JP2000274990A - Structure of exhaust gas cooler - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an EGR cooler that suppresses the vibration of a heat transfer pipe for especially relieving the stress concentration of the heat transfer pipe support part at both ends, and at the same time can prevent air from being stored in a water channel when being installed horizontally. SOLUTION: Inside a cooler case 1, a partition board 9 that divides the inside into two parts and allows each heat transfer pipe 4 to pass is provided, and the partition board 9 is formed in a net shape for circulating cooling water W. Alternatively, the partition board that divides the inside into two parts and allows each heat transfer pipe 4 to pass is provided. In each of the divided cooler case 1, a cooling water inlet is provided on the lower surface of one end of a longitudinal direction, a cooling water outlet is provided on the upper surface of the other, and an air vent port is provided on an upper surface that is at the opposite position of the cooling water inlet of one end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is configured such that a plurality of heat transfer tubes are provided in parallel in a cylindrical cooler case so that exhaust gas flows inside the heat transfer tubes and cooling water flows outside the heat transfer tubes. The present invention relates to a structure of an exhaust gas cooler (hereinafter, referred to as an EGR cooler) provided in an exhaust gas recirculation system of an internal combustion engine.

[0002]

2. Description of the Related Art A conventional EGR cooler is shown in FIGS.
As shown in FIG. 2, a plurality of heat transfer tubes 4 are provided in parallel in a cylindrical cooler case 1 and exhaust gas inlets 2 and outlets 3 are provided at both ends thereof, which are connected to a pipeline of an exhaust gas recirculation system. Have been. A cooling water inlet 5 is provided on the lower surface near the end of the cooler case 1, and an outlet 6 is provided on the other upper surface. Cooling water W is introduced into the cooler case 1, and the cooling water W W flows to exchange heat with the exhaust gas G inside the heat transfer tube 4 to cool the exhaust gas G of the exhaust gas recirculation system.

As shown in FIG. 6, both ends of these heat transfer tubes 4 are fixed to a support plate 8 and are supported in the cooler case 1. In such a configuration,
If the heat transfer tube 4 is long, it may bend, and the vibration may increase the stress of the support portion of the support plate 8 and cause a problem.

[0004]

SUMMARY OF THE INVENTION The present invention addresses the above-mentioned problems and suppresses the vibration of the heat transfer tube to relieve stress concentration particularly at the heat transfer tube support portions at both ends. Another object of the present invention is to provide an EGR cooler that can prevent accumulation of air in a water channel.

[0005]

According to the present invention, a plurality of heat transfer tubes are provided in parallel in a cylindrical cooler case, and exhaust gas flows inside the heat transfer tubes and cooling water flows outside the heat transfer tubes. In the structure of the exhaust gas cooler interposed in the exhaust gas recirculation system of the internal combustion engine configured as described above, a partition plate that divides the inside of the cooler case into two parts and through which each heat transfer tube penetrates is provided. It is formed in a net shape through which cooling water can flow.

According to the present invention, the heat transfer tubes in the cooler case are connected and supported by the partition plate, whereby bending and vibration are suppressed, and stress concentration at the heat transfer tube support portions at both ends is reduced. Further, since the partition plate is formed in a net shape, there is no obstacle to the flow of the cooling water, and the partition plate is sufficiently strong for supporting the heat transfer tube of the EGR cooler having such a configuration. There is an appropriate damping effect to suppress vibration.

Further, according to the present invention, a plurality of heat transfer tubes are provided in parallel in a cylindrical cooler case so that exhaust gas flows inside the heat transfer tubes and cooling water flows outside the heat transfer tubes. In the structure of an exhaust gas cooler interposed in an exhaust gas recirculation system of an internal combustion engine, a partition plate that divides the inside of the cooler case into two parts and through which each heat transfer tube penetrates is provided. A cooling water inlet is provided on the lower surface of one end in the longitudinal direction and a cooling water outlet is provided on the upper surface of the other end,
An air vent is provided on the upper surface, which is a position facing the cooling water inlet.

According to the present invention, the heat transfer tubes in the cooler case are connected to each other and supported by the partition plate, so that bending and vibration are suppressed. The cooling water flow path is 2 in the cooler case.
The divided cooling water flows in parallel from the inlets on the lower surface, flows through the case, cools the heat transfer tubes, and exits from the outlet on the upper surface. In addition, an air vent is provided on the upper surface of the case at a position opposite to the inlet to prevent air from accumulating in the case.

[0009]

Embodiments of the present invention will be described below with reference to the drawings. The same components as those shown in FIGS. 4 to 6 described in the section of the related art are denoted by the same reference numerals, and redundant description will be omitted. In FIG. 1, a partition plate 9 through which the heat transfer tubes 4 pass is provided at a substantially center of the cooler case 1 installed substantially horizontally, and the heat transfer tubes 4 are supported. The partition plate 9 is formed in a net shape as shown in detail in FIG. 2, and the adjacent heat transfer tubes 4 are connected to each other at a close position a, and the other portions b are arranged so that the cooling water flows. It is shaped like a hole.

The cooling water inlet 5 is provided below one end (right side in FIG. 1) of the cooler case 1, and a cooling water outlet 6 is provided above the other end. On the upper side of the case 1 facing the inlet 5, an air vent 7 having a small diameter is provided.

