JPH0814108A - IAC valve freeze prevention device - Google Patents

Abstract

(57) [Summary] (Correction) [Purpose] The heat of the EGR system is used to keep the idle air control (IAC) valve warm. [Structure] The IAC valve 1 and the EGR valve 6 are provided close to each other and provided integrally with the surge tank 8. The heat of the EGR system can be used as a countermeasure for the icing of the IAC valve 1. Therefore, there is no need to install a structure for keeping the IAC valve warm, and the structure is simple. IAC valve 1
The downstream opening 1b of the IAC passage 1a communicating with the EG,
The downstream opening 6 of the EGR passage 6a communicating with the R valve 6
and b in the surge tank. IAC passage and E
Since the gas ejection directions of the downstream openings 1a and 1b of both the GR passages are arranged so as not to be in the coaxial direction,
EGR gas does not flow back into the IAC passage, and idling is stable.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvement of the installation location of an IAC passage provided in an intake system passage of an automobile engine.

[0002]

2. Description of the Related Art A conventional general intake system passage is shown in FIG. Idle air control valve (hereinafter referred to as IAC
The valve 1) increases the amount of idle air when the engine idles up, functions as an idle up when the engine is cold, and as a dashpot during deceleration. The IAC valve 1 is attached to the throttle body 2 and serves to bypass the throttle valve 3 and introduce air into the surge tank 4. In order to prevent icing, the throttle body 2 usually has piping 5 for circulating hot water.
The throttle body 2 is warmed by this circulating hot water and is transmitted to the IAC valve 1 so that the IA
The icing of the C valve 1 is prevented.

Further, as shown in FIGS. 4 and 5, the IAC valve 1 may be separate from the throttle body 2 for the convenience of the layout of the intake system piping. In this case, however, the surge tank 4 has an IAC. The valve 1 is attached. Also,
Exhaust gas recirculation system (hereinafter referred to as EGR) that reduces nitrogen oxides by taking out a part of exhaust gas from the exhaust system and recirculating it into the intake system passage.
Is called). The EGR becomes hot due to the heat of the exhaust gas passing therethrough. The gas circulated by EGR is IA
Since the backward flow in the C valve 1 impairs the stability of idling, the EGR valve 6 is provided in a place apart from the installation place of the IAC valve 1, for example, in the middle of the intake manifold 7.

[0004]

As described above, in the method in which the IAC valve is arranged separately from the throttle body for the convenience of the intake system layout, the IAC valve for the IAC valve is provided separately from the hot water pipe for the throttle body. Hot water piping is required. Therefore, the number of parts has increased and the structure has become complicated.

The present invention has been made in view of the above problems, and its object is to provide a throttle body and an I
When the AC valve and the AC valve are provided at different positions, the IAC valve is placed at a position where the heat of the EGR system, which becomes high temperature, can be used as a measure to prevent icing of the IAC valve, so that an independent hot water circulation pipe for the IAC valve is provided. Is omitted.

[0006]

Means for Solving the Problems The means for solving the above problems according to the present invention is characterized in that an IAC valve and an EGR valve are provided close to each other and integrally provided with a surge tank.

In the present invention, a downstream opening portion of the IAC passage communicating with the IAC valve and a downstream opening portion of the EGR passage communicating with the EGR valve are bored in the surge tank, and the IAC passage and the EGR passage are formed. It is desirable that the gas ejection directions of the downstream openings of both the passages are opposed to each other so as not to be in the coaxial direction.

[0008]

The icing of the IAC passage is the narrowest part, I
It occurs around the AC valve. Therefore, it is necessary to keep the IAC valve warm. Therefore, in the device of the present invention, the IA
In order to utilize the heat of the EGR system as a measure against icing of the C valve, the IAC valve and the EGR valve are provided close to each other and integrated with the surge tank.

In addition to the provision of the IAC valve and the EGR valve close to each other and integrally provided with the surge tank,
A downstream side opening of the IAC passage communicating with the IAC valve and a downstream side opening of the EGR passage communicating with the EGR valve are bored in the surge tank to extend from the IAC valve and the EGR valve to each downstream opening. The handling is integrated with the surge tank. In addition, in order to prevent the EGR gas from flowing back into the IAC passage,
The downstream side openings of both GR passages are installed so as not to be coaxial with each other in the direction of gas ejection.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to FIGS.

FIG. 1 is a sectional view taken along the line AA of FIG. In the device of the present invention, the IAC valve 1 and the EGR valve 6 are integrally provided in the surge tank 8. At this time, IA
The C valve 1 is provided close to the EGR valve 6 and the EGR passage 6a that connects the EGR valve 6 to the surge tank 8. At this time, in order to transfer the heat of the EGR system to the IAC valve as efficiently as possible, as shown in FIG.
It is desirable that the AC valve 1 and the EGR valve 6 are arranged on the same vertical line and are arranged as close as possible in consideration of the shape of parts and the ease of assembly. By arranging in this way, not only the electrothermal effect due to heat conduction between each member, but also
Radiant heat from the EGR valve 6 to the IAC valve can be fully utilized to efficiently keep the IAC valve warm.

Further, the IAC passage 1a and the EGR passage 6
a is formed integrally with the surge tank 8. Then, the downstream side openings 1b and 6b of both the IAC passage and the EGR passage are provided inside the surge tank 8. At this time, the EGR gas is I
If it flows backwards into the AC passage, the stability of idling will be impaired, so the gas ejection direction in the IAC passage and the EGR passage will be
Set so that it is not in the coaxial direction. Further, when the downstream openings 1a and 1b of both the IAC passage and the EGR passage are installed side by side, the gas blows back and the EGR gas flows back into the IAC passage. By arranging in this way, the heat of the EGR system, which becomes high due to the heat of the exhaust gas, is directly transmitted to the IAC valve, so there is no need to install a structure for keeping the temperature of the IAC valve particularly.

[0013]

As described above, the present invention has the following effects. By providing the IAC valve and the EGR valve in close proximity to each other and integrally providing with the surge tank,
The heat of the EGR system can be used as a countermeasure for icing of the IAC valve. Therefore, there is no need to install a structure for keeping the IAC valve warm, and the structure is simple.
Further, the heat of the EGR system can be effectively used.

Since the IAC valve and the EGR valve are provided close to each other and integrated with the surge tank, the I
A downstream opening of the IAC passage communicating with the AC valve;
Since the downstream opening of the EGR passage communicating with the GR valve is bored in the surge tank, the routing from the IAC valve and the EGR valve to each downstream opening is integrated with the surge tank. Therefore, the layout of the other parts of the engine is not affected because the pipe routing is taken into consideration. Also, IAC passage and E
Since the gas ejection directions of the downstream openings of both the GR passages are opposed to each other so as not to be in the coaxial direction, the EGR gas does not flow backward into the IAC passage and the idling stability of the engine is not impaired.

Further, since it is not necessary to attach the IAC valve to the throttle body, the throttle body can be downsized, and the layout setting around the throttle body becomes free.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an IAC valve freeze prevention device showing an embodiment of the present invention.

FIG. 2 is a front view of an IAC valve antifreezing device showing an embodiment of the present invention.

FIG. 3 is a schematic diagram of an intake system showing a conventional example.

FIG. 4 is a top view of an intake system passage showing a conventional example.

FIG. 5 is a side view of an intake system passage showing a conventional example.

[Explanation of symbols]

 1 IAC valve 1a IAC passage 1b Downstream opening 6 EGR valve 6a EGR passage 6b Downstream opening 8 Surge tank

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Claims (2)

[Claims] 1. An IA characterized in that an IAC valve and an EGR valve are provided close to each other and integrally provided with a surge tank.
C valve freeze prevention device. 2. A downstream side opening of an IAC passage communicating with the IAC valve and a downstream side opening of an EGR passage communicating with the EGR valve are bored in the surge tank.
The IAC valve antifreezing device according to claim 1, wherein the gas ejection directions of the downstream openings of both the AC passage and the EGR passage are oppositely arranged so as not to be in the coaxial direction.