 0 is different from that of the third embodiment. In the present embodiment, the metal spacer 60 is provided with the concave groove 65 on the side surface 60a on the cylinder head 16 (see FIG. 5) side, and the concave groove 65 individually surrounds the entire circumference of each of the through holes 61. At the same time, annular portions corresponding to the respective through holes 61 are formed so as to communicate with each other.

Further, in the groove 65, each through hole 61 is formed.
The heating wire heater 70 is accommodated in the annular portion corresponding to the above, and the wiring 71 is accommodated in the portion communicating with the annular portion. An insulating layer 66 is provided in the groove 65 between the inner surface thereof and the outer surfaces of the heating wire heater 70 and the wiring 71.

As described above, according to the fuel supply system of this embodiment, the above (1) in the first embodiment is used.
And (2), in addition to the effects described in (3) and (4) in the second embodiment and (5) to (9) in the third embodiment, the following excellent effects are further provided. The effect will be obtained.

(10) In this embodiment, each heating wire heater 70 is provided so as to individually surround each through hole 61 of the metal spacer 60. As a result, the heating wire heater 7
The heating area for the metal spacer 60 of 0 can be made large. As a result, during heating by the heating wire heater 70, the metallic spacer 60 is wholly heated, and the opening 6 of the fuel injection passage 62 in the metallic spacer 60 is heated.
It becomes difficult for the heat of 3 to be transmitted to the surrounding area and the outside air. Therefore, the opening 63 is maintained at a high temperature, the heating effect of the heating wire heater 70 can be more reliably obtained, and the temperature gradient in the fuel injection passage 62 can be more reliably obtained.

The present embodiment can be modified as appropriate, for example, as follows. In the fourth embodiment, a plurality of (four in this example) through holes 61 provided for the metal spacer 60.
The heating wire heater 70 may be provided so that some of them are surrounded by one heating wire heater 70. In this case, the arrangement of the concave groove 65 is also changed.

In the fourth embodiment, the heating wire heater 70 is provided, for example, in a C-shape, a U-shape, a V-shape, a U-shape, and a U-shape on the periphery of the through hole 61 of the metal spacer 60. It may be configured so as to form the above.

(Fifth Embodiment) Next, the fifth embodiment of the present invention will be described.
The third embodiment will be described with reference to FIGS. 13 and 14 focusing on parts different from the third embodiment. In addition,
13 and 14, the same components as those in FIG. 5 are designated by the same reference numerals.

In the fifth embodiment, as shown in FIG. 13, the heating wire heater 7 in the metal spacer 60 is used.
The arrangement mode of 0 is different from that of the third embodiment. In the present embodiment, the heating wire heater 70 includes the fuel injection passages 6
2 between the injection port 17a of the fuel injection valve 17 (see FIG. 5) and the opening 63 of the metal spacer 60, a part of the fuel injection passage 62 is surrounded at a position separated from the injection port 17a of the fuel injection valve 17. It is provided to do. The configuration will be described in detail below.

As shown in FIG. 13, the heating wire heater 70 is provided in a portion corresponding to the fuel injection passage 62 inside the metallic spacer 60 in a coiled state.

Further, as shown in FIG. 14, the metal spacer 60 has a through hole 61 and a heat insulating member 4 at a position corresponding to the fuel injection passage 62.
An engagement hole 69 that communicates with the fuel injection passage 62 at 0 is provided. The engagement hole 69 is formed by the metal spacer 6
The inner diameter of the fuel injection passage 62 in the heat insulating member 40 is larger between the opening in the side surface 60b of the heat insulating member 40 and the opening in the inner surface of the through hole 61.

Further, the engaging hole 6 of the metal spacer 60
9 has an outer diameter approximately the same as the inner diameter of the engaging hole 69 from the side surface 60b of the metal spacer 60 on the heat insulating member 40 side to the through hole 61, and the fuel injection passage in the heat insulating member 40 is provided. A cylindrical body 80 having an inner diameter approximately equal to the inner diameter of 62
Has been inserted.

In the present embodiment, the tubular body 80 is made of an insulating material such as resin or rubber, and the inner peripheral surface thereof constitutes the fuel injection passage 62 in the metallic spacer 60. In addition, it is desirable that the tubular body 80 be formed of a material having high insulation properties, high thermal conductivity as much as possible, and heat resistance that can withstand use in the operating state of the heating wire heater 70. As a material having such properties and capable of forming the cylindrical body 80, for example, a plastic material such as polyacetal or a ceramic material such as silicon nitride or aluminum nitride can be used.

