JPH0540294Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a mounting structure for an exhaust gas recirculation valve in an internal combustion engine.

[Prior Art] In order to make the intake manifold of an internal combustion engine cast from an aluminum alloy lighter and to reduce manufacturing costs, for example, as disclosed in Japanese Utility Model Application Publication No. 60-183265, resin is used. Attempts are being made to use molded products. However, it has become common practice to attach the exhaust recirculation valve directly to the intake manifold for layout reasons and to simplify the configuration. There is a risk of thermal deformation or melting damage to the valve mounting part.

[Problems to be Solved by the Invention] In view of the above-mentioned problems, an object of the present invention is to provide an exhaust recirculation valve mounting structure that does not cause thermal deformation of the resin intake manifold.

[Means for solving the problem] In order to achieve the above object, the structure of the present invention includes an annular groove that surrounds the exhaust outlet and through which a cooling medium flows through the overlapped joint of the exhaust recirculation valve with the resin intake manifold. It has been established.

[Function] According to the present invention, an annular groove surrounding the exhaust outlet is provided at the overlapped portion of the exhaust recirculation valve with the mounting wall of the intake manifold, and intake air or cooling water is allowed to flow through this annular groove, thereby improving the operation of the intake manifold. Since the heat load on the mounting wall is reduced, the mounting wall portion of the intake manifold will not be thermally deformed or melted. Furthermore, by providing a heat shield tube projecting into the intake manifold at the exhaust outlet of the exhaust recirculation valve, the mounting wall is protected from exhaust heat from the exhaust outlet.

[Embodiment of the invention] As shown in FIG. 1, the intake manifold is formed by integrally forming an intake pipe 2 extending in the longitudinal direction on one side wall of an elongated collection box 3, and an air cleaner (not shown) is attached to the end of the intake manifold. is connected. A large number of branch pipes 5 extending obliquely downward are integrally formed on the other side wall of the collecting box 3, and a mounting flange 4 at the end thereof is connected to an intake port of a cylinder head (not shown). Such an intake manifold may be integrally formed by a known resin molding method, or may be formed as separate parts and then bonded together with an adhesive.

An exhaust gas recirculation valve 6 is attached to a mounting wall 19 of the collecting box 3 and communicates with this exhaust outlet 17. Specifically, the spacer 14 is sandwiched between the mounting wall 19 and the exhaust gas recirculation valve 6 via a pair of gaskets 7, and is connected to the mounting wall 19 with bolts (not shown). A hole 20 communicating with the exhaust outlet 17 is provided in the spacer 14 . This hole 20 is extended by a heat shield cylinder 10, and this heat shield cylinder 10 penetrates the exhaust gas introduction hole 9 and projects into the inside of the collection box 3. An annular groove 12 is formed on the surface of the spacer 14 facing the mounting wall 19 so as to surround the hole 20.
An inlet pipe 13 for introducing intake air is connected to the
An outlet 8 is provided in the mounting wall 19 that communicates with the annular groove 12 .

As shown in FIG. 2, the spacer 14 is coupled to the mounting wall 19 together with the exhaust recirculation valve 6 by bolts (not shown) inserted through a pair of holes 15. The annular groove 12 is configured to have a groove width as wide as possible in accordance with the shape of the spacer 14. The exhaust gas recirculation valve 6 is constructed integrally with an actuator 16 that opens and closes the valve. Such a configuration is well known and is not directly related to the gist of the present invention, so it will not be described further.

Next, the operation of the mounting structure for the exhaust gas recirculation valve 6 according to the present invention will be explained. When the exhaust recirculation valve 6 is opened,
A portion of the exhaust gas passes through the exhaust outlet 17 of the exhaust gas recirculation valve 6 and the hole 20 of the spacer 14, enters the collection box 3 of the intake manifold, is further mixed with fresh intake air, and is sent to the engine from each branch pipe 5. In the present invention, an annular groove 12 is provided to surround the exhaust outlet 17 of the spacer 14, and fresh intake air is introduced into the annular groove 21 from the air cleaner through the inlet pipe 13, and the mounting wall 1
9 into the inside of the collecting box 3, the heat transferred from the exhaust gas recirculation valve 6 to the mounting wall 19 is absorbed by the intake air flowing through the annular groove 12, and the temperature of the mounting wall 19 decreases. The rise can be suppressed.
Therefore, even if the exhaust gas recirculation valve 6 is directly attached to the resin intake manifold, the mounting wall portion 19 is prevented from being deformed or melted.

