JPS59226262A - Control of suction air heating device for internal- combustion engine - Google Patents

Abstract

PURPOSE:To permit the preheating of a heating cylinder before starting operation and improve the starting property of the engine by a method wherein the plated electrode of one pole of a heating cylinder is divided into a plurality of pieces and a part of the plated parts are conducted from putting ON of an ignition switch to the accomplishment of explosion. CONSTITUTION:In a heating body 6 utilized by incorporating into a carburettor below a throttle valve, the heating body 6 is constituted of a heating cylindrical part 7 of PTC element and the flange 8 of a resin material of non-heating property. In this case, the inner peripheral surface of the heating cylindrical part 7 and the upper surface of the flange 8 are formed with the plated electrode 9 forming one pole while the outer peripheral surface of the heating cylindrical part 7 and the lower surface of the flange 8 are formed with the plated electrode 10 forming the other pole. One plated electrode 9 is divided into two plated parts 9A, 9B. A heater circuit I (9A, 10) is put ON only during the warm- up of the engine and the heater circuit II (9B, 10) is controlld so as to be put ON during putting ON of the ignition switch to the accomplishment of explosion.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for controlling an intake air heating device installed at a joint between a carburetor and an intake manifold in an intake system of an internal combustion engine.

A heating device can be installed at the joint between the carburetor and the intake manifold in order to heat the intake air when starting an internal combustion engine at a low temperature to improve fuel atomization and improve engine drivability. It is being done. Recently, a positive temperature characteristic heating element (hereinafter referred to as a PTC heating element) has come to be used as a heating element in this heating device.

As an intake air heating device using such a PTC heating element,
A PTC element mainly composed of crystalline resin and conductive particles is formed into a cylindrical shape with a flange, and an electrode extraction part is installed in the flange part, and electrode plating is applied to the inner and outer peripheral surfaces of the heating cylinder to form different poles. An intake air heating device has been proposed in which a heated intake air heater is held at the joint between the carburetor and the intake manifold by sandwiching the flange portion between the carburetor and the intake manifold (Japanese Patent Application Laid-Open No. 57-13525
(See Publication No. 3). However, in such conventional intake air heating devices, electrode plating that constitutes different poles is applied to the entire inner and outer circumferential surfaces of the heat generating tube. : Power consumption is relatively large due to the formation of a surface (heater surface). However, especially in internal combustion engines of automobiles, it is necessary to ensure power consumption for various electrical systems with limited power supply, so one of the most important requirements for an intake air heating device is power consumption. This means that there are few. However, it cannot be said that conventional intake air heating devices sufficiently meet this demand.

By the way, the atomization state of the air-fuel mixture in the carburetor depends on the outside temperature,
Alternatively, it naturally differs depending on before and after completion of warm-up. Immediately, when the outside temperature is high or after warm-up is completed, there is less need to heat the intake air than when the outside temperature is low or before warm-up is completed, so the degree of heating of the air-fuel mixture is reduced by such operation. It should be changed depending on the conditions. In addition, when looking at the flow of the air-fuel mixture in the carburetor, the distribution of fuel is not uniform, and naturally the fuel suction boats (slow boat 1, idle boat i)
. Therefore, for the purpose of promoting atomization of the fuel, rather than uniformly heating the entire circumference of the heating cylinder, it is necessary to heat the part of the air-fuel mixture containing a large amount of fuel more intensively than other parts. Conventional intake air heating devices have been unable to meet such demands. That is, in the conventional intake air heating device, there was no concept of partial heating of the heating cylinder.

Therefore, in another application filed on the same day as the present application, the applicant of the present application made it possible to partially heat the heat generating cylinder by dividing the heating surface of the heat generating cylinder into a plurality of parts. We have proposed an intake air heating device that reduces overall power consumption by stopping the power supply to heating surfaces in unnecessary parts.This allows the intake air to be partially heated with less power as needed. This makes it possible to heat the intake air even under operating conditions where heating had previously been forced to be postponed due to power consumption.

That is, conventionally, due to power consumption considerations, intake air heating was performed only from the time when cranking was completed and the engine started self-operation until the engine was warmed up. However, it is desirable to improve starting performance by promoting vaporization of fuel during starting, which is originally the least flammable time. That is, it is desirable to actively vaporize the fuel by heating the intake air during cranking before the engine starts self-driving operation. However, since a relatively large amount of power is consumed during cranking, it has been impossible to heat the intake air during cranking using a conventional intake air heating device that consumes a large amount of power. Furthermore, P.T.
Since the temperature rise of the C heating element is not very high, if you preheat the heating element by partially energizing it before cranking, you can quickly heat the intake air during cranking.
This was not possible with conventional intake air heating devices that consumed a large amount of power.

The purpose of the present invention is to use an intake air heating device that can partially heat the heating surface by dividing it into a plurality of parts, so that the heating cylinder can be partially heated to the minimum size during cranking or before cranking as necessary. The aim is to improve engine starting and ignition performance by heating with power consumption.

