阅读说明：本技术 内燃机的进气装置 (Air intake device for internal combustion engine ) 是由 石井正人 山口智广 矢野秀任 于 2019-11-29 设计创作，主要内容包括：本发明提供一种能够促进利用加热器进行的燃料的汽化,并且也能够确保对于从喷射器喷射的燃料的密封性的内燃机的进气装置。该内燃机E的进气装置3具备：将空气导入至气缸4的进气装置主体部32；一体地设于进气装置主体部32的下游侧端部,并被插入至缸盖2内的进气接口21的接口部33；设于进气装置主体部32,并将燃料F导入至进气通道35内的喷射器31；以及对通过喷射器31导入的燃料F进行加热的加热器37。喷射器31配置于能够将燃料喷射至加热器37的位置。(The invention provides an intake device for an internal combustion engine, which can promote vaporization of fuel by a heater and can ensure sealing performance of fuel injected from an injector. The intake device 3 of the internal combustion engine E includes: an intake device main body portion 32 that introduces air into the cylinders 4; a connecting portion 33 integrally provided at a downstream side end portion of the intake device main body portion 32 and inserted into the intake port 21 in the cylinder head 2; an injector 31 provided in the intake device body portion 32 and introducing the fuel F into the intake passage 35; and a heater 37 that heats the fuel F introduced through the injector 31. The injector 31 is disposed at a position where fuel can be injected to the heater 37.)

1. An intake device for an internal combustion engine, comprising:

an intake device main body portion that introduces air into a cylinder;

a connecting port portion integrally provided at a downstream side end portion of the intake device main body portion and inserted into an intake port in a cylinder head;

an intake passage formed inside the intake device main body portion and the interface portion and through which a mixture gas containing air and fuel flows;

an injector provided in the intake device main body portion and configured to introduce fuel into the intake passage; and

a heater that heats the fuel introduced through the injector,

the injector is disposed at a position where fuel can be injected to the heater.

2. The intake apparatus of an internal combustion engine according to claim 1,

at least a part of the heater is disposed at a part of the interface portion corresponding to an injection region of the fuel injected from the injector.

3. The intake apparatus of an internal combustion engine according to claim 1 or 2,

at least a part of the heater is provided on an inner surface side of the interface portion.

4. The intake device for an internal combustion engine according to any one of claims 1 to 3,

the intake device main body portion includes a flange portion that is disposed so as to face an outer surface of the cylinder head around an opening at an upstream end portion of the intake port and is integrated with an end portion of the port portion on the intake device main body portion side,

the intake device of the internal combustion engine further includes a seal member disposed between the flange portion and the outer surface of the cylinder head.

5. The intake apparatus of an internal combustion engine according to claim 4,

the sealing member is formed in a circumferential shape.

6. The intake apparatus for an internal combustion engine according to any one of claims 1 to 5,

the tip portion of the ejector is disposed upstream of a boundary portion between the intake device main body portion and the connecting port portion in the intake air flow direction.

7. The intake apparatus for an internal combustion engine according to any one of claims 1 to 6,

the intake device of the internal combustion engine further includes a concave portion that is recessed in an outer direction in a direction orthogonal to an intake air flow direction at least on an inner surface of the interface portion,

the heater is disposed in the recess.

8. The intake apparatus of an internal combustion engine according to claim 7,

in the recessed portion, a heat insulating member is disposed on an outer side in the direction orthogonal to the intake air flow direction, and the heater is laminated on an inner side of the heat insulating member.

9. The intake apparatus for an internal combustion engine according to any one of claims 1 to 8,

the intake device main body portion and the interface portion are provided at each of a plurality of intake interfaces that supply a mixture to each of a plurality of cylinders in the internal combustion engine.

10. The intake apparatus for an internal combustion engine according to any one of claims 1 to 9,

an air insulation layer is arranged between the outer surface of the interface part and the inner surface of the air inlet interface in the direction orthogonal to the air inlet flowing direction.

Technical Field

The present invention relates to an intake device for an internal combustion engine, and more particularly to an intake device for an internal combustion engine provided with a heater.

Background

Conventionally, an intake device for an internal combustion engine provided with a heater is known (for example, see patent document 1).

Patent document 1 discloses an intake device for an internal combustion engine, which is provided with a PTC (Positive Temperature Coefficient) heat generating sheet (heater). The intake device of the internal combustion engine of patent document 1 includes an intake pipe, a plate (plate), a cylindrical surface, and a fuel injector (injector).

The plate of the above-mentioned patent document 1 is disposed between a downstream-side end surface of the intake pipe and an outer surface of the cylinder head in the periphery of an opening of an upstream-side end portion of the cylinder head in the intake flow direction. The cylindrical surface of patent document 1 projects from the downstream end of the plate in the intake air flow direction into the intake passage of the cylinder head along the intake air flow direction. The fuel injector of patent document 1 is disposed at a downstream side portion in the intake pipe in the intake air flow direction. The PTC heater of patent document 1 is disposed outside the cylindrical surface in a direction orthogonal to the intake air flow direction.

In the intake system of the internal combustion engine of patent document 1, the fuel injected from the fuel injector toward the inner surface of the cylindrical surface is heated by the PTC heater, thereby promoting vaporization of the fuel.

Patent document

Patent document 1: japanese examined patent publication (Kokoku) No. 5-29784

Disclosure of Invention

However, the intake system for an internal combustion engine of patent document 1 has the following disadvantages: the fuel injected from the fuel injector may infiltrate between the plate and the downstream-side end surface of the intake pipe, and between the plate and the outer surface of the cylinder head in the periphery of the opening of the upstream-side end portion of the cylinder head. Therefore, the intake system for an internal combustion engine of patent document 1 has a problem that vaporization of fuel by the PTC heater (heater) is promoted and sufficient sealing performance against fuel injected from the fuel injector (injector) cannot be ensured.

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide an intake system for an internal combustion engine, which can promote vaporization of fuel by a heater and can ensure sealing performance with respect to fuel injected from an injector.

In order to achieve the above object, an intake device for an internal combustion engine according to one aspect of the present invention includes: an intake device main body portion that introduces air into a cylinder, an interface portion, an intake passage, an injector, and a heater; the interface part is integrally arranged at the downstream end part of the main body part of the air inlet device and is inserted into an air inlet interface in the cylinder cover; the intake passage is formed inside the intake device main body part and the interface part, and through which a mixture gas containing air and fuel flows; the injector is arranged on the main body part of the air inlet device and guides fuel into the air inlet channel; the heater heats fuel introduced through the injector, and the injector is disposed at a position where the injector can inject the fuel to the heater.

In the intake device for an internal combustion engine according to one aspect of the present invention, as described above, the intake device main body, the interface portion integrally provided at the downstream end portion of the intake device main body, and the heater are provided. The injector is disposed at a position where fuel can be injected to the heater. In this way, by integrating the intake device main body portion and the interface portion, at least fuel can be prevented from entering between the intake device main body portion and the interface portion, and therefore, fuel injected from the injector and adhering to the inner surface of the intake device can be made less likely to enter between the intake device main body portion and the cylinder head. Further, the fuel adhering to the inner surface of the intake device without being vaporized may be vaporized by the heater. As a result, vaporization of the fuel by the heater can be promoted, and the sealing property with respect to the fuel injected from the injector can be ensured.

In the intake system for an internal combustion engine according to the one aspect, at least a part of the heater is preferably disposed in a portion of the interface portion corresponding to an injection region of the fuel injected from the injector.

With this configuration, the fuel adhering to the inner surface of the intake device can be reliably vaporized by disposing at least a part of the heater at the portion of the interface portion corresponding to the injection region of the fuel. Accordingly, in the internal combustion engine, the air-fuel ratio in the combustion chamber can be stabilized, and therefore, an ideal combustion state is formed in the combustion chamber, and unburned exhaust gas can be reduced.

In the intake system for an internal combustion engine according to the above-described aspect, at least a part of the heater is preferably provided on the inner surface side of the interface portion.

With this configuration, the heater can be provided closer to the inner surface of the intake device to which the fuel adheres, and therefore the fuel adhering to the inner surface of the intake device can be sufficiently heated. This makes it possible to reliably vaporize the fuel adhering to the inner surface of the intake device.

In the intake device for an internal combustion engine according to the above aspect, the intake device main body portion preferably includes a flange portion that is disposed so as to face an outer surface of the cylinder head around the opening at the upstream end of the intake port and is integrated with an end portion of the port portion on the intake device main body portion side, and the intake device for an internal combustion engine further includes a seal member that is disposed between the flange portion and the outer surface of the cylinder head.

With this configuration, unlike the case where the intake device main body portion and the connecting port portion are provided as separate members and the flange portions are provided on the intake device main body portion and the connecting port portion, the sealing member only needs to be disposed between the flange portion of the intake device main body portion and the outer surface of the cylinder head, and therefore the number of required sealing members can be reduced. Further, by integrating the flange portion with the end portion of the interface portion on the intake device main body portion side, it is possible to suppress the intrusion of the fuel from between the interface portion and the flange portion, and therefore, the amount of the fuel adhering to the seal member can be reduced.

In this case, the seal member is preferably formed in a circumferential shape.

With this configuration, the opening at the upstream end in the intake port in the intake air flow direction can be surrounded by the sealing member, and thereby, it is possible to prevent foreign matter from entering the intake port.

In the intake device for an internal combustion engine according to the one aspect, the tip end portion of the injector is preferably disposed upstream of a boundary portion between the intake device main body portion and the connecting port portion in the intake air flow direction.

With this configuration, the distance between the tip end portion of the injector and the combustion chamber can be sufficiently ensured, and therefore, the time until the fuel injected from the injector flows into the combustion chamber can be sufficiently ensured. Therefore, vaporization of the fuel injected from the injector can be further promoted. Further, since the distance between the tip end portion of the injector and the combustion chamber can be sufficiently ensured, it is possible to suppress the adhesion of dirt to the injector due to the backflow of high-temperature gas in the combustion chamber to the intake port.

In the intake system of the internal combustion engine according to the above-described aspect, the following configuration is also conceivable.

(Note with 1)

That is, in the intake apparatus for an internal combustion engine according to the one aspect, the intake apparatus for an internal combustion engine further includes a recess portion that is recessed in an outer direction in a direction orthogonal to an intake air flow direction at least in an inner surface of the interface portion, and the heater is disposed in the recess portion.

With this configuration, since the heater is disposed in the concave portion of the interface portion, the intake air flowing through the intake passage does not directly collide with the heater, and therefore, a decrease in the temperature of the heater due to the intake air flowing through the intake passage can be suppressed.

(Note with 2)

In this case, the heat insulating member is disposed on the outer side of the recess in the direction orthogonal to the intake air flow direction, and the heater is laminated on the inner side of the heat insulating member.

With this configuration, when the heater is heating, the heat insulating member can suppress the heat generated in the heater from being transferred to the interface portion, and therefore, the heat of the heater can be suppressed from being emitted to a position other than a desired heating position. Therefore, the heat generated in the heater can be efficiently transferred to the fuel adhering to the inner surface of the intake device, and thus vaporization of the fuel can be efficiently performed.

(Note with 3)

In the intake device for an internal combustion engine according to the above-described aspect, the intake device main body portion and the interface portion are provided at each of a plurality of intake ports that supply the mixture to each of a plurality of cylinders in the internal combustion engine.

With this configuration, even in a multi-cylinder internal combustion engine, vaporization of fuel by the heater can be promoted in each cylinder, and the sealing property with respect to the fuel injected from the injector can be ensured.

(Note attached 4)

In the intake device for an internal combustion engine according to the above-described aspect, an air insulating layer is provided between the outer surface of the interface portion and the inner surface of the intake interface in the direction orthogonal to the intake air flow direction.

With this configuration, even if the temperature of the cylinder head rises and reaches a high temperature, the heat transfer from the cylinder head to the interface portion can be suppressed, and therefore, the rise in the intake air temperature in the intake passage can be suppressed.

Drawings

Fig. 1 is a cross-sectional view showing a state in which an intake manifold according to the present embodiment is attached to a cylinder head.

Fig. 2 is a perspective cross-sectional view of a portion on the downstream side of the intake manifold in the present embodiment.

Fig. 3 is a perspective view of the intake manifold of the present embodiment as viewed from the upstream side in the intake air flow direction.

Fig. 4 is a perspective view of the intake manifold of the present embodiment as viewed from the direction Z1.

Fig. 5 is a cross-sectional view taken along line 100-100 of fig. 1.

Fig. 6(a) in fig. 6 is a front view of the seal member. Fig. 6(B) is a cross-sectional view taken along line 120-120 in fig. 6 (a).

Fig. 7 is a schematic diagram showing a cross section taken along line 110-110 in fig. 5, a temperature sensor, and a control section.

Fig. 8 is a flowchart showing a heater heating process performed when an initial start (initial motion) of the engine is performed in the control unit of the engine including the intake manifold according to the present embodiment.

Fig. 9 is a flowchart showing a heater heating process performed when the engine is restarted in the control unit of the engine including the intake manifold according to the present embodiment.

Fig. 10 is a sectional view of an interface section according to modification 1 of the present embodiment, and corresponds to a sectional view taken along line 110 and 110 in fig. 5.

Fig. 11 is a sectional view of an interface section according to modification 2 of the present embodiment, and corresponds to a sectional view taken along line 110-110 in fig. 5.

Detailed Description

An embodiment of the present invention will be described below with reference to the drawings.

As shown in fig. 1, an engine E for an automobile (an example of an "internal combustion engine" in the claims) includes a cylinder block 1, a cylinder head 2, and an intake manifold 3 (an example of an "intake device for an internal combustion engine" in the claims).

The engine E is configured such that the cylinder head 2 is fixed to the cylinder block 1 on the Z1 direction side. The cylinder head 2 has a plurality of intake ports 21 and a plurality of exhaust ports (not shown) that communicate with the combustion chamber 22. Further, the cylinder head 2 is provided with an intake valve 13 and an exhaust valve (not shown), and the intake valve 13 and the exhaust valve open and close openings that communicate the combustion chamber 22 with each of the plurality of intake ports 21 and the plurality of exhaust ports.

In the present embodiment, the upstream and downstream are defined based on the flow of the airflow that flows through the intake port 21 and is drawn into the combustion chamber 22 (hereinafter referred to as the intake air flow direction a). In a state where the engine E including a plurality of cylinders 4 (only 1 cylinder is shown in fig. 1) is mounted on a vehicle (not shown), the extending direction of the cylinders 4 is defined as a Z direction (vertical direction), one of the Z directions is defined as a Z1 direction (upper direction), and the other of the Z directions is defined as a Z2 direction (lower direction). The arrangement direction of the plurality of cylinders 4 is defined as an X direction (front-rear direction), one of the X directions is defined as an X1 direction (front), and the other of the X directions is defined as an X2 direction (rear). A direction orthogonal to the Z direction and the X direction is defined as a Y direction (left-right direction), one of the Y directions is defined as a Y1 direction (right direction), and the other of the Y directions is defined as a Y2 direction (left direction).

The intake port 21 is provided at a position between an opening 23 on the upstream side in the intake air flow direction a and an intake port 24 on the downstream side in the intake air flow direction a. The intake port 24 communicates with the intake port 21 and the combustion chamber 22. The intake port 21 is inclined in the Z2 direction as it goes to the Y1 direction. The intake port 21 includes an enlarged portion 21a, a stepped portion 21b, and a reduced portion 21 c. The intake port 21 is provided with an expanding portion 21a, a step portion 21b, and a narrowing portion 21c in this order from the upstream side in the intake air flow direction a.

The enlarged portion 21a is formed of a through hole extending in the intake air flow direction a. The enlarged portion 21a has a substantially rectangular shape as viewed from the upstream side in the intake air flow direction a (see fig. 5). The enlarged portion 21a is provided up to the center portion of the intake port 21 in the intake air flow direction a. The length of the expanded portion 21a is greater than the length of the reduced portion 21c in the direction orthogonal to the intake air flow direction a. The maximum length of the enlarged portion 21a is smaller than the maximum length of the reduced portion 21c in the intake air flow direction a.

The step portion 21b connects the enlarged portion 21a and the reduced portion 21c in the intake air flow direction a. That is, the upstream end of the stepped portion 21b is integrated with the downstream end of the enlarged portion 21a in the intake air flow direction a. The downstream end of the stepped portion 21b is integrated with the upstream end of the reduced portion 21c in the intake air flow direction a. The step portion 21b has a tapered shape that is tapered on the downstream side in the intake air flow direction a. That is, the stepped portion 21b gradually inclines toward the central portion side (inner side) of the intake port 21 in the direction orthogonal to the intake air flow direction a as it goes toward the intake air flow direction a.

The constricted portion 21c is formed by a through hole extending in the intake air flow direction a. The constricted portion 21c has a rectangular shape when viewed from the upstream side in the intake air flow direction a (see fig. 5). The narrowed portion 21c extends from the central portion to the downstream end of the intake port 21 in the intake air flow direction a.

(air intake manifold)

As shown in fig. 1, the engine E is configured to supply an air-fuel mixture M containing air K and fuel F into the combustion chambers 22 of the cylinders 4 through the intake manifold 3. Specifically, the intake manifold 3 includes: the injector 31, the intake device body 32, the connecting port 33, the gasket 34 (an example of a "sealing member" in the claims), the intake passage 35, the embedded recess 36, the heater 37, the heat insulating member 38 (see fig. 5), and the heater protection film 39.

(ejector)

The injector 31 is configured to inject the atomized fuel F toward the air K flowing toward the combustion chamber 22. The injector 31 is provided in the intake device body portion 32 and configured to introduce the fuel F into the intake passage 35.

Specifically, the injector 31 injects the fuel F so that the fuel F gradually diffuses toward the surroundings as it goes toward the combustion chamber 22 in the intake air flow direction a. Here, the injector 31 diffuses the fuel F in the injection region 6. That is, the injection region 6 gradually expands in a direction orthogonal to (intersecting) the injection direction of the fuel F as it goes downstream in the injection direction of the fuel F.

The injector 31 is inclined toward the Z1 direction (upward) with respect to the extending direction of the intake port 21. That is, the injector 31 is inclined by only the prescribed angle θ with respect to the extending direction of the intake port 21.

The predetermined angle θ of the injector 31 is an angle at which at least a part of the heater 37 can be disposed in the range of the downstream end of the injection region 6. Further, the predetermined angle θ of the injector 31 is an angle at which a part of the intake port 24 can be disposed in the range of the downstream end of the injection region 6. Note that a part of the heater 37 is a part of the surface of the heater 37 on the intake passage 35 side in the direction orthogonal to the intake air flow direction a. Further, a part of the intake port 24 refers to a portion from the center position of the intake port 24 to the end portion on the intake manifold 3 side in the direction orthogonal to the intake air flow direction a.

The injector 31 is disposed at a position where the fuel F can be injected to the heater 37. That is, the injector 31 is disposed on the downstream side of the intake device main body portion 32 in the intake air flow direction a in a state of being inclined by the predetermined angle θ. Here, the tip end portion 31a of the injector 31 is disposed upstream of a boundary portion D, which will be described later, between the intake device main body portion 32 and the connecting portion 33 in the intake air flow direction a. Specifically, the tip end portion 31a of the injector 31 is provided at a position on the upstream side in the intake air flow direction a than the outer surface 2a of the cylinder head 2 around the opening 23 of the intake port 21. That is, the tip end portion 31a of the injector 31 is provided at a position on the upstream side of the gasket 34 in the intake air flow direction a.

A part of the tip end portion 31a of the injector 31 is disposed in the intake passage 35. Specifically, a portion of the front end portion 31a of the injector 31 on the cylinder block 1 side is disposed in the intake passage 35 in a direction orthogonal to the intake air flow direction a.

The fuel F is, for example, gasoline, gas fuel, ethanol, or the like. In this way, the engine E is a port injection engine in which the fuel F is injected into the intake port 21.

(air intake device body and interface part)

As shown in fig. 1 to 4, the intake device main body portion 32 and the interface portion 33 are provided at each of the plurality of intake interfaces 21, and the plurality of intake interfaces 21 supply the air-fuel mixture M to each of the plurality of cylinders 4 in the engine E. Therefore, only the configurations of the intake device main body portion 32 and the interface portion 33 arranged at the end portion on the X2 direction side among the plurality of cylinders 4 will be described below. Similarly, only the gasket 34, the air intake duct 35, the embedded recess 36, the heater 37, the heat insulating member 38 (see fig. 5), and the heater protection film 39 provided at the end portion on the X2 direction side will be described.

As shown in fig. 1, the intake device main body portion 32 is configured to introduce air K into the combustion chamber 22.

Specifically, the intake device main body portion 32 is formed of resin. The intake device main body portion 32 includes a surge tank (not shown), an intake pipe portion 32a, a flange portion 32b, an injector mounting portion 32c, and a recess portion 32 d.

The buffer tank temporarily stores air K. The surge tank is disposed at an upstream end portion in the intake air flow direction a in the intake manifold 3. The air intake duct portion 32a allows the air K to flow along a passage formed therein. The intake pipe portion 32a is disposed downstream of the surge tank. The intake pipe portion 32a connects the surge tank and the flange portion 32 b.

The flange portion 32b is provided for inserting the intake manifold 3 into a fastener (not shown) fixed to the cylinder head 2. The intake manifold 3 is fixed to the cylinder head 2 via a flange portion 32 b.

The flange portion 32b has a flange shape. The flange portion 32b is disposed to face the outer surface 2a of the cylinder head 2, and is integrated with an end portion of the connecting portion 33 on the intake device body portion 32 side. That is, the flange portion 32b has an opposing surface 132 that faces the outer surface 2a of the cylinder head 2. The inner end of the opposing surface 132 is integrally connected to the connecting port 33 in a direction orthogonal to the intake air flow direction a.

As shown in fig. 1 and 2, the injector mounting portion 32c is provided to mount the injector 31 to the intake device main body portion 32. The injector mounting portion 32c has a space into which the injector 31 is inserted. In order to attach the injector 31 to the intake device main body portion 32 while being inclined by the predetermined angle θ, the space of the injector attachment portion 32c extends in a direction inclined by the predetermined angle θ with respect to the extending direction of the intake port 21.

The injector mounting portion 32c is provided in a portion of the intake device main body portion 32 on the Z1 direction side (upper side). The injector mounting portion 32c is provided at a downstream end portion of the intake device main body portion 32 in the intake air flow direction a. That is, the injector mounting portion 32c is provided from the downstream side portion of the intake pipe portion 32a to the downstream side end portion of the flange portion 32b in the intake air flow direction a. The injector mounting portion 32c projects from a portion on the Z1 direction side (upper side) of the intake device body portion 32 in a direction inclined by a predetermined angle θ.

As shown in fig. 1 and 3, the recess 32d is configured to fit the washer 34. Specifically, the recess 32d is formed by recessing the end surface of the flange portion 32b on the downstream side in the intake air flow direction a in the direction opposite to the intake air flow direction a. The concave portion 32d is formed in a circumferential shape so as to surround an upstream end portion of the connecting port portion 33 in the intake air flow direction a.

As shown in fig. 1, the interface 33 forms a heat insulating interface structure that blocks heat from the cylinder head 2. That is, the interface portion 33 has a resin pipe shape that suppresses heat transfer from the cylinder head 2 to the air K supplied from the intake manifold 3 to the combustion chamber 22. The interface 33 is a cylindrical portion inserted into the intake port 21 from the opening 23 on the upstream side of the intake port 21.

The interface 33 is formed to have heat resistance against heat transmitted from the cylinder head 2 and heat from the combustion chamber 22. Specifically, the connecting port portion 33 is formed of a non-foamed resin material. For example, the interface 33 is formed of polyamide-6 having heat resistance. Accordingly, in the range where the interface 33 is disposed, a change in physical properties (e.g., melting) with respect to the heat transmitted from the cylinder head 2 and the heat from the combustion chamber 22 can be suppressed.

The connecting port portion 33 of the present embodiment is integrated with the downstream end portion of the intake device main body portion 32, and is inserted into the intake port 21 in the cylinder head 2. That is, the upstream end of the connecting port portion 33 is integrated with the downstream end of the intake device main body portion 32 in the intake air flow direction a. Specifically, the connecting port portion 33 integrally protrudes along the intake air flow direction a from a downstream side end portion (a downstream side end portion of the flange portion 32 b) of the intake device main body portion 32 in the intake air flow direction a. Further, the upstream end of the connecting port portion 33 and the downstream end of the intake device main body portion 32 are integrally formed in the entire circumferential direction around the center axis extending in the intake air flow direction a.

Here, a connecting portion between the upstream end of the connecting port portion 33 and the downstream end of the intake device main body portion 32 is a boundary portion D. The boundary portion D is also a contact portion of the outer surface 2a of the head 2 and the opposing surface 132 of the flange portion 32 b. In the Y direction, a part of the boundary portion D is disposed at a position further to the outside than the outer surface of the cylinder block 1. That is, in the Y direction, the maximum distance between the boundary portion D and the combustion chamber 22 is larger than the distance between the outer surface of the cylinder block 1 and the combustion chamber 22.

The interface portion 33 faces the inner surface 21d of the intake interface 21. Specifically, the interface portion 33 has a length in the intake air flow direction a that can be inserted from the upstream side end portion of the intake interface 21 to the vicinity of the central position of the intake interface 21. That is, the protruding tip end portion of the connecting port portion 33 is disposed on the upstream side of the narrowed portion 21c of the intake port 21 (the upstream side between the center position and the downstream end position of the intake port 21) in the intake air flow direction a. Therefore, the interface 33 is disposed between the inner surface 21d of the intake port 21 and the intake passage 35 at the upstream side portion from the upstream side end of the intake port 21 to the narrowed portion 21c of the intake port 21. This can suppress heat transfer from the cylinder head 2 to the air K flowing in the intake passage 35 at the upstream side portion from the upstream side end portion of the intake port 21 to the narrowed portion 21c of the intake port 21.

In a cross section in the intake air flow direction a, the interface portion 33 has a shape along the inner surface 21d of the intake interface 21. That is, in the cross section in the intake air flow direction a, the connecting port portion 33 has a shape of a portion along the enlarged portion 21a and the step portion 21b in the inner surface 21d of the intake port 21.

Specifically, as shown in fig. 3 and 4, the connecting port portion 33 has a tapered shape extending in the intake air flow direction a. That is, the portion of the interface 33 corresponding to the enlarged portion 21a is linear along the intake air flow direction a. A portion of the interface portion 33 corresponding to the step portion 21b has a tapered shape.

In detail, in the portion of the interface portion 33 corresponding to the step portion 21b, the portions on both sides in the X direction are each formed in a tapered shape. That is, in the portion of the connecting port portion 33 corresponding to the step portion 21b, the portions on both sides in the X direction are each gradually inclined toward the center position side in the Z direction of the intake passage 35 as going toward the intake air flow direction a. Here, in the portions of the connecting port portion 33 corresponding to the step portions 21b, the portions on both sides in the X direction are each disposed at a position on the downstream side in the intake air flow direction a from the portions on both sides in the Z direction.

As shown in fig. 5, an air insulating layer 5 is formed between the outer surface 33b of the connecting port portion 33 and the inner surface 21d of the air inlet port 21 in the direction perpendicular to the air flow direction a. That is, the air insulation layer 5 is an air layer formed between the outer surface 33b of the connection port portion 33 and the inner surface 21d of the intake port 21 in a state where the connection port portion 33 is inserted into the intake port 21. Here, in order to form the air insulation layer 5 in the direction orthogonal to the intake air flow direction a, the cross-sectional shape of the connecting port portion 33 is formed smaller than the cross-sectional shape of the intake port 21.

