JPH06101587A - Intake manifold for internal combustion engine - Google Patents

Abstract

PURPOSE:To reduce the amount of heat transfer from a high-temperature component such as an EGR valve to a manifold main body made of synthetic resin. CONSTITUTION:Attachment 5 for mounting an EGR valve 6 on a manifold main body made of synthetic resin is provided with a wavy, thin-walled attachment housing 11, and the intake-passage side wavy end portion (valley portion) of the housing is projected into an intake passage and thereby a flow of intake is created around the wavy form and heat transfer from the attachment housing 11 to intake gas is accelerated and heat that the attachment housing 11 conducts is absorbed so that the manifold main body made of synthetic resin is thermally protected.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intake manifold of an internal combustion engine, and more particularly to a structure for mounting high temperature parts such as an exhaust gas recirculation valve (EGR valve) on a synthetic resin manifold body.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 2-146251 discloses an intake manifold for an internal combustion engine in which high temperature parts such as a valve for an exhaust gas recirculation device are attached to a synthetic resin manifold body through a heat resistant adapter. ing. Where,
Cooling fins that also function as reinforcing ribs are formed on the back surface of the heat resistant adapter to prevent a large amount of heat from the high temperature components from being transferred to the resin intake manifold body.

[0003]

However, in the conventional structure described above, the cooling fin is cooled by the intake air in the method of removing the conduction heat from the EGR valve heated by the recirculation of the exhaust gas having a high temperature of 300 ° C. or more. Since it depends only on the effect, the cooling rate is slow, and it was difficult to follow a large amount of EGR (returning exhaust gas by 20-30%).

An object of the present invention is to provide an intake manifold for an internal combustion engine which can sufficiently reduce heat conduction from a high temperature component to a synthetic resin intake manifold body even during a large amount of EGR.

[0005]

According to the present invention, a high temperature component such as a valve for an exhaust gas recirculation device is provided in a synthetic resin manifold body having an intake passage formed therein through a heat resistant attachment. It is achieved by an intake manifold of an internal combustion engine in which a part of the attachment is composed of a corrugated mounting housing, and a corrugated intake passage side end portion of the mounting housing is projected into the intake passage.

[0006]

In the intake manifold for an internal combustion engine according to the present invention, the heat of the high temperature component is transmitted to the synthetic resin manifold main body through the attachment housing of the attachment. However, since the mounting housing is formed in a corrugated shape, and the end portion (valley) on the side of the intake passage of the corrugation projects into the intake passage, it is exposed to the low-temperature intake gas flow, and heat is attached to the mounting housing. The heat transferred between the intake passage side end portion and the intake gas flow is removed by the intake gas, and the heat transferred to the synthetic resin manifold body by heat conduction is greatly reduced. Therefore, there is no problem in heat resistance even if the manifold body is made of synthetic resin.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of an intake manifold for an internal combustion engine according to the present invention will be described below with reference to the drawings. As shown in FIG. 1, an intake manifold for an internal combustion engine according to an embodiment of the present invention is a high temperature component such as a synthetic resin manifold body M and an exhaust gas recirculation device valve (EGR valve) 6 attached to the manifold body M. (Hereinafter, the case where the high temperature component is the EGR valve 6 will be taken as an example) and the heat resistant attachment 5 for mounting the EGR valve on the manifold body.
(Hereinafter, simply referred to as an attachment).

The manifold body M comprises a port portion 1 having the same number of ports as the number of cylinders, a surge tank portion 2 where these ports are gathered, and a mounting flange portion 3 for mounting on the cylinder head. The EGR valve 6 is attached to the surge tank portion 2 via the attachment 5.

FIG. 2 is an enlarged view of the attachment 5 and its peripheral portion. The attachment 5 includes a mounting seat portion 9 for mounting the EGR valve 6, a guide pipe 10 for introducing high temperature exhaust gas into the surge tank portion 2, and a mounting housing 11 for connecting the EGR valve side end and the manifold main body side end. , A packing 8 between the mounting seat portion and the EGR valve, and a seal member 13 between the mounting housing and the manifold body.

By cooling the heat from the EGR valve 6 which becomes high temperature by the reflux exhaust gas 14 which becomes 300 ° C. or more, the temperature of the attachment mounting portions 7a, 7b of the manifold body is kept at 120 ° C. or less which is the heat resistant temperature of the resin. In order to achieve this, the attachment 5 is configured as follows.

First, the guide tube 10 is formed separately from the mounting housing 11, and is extended and opened to the vicinity of the center of the intake passage in the surge tank portion 2. As a result, the recirculated exhaust gas 1
4 can be efficiently mixed with low-temperature intake gas, and as a result, the exhaust gas temperature in the surge tank section 2 becomes sufficiently low.

The guide tube 10 is disposed inside the mounting housing 11 and projects into the surge tank portion 2 more than the mounting housing 11. This prevents the recirculated exhaust gas 14 flowing in the guide tube 10 from directly contacting the mounting housing 11 at high temperature. That is, there is no direct heat transfer from the recirculated exhaust gas 14 to the mounting housing 11.

The mounting housing 11 is thin (0.1-3
It is made of a stainless material of about (mm) and is formed in a wave shape. This waveform undulates up and down in a direction perpendicular to the direction in which the wall surface of the surge tank portion 2 extends (that is, the intake air flow direction), and is defined as one or more waveforms (two waves in the example of FIG. 2). There is.

