JPH06341353A - Suction gas heating device - Google Patents

Abstract

PURPOSE:To make gasification of liquid fuel upon heating it effectively. CONSTITUTION:The cylindrical part 2A of the first heat radiator 2 is fitted in the internal circumferential surface of a heat insulator 1, while the cylindrical part 3A of the second heat radiator 3 is fitted in the internal circumferential surface of the same insulator 1. The first PTC heat emitting body 4 is furnished on the undersurface of a flange 2B provided on the first heat radiator 2 while the second PTC heat emitting body 5 is through a joint part 8 joined with the under-side of the first PTC heat emitting body 4. A plate 7 is installed on the undersurface of the second PTC heat emitting body 5, and an electrode 6 is arranged between the plate 7 and the flange part 3B of the second heat emitting body 3. Leads 9A, 9B for supplying the power to the flange part 2B of the first heat emitting body 2 and the flange part 3B of the second heat emitting body 3, and another lead 9C for grounding is connected with the joint part 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake air heating device,
In particular, the present invention relates to an intake air heating device suitable for heating an intake air-fuel mixture of an internal combustion engine.

[0002]

2. Description of the Related Art Conventionally, as an intake air heating device attached to a carburetor of an internal combustion engine, there is, for example, a structure shown in FIG. In FIG. 5, at the upper end portion of the intake pipe 53 connected to the cylinder portion of the engine 50 by the bolts 51 and 52,
A carburetor 56 having a throttle valve 55 in the intake passage 54.
Through the heat insulator 57, the bolts 58, 59
The heat insulator 57 and the intake pipe 53 are connected to each other by an annular PTC heating element 6 on the inner peripheral wall of the upper end portion.
An intake air heating device 63 including 0, a cylindrical radiator 61, and a mounting member 62 is provided. When the intake air heating device 63 is energized from a power source (not shown) via the lead wires 64 and 65, the liquid fuel flowing down along the inner peripheral surface of the intake passage 54 is heated by the PTC heating element 60 and the radiator 61. It is becoming vaporized. In this case, by using the PTC heating element 60, the intake air is heated when the temperature of the engine 50 is low and the atomization of the liquid fuel is promoted.

Further, as an intake air heating device capable of efficiently vaporizing liquid fuel in a short time, for example, Japanese Utility Model Publication No. 60-2
The device described in Japanese Patent No. 4925 has been proposed. In the apparatus, as shown in FIG. 6, a pair of flange portions 71 and 72 are formed on the outer peripheral portion of a cylindrical member 70 at intervals in the vertical direction, and the first portion is formed on the lower surface portion of the flange portion 71. PTC
The heating element 73 is provided, and the second PTC heating element 74 is provided on the upper surface of the flange portion 72. Further, a corrugated annular spring member 75 is interposed between the first and second PTC heating elements 73, 74. Reference numerals 76 and 7 in the figure
Reference numeral 7 indicates a lead wire for energization. In this case, the cylindrical member 7
0 is drawn as an integrally molded product.

Further, as an intake air heating device which facilitates the processing of the above-mentioned cylindrical member, for example, Japanese Utility Model Publication 60-278.
The device described in Japanese Patent No. 18 has been proposed. As shown in FIG. 7, the device has a cylindrical shape in which a cylindrical member 82 is disposed in a groove portion 81 formed in an inner peripheral wall of a heat insulator 80 via a flange portion 83 and fixed to the cylindrical member 83. The member 84 is arranged via the flange portion 85. Further, the first PTC heating element 86 is provided on the lower surface of the flange portion 85, and the second PTC heating element 86 is provided on the upper surface of the flange portion 83.
The PTC heating element 87 is disposed, and the electrode 88 is interposed between the first and second PTC heating elements 86 and 87. Reference numerals 89 and 90 in the figure denote lead wires for energization.
In this case, the cylindrical members 82 and 84 are processed by press molding.

