JPS606059A - Heating device of internal-combustion engine - Google Patents

Abstract

PURPOSE:To enable facilitation of assembly and carriage, improvement of airtight performance, and increase of a heat resisting life, by a method wherein a heat insulating material is formed integrally with a heater, and plane precision of a mating surface is increased. CONSTITUTION:A heater 3 is formed such that an outer cylinder 5, an inner cylinder 7, an insulating plate 9, PTC elements 10, 10, and an insulating packing 12 are mounted, and they are fitted in mating molds 13 and 14, and an injection molding, in which stock solution of heat insulating synthetic resin is injected in the molds 13 and 14, takes place. This produces a heater in a one-piece structure in which brims 6 and 8, an insulating plate 9 are embedded in a heat insulating bring 11 made of resin. This facilitates mounting, and an increase in size precision of an insert mold enables the mating surface of the heat insulating brim 11 to be finished in high-precise flatness. As a result, assembly precision is improved, airtightness is also held, and durability is also improved.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heating device for effectively heating intake air in an internal combustion engine.

Heats the air-fuel mixture supplied to the internal combustion engine to promote fuel vaporization, improves ignition and combustion of the air-fuel mixture in the engine, improves starting performance, and reduces the generation of hydrocarbons and carbon oxides. Various heating devices that can improve the fuel consumption rate have been proposed in the past, and two representative examples are shown in FIGS. 3 and 4. A cylindrical heater (3) consisting of a flanged outer cylinder (5), a flanged inner cylinder (7), an insulating plate (9), and a heating element QO is fixed to the heat insulating member αη by tightening the rivet edge αQ or bolting. By sandwiching this heat insulating part to the joint between the intake manifold (2) and the carburetor (1), the heater (3)
It has a structure in which it is arranged at a predetermined position.

In this example, when fixing the heat insulating member αη and the heater (3), the surface of the heat insulating member 0η and the surface of the flange of the flange f1 outer cylinder (5) are difficult to separate, making it difficult to achieve flatness. Even if the method (4) is used for airtight treatment, the following problems occur, which is not preferable.

In other words, if the surface of the brim protrudes beyond the surface of the heat insulating member, the sealing performance will deteriorate and excess air will be sucked into the manifold, making it impossible to maintain the air-fuel ratio at a predetermined value. On the other hand, when the surface of the heat insulating member (17) protrudes, fuel (gasoline) accumulates in the gap in contact with the surface of the collar, staining the heat insulating member 0η and the gasket (4),
This is inconvenient as it causes deterioration.

On the other hand, the one shown in FIG.
It is known from the publication No.
The flange of the heater (3) is fitted into the four parts provided on the two end edges, so that when the carburetor (1) and the intake manifold (2) are tightly tightened, the carburetor (1) and the heat insulating member a force are connected. Although this structure is fixed by being clamped, it also has the same drawbacks as the example shown in FIG. 3 because it is difficult to achieve flatness.

Furthermore, in this example, until the carburetor (1) and the intake manifold (2) are fixed by bolting, the heat insulating member Q7) and the heater (3) are either separated or temporarily connected with the gasket 1 by adhesive. Therefore, there is a problem in that the workability of carrying is lacking due to the large number of parts during transportation.

The present invention has been made in order to eliminate the drawbacks of such conventional heating devices, and the integration of the heat insulating member and the heater has been achieved by improving the precision of the W surface of the mating surfaces, thereby facilitating assembly. The main purpose is to improve airtightness.

To this end, the present invention provides an outer cylinder and an inner cylinder each having a flange, which are arranged concentrically so that the flange closely faces each other, and an insulating plate is inserted between the flange, and between the outer cylinder and the inner cylinder. A cylindrical heater integrally equipped with an insulating flange of a predetermined thickness is obtained by interposing a positive characteristic two-mister element into the cylindrical heater and embedding both the flange and the insulating plate in a heat-insulating molded material by insert molding means. The heater is inserted into the joint between the intake manifold and the carburetor, and the heat insulation collar is sandwiched between the top of the intake manifold and the bottom of the air horn of the carburetor. Since the collar functions as a heat insulating member interposed between the intake manifold and the carburetor, it has a highly precise mating surface and is in airtight contact with the intake manifold and the carburetor, and the heat insulating collar and heater are integrated. Therefore, the overall sea/search performance is extremely high, and thus the stated purpose is achieved here.

