JPS6047861A - Suction air path heating device for internal-combustion engine - Google Patents

Abstract

PURPOSE:To prevent moisture in air from icing and adhering to a throttle valve or the like by a method wherein a heating body is provided on an insulator interposed between the throttle valve section of suction air path and suction air manifold and the heating body is pushed to the side of the throttle valve by a resilient body. CONSTITUTION:A heat radiating plate 25 is abutted against the lower surface of flange 23 for the throttle valve section 11 of a carburettor and the heating body 27 is attached to the lower surface of the heat radiating plate 25. A mounting hole 33 is provided below the upper inserting hole 29 of the insulator, into which the heating body 27 is inserted, and the resilient body 31, such as a spring or the like and which is energizing the heating body 27 toward upper direction or the side of the flange section 23, is mounted in the mounting hole 33. When the key switch of the internal-combustion engine is put ON, an electrode plate 37 is conducted and the heating body 27 is heated through an electroconductive member 39 and an electrode 43. Heat from the heating body 27 is transferred to the heat radiating plate 25 and is transferred further to the throttle valve section 11 through the flange section 23. According to this method, the moisture in air may be prevented from icing and adhering to the throttle valve 17 or the like.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an air intake passage heating device for an internal combustion engine, and more specifically, to a device for heating an intake passage of an internal combustion engine. The present invention relates to an intake passage heating device for an internal combustion engine for preventing the so-called icing phenomenon.

[Prior Art] The vaporizer 1 shown in FIG. 1 is a vaporizer 11! It is a so-called two-barrel carburetor equipped with two IL3s. The upstream side (upper part of Fig. 1) of this vaporizer 1 is connected to the atmosphere, and the downstream side (the first
The lower part of the figure communicates with the cylinder connected to the internal combustion engine via the intake manifold 5.

A venturi 9 is installed in each carburetor 3 in the fuel sub-volume section 7 of the carburetor 1. A heat insulator tA 13 is provided between the fuel oil supply section 7 and the throttle valve section 11. Each fuel passage 15 serves as a part of the intake passage of this throttle valve portion 11.
A throttle valve 17 is installed inside the throttle valve 17.Furthermore, between the throttle valve part 11 and the intake manifold 5, there is a thermal insulator sandwiched between the upper and lower sides of FIG. 1 by gaskets 1 to 19. A sexual insulation 21 is interposed.

4. Like this. When the internal combustion engine is started and the temperature inside the engine room becomes high in the Hy configuration, the temperature of the intake manifold 5 connected to the engine room also rises. The heat of the intake manifold 5 whose temperature has increased is blocked by the thermally insulating insulator 21 and the heat insulating member 13, and not much of it is transmitted to the throttle valve section 11 and the fuel fitting section 7.

Therefore, since the vaporizer 1 is unlikely to reach a high temperature, percolation, vapor lock, etc. do not occur.

Furthermore, as shown in Japanese Patent Application Laid-open No. ++B 56-110550, a heating element is annularly protruded from a thermally insulating insulator into the fuel passage, and the fuel in the air-fuel mixture flowing down the inner wall of the vaporizer cylinder is heated by the heating element. Some fuels are heated by the body and vaporize the fuel in the mixture.

In this case as well, the heat transmitted from the engine room to the intake manifold due to the action of the insulator is not transmitted to the throttle valve section and the fuel gauge section 8, that is, the carburetor, as in the case of Fig. 1, so the percolation damage described above is No barotsuk etc. will occur.

1 and 110550 of 1983 explained above have the primary purpose of preventing percolation, etc., and are intended to prevent the throttle valve part and the fuel metering part even when the operating temperature conditions of the internal combustion engine change. It has a structure that makes it difficult for heat to be transferred to.

For this reason, immediately after the throttle valve, the intake air temperature decreases due to the adiabatic expansion of the air and the vaporization of combustion, which lowers the temperature at the throttle valve. When an internal combustion engine is started, moisture in the air freezes on the throttle valve or vent of the carburetor, causing what is known as icing.

However, if the heat on the intake manifold side is transferred to the carburetor side, there is a problem that the above-mentioned percolation and vapor lock occur.

[Purpose of the Invention] This invention was devised in view of the above-mentioned problems, and it prevents percolation and vapor lock, and also prevents the throttle valve of the vaporizer or the bench h The purpose is to prevent moisture in the air from turning into ice and adhering to the icing. Intake passage heating H'? i.