[0005]

However, in the case of the conventional intake air heating device shown in FIGS. 6 and 7, although two PTC heating elements are provided, each heating element is a cylindrical member. Since it is not exposed on the peripheral surface side, it takes time to sufficiently heat the cylindrical member, and it is not possible to completely vaporize the liquid fuel at the initial start of the engine. Therefore, there are problems such as deterioration of fuel consumption. there were. Further, since the cylindrical member constituting the intake air heating device shown in FIG. 6 is drawn as an integrally molded product, there is a restriction on the drawing length at the time of drawing, and therefore, the axial dimension as shown in the drawing. However, there is a problem that the contact area of the cylindrical member with the fuel becomes small and the heating efficiency deteriorates. Further, in the conventional intake air heating device shown in FIG. 5, since the liquid fuel is heated by one PTC heating element, there is a problem when the PTC heating element does not generate heat due to deterioration or the like. There was a problem.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to improve the inconveniences of the above-mentioned conventional example, and in particular, to make it possible to effectively heat the liquid fuel flowing down from the carburetor into the intake pipe to efficiently vaporize it. The purpose is to provide a heating device.

[0007]

DISCLOSURE OF THE INVENTION The present invention has a cylindrical shape having a flange portion and arranged in a fitted state on an inner peripheral wall portion of an intake pipe connecting an intake passage of a carburetor and a cylinder portion of an engine. Intake that includes an electric heating member and a heat generating member that is attached to the electric heating member and generates heat by energization from the outside, and the liquid fuel that has flowed into the intake pipe from the vaporizer is heated by the electric heating member and the heat generating member to be vaporized. In the heating device, two electric heating members are provided, and the electric heating members are arranged in a fitted state on the inner peripheral wall portion of the intake pipe so that the outer end surfaces of the flange portions face each other with a predetermined gap, Alternatively, two or more heat generating members are annularly arranged between the flange portions of the electric heating members. This is intended to achieve the above-mentioned object.

[0008]

According to the present invention, when the heat generating member of the intake air heating device is energized from the outside, the heat generating member generates heat and the heat generated from the heat generating member is transmitted to the two electric heating members. When liquid fuel in an unvaporized state flows into the intake pipe side along the inner peripheral wall of the intake passage of the carburetor, two electric heating members are arranged so as to sandwich the heating member in the axial direction of the intake pipe. For,
The liquid fuel is first heated and vaporized by coming into contact with one electric heating member close to the vaporizer side, and is further sufficiently heated and vaporized by the heat generating member and the other electric heating member. Then, the vaporized fuel is supplied to the cylinder portion of the engine. As a result, heat can be efficiently conducted from the heat generating member to each electric heating member, and the contact area of each electric heating member with the liquid fuel can be increased as compared with the conventional case, so that the liquid fuel can be effectively heated. It becomes possible to vaporize efficiently.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS First to third embodiments to which the intake air heating device of the present invention is applied will be described below with reference to the drawings.

(1) First embodiment. FIG. 1 is a cross-sectional view showing the configuration of the intake air heating apparatus according to the first embodiment, which has a substantially annular heat insulator 1, a hollow substantially cylindrical first radiator 2, and a hollow substantially cylindrical second member. Radiator 3, ring-shaped first PTC heating element 4, ring-shaped second
The PTC heating element 5, the electrode 6, and the plate 7 are provided. In this case, in the first radiator 2, the cylindrical portion 2A and the flange portion 2B are integrally formed by drawing, and also in the second radiator 3, the cylindrical portion 3A and the flange portion 3B are integrally formed by drawing. It has become so.

Explaining the structure of the intake air heating device in detail, an annular groove portion 1A is formed on the inner peripheral side of the heat insulator 1, and a flange portion 2B is formed on the outer peripheral side of the cylindrical portion 2A of the first radiator 2. And a flange portion 3B is formed on the outer peripheral side of the cylindrical portion 3A of the second radiator 3. In the first radiator 2, the cylindrical portion 2A is fitted to the inner peripheral portion of the heat insulator 1, and the flange portion 2B is in close contact with the upper wall surface portion of the groove portion 1A. Similarly, the second radiator 3
The cylindrical portion 3A is fitted to the inner peripheral portion of the heat insulator 1, and the flange portion 3B is in close contact with the lower side wall surface portion of the groove portion 1A.

A first PTC heating element 4 is arranged on the lower surface of the flange portion 2B of the first heat radiating body 2, and further,
The second PTC heating element 5 is joined (brazed) to the lower side of the first PTC heating element 4 via a joining portion 8 made of silver solder or the like. In this case, the first PTC heating element 4 and the second PTC heating element 5 which are manufactured in advance are joined by brazing. Also, the second PTC
A plate 7 is arranged on the lower surface of the heating element 5,
Further, the electrode 6 is arranged between the plate 7 and the flange portion 3B of the second radiator 3. In this case, the electrode 6
Is taken out from the joint portion 8 of the first and second PTC heating elements 4 and 5.

Further, the lead wire 9A is connected to the flange portion 2B of the first heat radiator 2, and the lead wire 9B is connected to the flange portion 3B of the second heat radiator 3, and each lead wire is connected. 9A and 9B are connected to the positive terminal of a battery (not shown). A lead wire 9C is connected to the joint portion 8 between the first and second PTC heating elements 4 and 5, and the lead wire 9C is grounded.

The above-described intake air heating device is arranged between the lower end of the intake passage of the carburetor and the upper end of the intake pipe connected to the cylinder of the engine (not shown). There is. When vaporizing the liquid fuel flowing down along the intake passage of the carburetor by the intake air heating device, the lead wire 9 is transferred from the battery to the first radiator 2 and the second radiator 3.
The first PTC heating element 4 and the second PTC heating element 4 are energized via A and 9B.
By causing the PTC heating element 5 to generate heat, the liquid fuel is heated and vaporized.

Next, the operation of the first embodiment constructed as described above will be described.

When the first heat radiator 2 and the second heat radiator 3 constituting the intake air heating device are energized by the lead wires 9A and 9B from the battery at the time of starting the engine, the first heat radiator 2 and the second heat radiator 2 are connected. The first PTC heating element 4 via the radiator 3
And the second PTC heating element 5 is energized, and the first PT
The C heat generating element 4 and the second PTC heat generating element 5 generate heat, and the heat generated from the first PTC heat generating element 4 and the second PTC heat generating element 5 is the first heat radiating element 2 and the second heat radiating element. Conducted to 3.

At this time, the liquid fuel in the intake passage of the carburetor is the cylindrical portion 2 which constitutes the first radiator 2 of the intake heating device.
When the liquid fuel flows down along the inner peripheral surface of A, the liquid fuel is heated by the first radiator 2 and vaporized, and then the second radiator 3, the first PTC heating element 4, and the second PTC heating element 4. Is sufficiently heated by the PTC heating element 5 to be vaporized. Then, the vaporized fuel is supplied to the cylinder portion of the engine through the intake pipe.

That is, according to the first embodiment, the two first
Since the PTC heating element 4 and the second PTC heating element 5 are disposed in an exposed state so as to face the insides of the cylindrical portions 2B and 3B of the first radiator 2 and the second radiator 3, respectively. It becomes possible to effectively heat the liquid fuel that has flowed down from the inner peripheral wall of the intake passage of the carburetor through the cylindrical portion 2B of the first radiator 2, and therefore the liquid fuel can be efficiently vaporized. .

In addition, the first radiator 2 is disposed above the first PTC heating element 4, and the second PTC heating element 5 is provided.
Since the second radiator 3 is disposed in the lower part of the, the heat generated from the first PTC heating element 4 and the second PTC heating element 5 is applied to the first radiator 2 and the second radiator. Therefore, the liquid fuel can be effectively heated and vaporized efficiently as described above.

Further, since the heat radiator is divided into the two first heat radiators 2 and the second heat radiator 3, the drawing length of the first and second heat radiators 2 and 3 at the time of drawing processing. Even if the length is shortened, the cylindrical portions 2A, 3 of the first and second radiators 2, 3 are
Since the contact area of the portion where A is combined with the liquid fuel can be increased as compared with the conventional structure, the liquid fuel can be effectively heated and vaporized efficiently as in the above case.

Further, since the two first PTC heating elements 4 and the second PTC heating elements 5 are used, for example, even when one PTC heating element cannot perform its heating function due to deterioration or the like, Since the other PTC heating element can heat the first radiator 2 and the second radiator 3, the reliability of the intake air heating device can be improved. Also, two PTs
Since the shape of each heating element can be reduced by using the C heating element, the manufacturing control of the PTC heating element can be simplified.