As shown in fig. 1, the distance between the outer surface 33b of the connecting port portion 33 and the inner surface 21d of the intake port 21 is substantially constant. That is, the interval between the outer surface 33b of the connecting port portion 33 and the portion of the enlarged portion 21a in the inner surface 21d of the intake port 21 in the direction orthogonal to the intake air flow direction a is substantially fixed. Further, in the direction orthogonal to the intake air flow direction a, the interval between the outer surface 33b of the connecting port portion 33 and the portion of the stepped portion 21b in the inner surface 21d of the intake port 21 is substantially fixed. In this way, the outer surface 33b of the connecting port 33 is disposed at a position shifted inward in the direction orthogonal to the intake air flow direction a.

The interface 33 is configured to allow the air K to smoothly flow out into the intake interface 21. Specifically, the inner surface 33a of the connecting port portion 33 is substantially flush with the inner surface 21d of the intake port 21 in the intake air flow direction a.

(gasket)

The gasket 34 is configured to prevent foreign matter such as water from entering the intake port 21. Specifically, the gasket 34 is formed of an elastic member. That is, the gasket 34 is formed of heat-resistant nitrile rubber, hydrogenated nitrile rubber, silicone rubber, fluororubber, or the like.

The gasket 34 is interposed and compressed between the flange portion 32b of the intake device main body portion 32 and the outer surface 2a of the cylinder head 2, thereby improving the sealing performance. That is, the gasket 34 is disposed between the flange portion 32b of the intake device main body portion 32 and the outer surface 2a of the cylinder head 2. Here, the washer 34 is fitted into the recess 32d formed in the flange portion 32 b.

As shown in fig. 3 and 6(a), the gasket 34 is provided so as to surround the upstream end of the connecting port 33 in the intake air flow direction a. The gasket 34 is formed in a circumferential shape. That is, the gasket 34 has a shape along a circumferential direction around a central axis extending in the intake air flow direction a. The gasket 34 has a substantially rectangular shape as viewed from the downstream side in the intake air flow direction a.

Further, as shown in fig. 6(B), the sectional shape of the gasket 34 in the direction along the intake air flow direction a has a substantially elliptical shape extending along the intake air flow direction a. Specifically, the gasket 34 includes a compression portion 34a and a rib portion 34 b.

The compression portion 34a is compressed by the flange portion 32b of the intake device main body portion 32 and the outer surface 2a of the cylinder head 2. An upstream end of the compression portion 34a contacts a downstream end face of the flange portion 32b of the intake device main body portion 32 in the intake air flow direction a. An end portion on the downstream side of the compression portion 34a in the intake air flow direction a contacts the outer surface 2a of the cylinder head 2.

The rib 34b holds the posture of the washer 34 fitted into the recess 32 d. The rib 34b contacts each of a pair of inner surfaces of the recess 32d facing each other in the X direction. That is, the rib 34b protrudes in the X1 direction from the side surface of the compression portion 34a on the X1 direction side. The rib 34b projects in the X2 direction from the side surface of the compression portion 34a on the X2 direction side. The rib 34b is disposed in the center of the compression portion 34a in the intake air flow direction a.

(air inlet channel)

As shown in fig. 1, the intake passage 35 is formed inside the intake device main body portion 32 and the connecting portion 33, and the air-fuel mixture M flows therethrough. That is, the intake passage 35 is an internal space of the intake device main body portion 32 and the connecting portion 33. Specifically, the intake passage 35 penetrates the intake device main body portion 32 and the interface portion 33 in the intake air flow direction a. The intake passage 35 has a flat shape having a length in the Z direction smaller than that in the X direction as viewed from the downstream side in the intake air flow direction a (see fig. 5).

(buried recess)

The embedded recess 36 is formed by recessing the inner surface 3a of the intake manifold 3 in a direction orthogonal to the intake air flow direction a. Specifically, the embedded recess 36 is formed such that the inner surface 33a of the connecting port 33 is recessed outward in the direction orthogonal to the intake air flow direction a. The embedded recess 36 is disposed in a portion of the interface 33 corresponding to the injection region 6 of the fuel F injected from the injector 31.

As shown in fig. 5, the cross-sectional shape of the embedded recess 36 has a substantially U-shape in a direction orthogonal to the intake air flow direction a. The embedded recess 36 is formed in a lower portion of the intake manifold 3 (closer to the Z1 direction side portion than the Z direction center portion) in a direction orthogonal to the intake air flow direction a.

Here, the heater 37 is disposed in the embedded concave portion 36. Further, in the embedding recess 36, a heat insulating member 38 is disposed on the outer side in the direction orthogonal to the intake air flow direction a, and a heater 37 is laminated on the inner side of the heat insulating member 38. Specifically, a laminated structure including a heater protective film 39, a heater 37, and a heat insulating material 38 is embedded in the embedded recess 36.

Here, the heater protection film 39, the heater 37, and the heat insulating member 38 are embedded in the embedding recess 36 in a state of being laminated in the order of the heater protection film 39, the heater 37, and the heat insulating member 38 in a direction orthogonal to the intake air flow direction a.

(Heater)

As shown in fig. 7, the heater 37 is configured to heat the fuel F introduced through the injector 31. Specifically, the fuel F that is not vaporized and adheres to the inner surface 3a of the intake manifold 3 is vaporized at a low temperature immediately after the engine is started (before a three-way catalyst (three-way catalyst) disposed in the exhaust pipe is warmed up). This stabilizes the a/F (Air/Fuel ratio) at the time of the cooling start, and can control the Fuel injection amount to be small, thereby suppressing the supply of excessive Fuel F into the combustion chamber 22.

Specifically, the heater 37 includes a heating element having a high temperature rise characteristic. That is, the heater 37 preferably has a high temperature rise characteristic in which the temperature reaches a predetermined temperature (about 70 ℃) in a short time (about 3 to 5 seconds) from the initial start of the engine. Therefore, the heater 37 includes a heating element mainly composed of carbon, such as carbon graphite (carbon graphite) or carbon nanotubes. Here, the heater 37 is more preferably formed by attaching a sheet-like carbon nanotube to the heater protection film 39 or coating a liquid carbon nanotube on the heater protection film 39.

As shown in fig. 1 and 7, the heater 37 is disposed at a position where it can directly supply heat to the fuel F that is not vaporized and adheres to the inner surface 3a of the intake manifold 3. That is, at least a part of the heater 37 is disposed at a portion of the interface portion 33 corresponding to the injection region 6 of the fuel F injected from the injector 31.

Specifically, the heater 37 is provided with the interface 33 in the intake air flow direction a. Here, the heater 37 is disposed between the tip end portion 31a of the injector 31 and the downstream end portion of the connecting port portion 33 in the intake air flow direction a. That is, the heater 37 is disposed near the front end of the intake manifold 3.

As shown in fig. 1 and 5, the heater 37 is configured to reliably supply heat to the fuel F diffused and adhered to the inner surface 33a of the interface 33. Specifically, the cross-sectional shape of the heater 37 has a substantially U-shape in a direction orthogonal to the intake air flow direction a. The heater 37 is formed in a lower portion of the intake manifold 3 (closer to the Z1 direction side portion than the Z direction center portion) in a direction orthogonal to the intake air flow direction a. The heater 37 is a planar heater along the shape of the embedded recess 36 in the direction orthogonal to the intake air flow direction a.