Hereinafter, one embodiment of the present invention will be described based on the accompanying drawings.

FIG. 1 and FIG. 2 show an example of the present invention, and (
1) has an air horn (1a) extending vertically in the carburetor. (2) is the air horn (1) at the intake manifold.
A mixture intake passage having an opening slightly wider than the bottom opening in a) is provided.

The carburetor (1) and intake manifold (2) are connected with the former at the top and the latter at the bottom, but there is a gasket at this joint)
(4), A cylindrical heater (3) is inserted and fixed between (4), and the cylindrical part that becomes the heating part is attached to the intake manifold (2).
) is stuck in the air-fuel mixture intake passage.

- The heater (3) has an outer cylinder (5) having a collar (6) and an inner cylinder (7) having a collar (8).
) are arranged concentrically so that they closely face each other, and both the above-mentioned tsuba (6)
, (8) with the insulating plate (9) inserted between them, and the outer cylinder (
A plurality of positive temperature coefficient therminuta elements (hereinafter referred to as P, T, C elements) (10, (10) are interposed between the outer cylinder (5) and the inner cylinder (7). By interposing an insulating seal made of, for example, fluororubber, between the edges of the air-fuel mixture discharge side of 7), P and T are kept in the airtight space.
, C element (10, constitutes an outer cylinder or polygonal cylinder heater containing QO, but both the above-mentioned tsuba (6), (
8) and an insulating plate (9), and is integrally provided with a heat insulating flange θ.

Therefore, both the tsuba (6) +' (8) and the insulating plate (9) are embedded in the molding phase forming the heat insulating tsuba (1υ).

Although the gap is not shown, it communicates with the outside air through the electrode terminal extraction part, and prevents the withstand voltage from deteriorating when the P, T, and C elements are used in an airtight container.

mosquito! As shown in Fig. 1, the heater (3) has a structure in which it is formed into a cylindrical shape integrally equipped with a heat insulating flange 01) by molding means using two mating molds Q31 and Q4). It is formed in the heater (3).

That is, as described above, the outer cylinder (5); the inner cylinder (7), the insulating plate (9), the P, T, and C elements QO, 0[), and the absolute
(Make n (':I) and combine it (13
, α, and then the mold ag, (1
4) Injection molding is performed by injecting a stock solution of heat insulating synthetic resin into the resin heat insulating material 0]) inside the tsuba (6).
(8) A heater (3) having an integral structure in which an insulating plate (9) is embedded can be easily obtained.

Although not shown, the glue wires for energizing the P, T, and C elements (10, (11) are drawn out from the periphery of the nuclear material 01 by airtightly crossing the layer of the heat insulating collar (1). It is convenient to leave it there.

Thus, the cylindrical heater (3) is inserted into the joint between the carburetor (1) and the intake manifold (2), and the heat insulating collar (1) is inserted into the cylindrical heater (3). Intake manifold F (
2) and the bottom of the air horn (1a) of the carburetor (1) with the gaskets L-(4), (4) and (4) being sandwiched between the top of the gasket and the bottom of the air horn (1a) of the vaporizer (1).
This allows it to be stably fixed in a predetermined position.

During this installation, the insulation and heat flange 01), which is integrally constructed with the cylindrical body part, corresponds to the heat insulation part of the conventional installation equipment, so assembly is easy and the installation is easy. 1. By increasing the dimensional accuracy of the mold used during molding, it is possible to finish the flatness of the mating surface of the heat insulating flange (11) with high accuracy, so the assembly accuracy is 2 degrees when taking it out. is high, and airtightness is sufficiently maintained.

In addition, by using a gasket having an elastic material such as silicone rubber or fluorine rubber on the insulating plate (9) inserted between both the flanges (6) and (8), a heat insulating flanges (1'O) can be formed. This elastic gasket (9) is compressed by the molding pressure at the time of molding, and as a result, the sealing performance between the outer cylinder (5) and the inner cylinder (7) is further improved, which is a preferable configuration.

