JP2001248448A - Intake air cooling device of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase an intake air cooling efficiency, increase an engine thermal efficiency by preventing a knocking, and reduce the size and facilitate the assembly of a cooling device. SOLUTION: In an intake air cooling device of an internal combustion engine for cooling intake air by double stages using two cooling cores 5 and 6 for making cooling water therethrough, both cooling cores 5 and 6 are connected integrally with each other and incorporated in an intake air manifold 2. The temperature of the cooling water in the first stage cooling core 5 in the upstream of the intake air is set higher, and that in the second stage cooling core 6 in the downstream of the intake air is set lower. The intake air manifold 2 is desirably formed into a split structure comprising an upstream case 26 and a downstream case 27, the cases 26 and 27 form connection flange parts 35 and 36 respectively, and the mounting parts 40 and 40 of the cooling cores 5 and 6 are held between the connection flange parts 35 and 36 and tightened together. Thus, both cooling cores 5 and 6 are fixed connected to each other as well as the intake air manifold 2 is assembled.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air supply cooling device for an internal combustion engine such as a gas engine, and more particularly, to an air supply cooling device for a gas engine.
The first stage on the upstream side cools the supply air with high-temperature water,
The second stage on the downstream side relates to an air supply cooling device for cooling with low-temperature water.

[0002]

2. Description of the Related Art As a two-stage type air supply cooling device of this kind,
For example, there is JP-A-8-291715, and as shown in FIG. 5, an intercooler 81 is provided in the middle of an air supply pipe 80 as a first-stage cooling mechanism, and the intercooler 81 is provided as a second-stage cooling mechanism. The air supply manifold 83 is provided with a blower air supply cooling cooler 85 at each air supply outlet 84 of the air supply manifold 83 in a separated state. The intercooler 81 has a high temperature (for example, 80 ° to 100 °).
The cooling water of C) is made to circulate, and the cooling water of low temperature (for example, 30 ° C. to 35 ° C.) is made to flow through the blower supply air cooling cooler 85.

[0003]

In the prior art shown in FIG. 5, the cooling efficiency can be improved by performing two-stage cooling at a high temperature and a low temperature, while cooling the blowback gas from the combustion chamber and cooling at a high temperature. The use of water can increase the amount of heat recovery. However, the intercooler 81 for cooling the first stage and the blower supply cooling coolers 85 for performing the second stage cooling are individually arranged at positions separated from each other. Since the coolers 85 are provided separately for each cylinder, the number of parts and the number of assembling steps are increased, and the size of the entire cooling device is increased.

[0004]

It is an object of the present invention to (1) reduce the size of the air supply manifold and the air supply cooling device, (2) improve engine efficiency by preventing knocking, and improve overall efficiency by increasing heat recovery; 3) To facilitate assembly and maintenance of the cooling device.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, two cooling cores, through which cooling water flows, are connected to each other close to each other, and the cooling core in an air supply manifold is connected. A second-stage cooling core downstream of the supply air, which is built in the air supply manifold so as to cool the airflow in two stages and is lower than the temperature of the cooling water flowing through the first-stage cooling core upstream of the air supply. And a cooling water supply device for the internal combustion engine.

According to a second aspect of the present invention, in the air supply cooling device for an internal combustion engine according to the first aspect, the air supply manifold has a two-part structure of an upstream case and a downstream case, and each case has a connecting flange. The cooling air supply manifold is formed by forming a mounting part on each cooling core, holding the mounting parts of both cores between the connecting flange parts of both cases, and fastening the two connecting flange parts. It is characterized in that both cooling cores are connected and fixed at the same time as assembly.

[0007]

FIG. 1 is a schematic diagram of a cooling water system piping of a six-cylinder gas engine to which the present invention is applied. An air supply manifold 2 is attached to an end face of a cylinder head 1 on an air supply port side. The air inlet 8 of the manifold 2 is connected to the turbocharger 7
And an air supply outlet 56 for each cylinder is formed on the end face of the air supply manifold 2 on the cylinder head side. In the air supply manifold 2, a first-stage cooling core 5 on the upstream side of the air supply and a second-stage cooling core 6 on the downstream side integrally connected thereto are incorporated.