"(Structure) of the Invention" In order to achieve this object, the present invention provides a heat insulating insulator interposed between a throttle valve part and an intake manifold in an intake path of an internal combustion engine. A heating element is provided whose surface is a heat radiation surface, and a bullet is provided between the lower surface of the heating element and the upper surface of the insulator to press the heating element upward.

[Example] Hereinafter, an example of the present invention will be described in detail based on FIGS. 2 to 10. Note that the same parts as those in FIG. 1, which is a conventional example, are designated by the same reference numerals to simplify the explanation.

FIG. 2 is a sectional view substantially similar to FIG. 1 in which the intake manifold 5 is connected to the carburetor 1, and the structure of section A of the insulator 21 in FIG. 2 is shown in FIG. 3
This will be explained using figures.

A heat sink 25 is in contact with the lower surface of the flange portion 23 of the throttle valve portion 11, and a heat generating element 27, which is a semiconductor heat generating member (PTC heater) having a positive temperature coefficient, is mounted on the lower surface of the heat sink 25.
is installed. Here, it is assumed that the temperature point of this semiconductor heating member is around 100°C. That is, when the temperature exceeds this point, the electrical resistance of the heating element 27 becomes extremely large.

From the insertion hole 29 vertically bored in the insulator 21 into which the heating element 27 is inserted, proceed further downward to a mounting hole 33 for a spring bullet 31, which will be described later.
is drilled. In this mounting hole 33, the heating element 27 is placed upwardly, that is, the flange portion 2 of the throttle valve portion 11
A bullet 31 like a spring is loaded on the 3 side.

Further, a communication hole 35 is bored in the insulator 21 for communicating the bottom of the mounting hole 33 with the atmosphere and supplying oxygen to the heating element 27.

From the vicinity of both ends of the heating element 27 in FIG. 5, which is a sectional view taken along line V-■ in FIG.
As shown in FIG. 4, which is a V-IV sectional view, a pair of electrode plates 37 with a cross-sectional shape shown in FIG.
1 and is integrally molded with the insulator 21. The guide groove 41 of the conductive part vJ39, which will be described later, is connected to the insulator 21 at the end of the cross-sectional shape of the electrode plate 37 (from near J to the two insertion holes).
It is formed in 'C'.

Electrodes 43 are formed on each side of the heating element 27 in the vertical direction in FIG. 5 by aluminum spraying or the like. Each electrode 7! One end of a conductive member 39, such as a lead wire, is connected to I3, and the other end of each conductive member 39 is connected to the end of the electrode plate 37, which has a cross-sectional shape, through a guide groove 41. . Further, the portion of each electrode plate 37 that protrudes from the insulator 21 to the outside is connected to a battery (not shown).

Next, the operation of this embodiment will be explained.

Turn on the key switch (not shown) to start the internal combustion engine.
Accordingly, a mixture of fuel and air is created in the carburetor 1, and this mixture is guided from the intake manifold 1 (5) to the cylinder via the throttle valve 17. When the key switch of the engine is turned on, electricity is applied from the battery to the electrode plate 37. When the electrode plate 37 is energized, the heating element 27 generates heat via the conductive member 39 and the electrode 43. The heat is transmitted to the heat sink 25, and this heat is further transmitted to the throttle valve part 11 via the flange part 23.

At this time, if the outside temperature is low, around 0°C, the semiconductor 1*''R as the heating element 27 and the heating member have low electrical resistance, so
Current easily flows through the heating element 27, and the amount of heat generated by the heating element 27 becomes large. As described above, the heat generated from the heat generating hole 27 is transmitted to the flange portion 23 of the throttle valve section 11 via the heat sink 25, and this heat is further transmitted to the throttle valve section 11.

Since the throttle valve part 11 is heated in this way, the temperature near the throttle valve 17 does not decrease even though the outside air temperature is low.
The moisture in the air turns into ice ((u-!Jru, so-called icing does not occur.

On the other hand, when the outside air temperature is relatively high, outside air 24. As the temperature of the heating element 27 increases due to H degrees, the electrical resistance of the heating element 27 gradually increases. When the temperature of the heating element 27 exceeds the Curie point, that is, close to 100'Cf; J, the electrical resistance of the heating element 27 becomes extremely large, making it difficult for current to flow. When it becomes difficult for current to flow through the heating element 27, the amount of heat generated by the heating element 27 decreases, and the flange portion 23 is not heated, so the throttle valve portion 11 is not heated either.

In addition, the insulator 21 to which the heating element 27 is attached
has the property of not transmitting heat, so even if the intake manifold 5 is heated by the cold 7J water or exhaust heat after a car equipped with this internal combustion engine is driven at high speed, the flange No heat is transferred to the portion 23.