In addition, when a thin insulating sheet is used as the insulating plate (9), the insulating collar (11) serving as the insulating member can be made thinner, which has the advantage of downsizing the heating device and improving the ease of assembly. .

Therefore, the heater (3) in the illustrated example is manufactured by bending the end edge '1i-1 of the air-fuel mixture discharge side of the inner cylinder (7) inwardly to provide a lip of 0. The inner diameter of the air-fuel mixture discharge 1'' is made slightly smaller than the inner diameter of the cylinder (7).

By providing the lip a in this way, (a) the flange (8) of the inner cylinder (7) has some cases in which the gasoline (fuel)) 1 hits the root surface; 4) is subject to severe deterioration due to heat and contact with gasoline, so the tsuba no tsuke has a structure in which the gasoline is applied to the surface of the root, and the lip (formerly) is provided to allow gasoline to contact the lip to vaporize the gasoline. It is preferable to promote this process in order to reduce deterioration. (b) Gasoline leaked from the idle hoard travels along the inner surface of the air horn (1a) and flows into the inner cylinder (1a).
7), it reaches the lip U through the inner wall surface of Additional advantages include good vaporization.

As described above, according to the present invention, this function corresponds to the heat insulating section that was conventionally provided separately to be interposed between the carburetor (1) and the intake manifold (2) and brought into close contact with the cylindrical heater. Since the material is integrated into the heater (3) as a heat insulating collar (1), it is easy to assemble the heater (3) at a predetermined location with a simple operation, and it is difficult to achieve flatness. Problems such as deterioration of sealing performance due to liquid fuel accumulation, damage to insulation due to accumulation of liquid fuel, and deterioration of gaskets can be solved here. In addition, the reduced number of parts improves ease of assembly and makes it more convenient to carry.

Furthermore, even if an abnormality occurs in which the internal combustion engine stops operating when the heater (3) is energized, there is good thermal contact between the cylinder body as a heating part and the heat insulating collar (11).
) is suppressed to a low level, and on the other hand, during normal operation, it is kept at a hair temperature compared to conventional heaters, so it is possible to meet the temperature resistance and silent temperature conditions of the heater parts, or to extend the heat resistance life. This improves the reliability of the heater.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional structural diagram of an example of the heating device of the present invention, FIG. 2 is a structural diagram of an internal combustion engine intake system according to an embodiment of the present invention, and FIGS. 3 and 4 are conventional internal combustion engine intake system diagrams. Figure 2 is a structural diagram of each side of the system. (1)... Carburetor, (2)... Intake manifold,
(3)...Heater, (5)...Outer cylinder, (6)...
Tsuba, (7)...Inner tube, (8)...Tsuba, (9)・
...Insulating plate, (l[)...Positive temperature coefficient thermistor element, (]1)...Insulating flange, Patent applicant: Nihon Insulator Co., Ltd. (1 person) Figure 1 Figure 2 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. An outer cylinder (5) having a flange (6) and an inner cylinder (7) having a flange (8) are concentrically arranged so that both the flange (6) and (8) are closely opposed to each other. the outer cylinder (5) and the inner cylinder (7).
A positive temperature coefficient thermistor element ◇Q. 00 is interposed to form a heater (3), and both the above-mentioned brim (6)
, (8) and by embedding the insulating plate (9) in a heat insulating molded material by insert molding means,
A heat insulating collar 01 that is inserted into the joint between the intake manifold (2) and the carburetor (1) and clamped between the top of the intake manifold (2) and the bottom of the air horn of the carburetor (1).
) A heating device for an internal combustion engine, characterized by being integrally equipped with. 2. The insulating plate (
The heating device for an internal combustion engine according to claim 1, wherein 9) is an elastic gasket. 3. The insulating plate (
9) A heating device for an internal combustion engine according to claim 1, wherein the heating device is a thin insulating sheet. 4 The inner cylinder (7) has a lip on the edge of the mixture discharge side.
A heating device for an internal combustion engine according to claim 1, comprising: