JP4293323B2 - Exhaust gas cooler structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides an internal combustion engine exhaust gas recirculation 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 the structure of an exhaust gas cooler (hereinafter referred to as an EGR cooler) interposed in the system.
[0002]
[Prior art]
As shown in FIGS. 4 and 5, the conventional EGR cooler is provided with a plurality of heat transfer tubes 4 in parallel in a cylindrical cooler case 1, and an exhaust gas inlet 2 and an outlet 3 are provided at both ends thereof. Connected to the pipe of the exhaust gas recirculation system. 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 upper surface of the other end so that the cooling water W is introduced into the cooler case 1. W flows and exchanges heat with the exhaust gas G inside the heat transfer tube 4 to cool the exhaust gas G of the exhaust gas recirculation system.
[0003]
Then, as shown in FIG. 6, these heat transfer tubes 4 are supported in the cooler case 1 with their both ends fixed to a support plate 8.
In such a configuration, if the heat transfer tube 4 is long, bending occurs, and the stress of the support portion of the support plate 8 increases due to vibration, which may cause a problem.
[0004]
[Problems to be solved by the invention]
The present invention addresses the above-mentioned problems, suppresses vibration of the heat transfer tubes, relieves stress concentration particularly at the heat transfer tube support portions at both ends, and also collects air in the water channel when installed horizontally. It aims at providing the EGR cooler which can prevent.
[0005]
[Means for Solving the Problems]
According to the present invention, a cooler case (1) formed in a cylindrical shape and provided with exhaust gas inlets (2, 3) at both ends thereof, and provided in parallel in the cooler case (1) and exhausted inside. In the structure of an exhaust gas cooler interposed in an exhaust gas recirculation system of an internal combustion engine having a plurality of heat transfer pipes (4) for flowing gas and flowing cooling water to the outside, the interior of the cooler case (1) has 2 A partition plate through which each heat transfer tube (4) passes is provided (19), and cooling water is provided on the lower surface of one end in the longitudinal direction near the exhaust gas outlet (3) in each of the two divided cooler cases (1A, 1B). An inlet (15a, 15b) is provided, an inlet pipe (15) communicating with the cooling water inlet (15a, 15b) is provided, and a cooling water outlet (16a, 16b) is provided on the upper surface at the other end in the longitudinal direction near the exhaust gas inlet (3). ) And cooling water inlets (15a, 15b) The air outlets (17a, 17b) are provided on the upper surface, which is the opposite position of the air outlet, the cooling water outlets (16a, 16b) and the outlet pipes (16) communicating with the air outlets (17a, 17b) are provided. (19) is formed in a net shape through which cooling water can flow.
[0008]
According to the present invention, the heat transfer tubes in the cooler case are connected and supported by the partition plate, and bending and vibration are suppressed. In the cooler case, the flow path of the cooling water is divided into two, and the cooling water flows in parallel from the inlets on the lower surface, respectively flows in the case to cool 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 facing the inlet, and air is prevented from accumulating in the case.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same component as FIGS. 4-6 demonstrated by the said prior art term, and the overlapping description is abbreviate | omitted.
In FIG. 1, a partition plate 9 through which each heat transfer tube 4 is penetrated is provided at approximately the center in a cooler case 1 installed almost horizontally, and the heat transfer tube 4 is supported. The partition plate 9 is formed in a net shape as shown in detail in FIG. 2, the adjacent heat transfer tubes 4 are connected to each other at the closest position a, and cooling water flows through the other portions b. It has a hole shape.
[0010]
The cooling water inlet 5 is provided below one end (right side of FIG. 1) of the cooler case 1, and the cooling water outlet 6 is provided above the other end. An air vent 7 having a small diameter is provided on the upper side of the case 1 facing the inlet 5.
[0011]
Therefore, in the present embodiment, the heat transfer tubes 4 are connected and supported by the partition plate 9 at the center thereof, and bending and vibration are suppressed, so that the stress concentration of the heat transfer tube 4 support portions of the support plates 8 at both ends is reduced. Alleviated. The partition plate 9 is formed in a net shape, has no hindrance to the flow of the cooling water W, and is sufficient in strength to support the heat transfer tube 4 of the EGR cooler having such a configuration. In addition, vibration suppression is achieved with a moderate damping effect.