Further, the liquid fuel which has flowed down the inner wall of the intake passage of the carburetor and has flowed down to the intake pipe side has the first PTC heating element 4 and the second PTC heating element 5 before coming into contact with the first fuel.
Since it contacts the inner peripheral surface of the cylindrical portion 2A of the heat radiator 2 and is vaporized, the thermal shock to the first and second PTC heat generating bodies 4 and 5 can be alleviated.

From the above, the liquid fuel flowing down from the intake passage of the carburetor to the intake pipe side can be efficiently vaporized, especially at the time of starting in a cold season when engine startability is poor. It is possible to improve fuel efficiency.

(2) Second embodiment. FIG. 2 is a cross-sectional view showing the configuration of the intake air heating apparatus according to the second embodiment, which has a substantially annular heat insulator 11, a hollow substantially cylindrical first radiator 12, and a hollow substantially cylindrical second member.
Of heat radiation body 13, annular first PTC heating element 14, annular second PTC heating element 15, first cushion member 16, second cushion member 17, and spring member 18. It is composed. In this case, the first radiator 1
2, the cylindrical portion 12A and the flange portion 12B are integrally formed by drawing, and the second radiator 13 also has a cylindrical portion 13A.
The flange portion 13B and the flange portion 13B are integrally formed by drawing.

The structure of the intake air heating device will be described in detail. An annular groove portion 11A is formed on the inner peripheral side of the heat insulator 11, and a flange portion 12B is formed on the outer peripheral side of the cylindrical portion 12A of the first radiator 12. And a flange portion 13B is formed on the outer peripheral side of the cylindrical portion 13A of the second radiator 13. In the first radiator 12, the cylindrical portion 12A is fitted to the inner peripheral portion of the heat insulator 11, and the flange portion 12B is in close contact with the upper wall surface portion of the groove portion 11A. Similarly, in the second radiator 13, the cylindrical portion 13A is fitted to the inner peripheral portion of the heat insulator 11, and the flange portion 13B is in close contact with the lower side wall surface portion of the groove portion 11A.

A first PTC heating element 14 is disposed on the lower surface of the flange portion 12B of the first radiator 12,
Further, a spring member 18 is arranged below the first PTC heating element 14 via a first cushion member 16. The second PTC heating element 15 is disposed below the spring member 18 via the second cushion member 17, and the lower surface portion of the second PTC heating element 15 is the second radiator. The flange portion 13 </ b> A of 13 abuts on the upper surface portion. The first and second cushion members 16 and 17, and the spring member 18 allow the first and second heat generating elements 14 and 15 and the flange portions 12B of the first and second heat radiating elements 12 and 13,
13B and pressure contact.

The flange portion 12 of the first radiator 12
The lead wire 19A is connected to B, and the second heat radiator 13
A lead wire 19B is connected to the flange portion 13B of the above, and each lead wire 19A, 19B is connected to a plus side terminal of a battery (not shown). A lead wire 19C is connected to the spring member 18, and the lead wire 19C is grounded.

The intake air heating device described above is arranged between the lower end of the intake passage of the carburetor and the upper end of the intake pipe (not shown) connected to the cylinder of the engine. There is. When vaporizing the liquid fuel flowing down along the intake passage of the carburetor by the intake air heating device, the battery is energized to the first radiator 12 and the second radiator 13 through the lead wires 19A and 19B. First PTC heating element 1
The liquid fuel is heated and vaporized by heating the fourth and second PTC heating elements 15.

That is, also in the second embodiment, the first
Similar to the embodiment, the first and second PTC heating elements 14, 1
5 efficient heat conduction from the first and second heat radiators 12 and 13, the contact area of the first and second heat radiators 12 and 13 with respect to the liquid fuel, the reliability improvement of the intake air heating device, Mitigation of thermal shock to the first and second PTC heating elements 14 and 15, first and second PTC heating elements 14 and 1
5 can be miniaturized, and liquid fuel can be efficiently vaporized.