In order to achieve the above object, according to the present invention, electrode plating is not applied to the inner and outer circumferential surfaces of the heating cylinder having positive temperature characteristics to form different poles, and one electrode is plated. An intake air heating device for an internal combustion engine, which is divided into a plurality of mutually independent plated parts, and an electrode removal tool can be accessed from each plated part to selectively energize these electrode plated parts. 2, the control method is characterized in that the electrode plated portion of one of the poles is energized continuously from the time when the ignition switch is turned on until the end of cranking, or partially as necessary. .

Actual evidence Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an intake IJlj device for an internal combustion engine according to the present invention incorporating a PTC heating element. In the figure, 1 is a carburetor main body, which is provided on the upper part of an intake manifold 2. A heat insulator 3 as shown in FIG. The structure is such that gaskets 4 and 5 are interposed between the two, and these are joined together with bolts 21. 6 is a PTC heating element formed into a roughly cylindrical shape, and is connected to the carburetor part below the throttle valve 23 and the intake manifold 2.
and is supported within the support groove 25 of the heat insulator 3, and serves to guide the air-fuel mixture from the throttle valve 23 to the intake manifold 2, as well as heat the intake air passing through it. .

The heating element 6 includes a 5H45 cylindrical portion 7 composed of a PTC element mainly composed of crystalline resin and conductive particles;
The flange portion 8 is made of a non-heat generating resin material. Such a PTC element is made by, for example, melting a crystalline resin, adding carbon blank particles therein, dispersing and kneading the resin, then finely pulverizing the kneaded material, and adding glass fiber-containing thermosetting polyester into powder. (・It is possible to make a cylindrical shape by blending 1j fat and putting this mixture into a mold and heat-forming it.The heat-generating cylindrical part 7 formed in this way is
A flange portion 8 made of non-heat generating 4'J grease is pressed onto the outer periphery of the fil.

The heating element 6 is constructed by integrally joining them with an adhesive or the like.

After joining the flange part 8 to the heat generating cylinder part 7, an electrode plating 9 forming one pole is applied to the inner peripheral surface of the heat generating cylinder part 7 and the upper surface of the flange part 8, and also to the outer peripheral surface of the heat generating cylinder part 7 and the flange part. Electrode plating 1o forming the other pole is applied over the lower surfaces of the electrodes 8, respectively. Note that the lower end surface of the heating cylinder 6 is not plated.

According to the present invention, one side of the electrode plating, for example, a plurality of electrode plating portions 9, for example two plating portions 98.

It is divided into 9B. The plated parts 9A and 9B are electrically isolated from each other by an insulating layer (a part of the flange part 8) 13. In the illustrated embodiment, the plated portion 9A is the plated portion 9B.
Although the surface area is much larger than that of , the area ratio is arbitrary. f+';J, the number of division functions is not limited to two, and may be more than two. Minute 7:11 The more functions you increase, the more heat f
l? Partial heating control of i6 becomes possible.

Each plated portion 98 is provided on the overhanging portion 18 of the flange portion 8 .

Electrode extraction fittings 11A, 111 corresponding to 9It, 10
3.12 is embedded. Each metal fitting 11A, 1113.
The tips of 12 are plated with electrodes 9A, 9B, 1, respectively.
0, and a voltage is applied to each electrode plating via these electrode extraction fittings.

As shown in FIG. 1, the heating element 6 configured as described above is inserted into a holder by interposing its flange portion 8 together with the heat insulator 3 at the joint between the carburetor I and the intake manifold 2.
-21 to form an intake air heating device. Incidentally, when the flange portion 8 of the heat generating tube 6 is assembled into the groove 25 of the insulator 3, sealing performance can be improved by applying a filler to the flange portion.

In the intake air heating device constructed as described above, for example, the polarity of the plated portions 9A and 9B is the same (anode or cathode), and the polarity of the plated portion 10 is opposite (cathode or anode).

Preferably, the plated portion 913 is the slow boat 27 of the vaporizer.
, is located below the idle boat 29, and as described above, the plating part 9B12i1Jlyf is made so that the amount of liquid film fuel in the air-fuel mixture is larger than that in other parts. Moreover, by arranging the boat in this manner, most of the fuel sucked out from the slow boat flows near the plated portion 9B even during idling operation. Although not particularly shown, the entire surface of the heating element 6 is coated to prevent fuel from penetrating into the interior of the heating element 6. Ji tu is performed.

According to the present invention, the operation of the intake air heating device configured as described above is controlled as follows (see FIG. 5).

In FIGS. 5 and 6, I indicates a combination of electrode plating 9A and 10 (heater circuit), and II indicates a combination of electrode plating 9B and 10 (heater circuit).