Furthermore, since the heat shield tube 10 is integrally formed with the spacer 14, the exhaust air from the exhaust inlet 17 does not directly hit the mounting wall 19, thereby further protecting the mounting wall 19. Since the heat shield tube 10 is projected into the collecting box 3 with a gap between it and the exhaust gas introduction hole 9, heat transfer from the heat shield tube 10 to the mounting wall 19 is alleviated. Further, since the spacer 14 is interposed between the mounting wall 19 and the exhaust gas recirculation valve 6, the exhaust gas recirculation valve 6 having the same specifications as that installed on a conventional aluminum intake manifold can be installed as is.

In the embodiment shown in FIG. 3, the gap between the exhaust gas introduction hole 9 of the mounting wall 19 and the heat shield tube 10 is made sufficiently large, and the cooling intake air introduced into the annular groove 12 flows into the collection box 3 through this gap. It was made to look like it was blowing out. Thereby, the entire circumferential surface of the heat shield cylinder 10 is cooled by the intake air.

In the embodiment shown in FIG. 4, an annular groove 22 is provided directly on the mounting wall of the exhaust gas recirculation valve 6, and intake air is introduced from the inlet pipe 13 into the annular groove 22, and then flows out from the outlet 8 into the inside of the collecting box 3. This is what I did. This requires a change in the specifications of the exhaust recirculation valve 6, but
Since no spacer is required, the number of parts is eliminated.

Note that in the case of a supercharged internal combustion engine, the intake pressure is higher than atmospheric pressure, so the intake air for cooling is
In the embodiments shown in FIGS. 3, 3, and 4, it is assumed that the air flows in the opposite direction to the aforementioned air flow, that is, from the collecting box 3 to the inlet pipe 13. In addition, in a turbocharger that has an intercooler downstream, if the air on the inlet side of the intercooler (air before being cooled) is guided to the inlet pipe 13, the pressure difference between the inlet cooler and the outlet side will cause the annular Exit 8 via groove 12
It can be made to flow through from to the collection box 3.

In the above embodiment, in order to reduce the heat load on the mounting wall, the mounting part of the exhaust recirculation valve, especially the area around the exhaust outlet, is cooled by intake air, but cooling water can be used instead of intake air. .

The embodiment shown in FIG. 5 is similar to that shown in FIG.
is connected. Since the mounting wall 19 is cooled by the cooling water flowing through the annular groove 12, melting damage due to exhaust heat sent from the outlet of the exhaust gas recirculation valve 6 to the collecting box 3 does not occur. The annular groove 22 through which the cooling water flows can also be applied to the annular groove 12 in the embodiment of FIG. 4.

[Effects of the invention] As described above, the present invention is provided with an annular groove surrounding the exhaust outlet and through which the cooling medium is circulated at the overlapping joint portion of the exhaust gas recirculation valve with the resin intake manifold. The mounting wall that receives the exhaust heat introduced into the intake manifold via the valve is cooled by the intake air or cooling water introduced into the annular groove surrounding the exhaust outlet of the exhaust recirculation valve, so the thermal load on the mounting wall is reduced. Heat deformation and melting damage are avoided.

Furthermore, by providing a heat shield tube on the exhaust recirculation valve side that penetrates the exhaust introduction hole in the mounting wall and protrudes into the intake manifold, it is possible to prevent the exhaust from directly hitting the mounting wall, making it easier to install. Walls are protected from exhaust heat.

As described above, according to the mounting structure according to the present invention, even a resin intake manifold can sufficiently withstand thermal load, and the exhaust recirculation valve can be directly attached, so that the layout of the intake/exhaust system in an internal combustion engine becomes orderly.

[Brief explanation of the drawing]

Fig. 1 is a front view with a cutaway view of the main parts of the mounting structure for the exhaust recirculation valve according to the present invention, Fig. 2 is a left side view of the spacer and the exhaust recirculation valve removed from the intake manifold, and Fig. 3 - Figure 5 shows the second part of this invention.
FIG. 7 is a front sectional view of the mounting structure for the exhaust gas recirculation valve according to the third and fourth embodiments. 3... Collection box, 6... Exhaust recirculation valve, 9... Exhaust gas introduction hole, 10... Heat shield tube, 12, 22... Annular groove, 14... Spacer, 19... Mounting wall.

Claims (1)

[Claims for Utility Model Registration] (1) An exhaust recirculation valve characterized in that an annular groove surrounding an exhaust outlet and through which a cooling medium flows is provided at the overlapping joint portion of the exhaust recirculation valve with a resin intake manifold. mounting structure. (2) The exhaust recirculation valve mounting structure according to claim (1), which is provided with a heat shield tube that protrudes from the exhaust outlet into the interior of the resin intake manifold. (3) The mounting structure for the exhaust gas recirculation valve according to claim (1), which is a utility model registration, and is provided with an inlet for introducing intake air into the annular groove and an outlet communicating with the inside of the intake manifold. (4) The exhaust recirculation valve mounting structure according to claim (1), wherein the annular groove and the heat shield cylinder are formed in a spacer separate from the exhaust recirculation valve.