(3) Third embodiment. FIG. 3 is a cross-sectional view showing the structure of the intake air heating device according to the third embodiment, which has a substantially annular heat insulator 21, a hollow substantially cylindrical first radiator 22, and a hollow substantially cylindrical second member.
Radiator 23, an annular first PTC heating element 24, an annular second PTC heating element 25, a first cushion member 26, a second cushion member 27, and a third cushion member 28. And a fourth cushion member 29, a first spring member 30, and a second spring member 31. In this case, the first radiator 22 has the cylindrical portion 22.
A and the flange portion 22B are integrally formed by drawing, and the second radiator 23 also includes the cylindrical portion 23A and the flange portion 2
3B and 3B are integrally formed by drawing.

Explaining the structure of the intake air heating device in detail, an annular groove portion 21A is formed on the inner peripheral side of the heat insulator 21, and a flange portion 22B is formed on the outer peripheral side of the cylindrical portion 22A of the first radiator 22. And a flange portion 23B is formed on the outer peripheral side of the cylindrical portion 23A of the second radiator 23. In the first radiator 22, the cylindrical portion 22A is fitted to the inner peripheral portion of the heat insulator 21, and the flange portion 12B is arranged in the groove portion 11A. Similarly,
In the second radiator 23, the cylindrical portion 23A is fitted to the inner peripheral portion of the heat insulator 21, and the flange portion 23B is formed.
Are arranged in the groove portion 21A.

A first spring member 30 is arranged on the lower surface of the flange portion 22B of the first heat radiator 22.
Spring member 30 and the flange portion 22B of the first radiator 22
The first PTC heating element 24 is provided between the first and second cushion members 26 and 27 via the first cushion member 26 and the second cushion member 27. Similarly, the flange portion 2 of the second radiator 23
The second spring member 31 is disposed on the upper surface of 3B, and the third cushion member 28 and the third cushion member 28 are provided between the second spring member 31 and the flange portion 23B of the second radiator 23. The second PTC heating element 2 via the fourth cushion member 29.
5 are provided. Then, the first and fourth cushion members 26, 27, 28, 29 and the first and second spring members 30, 31 are used for the first and second radiators 22, 23.
The first and second heating elements 24, 25 are brought into pressure contact with the respective flange portions 22B, 23B.

Further, the cylindrical portion 22A of the first radiator 22 has a large number of holes 33 along the circumferential direction of the first PTC.
It is formed at a position facing the heating element 24 (see FIG. 4), and similarly, in the cylindrical portion 23A of the second radiator 23,
A large number of holes 34 are formed at positions facing the second PTC heating element 25 along the circumferential direction. This allows
The first and second heating elements 24 and 25 are exposed to the inside of the cylindrical portions 22B and 23B of the first and second heat radiators 22 and 23.

The flange portion 22 of the first radiator 22
The lead wire 35A is connected to B, and the second heat radiator 23
A lead wire 35B is connected to the flange portion 23B of the above, and each lead wire 35A, 35B is connected to a positive side terminal of a battery (not shown). In addition, the flange portions 22B and 23B of the first and second radiators 22 and 23, respectively.
A lead wire 35C is connected between the two, and the lead wire 35C is grounded.

The intake air heating device described above is arranged between the lower end of the intake passage of the carburetor and the upper end of the intake pipe (not shown) connected to the cylinder of the engine. There is. When vaporizing the liquid fuel flowing down along the intake passage of the carburetor by the intake air heating device, the battery is energized to the first radiator 22 and the second radiator 23 through the lead wires 35A and 35B. First PTC heating element 2
By heating the fourth and second PTC heating elements 25, the liquid fuel is heated and vaporized.

That is, also in the third embodiment, the first
Similar to the embodiment and the second embodiment, the first and second PTCs
From the heating elements 24, 25 to the first and second radiators 22, 23
Efficient heat conduction to the first and second radiators 22, 3
The contact area with the liquid fuel, the reliability of the intake air heating device is improved, the thermal shock to the first and second PTC heating elements 24 and 25 is reduced, and the first and second PTC heating elements 24 and 25 are downsized. Further, it is possible to achieve the effects such as efficient vaporization of the liquid fuel.