The heater 37 is provided on the inner surface 33a side of the interface 33. That is, the heater 37 is disposed at a position adjacent to the intake duct 35 via the heater protection film 39 in a direction orthogonal to the intake air flow direction a.

(Heat insulating Material)

As shown in fig. 7, the heat insulating member 38 is formed to function as a heat insulating material that suppresses the transfer of heat from the heater 37. Specifically, the heat insulating member 38 has a foamed resin material. That is, the heat insulating material 38 is formed by foam molding of polyamide. In this way, the heat insulating material 38 improves the heat insulating performance by forming bubbles in which gas is sealed. The heat transfer coefficient (heat transfer coefficient) of the heat insulating member 38 is preferably about 10% or less of the heat transfer coefficient of the heater protective film 39.

The heat insulating member 38 is disposed inside the intake manifold 3. Specifically, the heat insulating material 38 is embedded in the embedding recess 36. Here, the heat insulating member 38 is provided in direct contact with the inner surface 3a of the intake manifold 3.

As shown in fig. 5, the heat insulating member 38 has a substantially U-shape when viewed from the downstream side in the intake air flow direction a. The heater 37 is formed in a lower portion of the intake manifold 3 (closer to the Z1 direction side portion than the Z direction center portion) in a direction orthogonal to the intake air flow direction a.

(Heater protective film)

The heater protection film 39 is formed in a structure to protect the heater 37 so that the fuel F injected from the injector 31 does not adhere to the heater 37. Specifically, the heater protection film 39 covers the heater 37 from the intake passage 35 side. That is, the heater protection film 39 is provided over the entire cross-sectional shape of the heater 37 that is orthogonal to the intake air flow direction a. As such, the heater protection film 39 is provided along the inner surface of the heater 37.

The heater protection film 39 is formed of a material that easily conforms to the inner surface of the heater 37. Specifically, the heater protection film 39 is formed of a resin film. Here, the heater protection film 39 is preferably a resin material having heat resistance, oil resistance, and chemical resistance. For example, polyimide or the like is preferably used as the heater protection film 39.

The heater protection film 39 is formed to easily transmit heat from the heater 37. Specifically, the heater protection film 39 is formed by a resin film of a thin film so as not to hinder heat release from the heater 37 to the intake passage 35 side. That is, the heater protection film 39 is preferably a resin film having a thickness of about 0.125[ mm ], for example.

The heater protection film 39 has lower heat insulation properties than the heat insulating member 38. Specifically, the heat transfer coefficient of the heater protection film 39 is preferably about 10 times or more the heat transfer coefficient of the heat insulating member 38.

(laminated Structure)

As shown in fig. 7, the internal structure of the portion of the intake manifold 3 that embeds the recess 36 is configured as a four-layer structure. Specifically, the heater protective film 39, the heater 37, the heat insulating member 38, and the intake manifold 3 are laminated in this order in a direction orthogonal to the intake air flow direction a. That is, a laminated structure including the heater protective film 39, the heater 37, the heat insulating member 38, and the intake manifold 3 is formed in a part of the intake manifold 3.

Specifically, the heat insulating member 38 is formed to be laminated on the outer side of the heater 37 in the direction orthogonal to the intake air flow direction a, and to block heat from the heater 37. That is, the heat insulating member 38 is in contact with the heater 37. The heater protection film 39 is laminated inside the heater 37 in a direction orthogonal to the intake air flow direction a. That is, the heater protective film 39 is in contact with the heater 37.

The intake manifold 3 is formed to wrap the peripheral edge of the heat insulating member 38. That is, the intake manifold 3 is configured to thermally protect the heat insulating member 38 by having higher heat resistance than the heat insulating member 38.

Specifically, the connecting port portion 33 has a flange portion 33c protruding toward the center of the cross-sectional portion of the intake passage 35 at the downstream side end portion in the intake air flow direction a. That is, the heat insulating member 38 is covered by the flange portion 33c from the opposite side to the intake air flow direction a. Here, the flange portion 33c forms an end portion in the intake air flow direction a of the embedding recess portion 36. In this way, the intake manifold 3 thermally isolates the heat insulating member 38 from the high heat released from the combustion chamber 22 (see fig. 1) by the flange portion 33 c.

The intake manifold 3 is configured to prevent the heater protection film 39 provided with the heater 37 from being peeled off from the heat insulating member 38. Specifically, the interface part 33 has a protruding pressing part 33d, and the protruding pressing part 33d presses the heater protection film 39 provided with the heater 37 from the direction orthogonal to the intake air flow direction a. The protruding pressing portion 33d presses the peripheral edge portion of the surface of the heater protection film 39 provided with the heater 37 on the intake passage 35 side. That is, the protruding pressing portion 33d protrudes from the peripheral edge portion of the embedded recess 36 on the intake air flow direction a side toward the center of the embedded recess 36. The protruding pressing portion 33d protrudes from the peripheral edge portion of the embedded concave portion 36 on the opposite side to the intake air flow direction a toward the center of the embedded concave portion 36.

(ECU)

As shown in fig. 7, the engine E includes a temperature sensor 7 that measures the temperature of the heater 37, and a control unit 8 that controls the temperature of the heater 37 based on the temperature measured by the temperature sensor 7.

The Control Unit 8 is composed of a CPU (Central Processing Unit) (not shown) as a Control circuit and an ECU (Engine Control Unit) (not shown) including a memory (not shown) as a storage medium.

The control unit 8 controls each unit of the engine E by executing an engine control program stored in the memory by the CPU. The control unit 8 is configured to grasp the 1 st specified condition, the 2 nd specified condition, and information such as the temperature of the heater 37.

Here, the 1 st predetermined condition is a condition when the heater 37 is preheated (warmed up) before the engine is initially started, and includes at least one of, for example, approach of a user holding a wireless key to the vehicle, door unlocking by the user, seating of the user on a seat, and stepping on a brake pedal by the user. Note that the 2 nd specified condition is a condition when the heater 37 is preheated (warmed up) before the engine is restarted, and includes at least one of, for example, the outside air temperature, the temperature of the three-way catalyst disposed in the exhaust pipe, the temperature of the inner wall surface of the intake port 21, and the temperature of the coolant of the engine E.

The control unit 8 is configured to prevent excessive heat generation of the heater 37 based on the temperature measured by the temperature sensor 7 by using an engine control program. Further, the controller 8 is configured to reliably vaporize the fuel F, which is not vaporized and adheres to the inner surface 33a of the interface portion 33, by the heater 37 based on the 1 st prescribed condition and the 2 nd prescribed condition using the engine control program.

As for the temperature sensor 7, the most suitable sensor is selected from, for example, a thermistor, a thermocouple, a temperature measuring resistor, and the like. As the temperature sensor 7, a sensor that responds relatively quickly to a temperature change is preferably used.