Inside the tubular body 80, the coil-shaped heating wire heater 70 is provided over almost the entire range from the end portion 80a on the heat insulating member 40 side to the end portion 80b on the through hole 61 side. It is embedded so as not to be exposed from the outer peripheral surface.

Further, as shown in FIG. 13, the heating wire heaters 70 provided on the metal spacer 60 are connected to each other by the wiring 71 which is covered with an insulating material, for example.

The tubular body 80 in which the heating wire heater 70 is thus embedded can be formed, for example, by the following procedure. That is, first, an inner cylindrical body having an inner diameter approximately the same as the inner diameter of the fuel injection passage 62 in the heat insulating member 40 and an outer diameter smaller than the inner diameter of the engagement hole 69 of the metal spacer 60 is formed. Next, the heating wire heater 70 is wound into a coil around the outer peripheral surface of the inner cylinder. Thereafter, the outer peripheral surface of the inner cylindrical body around which the heating wire heater 70 is wound is covered with the same material as that of the inner cylindrical body together with the heating wire heater 70, and the engagement hole 6 of the metal spacer 60 is formed.
Finish so that it has an outer diameter approximately the same as the inner diameter of 9.

As described above, according to the fuel supply system of this embodiment, the above (1) in the first embodiment is used.
And (2), (3) and (4) in the second embodiment, and (5), (6) in the third embodiment,
In addition to the effects described in (7) and (8), the following excellent effects can be obtained.

(11) In the present embodiment, the heating wire heater 7
0 is provided in the metal spacer 60 so as to surround the fuel injection passage 62 at a portion corresponding to the tubular body 80 forming the fuel injection passage 62. This allows
The heating wire heater 70 can be provided in a portion of the metal spacer 60 closer to the fuel injection passage 62. Further, the heating wire heater 70 includes the metal spacer 60.
Since it is provided so as to surround almost the entire fuel injection passage 62, the heating wire heater 70 efficiently and locally heats the periphery of the opening 63 in the fuel injection passage 62 by the heating wire heater 70. can do. Therefore, when heating by the heating wire heater 70, a sufficient temperature gradient can be formed in the fuel injection passage 62.

(12) In this embodiment, the heating wire heater 70 is embedded in the tubular body 80 which is an insulator, and the tubular body 80 in which the heating wire heater 70 is embedded is attached to the metal spacer 60.
It is fitted in the engaging hole 69 of. Thereby, the tubular body 80
In the state in which is engaged in the engagement hole 69 of the metal spacer 60, the heating wire heater 70 in the tubular body 80 does not come into contact with the inner peripheral surface of the engagement hole 69 of the metal spacer 60. Therefore, the electric current flowing through the heating wire heater 70 does not leak to the metal spacer 60 during heating by the heating wire heater 70. Wiring 71 connecting each heating wire heater 70
Since is covered with an insulating material, for example, there is no electric leakage from the wiring 71 to the metal spacer 60.

The present embodiment can be modified as appropriate, for example, as follows. In the fifth embodiment, the cylindrical body 80 is covered with the inner cylindrical body around which the heating wire heater 70 is wound, and the outer peripheral surface thereof is covered with a material different from that of the inner cylindrical body together with the heating wire heater 70. It may be configured. However, in this case, a material having an insulating property is used as a material different from that of the inner cylindrical body.

Further, in this case, as the material forming the inner cylinder, a material having a higher thermal conductivity than a material different from the inner cylinder may be used.
Further, with respect to the inner cylindrical body around which the heating wire heater 70 is wound,
For example, the outer peripheral surface of each of the heating wire heaters 70 may be coated with an insulating material,
It may be configured to be covered with an insulating tape or the like.

In the fifth embodiment, the coil-shaped heating wire heater 7 is arranged, for example, in the mode as shown in FIG.
0 may be provided on the surface of the tubular body 80, and the tubular body 80 provided with the heating wire heater 70 may be fitted into the engagement hole 69 of the metal spacer 60.

In this case, even if a spacer made of an insulating material (for example, phenol resin) is used in place of the metallic spacer 60, the insulating spacer and the heating wire heater 70 are used. There is no electric leakage from the heating wire heater 70 to the spacer due to contact with the heater. Therefore, as in the fifth embodiment, the heating wire heater 70
It is not necessary to embed the inside of the cylindrical body 80, and the heating wire heater 70 can be provided by, for example, winding or printing on the surface of the cylindrical body 80. As a result, the manufacturing process of the spacer provided with the heating wire heater 70 can be simplified.

In the above fifth embodiment, the cylindrical body 80 provided with the heating wire heater 70 is replaced with the metal spacer 60.
However, the structure is not limited to the structure in which the whole of the engaging hole 69 is provided from the opening on the heat insulating member 40 side to the opening on the through hole 61 side. The cylindrical body 80 is replaced with a metal spacer 6
In the zero engagement hole 69, a part may be provided between the opening on the heat insulating member 40 side and the opening on the through hole 61 side.

In the fifth embodiment, the tubular body 80 provided with the heating wire heater 70 is provided only on the metallic spacer 60, but the tubular body 80 is provided only on the metallic spacer 60. The configuration is not limited. The tubular body 80 may be provided only in a portion corresponding to the fuel injection passage 62 in the heat insulating member 40, or may be provided in a portion corresponding to the fuel injection passage 62 in both the metal spacer 60 and the heat insulating member 40. May be However, when the tubular body 80 is provided inside the heat insulating member 40, in order to prevent the heat of the tubular body 80 heated by the heating wire heater 70 from being transferred to the intake manifold 14, the tubular body 80 is It is provided so as not to contact the intake manifold 14.

In the above fifth embodiment, the cylindrical body 80
The heating wire heater 70 provided in the above is not limited to the coil shape. The heating wire heater 70 may be provided by being folded back at a plurality of locations or bent at a plurality of locations with respect to the tubular body 80, or the plate-shaped heating wire heater 70 may be configured as a tubular body. It may be configured to be bent into a shape.

In the fifth embodiment, the heating wire heater 70 is provided at the end portion 8 of the tubular body 80 on the heat insulating member 40 side.
It is not limited to the configuration in which it is provided over almost the entire end portion 80b from the side 0a to the through hole 61 side. This heating wire heater 70
May be provided in a part of the tubular body 80 on the end portion 80b side on the through hole 61 side.

In the fifth embodiment, the cylindrical body 80 provided with the heating wire heater 70 is provided between the cylinder head 16 and the intake manifold 14 by the metal spacer 60.
An example provided in the fuel supply device of the internal combustion engine including the heat insulating member 40 and However, this heating wire heater 70
The cylindrical body 80 provided with is also similarly provided in the fuel supply device of the internal combustion engine including the heat insulating member 40 between the cylinder head 16 and the intake manifold 14 as shown in the first embodiment. it can. When the heating wire heater 70 is provided in this fuel supply device, for example, a configuration as shown in FIG. 16 can be adopted.

That is, as shown in FIG. 16, an engagement hole 16c into which the above-mentioned cylinder 80 is fitted is provided in a portion of the cylinder head 16 corresponding to the fuel injection passage 42. However, since the cylinder head 16 is generally formed using a material having conductivity, the heating wire heater 70 is provided in order to prevent the heating wire heater 70 from contacting the inner surface of the engagement hole 16c of the cylinder head 16. Is embedded inside the cylindrical body 80.

As shown in FIG. 16, the heating wire heater 70 is not limited to the structure in which it is embedded in the tubular body 80. For example, the heating wire heater 70 is attached to the outer peripheral surface of the tubular body 80. It may be configured to be covered with a coating having an insulating material.

Even with such a configuration, the fuel injection passage 42 is heated by the heating wire heater 70 regardless of the property of the liquefied gas fuel, the operating state of the internal combustion engine 10 and the operating environment.
Of the fuel injection valve 17 compared to the vicinity of the opening 43 in
It is possible to obtain a sufficient temperature gradient that the temperature becomes low in the vicinity of the portion communicating with the injection port 17a (see FIG. 3).

In the fifth embodiment, the heating wire heater 70 may be provided on the inner peripheral surface side of the cylindrical body 80. In this case, the heating wire heater 70 may be configured to cover the inner peripheral surface of the tubular body 80 as necessary.

In addition, as elements that can be changed in common among a plurality of the above embodiments, there are the following elements. -In each of the said 2nd-5th embodiment, the metal spacer 6
Although 0 is made of an aluminum alloy, the material of the metallic spacer 60 is not limited to the aluminum alloy. The metal spacer 60 may be made of a metal such as iron, copper, a copper alloy, or aluminum. In any case, it is desirable that the metal spacer 60 is formed of a material having good thermal conductivity.

In both the third and fourth embodiments, an insulating spacer 68 made of, for example, resin or rubber and having an insulating property may be used instead of the metallic spacer 60.

In this case, as shown in FIG. 10, when the heating wire heater 70 is provided on the insulating spacer 68, an insulating layer is provided between the heating wire heater 70 and the insulating spacer 68. There is no need to provide it. That is, the heating wire heater 70 and the wiring 71 (see FIG. 7) are housed in the concave groove 65 of the insulator spacer 68, and the insulating layer is not provided. Therefore, when the heating wire heater 70 and the wiring 71 are provided to the insulator spacer 68, the step of forming an insulating layer can be omitted, and the insulator spacer 68 can be easily formed.

In both of the third and fourth embodiments, the concave groove 65 is provided so as to have an opening on the side surface 60b (see FIG. 5) of the metal spacer 60 facing the heat insulating member 40. Good.

In both the third and fourth embodiments, the heating wire heater 70 and the wiring 71 are provided only on the metallic spacer 60. However, the heating wire heater 70 and the wiring 71 are provided on the metallic spacer 60. It is not limited to the configuration provided only in. These heating wire heater 70 and wiring 71
May be provided only on the cylinder head 16, or may be provided on both the cylinder head 16 and the metal spacer 60.

Further, in both the third and fourth embodiments, the heating wire heater 70 is provided with the metal spacer 60 and the heat insulating member 40 between the cylinder head 16 and the intake manifold 14, and the fuel supply for the internal combustion engine. An example provided in the device is shown.

However, this heating wire heater 70 is
Cylinder head 1 as shown in the first embodiment
6 and the intake manifold 14 between the heat insulating member 40
The fuel supply device for an internal combustion engine including the above can be similarly provided. When the heating wire heater 70 is provided in this fuel supply device, for example, a configuration as shown in FIG. 12 can be adopted.

That is, as shown in FIG. 12, the side surface 16 of the cylinder head 16 facing the heat insulating member 40.
A concave groove 16e is provided near the intake port 16a of d, and the heating wire heater 70 and the wiring 71 are housed in the concave groove 16e. Further, as described above, since the cylinder head 16 is generally formed by using a material having conductivity, the heating wire heater 70 and the wiring 71 are formed in the groove 16e in the groove 16e of the cylinder head 16. The outer surface of the heating wire heater 70 and the wiring 71 and the concave groove 1 so as not to contact the inner surface.
An insulating layer 66 is provided between the inner surface of 6e and the inner surface of 6e.

Even with such a structure, the fuel injection passage 42 is heated by the heating wire heater 70 regardless of the property of the liquefied gas fuel, the operating state of the internal combustion engine 10, and the operating environment.
Of the fuel injection valve 17 compared to the vicinity of the opening 43 in
It is possible to obtain a sufficient temperature gradient that the temperature becomes low in the vicinity of the portion communicating with the injection port 17a (see FIG. 3).

In each of the third to fifth embodiments,
A plurality of heating wire heaters 70 may be provided for each fuel injection passage 62 of the metal spacer 60. In each of the third to fifth embodiments described above, the heating wire heater 70 provided in the metal spacer 60 is not connected by the wiring 71, but all the heating wire heaters provided in the metal spacer 60 are used. The configuration may be 70.

In each of the third to fifth embodiments,
As shown in FIG. 17, a spacer side heat insulating layer 85 may be provided between the metal spacer 60 and the cylinder head 16. Further, the spacer-side heat insulating layer 85 may be provided between the metal spacer 60 and the heat insulating member 40.