When the waveform has a plurality of waves, the amount of protrusion into the intake passage is set to be gradually smaller as the end (valley) of the waveform on the intake passage side is farther from the guide pipe 10. For example,
In the example of FIG. 2, there are two waves, and when the projecting amount l from the inner wall surface of the surge tank of the guide tube 10 is used as a reference, the projecting length l _A of the wave end A near the guide tube 10 is 2/3 l. In addition, the protruding length l _B of the wave end B far from the guide tube 10 is 1/3 l
Is set to.

By changing the protruding amount of the waves as described above, the flow of the intake gas is made to hit the end portions on the intake passage side of all the waves, and around the waveform of the mounting housing 11, from the intake flow 12a. Flow 12b, 12c, 12d
And 12b ', 12c', 12d 'are formed. The heat transfer from the surface to the fluid when there is a flow is dramatically improved compared to the natural convection heat transfer, so that the heat transfer from the mounting housing 11 to the low temperature intake gas is large, and the heat transfer through the mounting housing 11 is conducted. As a result, most of the heat flowing from the EGR valve 6 side to the manifold main body side is taken away by the intake gas by heat transfer. The corrugation naturally increases the cooling effect by increasing the heat radiation surface area, but the cooling effect by forcibly forming the flow around the mounting housing 11 as described above is also significantly recognized.

The amount of protrusion l of the guide tube 10 is larger than the amount of protrusion of the mounting housing 11. This is because the guide tube 10 is behind the mounting housing 11 and the recirculated exhaust gas 14 emitted from the guide tube 10 is in the mounting housing 1.
This is to prevent the formation of heat spots by staying in the shade of 1.

Next, the operation will be described. The exhaust gas temperature at the EGR valve 6 is usually about 320 ° C. Therefore, the EGR valve 6 cannot be directly attached to the surge tank portion 2 of the synthetic resin manifold body. The recirculation exhaust gas 14 is guided by the guide pipe 10 and is discharged to the vicinity of the center of the intake passage in the surge tank portion without coming into contact with the mounting housing 11, and is mixed with the intake gas to have a low temperature.

Although the EGR valve 6 reaches a temperature close to the temperature of the exhaust gas flowing inside, heat is transmitted from the EGR valve 6 to the surge tank portion 2 made of synthetic resin only by heat conduction through the mounting housing 11. be able to.

However, since the mounting housing 11 is corrugated and protrudes into the intake passage, an intake flow is formed around the mounting housing 11, and heat transfer from the mounting housing 11 to the low temperature intake gas is performed. Be promoted.
This means that the heat transferred from the EGR valve 6 to the surge tank portion 2 in the mounting housing 11 by heat conduction is removed by the intake gas. Therefore, the temperature of the mounting housing 11 is sufficiently lowered at the end of the mounting housing 11 on the side where the surge tank 2 is mounted.

Reflux exhaust gas temperature 325 ° C. (guide pipe temperature 242
In case of (° C), the mounting housing 1 having two waves as shown in FIG.
When I measured the temperature at 1
C., 146.degree. C. in the B part, and 103.degree. C. at the end of the mounting housing 11 on the side where the surge tank part 2 is attached, and the target of the heat resistant temperature of the resin of 120.degree. C. or less was sufficiently achieved.

Conventionally, the intake manifold is made of aluminum casting in order to cope with a large amount of EGR, but since the temperature could be lowered to around 100 ° C. as described above, the intake manifold main body was Can be made into resin. In the case of using a synthetic resin intake manifold, weight reduction of about 50%, cost reduction of 10 to 20%, and improvement of engine performance of about 2 to 3% can be obtained as compared with those made of aluminum.

Further, in order to cope with a large amount of EGR with the conventional resin intake manifold, it is necessary to use a special high heat resistant resin, the mold temperature in the manufacturing process becomes high, and the energy cost becomes high. However, in the present invention in which the temperature can be lowered to around 100 ° C., the resin material does not need to have high heat resistance as compared with the conventional one, so that the degree of freedom in selecting the resin material is improved and the cost can be reduced.

Further, the EGR valve 6 is also provided with a conventional EGR valve.
The valve can be used as it is, which is advantageous for sharing parts with other engines. Therefore, the number of parts and cost can be reduced. Also, it is not necessary to provide the EGR system with a special device for cooling the EGR exhaust gas, for example an EGR cooler.

[0024]

According to the present invention, since the mounting housing has a wavy shape and the end portion of the corrugated intake passage side (the valley portion of the corrugated portion) is projected into the intake passage, the intake flow can be formed around the protruding portion. , The heat conducted in the mounting housing can be taken away by the heat transfer between the mounting housing and the intake gas, and the temperature of the mounting housing at the mounting part of the synthetic resin to the manifold body is below the heat resistant temperature of the resin. Can be lowered to

[Brief description of drawings]

FIG. 1 is an overall perspective view of an intake manifold of an internal combustion engine according to an embodiment of the present invention.

FIG. 2 is an enlarged cross-sectional view of the attachment and its vicinity in FIG.

[Explanation of symbols]

 2 Surge tank 5 Attachment 6 EGR valve 8 Packing 9 Mounting seat 10 Guide tube 11 Mounting housing 13 Sealing material

Claims (1)

[Claims] 1. An intake manifold for an internal combustion engine in which a high temperature component such as a valve for an exhaust gas recirculation device is attached to a synthetic resin manifold main body that forms an intake passage therein through a heat resistant attachment, and one of the attachments An intake manifold for an internal combustion engine, characterized in that the portion is composed of a corrugated mounting housing, and a corrugated intake passage side end portion of the mounting housing is projected into the intake passage.