[0037]

As described above, according to the intake air heating device of the present invention, the two electric heating members are fitted to the inner peripheral wall portion of the intake pipe so that the outer end surfaces of the flange portions face each other with a predetermined gap. Since the structure is such that one or more heat generating members are annularly arranged between the flange portions of each electric heating member, in other words, the two electric heating members generate heat in the axial direction of the intake pipe. Since the structure is such that the members are sandwiched, it is possible to efficiently conduct heat from the heat generating member to each electric heating member, and it is possible to increase the contact area of each electric heating member with the liquid fuel as compared with the conventional case. As a result, it becomes possible to effectively heat the liquid fuel and vaporize it efficiently.Therefore, even when the engine is started in a cold season when the startability is poor, the liquid fuel flows down from the intake passage of the carburetor to the intake pipe side. Coming liquid fuel It is possible to efficiently vaporization, it becomes possible to improve the fuel efficiency, it is possible to achieve the various effects etc.

Further, the intake heating device is provided with two electric heating members, and heat generating members are provided corresponding to the respective electric heating members. The electric heating members are provided on the inner peripheral wall portion of the intake pipe so that the outer end surfaces of the flange portions contact each other. In the case where the heating members are arranged in the fitted state and the openings are formed in the peripheral wall portion near the flange portion of each electric heating member, and each heating member is arranged on the outer peripheral side of each electric heating member and at a position facing the opening. In addition to the effect similar to the above case, it is possible to back up with the other heat generating member even when one heat generating member loses its heat generating function, improving the reliability of the intake air heating device. It is possible to achieve

[Brief description of drawings]

FIG. 1 is a sectional view showing a structure of an intake air heating device according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing the structure of an intake air heating device according to a second embodiment.

FIG. 3 is a sectional view showing the structure of an intake air heating device according to a third embodiment.

FIG. 4 is a cross-sectional view showing the structure of a radiator according to a third embodiment.

FIG. 5 is a cross-sectional view with a part omitted showing the configuration of an intake pipe and a carburetor and the like to which an intake air heating device according to a conventional example is attached.

FIG. 6 is a cross-sectional view showing the configuration of an intake air heating device according to another conventional example.

FIG. 7 is a cross-sectional view showing the configuration of an intake air heating device according to another conventional example.

[Explanation of symbols]

 1,11,21 Heat insulator 2,12,22 1st radiator as an electric heating member 3,13,23 2nd radiator as an electric heating member 4,14,24 1st PTC heating element as a heating member 5,15,25 Second PTC heating element as heat generating member 33,34 Hole portion as opening

Claims (3)

[Claims] 1. A cylindrical electric heating member having a flange portion and arranged in a fitted state on an inner peripheral wall portion of an intake pipe connecting an intake passage of a carburetor and a cylinder portion of an engine, and the electric heating member. An intake air heating device provided with an exothermic member which is attached and generates heat by energization from the outside, wherein the liquid fuel flowing from the vaporizer into the intake pipe is heated and vaporized by the electrothermal member and the exothermic member, wherein the electrothermal member is Two, each of the electrothermal members is disposed in a fitted state on the inner peripheral wall portion of the intake pipe such that the flange outer ends face each other with a predetermined interval, and one or more heat generating members are provided. An intake air heating device, wherein the heating device is annularly arranged between the flanges of the electric heating members. 2. A cylindrical electric heating member, which is disposed in a fitted state on an inner peripheral wall portion of an intake pipe connecting an intake passage of a carburetor and a cylinder portion of an engine, and has a flange portion, and the electric heating member. An intake air heating device provided with an exothermic member which is attached and generates heat by energization from the outside, wherein the liquid fuel flowing from the vaporizer into the intake pipe is heated and vaporized by the electrothermal member and the exothermic member, wherein the electrothermal member is Two heat generating members are provided corresponding to the respective electric heating members, and the electric heating members are arranged in a fitted state on the inner peripheral wall portion of the intake pipe so that the outer end surfaces of the flange portions contact each other. In addition, an opening is formed in the peripheral wall portion near the flange portion of each electric heating member, and each heat generating member is arranged on the outer peripheral side of each electric heating member and at a location facing the opening. Tosu Intake heating device. 3. The plurality of openings are formed along the circumferential direction of each electrothermal member.
Intake air heating device described.