[0012]
Also, in the 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 decreases, Further, the heat transfer tube 4 is heated to cause a problem. If the cooling water outlet 6 is in the upper part, the air flows out and there is no problem. However, when the partition plate is provided in the case, this serves as a barrier and the counter-exit side of the partition plate is connected to the outlet 6. Does not escape air. In the present embodiment, the partition plate 9 has a net shape, and the air vent 7 is provided on the upper side of the case 1 at the opposite position to the inlet 5 which is a position away from the cooling water outlet 6 to perform air bleeding. The air vent 7 is narrowed to a small diameter, and air is vented by bypass without affecting the main flow for cooling.
[0013]
Next, another embodiment will be described with reference to FIG.
In the figure, a partition plate 19 through which each heat transfer tube 4 is penetrated is provided at substantially the center in the cooler case 1 to support the heat transfer tube 4. Therefore, the cooling water flow path in the cooler case 1 is divided into two as shown by reference numerals 1A and 1B. Each of the bisected cooler cases 1A and 1B is provided with cooling water inlets 15a and 15b on the lower surface at one end in the longitudinal direction near the exhaust gas outlet 3, and an inlet pipe 15 communicating with the inlets 15a and 15b is provided. It is attached. Cooling water outlets 16a and 16b are provided on the upper surface of 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 and 17b are provided on the upper surfaces of the positions facing the inlets 15a and 15b, respectively, and communicate with the outlet pipe 16.
[0014]
In this embodiment, the flow path of the cooling water W is divided into 1A and 1B in the case 1 by the partition plate 19, and the cooling water W branched by the inlet pipe 15 is the inlet 15a on the lower surface of the case 1, respectively. 15b flows in parallel from each other, flows in the case 1 to the left in the drawing, cools the heat transfer tubes 4, exits from the outlets 16a and 16b on the upper surface of the case 1, and merges at the outlet tube 16. Further, air vents 17a and 17b are provided on the upper surface of the case 1 at positions opposed to the inlets 15a and 15b, which are positions away from the outlets 16a and 16b, respectively. Accumulation is prevented.
[0015]
【The invention's effect】
The present invention is configured as described above, and has the following effects.
(1) By providing a net-like partition plate in the cooler case and supporting the heat transfer tubes together, bending and vibration are suppressed, stress concentration at the heat transfer tube support parts at both ends is alleviated, and accidents due to malfunctions are prevented. The
(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 case, and an air vent is provided in each case to improve cooling performance and air venting performance. The heat transfer tube is supported without causing a problem, bending and vibration are suppressed, stress at the heat transfer tube support portions at both ends is relieved, and an accident due to a malfunction 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 the partition plate of the embodiment of FIG.
FIG. 3 is a side view showing another embodiment of the present invention.
FIG. 4 is a side view showing a conventional EGR cooler.
5 is a cross-sectional view taken along the line AA in FIG.
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 plates 9, 19 ... partition plate

Claims (1)

 A cooler case (1) formed in a cylindrical shape and provided with exhaust gas inlets (2, 3) at both ends thereof, and provided in parallel in the cooler case (1) to allow exhaust gas to flow inside and cool outside In the structure of an exhaust gas cooler interposed in an exhaust gas recirculation system of an internal combustion engine having a plurality of heat transfer tubes (4) through which water flows, the inside of the cooler case (1) is divided into two and each heat transfer tube A partition plate through which (4) passes is provided (19), and a cooling water inlet (15a, 15b) is provided on the lower surface of one end in the longitudinal direction near the exhaust gas outlet (3) in each of the two divided cooler cases (1A, 1B). An inlet pipe (15) communicating with the cooling water inlets (15a, 15b) is provided, and a cooling water outlet (16a, 16b) is provided on the upper surface at the other end in the longitudinal direction near the exhaust gas inlet (3). It is the opposite position of the entrance (15a, 15b) Air vents (17a, 17b) are provided on the upper surface, cooling water outlets (16a, 16b) and outlet pipes (16) communicating with the air vents (17a, 17b) are provided, and the partition plate (19) is cooled. An exhaust gas cooler structure characterized by being formed in a net shape through which water can flow.

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