When the heat insulating layer 85 is provided between the metal spacer 60 and the cylinder head 16, the heat insulating layer 85 is used for the cylinder head 1 of the metal spacer 60.
The side surface 60a on the 6 side and the side surface 16d on the side of the metal spacer 60 of the cylinder head 16 may be provided by coating one of the opposing surfaces. When the heat insulating layer 85 is also provided between the metal spacer 60 and the heat insulating member 40, the heat insulating layer 85 is formed on the side surface 60 b of the metal spacer 60 on the heat insulating member 40 side and the metal of the heat insulating member 40. It is also possible to adopt a configuration in which either one of both surfaces facing the side surface 40a on the spacer 60 side is provided by coating.

In this case, at least the heat insulating member 40 suppresses heat transfer from the metal spacer 60 to the intake manifold 14, and
The spacer-side heat insulating layer 85 between the metal spacer 60 and the cylinder head 16 suppresses heat transfer from the metal spacer 60 to the cylinder head 16. Therefore, during heating by the heating wire heater 70, the heat applied to the metal spacer 60 is less likely to move to the cylinder head 16 and the intake manifold 14, and the opening 63 of the fuel injection passage 62 in the metal spacer 60 is The temperature can be kept higher.

The spacer side heat insulating layer 85 is formed on the side surface 1 of the cylinder head 16, the metal spacer 60, and the heat insulating member 40.
By providing 6d, 60a, 60b, 40a by coating, it is possible to suppress an increase in the number of parts and to improve the assembling property when assembling the metal spacer 60 or the like to the internal combustion engine 10. .

In each of the third to fifth embodiments,
The heating wire heater 70 is not limited to the configuration in which all of them are connected in series, and may have a structure in which some of the heating wire heaters 70 are connected in parallel.

In each of the above third to fifth embodiments,
The heating means other than the heating wire heater 70 may be used. -In each of the said 1st-5th embodiment, the heat insulation member 40.
The phenolic resin that constitutes the above may be, for example, one to which fillers and reinforcing materials such as glass fibers, cloth strips, inorganic powder, wood flour and pulp are added. Further, the heat insulating member 40 is not limited to the one made of phenol resin.
In short, the heat insulating member 40 may be made of any material as long as it has a heat insulating property that does not generate vapor in the fuel injection valve 17 in a used state.

In each of the first to fifth embodiments, the fuel injection valve 17 of the fuel supply device is used as the intake manifold 1.
The example provided in FIG. However, the portion where the fuel injection valve 17 is provided is not limited to the intake manifold 14. The present invention is also a fuel supply device in which a fuel injection valve is provided in a heat insulating member, and a fuel injection passage extends from an injection port of the fuel injection valve to an intake port of an internal combustion engine via the heat insulating member. Good. Further, according to the present invention, a fuel injection valve is provided between the internal combustion engine and at least a heat insulating member, and a fuel injection passage is provided from an injection port of the fuel injection valve through at least the heat insulating member. The fuel supply device may be configured to reach the port.

Even in the fuel supply device having these configurations,
The temperature gradient in which the temperature becomes lower in the vicinity of the communication portion with the injection port of the fuel injection valve than in the vicinity of the opening portion of the intake port of the fuel injection passage can be reliably set with a simple configuration.

Further, when these structures are adopted, a metal spacer is interposed between the cylinder head of the internal combustion engine provided with the intake port and the intake manifold of the engine, and the spacer reaching the intake port is formed. The fuel injection passage may be opened in the metal spacer. In this case, the cylinder head can be shared between the internal combustion engine that uses liquefied gas fuel as the fuel and the internal combustion engine that uses gasoline.

In each of the first to fifth embodiments described above, FIG.
As shown in FIG. 1, a four-cylinder internal combustion engine 1 arranged in series
Although the example applied to 0 is shown, the number of cylinders of the internal combustion engine and the arrangement mode thereof are arbitrary.

In each of the first to fifth embodiments described above, the example in which the LPG is used as the fuel is applied to the internal combustion engine 10. However, according to the present invention, liquefied gas fuels other than LPG, such as liquefied natural gas (LNG), methanol, ethanol, liquid hydrogen, dimethyl ether, etc., are injected and supplied in a liquid state to an internal combustion engine and have large latent heat of vaporization. It can be similarly applied to an internal combustion engine using liquefied gas fuel.

