JP2013130378A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply a brazing material to a fixed portion between each tube and an outer pipe without any trouble, and to allow a fluid to flow through the outer tube without large resistance.SOLUTION: In an outer tube 1, a plurality of tubes 2 are stacked. At both ends of each tube 2, expanded regions 2c are formed. At the expanded region 2c, the tube 2 is fixed to the outer tube 1 in a close contact state by brazing etc. At both ends of the tube 2, an inclined part 2b expanded toward an open end side is formed on the inside of a fixed area α to the outer tube 1. At both ends of the outer tube 1, an inward protruding part 1b to be brought into contact with the inclined part 2b is formed, to position the tube 1 with respect to the outer tube 1.

Description

  The present invention relates to a heat exchanger.

  In a heat exchanger such as an intercooler or an EGR cooler, generally, a plurality of tubes each having a flat inner space are secured in the outer tube having a rectangular cross section so as to secure a clearance gap between them. Arranged in a laminated state, both ends of each tube are fixed in close contact with the outer tube. And, in the intermediate part between the fixed parts at both ends of each tube, for example, by enlarging the outer tube outward, it is possible to secure a large distribution space between each tube and the outer tube. Has been done. Such a heat exchanger is provided between a first fluid (for example, exhaust gas or air just after supercharging) flowing through each tube and a second fluid (for example, cooling water or air) flowing in the above-mentioned circulation gap and distribution space. Thus, heat exchange is performed through each tube.

  When fixing both ends of each tube to the outer tube, brazing is generally performed. When fixing by brazing, it is important that the outer tube and each tube are positioned in the longitudinal direction of each tube (flow direction of the first fluid). In order to position each tube in the longitudinal direction, Patent Document 1 discloses that a plurality of convex portions that are brought into contact with the inner wall portion of the outer tube are provided at an intermediate portion in the longitudinal direction of each tube.

JP 2007-225190 A

  As described in Patent Document 1, providing a convex portion for positioning at the intermediate portion of each tube means that when the second fluid flows between the outer tube and each tube, the convex portion becomes a resistance or stagnation. This is not preferable in terms of efficient heat exchange. From such a viewpoint, for example, positioning by providing an inward flange portion so as to contact the end surface of each tube at the end portion of the outer tube may be considered. However, in this case, when the brazing material is applied to the outer tube at both ends of each tube, the inward flange may interfere with the coating of the brazing material, which is difficult to adopt. It is.

  The present invention has been made in consideration of the circumstances as described above, and its purpose is that there is no hindrance to the application of the brazing material to the fixing portion between each tube and the outer tube, and between the outer tube and each tube. It is an object of the present invention to provide a heat exchanger in which the fluid flowing through the pipe is not subjected to great resistance.

In order to achieve the above object, the following solution is adopted in the present invention. That is, as described in claim 1,
An outer tube having a rectangular cross section and a plurality of tubes each having a flat inner space;
The plurality of tubes are disposed in the outer tube in a stacked state so as to ensure a clearance for circulation between each other,
Both ends of each tube are expanded and fixed in a state of being in close contact with the outer tube at the expanded site,
Between the outer tube and each tube, between both ends of each tube, a circulation space is formed,
A heat exchanger configured to exchange heat through the tube between the first fluid flowing in the tube and the second fluid flowing in the circulation space and the gap for circulation;
In each end portion of each tube, an inclined portion is formed to expand toward the open end side on the inner side of the fixed portion with respect to the outer tube,
Inward protrusions are formed at both ends of the outer tube to abut against the inclined portion and restrict relative displacement of the tubes relative to the outer tube in the longitudinal direction.
It is like that.

  According to the above-described solution technique, each tube is positioned with respect to the outer tube by the inclined portions formed at both ends of each tube and the inward projections formed on the outer tube, that is, the flow of the second fluid is obstructed. It is not necessary to provide such a convex part, and heat exchange can be performed efficiently. Also, in the positioning state of each tube and the outer tube, there is no obstacle when viewed from the longitudinal direction of each tube. For example, prior to brazing, the brazing material can be applied without any trouble. It is preferable for securely fixing the outer tube and the outer tube as desired.

