JPH06257523A - Intake air heating device of engine - Google Patents

Abstract

PURPOSE:To obtain an intake air heating device of an engine which simplifies the construction of an intake air heating body, reduces production cost, maintains accuracy, and gives excellent responsiveness to heating. CONSTITUTION:A heating body 1 made by inserting a PTC heating body 3 of slender plate between the divided surfaces of a radiation tube 2 is provided, the heating body 1 is installed at the inlet of an air intake hole of an engine, and intake air passes through the inside of the heating body 1 is heated by passing electricity at lower ambient temperatures. Then the heating body 1 is installed on an insulator 6 between the air intake hole 4 and a carburetor 5 of the engine, and electrode terminals to pass electricity to the heating body 1 are installed on the insulator 6.

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 for an engine, which heats intake air of the engine when the engine is cold started.

[0002]

2. Description of the Related Art When a reciprocating engine is started at a low temperature, the vaporization of gasoline or the like is poor, so a rich fuel is supplied until the engine starts and warms up. It is designed to be easy to start. Further, while the fuel is rich, the vaporization property is poor, so combustion becomes unstable, and many harmful components such as hydrocarbons and carbon monoxide contained in the exhaust gas.

In order to solve such a problem, a PTC having a tubular shape or the like is provided inside according to the size of the intake pipe of the engine.
Attach a heating element, heat the intake air by energizing it from the battery, and start it with intake air with an appropriate air-fuel ratio,
The amount of harmful components in the exhaust gas is also reduced.
See, for example, Japanese Utility Model Publication No. 59-18133.

[0004]

[Problems to be Solved by the Invention] PTC for heating intake air
The heating element (positive temperature coefficient thermistor element) is made of ceramics. It is troublesome to form ribs inside the tubular shape so that it can easily hit the intake air, and since it is fired, the finished dimensions are highly accurate. It is difficult to keep, and it is inconvenient and expensive to manufacture.

In view of the above points, it is an object of the present invention to provide an intake air heating device for an engine, which can simplify the structure of the intake air heating body, reduce the manufacturing cost, maintain accuracy, and have good heating response. .

[0006]

In order to achieve the above object, an intake air heating apparatus for an engine according to the present invention is provided with a heating body in which an elongated plate-shaped PTC heating element is sandwiched between divided surfaces of a heat radiating cylinder. , Attach the heating element to the inlet of the intake hole of the engine,
It is to heat by energizing at low temperature. The heating element is attached to the insulator sandwiched between the intake hole of the engine and the carburetor, and the insulator is provided with electrode terminals for energizing the heating element.

[0007]

The heat radiating cylinder is divided into a plurality of pieces in the circumferential direction, and the PTC heating element is sandwiched between the divided surfaces. The PTC heating element can be formed into a simple elongated plate shape, and it is easy to maintain finishing accuracy. Further, since the heating element having the PTC heating element attached to the heat radiation tube is attached to the insulator and inserted into the inlet of the intake hole to be attached, the assembly is easy. And PT
Since the fuel comes into direct contact with the inner surface of the C heating element, the heating effect occurs quickly and the response is significantly improved.

[0008]

Embodiments of the present invention will be described below with reference to FIGS. The heating element 1 has a PT formed in a thin plate shape on a divided surface of a heat radiating tube 2 having a good heat conductivity which is divided into a plurality of pieces in the circumferential direction.
The C heating element 3 (positive temperature coefficient thermistor element) is sandwiched and fastened. The heating element 1 is attached to the insulator 6 sandwiched between the intake hole 4 and the carburetor 5 and inserted into the inlet of the intake hole 4 for attachment. An electrode terminal 7 for energizing the heating body 1 is inserted in the insulator 6, and the heating body 1
It is possible to energize.

The PTC heating element 3 of the heating element 1 is in the form of a slender plate, and is easy to mold, easy to maintain dimensional accuracy, and inexpensive. Then, it can be assembled by attaching it to the insulator 6 sandwiched between the inlet of the intake hole 4 and the carburetor 5 and inserting it into the inlet of the intake hole 4 for assembly. or,
Since the electrode terminal 7 for energizing the heating element 1 is inserted in the insulator 6, the wiring can be simplified.

At the time of low temperature startup, the heating body 1 is energized for heating until it is warmed up, so that the intake air flowing through the intake hole 4 can be heated. By heating the intake air, the vaporization property of the fuel is improved, starting can be easily performed without using particularly rich fuel, and harmful components in the exhaust gas can be reduced. Further, since the inner surface of the heating element 3 is in direct contact with the intake air, the response is good and the intake air can be heated early.

[0011]

As described above, since the present invention is configured as described above, the shape of the heating element 3 of the heating element 1 can be simplified, the manufacturing cost can be reduced, and the manufacturing accuracy can be improved. You can Then, since it may be attached to the insulator 6 sandwiched between the intake hole 4 and the carburetor 5 and inserted into the inlet of the intake hole 4, the assembling work is simplified. In this way, the intake air can be heated at the time of low temperature start, the start can be facilitated, and the harmful components in the exhaust gas at the time of start can be reduced. Moreover, since the inner surface of the heating element 3 directly contacts the intake air,
It has good responsiveness and can be heated quickly.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1 showing an embodiment of the present invention.

FIG. 3 is a vertical cross-sectional view in which a heating body is attached to an insulator showing an embodiment of the present invention.

FIG. 4 is a plan view of a heating body showing an embodiment of the present invention.

FIG. 5 is an exploded perspective view of a heating body showing an embodiment of the present invention.

[Explanation of symbols]

 1 Heating Body 2 Radiator Cylinder 3 Heating Element 4 Intake Hole 5 Vaporizer 6 Insulator 7 Electrode Terminal

Claims (2)

[Claims] 1. A slender plate-shaped PT between the divided surfaces of the heat dissipation tube.
A heating element in which a heating element is sandwiched is provided, and the heating element is attached to the inlet of the intake hole of the engine so that the intake air flows inside the heating element and is energized and heated at a low temperature. The engine intake air heating device. 2. The engine according to claim 1, wherein a heater is attached to the insulator sandwiched between the intake hole of the engine and the carburetor, and electrode terminals for energizing the heater are provided to the insulator. Intake heating device.