When the outside air temperature is relatively high as described above, heat is not transferred from the heating element 27 to the flange portion 23, and the temperature of the intake manifold 5 increases after driving at high speed. : Even in case d3, the heat of this intake manifold 5 is not transmitted to the flange portion 23 due to the action of the insulator 210.

Therefore, the temperature of the vaporizer 1 does not rise more than necessary, so percolation, vapor lock, etc. do not occur.

FIG. 6 and FIG. 7 show a second embodiment of this invention.
Electrodes 45 are provided on the upper surface of the heating element 27, that is, between the heating element 27 and the heat sink 25, and on the lower surface of the heating element 27. Then, an electrode plate 4 whose end has a cross-sectional shape
7 is integrally molded within the insulator 21 with this 1-shaped side thereof, and the other end protrudes from the insulator 21 to the outside. The L-shaped light end of this electrode plate 47 is exposed to the communication hole 35, and the electrode plate 47 and the electrode/15 on the lower surface of the heating element 27 are exposed to the communication hole 35.
They are connected by a conductive member 49 such as a lead wire.

Figures 8 to 10 show a third embodiment of the present invention. An electrode 4 is provided on the upper surface '1J of the heating element 27, that is, between the photothermal element 27 and the heat sink 25, and on the -1 side of the heating element 27.
5 are provided for each. This heating element 27
In the space 51 in the insulator 21 below the insulator 21, an electrode (Φ plate 53) with a spring action whose both ends are integrally molded with the insulator 21 is disposed, and the upper surface of this electrode plate 53 is The heating element 27 is urged upward by contacting the electrode 45 on the lower surface of the heating element 27.One end of the electrical ridge board 53 projects outward from the insulation 21, and this projecting portion is connected to a battery not shown.

[Effects of the Invention] As described above, according to the present invention, at least the upstream surface of the thermally insulating insulator interposed between the throttle valve part and the intake manifold of an internal combustion engine is a heat radiation surface. A heating element is provided, and a bullet is provided between the lower surface of the heating element and the upper surface of the insulator to urge the heating element upward, so that the intake manifold does not close when the outside temperature is relatively high or after driving at high speed. When heated, the temperature on the vaporizer side does not rise more than necessary, which prevents percolation, vapor lock, etc. In addition, when the temperature is low and humid, the heat generated by the heating element heats the vaporizer side and makes icing. can be prevented.

Note that this invention is not limited to the embodiments described in the previous book. For example, in the embodiments described above, the present invention was applied to an internal combustion engine with a carburetor A, but the invention can also be applied to an internal combustion engine equipped with a fuel injection neck. That is, icing can be prevented by heating the throttle valve section d5 in the internal combustion engine of the fuel injection device 1 f at low temperatures. Also, at high temperatures, the insulator prevents heat from the intake manifold from being transferred to the throttle valve, so the heat is returned to the intake manifold. - It is possible to prevent the oil contained in the big gas from clinging to the throttle valve, increasing its viscosity and becoming so-called gum-like, which may cause failure in opening and closing of the throttle valve. In addition, icing is likely to occur in low temperature and high humidity conditions, and it is thought that it will not occur when the temperature exceeds a certain value, so it is recommended to use an atmospheric temperature detector or even a humidity detector.
When is above a predetermined value, it is desirable to cut off the current supply circuit to the heating element.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a conventional example with a part of the carburetor and intake manifold cut away, FIG. 2 is the same sectional view of the present invention, and FIG.
The figure is an enlarged cross-sectional view of section A in Figure 2, and Figure 4 is +V- in Figure 3.
IV sectional view, FIG. 5 is a V-V sectional view in FIG. 3, FIG. 6 is a sectional view similar to FIG. 8 is a sectional view similar to FIG. 3 in the embodiment of the present invention, FIG. 9 is a sectional view taken along line IX-IX in FIG. 8, and FIG. -X sectional view. <Show the main part of the drawing? J code explanation) 5... Intake manifold 11... Throttle valve part 15... Fuel passage 21... Insulator 27... Heating element 31... Bullet machine patent Applicant Nissan Motor Co., Ltd. No. Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 1-x j-x

Claims (1)

[Claims] Inside a thermally insulating insulator interposed between the intake manifold and the intake manifold in the intake path of the internal combustion engine,
An internal combustion air intake passage heating device characterized by being provided with a heating element whose surface facing at least upstream serves as a heat radiating surface, and having a stepped bullet that presses the heating element toward the throttle valve section.