This gas engine has two cooling water systems, one of which is a cylinder block 3 and a cylinder head 1.
High-temperature cooling water system for cooling the heat exchanger 10
And a cooling water pump 11, and a cooling water supply pipe 12 connected to a discharge port of the cooling water pump 11 is connected to the cylinder block 3.
Of the heat exchanger 10 is connected to a cooling water outlet 15 of the cylinder head 1 via a return pipe 16. The cooling water temperature of the high-temperature cooling water system is set to be, for example, about 80 ° C. to 100 ° C. at the cooling water inlet 14.

The first-stage cooling core 5 utilizes the cooling water of the high-temperature cooling water system, and the cooling water inlet 20 of the first-stage cooling core 5 is connected through a cooling water supply branch pipe 21. The cooling water supply pipe 12 is connected to the cooling water supply pipe 12, and the cooling water outlet 23 of the first stage cooling core 5 is connected to the cooling water return pipe 16 via a cooling water return branch pipe 24. Therefore, the temperature of the cooling water inlet portion 20 of the first stage cooling core 5 is set to 80 ° C. to 100 ° C., substantially similarly to the cylinder block cooling water inlet 14.
It has become about.

The low-temperature cooling water system is shown by a broken line in the drawing, and is used for supplying cooling water to the second stage cooling core 6, and is provided with a heat exchanger 28 and a cooling water separately from the high-temperature cooling water system. A pump 29 is provided. The cooling water supply pipe 31 connected to the discharge port of the cooling water pump 29 is connected to the cooling water inlet 32 of the second stage cooling core 6, and the second stage cooling core 6
The cooling water outlet 34 is connected to a return port of the heat exchanger 28 via a cooling water return pipe 33. The cooling water temperature of the low-temperature cooling water system is set lower than that of the high-temperature cooling water system.
The temperature is set to about 5 ° C.

FIG. 2 is a detailed sectional view taken along the line II-II of FIG. 1. The air supply manifold 2 has an upper and lower two-part structure, and includes an upper upstream case 26 and a lower downstream case 27.
Outward connecting flange portions 35 and 36 are integrally provided on the lower surface (matching surface) of the upstream case 26 and the upper surface (matching surface) of the downstream case 27, respectively.

[0012] The first and the first built in the air supply manifold 2
The second-stage cooling cores 5 and 6 have the same structure arranged vertically symmetrically. The first-stage cooling core 5 is located in the upstream side case 26 and the second-stage cooling core 6 Are located in the downstream side case 27, and each have an outwardly facing plate-like mounting portion 40,
40 is provided. Seals 40a, 40a are attached to the mating surfaces of the mounting portions 40, 40, respectively. The two mounting portions 40, 40 are joined to each other via a sheet member (spacing) 43 having heat insulation and airtightness, and are sandwiched between upper and lower connection flange portions 35, 36.
It is fastened together with the connection flanges 35 and 36 by the flange connection bolts 46 and nuts 47. That is, the case 2 is formed by the bolt 46 and the nut 47.
6 and 27, and at the same time, both cooling cores 5, 6
Are integrally connected and fixed in the air supply manifold 2.

In FIG. 4, which is a sectional view taken along the line IV-IV in FIG.
The first-stage cooling core 5 and the second-stage cooling core 6 have the same structure as described above, and are arranged in an upside-down orientation. Will be described in detail, and for the second stage cooling core 6, the same portions will be denoted by the same reference symbols, without redundant description. However, the cooling water inlet 20 of the first stage cooling core 5 and the second stage cooling core 6
The cooling water inlets 32 of the first cooling core 5 and the cooling water outlets 34 of the second cooling core 6 are also disposed opposite to each other. It is located on the opposite side.