(Heater heating treatment at initial Engine Start)

The heater heating process at the initial start of the engine included in the engine control process performed by the control unit 8 will be described below with reference to fig. 8. The heater heating process at the initial start of the engine is a process of starting heating of the heater 37 in advance before the initial start of the engine.

In step S1, the control unit 8 determines whether or not a 1 st predetermined condition (for example, door unlocking by the user) is satisfied. When the control unit 8 determines that the 1 st specification condition is satisfied, the process proceeds to step S2, and when it determines that the 1 st specification condition is not satisfied, the process returns to step S1. In step S2, the control unit 8 determines whether the temperature of the three-way catalyst is low, which is lower than a predetermined temperature. When the control unit 8 determines that the temperature of the three-way catalyst is low, the routine proceeds to step S3, and when it determines that the temperature of the three-way catalyst is not low (high), the routine proceeds to step S4, the engine E is started, and the heater heating process at the initial engine start is ended.

In step S3, after the control unit 8 starts heating by the heater 37, the process proceeds to step S4 to start the engine E. Subsequently, when the process proceeds to step S4, the control unit 8 ends the heater heating process at the initial start of the engine.

When the heater heating process at the initial start of the engine is completed, the control unit 8 stops heating of the heater 37. Here, the timing at which the heater 37 stops heating may be at the end of the three-way catalyst warm-up, at the elapse of a predetermined time (about 20 to about 30 seconds) after the engine is started, or the like.

(Heater heating treatment when restarting Engine)

The heater heating process at the time of engine restart included in the engine control process performed by the control unit 8 will be described below with reference to fig. 9. The heater heating process at the time of engine restart is a process of starting heating of the heater 37 in advance before the engine restart.

In step S11, the control unit 8 determines whether or not the 2 nd predetermined condition (for example, the temperature of the three-way catalyst is low) is satisfied. When the control unit 8 determines that the 2 nd prescribed condition is satisfied, the process proceeds to step S12, and when it determines that the 2 nd prescribed condition is not satisfied, the process proceeds to step S14, the engine E is started, and the heater heating process at the time of engine restart is ended.

In step S12, the control unit 8 starts heating by the heater 37. In step S13, the control unit 8 determines whether or not the temperature of the heater 37 is equal to or higher than a predetermined temperature. When the control unit 8 determines that the temperature of the heater 37 is equal to or higher than the predetermined temperature, the process proceeds to step S14, and when it determines that the temperature of the heater 37 is lower than the predetermined temperature, the process returns to step S13.

In step S14, the control unit 8 ends the heater heating process at the time of engine restart after the engine E is started.

When the heater heating process at the time of engine restart is completed, the control unit 8 stops heating of the heater 37. Here, the time for which the heater 37 stops heating may be at the end of the three-way catalyst warm-up, at the elapse of a prescribed time (about 20 to about 30 seconds) after the engine is restarted, or the like.

(Effect of the present embodiment)

The present embodiment can achieve the following effects.

In the present embodiment, as described above, the intake manifold 3 is provided with the intake device body portion 32, the interface portion 33 integrally provided at the downstream end portion of the intake device body portion 32, and the heater 37. The injector 31 is disposed at a position where the fuel F can be injected to the heater 37. Thus, by integrating the intake device body portion 32 and the connecting port portion 33, at least the fuel F can be prevented from entering between the intake device body portion 32 and the connecting port portion 33, and therefore the fuel F injected from the injector 31 and adhering to the inner surface 3a of the intake manifold 3 can be made less likely to enter between the intake device body portion 32 and the cylinder head 2. Further, the fuel F adhering to the inner surface 3a of the intake manifold 3 without being vaporized can be vaporized by the heater 37. As a result, vaporization of the fuel F by the heater 37 can be promoted, and the sealability with respect to the fuel F injected from the injector 31 can be ensured.

In the present embodiment, as described above, the heater 37 is disposed in the portion of the interface 33 corresponding to the injection region 6 of the fuel F injected from the injector 31. Thus, by disposing the heater 37 at the portion of the interface 33 corresponding to the injection region 6 of the fuel F, the fuel F adhering to the inner surface 3a of the intake manifold 3 can be reliably vaporized. Therefore, in the engine E, the air-fuel ratio in the combustion chamber 22 can be stabilized, so that a desired combustion state can be formed in the combustion chamber 22, and unburned exhaust gas can be reduced.

In the present embodiment, as described above, the heater 37 is provided on the inner surface 33a side of the interface portion 33. Thus, the heater 37 can be provided at a position closer to the inner surface 3a of the intake manifold 3 to which the fuel F adheres, and therefore, the fuel F adhering to the inner surface 3a of the intake manifold 3 can be sufficiently heated. Thereby, the fuel F adhering to the inner surface 3a of the intake manifold 3 can be reliably vaporized.

In the present embodiment, as described above, the flange portion 32b is provided in the intake device body portion 32 integrally with the end portion of the connecting port portion 33 on the intake device body portion 32 side. A gasket 34 is provided in the intake manifold 3. Thus, unlike the case where the intake device main body portion and the connecting portion are provided as separate members and the flange portions are provided at the intake device main body portion and the connecting portion, respectively, the gasket 34 may be disposed only between the flange portion 32b of the intake device main body portion 32 and the outer surface 2a of the cylinder head 2, and therefore the number of required gaskets 34 can be reduced. Further, by integrating the flange portion 32b with the end portion of the interface portion 33 on the intake device body portion 32 side, the fuel F can be suppressed from entering between the interface portion 33 and the flange portion 32b, and therefore, the amount of adhesion of the fuel F to the gasket 34 can be reduced.

In the present embodiment, as described above, the washer 34 is formed in a circumferential shape. Accordingly, the opening 23 at the upstream end of the intake port 21 in the intake air flow direction a can be surrounded by the gasket 34, and therefore, it is possible to prevent foreign matter from entering the intake port 21.

In the present embodiment, as described above, the tip end portion 31a of the injector 31 is provided at a position on the upstream side in the intake air flow direction a than the boundary portion D between the intake device main body portion 32 and the connecting port portion 33. Thus, the distance between the tip end portion 31a of the injector 31 and the combustion chamber 22 can be sufficiently secured, and therefore, the time until the fuel F injected from the injector 31 flows into the combustion chamber 22 can be sufficiently secured. Therefore, vaporization of the fuel F injected from the injector 31 can be further promoted. Further, since the distance between the tip end portion 31a of the injector 31 and the combustion chamber 22 can be sufficiently secured, it is possible to suppress adhesion of dirt to the injector 31 due to backflow of high-temperature gas in the combustion chamber 22 to the intake port 21.