In addition, the technical ideas that can be understood from the above-described embodiment and the above description will be described below together with their effects. (A) The internal combustion engine is a multi-cylinder internal combustion engine including a plurality of cylinders, the intake port and the fuel injection valve are provided corresponding to each cylinder in the cylinder head, and the fuel injection passage is The heating wire heater is provided in the vicinity of each fuel injection passage and communicates with the injection port of the corresponding fuel injection valve to reach the intake port of the internal combustion engine and is opened at the intake port. 24. The fuel supply device for an internal combustion engine according to claim 23, wherein the heating wire heaters are connected to each other by a wiring having a resistance value per unit length lower than a resistance value per unit length of the heating wire heater.

According to the above construction, since the opening of the intake port in the fuel injection passage is locally heated by the heating wire heater, a sufficient temperature gradient can be efficiently obtained in the fuel injection passage with low power consumption. You can

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing an internal combustion engine to which a fuel supply device according to a first embodiment is applied and its peripheral configuration.

FIG. 2 is a schematic configuration diagram showing the fuel supply device.

FIG. 3 is a partially enlarged cross-sectional view showing an enlarged vicinity of a fuel injection passage of the fuel supply device of the embodiment.

FIG. 4 is a partially enlarged cross-sectional view showing an enlarged vicinity of a fuel injection passage of a fuel supply device according to a second embodiment.

FIG. 5 is a partially enlarged cross-sectional view showing an enlarged vicinity of a fuel injection passage of a fuel supply device according to a third embodiment.

FIG. 6 is an enlarged cross-sectional view showing the cross-sectional structure of a metal spacer of the fuel supply device of the same embodiment in an enlarged manner.

FIG. 7 is a front view showing a planar structure of a metal spacer of the fuel supply device.

FIG. 8 is an enlarged cross-sectional view showing a cross-sectional structure of a metal spacer of a fuel supply device of a modification in an enlarged manner.

FIG. 9 is an explanatory view for explaining an arrangement mode of heating wire heaters of the fuel supply device of the modified example.

FIG. 10 is an enlarged cross-sectional view showing a cross-sectional structure of an insulator spacer of a fuel supply device of a modified example in an enlarged manner.

FIG. 11 is a front view showing a planar structure of a metal spacer of the fuel supply device according to the fourth embodiment.

FIG. 12 is a partially enlarged cross-sectional view showing, in an enlarged manner, a part of the fuel injection passage and its peripheral configuration in the fuel supply device of the modification.

FIG. 13 is a partial perspective view showing a part of a metal spacer of the fuel supply device according to the fifth embodiment.

FIG. 14 is a partially enlarged cross-sectional view showing an enlarged part of a fuel injection passage and its peripheral configuration in the fuel supply system of the embodiment.

FIG. 15 is a partially enlarged cross-sectional view showing an enlarged part of the fuel injection passage and its peripheral configuration in the fuel supply device of the modified example.

FIG. 16 is a partially enlarged cross-sectional view showing an enlarged part of the fuel injection passage and the peripheral configuration of the fuel supply device of the modified example.

FIG. 17 is a partially enlarged cross-sectional view showing an enlarged cross-sectional structure of a metallic spacer and its peripheral structure in the fuel supply device of the modified example.

[Explanation of symbols]

10 ... Internal combustion engine, 11 ... Intake path, 12 ... Air cleaner, 13 ... Surge tank, 14 ... Intake manifold, 15 ... Intake passage section, 16 ... Cylinder head, 16a
... intake port, 16b ... inner wall surface, 16c ... engagement hole, 16
d ... Side surface, 16e ... Groove, 17 ... Fuel injection valve, 17a ...
Nozzle, 18 ... Throttle valve, 19 ... Exhaust passage, 20
... Exhaust path, 21 ... Fuel tank, 22 ... Fuel supply path,
23 ... Delivery pipe, 23a ... Projecting piece, 24 ... Fuel pump, 25 ... Fuel filter, 26 ... Return path, 27
… Pressure regulator, 30… Flange part, 31…
Fuel injection valve mounting portion, 32 ... Fixed portion, 33 ... Seal rubber, 34 ... Bolt, 35 ... Recessed portion, 40 ... Heat insulating member, 40
a ... Side surface, 41, 61 ... Through hole, 42, 62 ... Fuel injection passage, 43, 63 ... Opening portion, 50 ... Intake air amount sensor,
51 ... Rotation speed sensor, 52 ... Cooling water temperature sensor, 53 ...
Electronic control unit (ECU), 60 ... Metal spacer, 60
a, 60b ... Side surface, 65 ... Recessed groove, 66 ... Insulating layer, 68 ...
Insulator spacer, 69 ... Engagement hole, 70 ... Heating wire heater,
71 ... Wiring, 72 ... Energizing device, 80 ... Cylindrical body, 80a, 8
0b ... end portion, 85 ... spacer side heat insulating layer.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) F02M 53/00 F02M 69/00 350H 35/10 102B (72) Inventor Masaharu Wakabayashi 1 Toyota Town, Toyota City, Aichi Prefecture Address Toyota Motor Co., Ltd. (72) Inventor Takao Komoda 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Co., Ltd. (72) Inventor, Kiminori Yasunaga 1 Toyota Town, Aichi Prefecture Toyota Motor Co., Ltd. ( 72) Inventor Mitsunobu Uchida 14 Iwatani, Shimohakaku-cho, Nishio-shi, Aichi Stock Company, Japan Automotive Parts Research Institute (72) Inventor, Toru Sato 1-1-1, Kyowa-cho, Obu City, Aichi Prefecture

Claims (24)

[Claims] 1. A liquefied gas fuel stored in a fuel tank in a saturated vapor pressure state is pressure-fed to a delivery pipe, and the fuel is supplied to an intake port of an internal combustion engine through a fuel injection valve provided in the delivery pipe. In a fuel supply device for an internal combustion engine for injection and supply, a fuel injection passage communicating with an injection port of the fuel injection valve to reach an intake port of the internal combustion engine and opened at the intake port is provided in the fuel injection passage, A fuel supply device for an internal combustion engine, wherein a temperature gradient is set such that a temperature becomes lower in a periphery of a communication portion with an injection port of the fuel injection valve than in a periphery of an opening of the intake port. 2. A heat insulating member is provided between a cylinder head of an internal combustion engine in which the intake port is provided and a portion in which the fuel injection valve is provided, and the fuel injection passage is the same as the injection port of the fuel injection valve. 2. The fuel supply device for an internal combustion engine according to claim 1, wherein the fuel supply device for an internal combustion engine is configured to reach the intake port through an area where a fuel injection valve is provided, the heat insulating member, and the cylinder head in order, and to be opened in the cylinder head. 3. A metal spacer and a heat insulating member are provided between a cylinder head of an internal combustion engine provided with the intake port and a portion provided with the fuel injection valve, and the fuel injection passage has the fuel injection valve. 2. The fuel supply for an internal combustion engine according to claim 1, wherein the fuel injection valve extends from the injection port of the fuel injection valve to the intake port through the portion where the fuel injection valve is provided, the heat insulating member, and the metal spacer, and is opened at the metal spacer. apparatus. 4. The fuel supply system for an internal combustion engine according to claim 2, wherein the portion where the fuel injection valve is provided is an intake manifold of the internal combustion engine. 5. The internal combustion engine according to claim 1, wherein the fuel injection valve is provided in a heat insulating member, and the fuel injection passage extends from an injection port of the fuel injection valve to the intake port of the internal combustion engine via the heat insulating member. Engine fuel supply system. 6. The fuel injection valve is provided between the internal combustion engine and at least a heat insulating member, and the fuel injection passage is provided in the internal combustion engine from an injection port of the fuel injection valve through at least the heat insulating member. The fuel supply device for an internal combustion engine according to claim 1, which reaches an intake port. 7. A metal spacer is interposed between a cylinder head of an internal combustion engine provided with the intake port and an intake manifold of the engine, and the fuel injection passage leading to the intake port is formed of the metal. The fuel supply system for an internal combustion engine according to claim 5 or 6, wherein the spacer is opened in the spacer. 8. A heating means is further provided in the vicinity of the fuel injection passage, and through the heating by the heating means,
2. The fuel supply device for an internal combustion engine according to claim 1, wherein a temperature gradient is set such that the temperature becomes lower in the vicinity of a portion communicating with the injection port of the fuel injection valve than in the vicinity of the opening of the intake port in the fuel injection passage. . 9. A heat insulating member is provided between a cylinder head of the internal combustion engine provided with the intake port and a portion provided with the fuel injection valve, and the fuel injection passage is provided from the injection port of the fuel injection valve. The heating means is provided in the cylinder head in the vicinity of the fuel injection passage, reaching the intake port through the portion where the fuel injection valve is provided, the heat insulating member, and the cylinder head in this order. The fuel supply device for an internal combustion engine according to claim 8, wherein the fuel supply device is provided in the. 10. A spacer and a heat insulating member are provided between a cylinder head of an internal combustion engine provided with the intake port and a portion provided with the fuel injection valve, and the fuel injection passage has an injection port of the fuel injection valve. From the portion where the fuel injection valve is provided to the intake port through the heat insulating member and the spacer in order, and the opening is formed in the spacer, and the heating means is provided in at least one of the spacer and the cylinder head. 9. The fuel supply device for an internal combustion engine according to claim 8, wherein the fuel supply device is provided near the fuel injection passage. 11. The fuel supply system for an internal combustion engine according to claim 10, wherein the spacer is a metal spacer, and an insulating layer is provided between the metal spacer and the heating means. 12. The spacer comprises an insulator.