The upper first stage cooling core 5 is composed of a pair of housing portions 51 arranged at both ends in the longitudinal direction, and a number of cooling water pipes 52 communicating and connecting the two housing portions 51. Each housing portion 51 is formed with inlet and outlet caps 53 and 54, respectively. Each of the bases 53, 54 protrudes to the outside through U-shaped grooves 66, 66 having an open lower end formed in the longitudinal end wall of the upstream case 26, and is provided with an O-ring from the outside for entrance. And outlet joint pipes 67 and 68 are fitted respectively to form the cooling water inlet 20 and the cooling water outlet 23. The joint pipes 67 and 68 integrally have mounting plates 67a and 68a,
The U-shaped grooves 66, 66 are detachably fixed to the end wall of the upstream case 26 by bolts or the like so as to seal the U-shaped grooves 66, 66.

The upper wall 26c of the upstream case 26 is formed so as to be inclined so that one side in the longitudinal direction is higher.
An air supply inlet 8 located above the first stage cooling core 5 is formed in one end wall 26a that is formed higher. In the downstream case 27, an air supply outlet 56 for each of the cylinders is opened at the end face on the cylinder head side. Each air supply outlet 56 is connected to each air supply port 59 of the cylinder head 1 via a connection pipe 57 as shown in FIG.

In FIG. 3, the connection flange 35 of the upstream case 26 is formed so as to surround the entire circumference of the air supply manifold 2. The cooling water inlet 20 and the cooling water outlet 23 are connected to each other. Are arranged at positions shifted from each other in the core width direction. The connecting flange 36 of the downstream case 27 in FIG.
5 and is formed so as to surround the entire circumference of the air supply manifold 2.

[0017]

In FIG. 1, cooling water discharged from a cooling water pump 11 of a high-temperature cooling water system is supplied from a cooling water supply pipe 12 to a cooling water inlet 14 of a cylinder block 3 and partially branched. Through the cooling water supply branch 21
The cooling water is supplied to the cooling water inlet 20 of the stage cooling core 5. The cooling water supplied to the cylinder block 3 cools the cylinder liner and the like through a cooling water jacket and the like, cools the inside of the cylinder head 1, and cools the cooling water through an upper cooling water outlet 15 of the cylinder head 1 as is well known. It is returned to the heat exchanger 10 via the return pipe 16. On the other hand, the cooling water supplied to the first stage cooling core 5 cools the supply air in the air supply manifold 2 as the first stage cooling, and the cooling water return branch pipe 24 extends from the cooling water outlet 23. Through the cooling water return pipe 16 and returned to the heat exchanger 10. At the cooling water inlet 20 of the first stage cooling core 5, the cooling water temperature is, for example, 80
°, the cooling water outlet 23
° C. Further, the temperature of the air supply is reduced from about 160 ° C. to about 100 ° C. by the first stage cooling core 5.

The cooling water discharged from the cooling water pump 29 of the low-temperature cooling water system is supplied from the cooling water supply pipe 31 to the cooling water inlet 32 of the second-stage cooling core 6, and the first-stage cooling water is supplied to the first-stage cooling water inlet 32. Subsequent to the cooling by the cooling core 5, the supply air is further cooled as a second stage, and is returned from the cooling water outlet 34 to the heat exchanger 28 via the cooling water return branch pipe 33. At the cooling water inlet 32 of the second stage cooling core 6, if the cooling water temperature is set to, for example, about 35 °, the cooling water outlet 3
In No. 4, the temperature rises to about 37 ° C. The supply air temperature is
100 ° C to 50 ° C depending on the stage cooling core 6
Can be lowered to the extent.

In FIG. 2, the air supply supplied from the air supply inlet 8 into the upstream case 26 of the air supply manifold 2 passes between the cooling water pipes 52 of the first stage cooling core 5, As described above, the cooling water pipe 5 of the second stage cooling core 6 is cooled from about 160 ° C. to about 100 ° C.
2 to 100 ° C to 50 ° C
Cool to a degree. Then, the air is sequentially supplied from the corresponding air supply outlet 56 to the air supply port 59 in accordance with the ignition order.

[0020]

(1) The air supply cooling device shown in FIG. 1 comprises a cooling water inlet 20 and a cooling water outlet 23 of a first stage cooling core 5 and a second stage cooling core. 6 cooling water inlet 3
Although the cooling water outlets 2 and 34 are arranged in reverse, the cooling water inlets 20 and 32 and the cooling water outlets 23 and 34 may be arranged on the same side.

(2) The structure of the cooling cores 5, 6 adopts a system in which the cooling water enters at one end and escapes to the other end (through system) in FIG. 4 and the like, thereby further reducing the size. For example, it is also possible to adopt a U-shaped pipe as the cooling water pipe 52 and adopt a reciprocating method in which the inlet end and the outlet end are located on the same side.

(3) The present invention can be applied to a diesel engine or a gasoline engine.

[0023]

As described above, according to the present invention, (1) an air supply cooling device for an internal combustion engine that uses two cooling cores 5 and 6 for circulating cooling water to cool air supply in two stages. In this case, the cooling cores 5 and 6 are integrally connected and are built in the air supply manifold 2, so that the cooling air supply device can be downsized and compact while improving cooling efficiency, and assembling and maintenance can be performed. Can be facilitated.

(2) First-stage cooling core 5 on the upstream side of air supply
The cooling water temperature of the second-stage cooling core 6 on the downstream side of the air supply is set low, so that, for example, the high-temperature water of the first-stage cooling core 5 is used as the cylinder block 3. Further, by using the cooling water of the cylinder head 1, the cooling water of the cylinder head 1 and the like can be maintained at a high temperature, the heat recovery amount increases, and the overall efficiency improves. On the other hand, since the cooling water temperature of the second stage cooling core 6 close to the air supply port is lowered, the blow-back gas from the combustion chamber is effectively cooled, knocking is reliably prevented, and the engine efficiency is reduced. Can be improved.

(3) As in the second aspect of the present invention, the air supply manifold 2 is connected to the upstream case 26 and the downstream case 27.
In each of the cases 26 and 27, connecting flanges 35 and 36 are provided, respectively.
Are formed with mounting portions 40, 40, and both connection flange portions 3 are formed.
By attaching the mounting portions 40, 40 of the cooling cores 5, 6 between the cooling cores 5, 36 and fastening the connection flange portions 35, 36, the air supply manifold 2 is assembled and at the same time, the cooling cores 5 are mounted. , 6 are connected and fixed, so that the assembling and maintenance of the cooling device are further facilitated, and the cooling device is also made compact.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a cooling water system piping of a gas engine to which the present invention is applied.

FIG. 2 is an enlarged cross-sectional view taken along the line II-II of FIG.

FIG. 3 is a sectional view taken along the line III-III in FIG. 2;

FIG. 4 is a sectional view taken along line IV-IV of FIG. 2;

FIG. 5 is a sectional view of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Cylinder head 2 Air supply manifold 3 Cylinder block 5 First stage cooling core 6 Second stage cooling core 7 Supercharger 26 Upstream case 27 Downstream case 35, 36 Flange for connection 40 Between mounting parts 43 seat

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02M 35/104 F02M 35/10 311C 35/10 311 102P 102A

Claims (2)

[Claims] 1. A cooling system in which two cooling cores through which cooling water flows are brought close to each other and coupled together, and built in the air supply manifold so as to cool the air supply flow in the air supply manifold in two stages. The temperature of the cooling water flowing to the second cooling core downstream of the air supply is set lower than the temperature of the cooling water flowing to the first cooling core on the side of the internal combustion engine. Supply air cooling device. 2. The air supply cooling device for an internal combustion engine according to claim 1, wherein the air supply manifold is divided into an upstream case and a downstream case, and each case is provided with a connecting flange portion. A mounting part is formed on the core, and the mounting part of both cores is sandwiched between the connecting flange parts of both cases, and the two connecting flange parts are fastened to assemble the air supply manifold and simultaneously cool both An air supply cooling device for an internal combustion engine, wherein a core is fixedly connected.