Therefore, in this embodiment, each heat transfer tube 4
Are connected and supported by a partition plate 9 at the center thereof,
Bending and vibration are suppressed, and stress concentration on the heat transfer tube 4 support portions of the support plates 8 at both ends is reduced. And the partition plate 9
Is formed in a net shape, does not hinder the flow of the cooling water W, is sufficiently strong for supporting the heat transfer tube 4 of the EGR cooler having such a configuration, and has an appropriate damping effect. As a result, vibration is suppressed.

In a horizontally installed cooler, if the air contained in the cooling water W accumulates in the upper part of the cooler case 1 and a part of the heat transfer tube 4 is exposed, the cooling efficiency is improved. In addition, the heat transfer tube 4 is heated, causing a problem. If the cooling water outlet 6 is at the upper part, the air flows out and there is no problem. However, if a partition plate is provided in the case, this acts as a barrier, and the counter outlet side of the partition plate is Does not escape air. In the present embodiment, the partition plate 9
Is formed in a net shape, and an air vent 7 is provided on the upper side of the case 1 at a position facing the inlet 5 at a position distant from the cooling water outlet 6 to perform air bleeding. The air vent 7 is narrowed to a small diameter, and the air is vented without affecting the main flow for cooling.

Next, another embodiment will be described with reference to FIG. In the figure, a partition plate 19 through which the heat transfer tubes 4 pass is provided at substantially the center of the cooler case 1 and supports the heat transfer tubes 4. Therefore, the cooling water flow path in the cooler case 1 is divided into two as indicated by reference numerals 1A and 1B. Further, cooling water inlets 15a and 15b are provided on the lower surface of one longitudinal end near the exhaust gas outlet 3 in each of the two divided cooler cases 1A and 1B.
An inlet pipe 15 communicating with 15b is attached. Cooling water outlets 16a and 16b are provided on the upper surface at the other end near the exhaust gas inlet 2, and an outlet pipe 16 communicating with the outlets 16a and 16b is attached. Further, small-diameter air vents 17a, 17b are provided on the upper surface at positions opposed to the inlets 15a, 15b, respectively.
Is communicated to.

In this embodiment, the flow path of the cooling water W in the case 1 is divided into two parts 1A and 1B by the partition plate 19, and the cooling water W branched by the inlet pipe 15 The air flows in parallel from certain inlets 15a and 15b, flows inside the case 1 to the left in the drawing, and
Is cooled and exits from the outlets 16a and 16b on the upper surface of the case 1 and merges at the outlet pipe 16. Also, on the upper surface of the case 1, the entrance 1 is located at a position away from the exits 16a and 16b, respectively.
Air vents 17a, 17b are provided at positions opposite to 5a, 15b, so that air is prevented from flowing out of the outlet pipe 16 and accumulating in the case 1.

[0015]

The present invention is configured as described above and has the following effects. (1) By providing a net-shaped partition plate in the cooler case and connecting and supporting the heat transfer tubes to each other, bending and vibration are suppressed, stress concentration at the heat transfer tube support portions at both ends is reduced, and accidents due to malfunctions are prevented. You. (2) In addition, when the inside of the cooler case is divided into two by the partition plate, cooling water is introduced in parallel into the divided two cases, and an air vent is provided in each case to improve the cooling performance and the air releasing performance. The heat transfer tubes are supported without problems,
The bending and the vibration are suppressed, the stress of the heat transfer tube supporting portions at both ends is reduced, and an accident due to a failure is prevented.

[Brief description of the drawings]

FIG. 1 is a side view showing an embodiment of the present invention.

FIG. 2 is a front view showing details of the shape of a partition plate of the embodiment of FIG. 1;

FIG. 3 is a side view showing another embodiment of the present invention.

FIG. 4 is a side view showing a conventional EGR cooler.

FIG. 5 is a sectional view taken along line AA of FIG. 4;

FIG. 6 is a side view showing a support state of a heat transfer tube of a conventional EGR cooler.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cooler case 2, 3 ... Exhaust gas inlet / outlet 4 ... Heat transfer tube 5, 15 ... Cooling water inlet 6, 16 ... Cooling water outlet 7 ... Air vent 8 ... Heat transfer tube support plate 9, 19 ... partition plate

Claims (2)

[Claims] 1. An exhaust gas recirculation system for an internal combustion engine, wherein a plurality of heat transfer tubes are provided in parallel in a cylindrical cooler case so that exhaust gas flows inside the heat transfer tubes and cooling water flows outside the heat transfer tubes. In the structure of the exhaust gas cooler interposed in the circulation system, a partition plate that divides the inside of the cooler case into two and that each heat transfer tube penetrates is provided. The structure of an exhaust gas cooler characterized by being performed. 2. An exhaust gas recirculation system for an internal combustion engine, wherein a plurality of heat transfer tubes are provided in parallel in a cylindrical cooler case so that exhaust gas flows inside the heat transfer tubes and cooling water flows outside the heat transfer tubes. In the structure of the exhaust gas cooler interposed in the circulation system, a partition plate is formed in the cooler case, the inside of which is divided into two, and each heat transfer tube penetrates. A cooling water inlet is provided on the upper surface of the other end of the cooling water inlet, and an air vent is provided on the upper surface opposite to the cooling water inlet.