In the present embodiment, as described above, the injector 31 is provided in the intake device main body portion 32. Thus, compared to the case where the injector 31 is provided in the cylinder head 2, the portion where the fuel F injected from the injector 31 collides with the inner surface 3a of the intake manifold 3 can be provided on the upstream side in the intake air flow direction a. At this time, depending on the position where the injector 31 is disposed, the heater 37 for heating the fuel F introduced by the injector 31 may be provided on the upstream side in the intake air flow direction a. Therefore, the connection port portion 33 can be disposed in a portion of the intake port 21 on the upstream side in the intake air flow direction a depending on the disposition positions of the injector 31 and the heater 37, and therefore, the amount of insertion of the connection port portion 33 into the intake port 21 can be suppressed. Here, by inserting the interface 33 into the intake interface 21, heat transfer from the cylinder head 2 to the air K in the intake passage 35 can be suppressed at the portion of the intake interface 21 where the interface 33 is inserted. As a result, it is possible to suppress a change in the structure of the cylinder head 2 (for example, a change in the arrangement of the water cooling jacket) that is required to insert the port portion 33 into the intake port 21, and to suppress a temperature increase of the air K in the intake passage 35.

In the present embodiment, as described above, the injector 31 is provided in the intake device main body portion 32. Thus, unlike the case where the injector 31 is provided in the cylinder head 2, the through hole for mounting the injector 31 can be eliminated from the cylinder head 2. Therefore, the cylinder head 2 can be reduced in size only by the portion where the through-hole is not provided.

[ modified examples ]

The embodiments disclosed herein are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than the description of the above embodiments, and all modifications (variations) within the meaning and scope equivalent to the claims are included.

For example, in the above embodiment, the heater protection film 39 is formed of a resin film, but the present invention is not limited thereto. For example, the heater protection film may be made of another material as long as it has heat resistance, oil resistance, and chemical resistance. The heater protection film may be configured to wrap the heater using the interface portion, or may be a metal tape.

In the above embodiment, the example in which the interface portion 33 is formed of the polyamide 6 is shown, but the present invention is not limited to this. In the present invention, the interface portion may be made of other material as long as it has heat resistance.

In the above embodiment, the heater protection film 39 is formed of a thin resin film having a thickness of about 0.125[ mm ], for example, but the present invention is not limited thereto. For example, the thickness of the heater protection film may be set to a thickness different from about 0.125[ mm ].

In the above embodiment, the example in which the heat insulating material 38 is formed by foam molding of polyamide is shown, but the present invention is not limited to this. For example, the heat insulating member may be glass, a melamine foam, a GOREs-TEX (GORE-TEX) fabric, cellulose, a special fiber, a resin material subjected to a thermal spraying treatment, or the like, as long as it has high heat insulating properties.

In the above-described embodiment, the heater 37 has been described as having the heating element mainly composed of carbon such as carbon graphite or carbon nanotubes, but the present invention is not limited to this. In the present invention, the heater may be a ceramic heater, a silicon rubber heater, a stainless steel heater, or the like.

In the above-described embodiment, the internal structure of the portion of the intake manifold 3 in which the recess 36 is embedded is formed by using a four-layer structure, but the present invention is not limited to this. For example, the internal structure of the embedded recess portion 236 of the intake manifold 203 may have a three-layer structure as in modification 1 shown in fig. 10. That is, instead of forming the embedded recess, the through hole 236 penetrating the interface section 233 may be formed in the interface section 233, and the heater protection film 39, the heater 37, and the heat insulating member 238 may be laminated in a surface-contact state in the through hole 236. The internal structure of the recessed portion of the intake manifold 303 may have a five-layer structure as in modification 2 shown in fig. 11. That is, the heater protection film 39, the heater 37, the heater protection film 340, the heat insulating member 338, and the interface 333 may be laminated in contact with each other in the embedded recess 336 of the interface 333.

In the above-described embodiment, the example in which the control unit 8 is configured by the CPU and the ECU including the memory has been described, but the present invention is not limited to this. For example, the control unit may be a dedicated control circuit for controlling the temperature of the heater, in addition to the ECU.

In the above-described embodiment, for convenience of explanation, an example in which the control process of the control unit 8 is explained using a flow-driven flowchart in which processes are sequentially performed along the process flow is shown, but the present invention is not limited to this. In the present invention, the control process of the control unit may be performed by an event-driven (event-driven) process in which the process is executed in event units. In this case, the event may be performed by a complete event-driven type, or may be performed by combining event-driven and flow-driven types.

In the above embodiment, the example in which the protruding distal end portion of the connecting port portion 33 is disposed on the upstream side portion of the narrowed portion 21c of the intake port 21 in the intake air flow direction a has been described, but the present invention is not limited to this. In the present invention, the projecting distal end portion of the connecting port portion may be disposed on the downstream side of the central position of the intake port in the intake flow direction, or the projecting distal end portion of the connecting port portion may be disposed on the upstream side of the central position of the intake port.

In the above embodiment, the heater 37 is provided on the inner surface 33a side of the interface 33, but the present invention is not limited to this. In the present invention, the heater may be provided across the inner surface side of the interface portion and the inner surface side of the intake device main body portion.

In the above embodiment, the heater 37 is provided in the interface unit 33, but the present invention is not limited to this. In the present invention, the heater may be provided across the interface portion and the downstream side end portion of the intake device main body portion in the flow direction of the intake air.

In the above embodiment, the example in which the boundary portion D is partially disposed at the outer side of the outer surface of the cylinder block 1 in the Y direction has been described, but the present invention is not limited to this. For example, the entire boundary portion may be disposed at a position further inward than the outer surface of the cylinder block in the Y direction.

In the above-described embodiment, the example has been described in which the upstream end portion of the connecting port portion 33 and the downstream end portion of the intake device main body portion 32 are integrated over the entire circumferential direction around the center axis extending in the intake air flow direction a, but the present invention is not limited thereto. For example, around the central axis extending in the intake air flow direction, a part of the upstream end of the interface portion and a part of the downstream end of the intake device body portion may be integrated with each other in correspondence to the portion where the heater is disposed.

In the above embodiment, the example in which the laminated structure including the heater protective film 39, the heater 37, the heat insulating member 38, and the intake manifold 3 is formed in a part of the intake manifold 3 has been described, but the present invention is not limited to this. For example, a laminated structure including a heater protective film, a heater, and an intake manifold may be formed in a part of the intake manifold.

Further, in the above-described embodiment, the example in which the specified angle θ of the injector 31 is an angle in which a part of the heater 37 can be arranged in the range of the downstream end of the injection region 6 and a part of the intake port 24 can be arranged is shown, but the present invention is not limited thereto. For example, the predetermined angle of the injector may be an angle at which only a part of the heater can be arranged in the range of the downstream end of the injection region.

In the above embodiment, the heater 37 is provided near the front end of the intake manifold 3, but the present invention is not limited to this. For example, the heater may be provided upstream of the vicinity of the front end of the intake manifold in the flow direction of the intake air.

Description of the symbols

2 Cylinder cover

2a (of the cylinder head) outer surface

3. 203, 303 air intake manifold (air intake device)

4 cylinder

6 spray area

21 air inlet interface

23 (of the upstream-side end of the air intake port) opening

31 ejector

31a (of the injector) front end portion

32 air intake device body

32b flange part

33. 233, 333 interface part

33a (of the interface part) inner surface

34 gasket (sealing component)

35 air intake channel

37 heater

A direction of flow of intake air

D boundary part

E engine (internal combustion engine)

F fuel

K air