First, to explain the conventional fall control method, as shown in FIG. Cranking starts with the operation of a switch (not shown), and the engine eventually starts self-blade operation (this moment is called a complete explosion), after which the engine cooling water temperature t reaches a predetermined temperature tl (for example, t+=60°). c), ON only until HIJ and warm-up are completed.
It was designed to heat the intake air. In other words, in the past, the heating device could not partially heat the heating device, and therefore the entire device was always turned on and off, consuming a considerable amount of power when turned on. Therefore, intake air heating was limited to only during warm-up. The complete explosion signal turns ON at the same time as the engine starts self-blade operation.
However, this can be detected, for example, by the negative pressure in the intake pipe. Incidentally, although the end of cranking and the complete explosion do not correspond exactly in practice, they are made to coincide for the sake of convenience. Cooling water/l!
! t is F when j<tl, and ON when t≧tl. Further, after a predetermined period of time has passed after the ignition switch is turned on, the cranking is turned on by the starter switch.

According to the first embodiment IEx, 1 of the present invention, the heater circuit I is turned on only during warm-up as in the conventional case, but the heater circuit ■ is turned on continuously until the warm-up is completed at the same time as the ignition switch is turned on. It is turned on. That is, from the time when the ignition switch is turned on until the complete explosion, partial heating of the intake air is performed only by the heater circuit (2). By doing this, it is possible to effectively partially heat only the necessary portion of the pre-explosion intake air (the portion containing a large amount of fuel) with much less power consumption than when the entire intake air heating device is turned on. Incidentally, since the intake air does not flow from the time when the ignition switch is turned on until the start of cranking, this period contributes to the preheating of the heating cylinder itself as described above.

According to the second embodiment Ex, 2 of the present invention, the heater circuit I is
This is the same as in x and 1, but the timing of energizing the heater circuit 11 before complete explosion is limited to only when the ignition switch is turned on and before cranking starts (that is, before the starter switch is activated). This avoids heating the intake air during cranking, taking into consideration the large power consumption during cranking. Therefore, in [ix, 2, the heater circuit (2), apart from heating the intake air during warm-up, contributes most to cranking and preheating the heating cylinder. Immediately, Hx, 2 is E,
Compared to No. 1, the heating cylinder is energized only in a more limited range, thereby reducing power consumption.

On the other hand, in cold regions or when the cooling water temperature is as low as 6 degrees (e.g. below -25 degrees Celsius), the heating voltage will drop considerably, so the heater circuit 1. It is preferable to make Kano F for both II and F.

FIG. 6 shows an example in which the first cranking fails and cranking is repeated 0 times. In this case, since the first cranking consumes a considerable amount of voltage, the power supply to the heater circuit ■ is immediately stopped when the first cranking ends (for example, when the starter switch OF If is activated) (lEx, 3). ). In this case, the complete explosion ON signal and cranking leaf 1? By controlling the signal with, for example, an AND circuit, it is possible to distinguish it from Ex, 1 in FIG. Ex, 4 is an embodiment corresponding to [Ex, 2] when the first cranking fails, and even if cranking is completed, the heater circuit (2) is not energized unless the complete explosion signal is turned ON. IE x, 3r
In li x -4, both heater circuits I are controlled in the same operating mode as before.

In any case, the heater circuit I is activated during warm-up.

■Of course, both are turned on.

As described above, according to the present invention, the electrode plated part of the heating cylinder is divided into two parts (from IM), and by selectively controlling the energization of these parts, it is possible to reduce the heat during cranking. Intake part or local heating and f emission before cranking
: It is possible to preheat the cylinder, thereby achieving optimal intake air heating with less power consumption.

[Brief explanation of the drawing]

FIG. 1 is a vertical sectional view of an intake air heating device used in the present invention incorporating a heating element, f? 2 is a perspective view of the insulator shown in FIG. 1, FIG. 3 is a perspective view of the heating cylinder used in the present invention, FIG. 48, FIG. 4B,
Figure 4C is IVA-IVAIVB-IVB of Figure 3, respectively.
, a sectional view taken along the IVC-IVC line, FIG. 5 is a diagram showing three types of operating modes of the control method of the present invention in comparison with the prior art, and FIG. 6 is a diagram showing a different operating mode from FIG.
Diagram showing. 6... Heating element, 7... Heat generating cylindrical part, 8... Flange part, 98, 9B, 10... Electrode plating, 11
8. 1113.12... Electrode extraction fitting. Figure 1 Figure 2

Claims (1)

[Claims] 1. Electrode plating is applied to the inner and outer circumferential surfaces of a heating cylinder with positive temperature characteristics to form mutually different poles, and the electrode plating of one pole is divided into a plurality of mutually independent plating parts, and each A method for controlling an intake air heating device for an internal combustion engine, in which an electrode removal device is attached to each plated portion to selectively energize the electrode plated portions, the electrode plated portion of one of the electrodes having an ignition A method of controlling an intake air heating device for an internal combustion engine, characterized in that electricity is supplied continuously or partially as necessary from the time when a switch is turned on until the end of cranking.