0. Fuel supply device for internal combustion engine according to item 0. 13. The heating means according to claim 10, wherein the heating means is provided at or near an opening of a through hole communicating with the intake port in the fuel injection passage inside the spacer. A fuel supply device for an internal combustion engine as described above. 14. The fuel supply device for an internal combustion engine according to claim 10, wherein the heating means is provided so as to surround a through hole communicating with the intake port of the spacer. 15. The fuel supply device for an internal combustion engine according to claim 10, wherein the heating means is provided in a plate shape. 16. The heating means is arranged in the fuel injection passage at a position apart from the injection opening of the fuel injection valve between the injection opening of the fuel injection valve and the opening portion of the intake port in the fuel injection passage. The fuel supply device for an internal combustion engine according to claim 8, wherein the fuel supply device is provided so as to surround a part thereof. 17. A heat insulating member is provided between a cylinder head of an internal combustion engine provided with the intake port and a portion provided with the fuel injection valve, and the fuel injection passage is the same as the injection port of the fuel injection valve. A portion of the fuel injection passage that is open from the fuel injection valve and reaches the intake port through the portion where the fuel injection valve is provided, the heat insulating member, and the cylinder head in this order. In, the heating means is provided so as to surround at least the opening portion of the fuel injection passage while engaging with the tubular insulator. The fuel supply system for an internal combustion engine according to claim 16. 18. A spacer and a heat insulating member are provided between a cylinder head of an internal combustion engine provided with the intake port and a portion provided with the fuel injection valve, and the fuel injection passage has an injection port of the fuel injection valve. From the portion where the fuel injection valve is provided to the intake port through the heat insulating member and the spacer in order, and the opening is formed in the spacer, and the fuel injection passage is a part separated from the fuel injection valve. In the above, the heating means is formed by the inner circumference of a tubular insulator, and the heating means is provided so as to surround at least the opening of the fuel injection passage at a portion corresponding to the tubular insulator. Item 16. A fuel supply device for an internal combustion engine according to item 16. 19. The heating means is embedded in the cylindrical insulator, and the insulator in which the heating means is embedded is provided on at least one of the heat insulating member and the spacer. The fuel supply device for an internal combustion engine according to claim 18, wherein the fuel supply device is fitted in the dowel hole. 20. The heating means is provided on the surface of the cylindrical insulator, and the insulator provided with the heating means is an engagement hole provided in at least one of the heat insulating member and the spacer. 19. The fuel supply device for an internal combustion engine according to claim 18, which is fitted inside. 21. The heating means is provided inside the spacer, and includes at least the spacer and the cylinder head between the spacer and the cylinder head and between the spacer and the heat insulating member. A spacer-side heat insulating layer is provided between them.
21. A fuel supply device for an internal combustion engine according to any one of 20 to 20. 22. The spacer-side heat insulating layer is provided on one of the facing surfaces of the cylinder head or the spacer, or on one of the facing surfaces of the spacer or the heat insulating member. The fuel supply device for an internal combustion engine according to claim 21, wherein the fuel supply device is provided by coating. 23. The fuel supply system for an internal combustion engine according to claim 8, wherein the heating means is a heating wire heater. 24. The fuel supply system for an internal combustion engine according to claim 1, wherein the liquefied gas fuel is liquefied petroleum gas.