A preferred mode based on the above solution is as described in claim 2 and the following claims. That is,
In the outer pipe, a bulging portion is formed to bulge outwardly and secure a large distribution space,
The inward projection is formed in an extension region of the bulging portion,
(Corresponding to claim 2). In this case, the inward projection is formed by effectively using the bulging portion while ensuring a sufficient flow space for the second fluid to flow between the outer tube and each tube by forming the bulging portion. Can do.

  The inward projections are formed continuously in the stacking direction of the plurality of tubes in a stacked state (corresponding to claim 3). In this case, all the plurality of tubes can be reliably and firmly positioned, and the outer tube can be easily processed, which is preferable in terms of cost.

  According to the present invention, the efficiency of heat exchange can be improved. Further, there is no hindrance to the application of the brazing material to the fixing portion between each tube and the outer tube, which is preferable in preventing the occurrence of fixing failure.

The side view which shows an example of the heat exchanger to which this invention was applied. It is side surface sectional drawing of the heat exchanger shown in FIG. 1, and is X2-X2 line equivalent sectional drawing of FIG. Sectional drawing which shows the state which removed the connection member in both ends from the state of FIG. The front view which looked at FIG. 3 from the left. Sectional drawing which shows the state which removed the tube from the state of FIG. FIG. 6 is a cross-sectional view corresponding to line X6-X6 in FIG. 3. FIG. 4 is a cross-sectional view corresponding to line X7-X7 in FIG. 3; The expanded sectional view in the D section of FIG.

  1 and 2, the heat exchanger H is an EGR cooler for automobiles. 1 is an outer tube, 2 is a plurality of tubes, 3 and 4 are connection members for supplying and discharging the first fluid, and 5 and 6 are connection pipes for supplying and discharging the second fluid. The outer tube 1 is fitted as a split structure by a U-shaped dividing member (see FIGS. 4 and 5), and the cross-sectional shape is a rectangular shape (quadrangle cylinder). A plurality of tubes 2 are provided, each having a flat rectangular shape, and a flat internal space 2A (see FIGS. 4, 6, and 7) through which the first fluid flows is defined. Yes. Each tube 2 is formed, for example, by bending a plate material into a rectangular shape and joining the bent ends (for example, brazing or welding). Of course, the outer tube 1 and the tube 2 are formed of a metal material having excellent heat conductivity as in the conventional case.

  As shown in FIG. 4, the plurality of tubes 2 are disposed in the outer tube 1 in a laminated state so that the wide surfaces thereof face each other. A plurality of convex portions 2a (see FIGS. 2 and 3) slightly projecting outwardly on the wide both surfaces of the tubes 2 (surfaces in the stacking direction and facing the adjacent tubes 2). In FIG. 6, the convex portion 2a is omitted). The tip of the convex portion 2a is a flat surface, and when stacked, the tip surfaces of the convex portions 2a of the adjacent tubes 2 are brought into contact with each other, and a flow gap is formed between the adjacent tubes 2. (See FIG. 6).

  Each tube 2 is expanded at both end portions thereof, and the expanded portion is fixed in a close state to the outer tube 1 by, for example, brazing (airtightness between the outer tube 1 and each tube 2). And liquid-tightness is ensured). A region serving as a fixing portion between the outer tube 1 and each tube 2 is indicated by a symbol α (see FIGS. 2 and 3), and the fixing region α occupies most of the above-described expanding portion of each tube 2. In the fixed region α, as shown in FIG. 7, the tubes 2 are in close contact with each other, and the tubes 2 and the outer tube 1 are in close contact with each other, and are supplied into the tubes 2. The first fluid is allowed to flow only in each tube 2.

  One of the pair of connection members 3 and 4 is fixed to one end of the outer tube 1 and the other is fixed to the other end of the outer tube 1. Each of the pair of connection members 3 and 4 includes a first member 10 obtained by processing a plate material and a second member 11 that constitutes a flange portion fixed to the first member 10. A large-diameter portion formed on one end side of the first member 10 is fixed to the outer tube 1 in a state of being fitted in the end portion of the outer tube 1 (for example, brazing). Further, the second member 11 is fixed to the outer periphery of the small-diameter portion formed on the other end side of the first member 10 in a fitted state. The connection members 3 and 4 are communicated only with each tube 2 and are disconnected from the outer tube 1. Of course, the connection members 3 and 4 are for supplying and discharging the first fluid.

  The connection pipes 5 and 6 are connected and fixed to one side split member of the outer pipe 1 having a split structure (see FIGS. 4 and 5). The connection pipe 5 is connected to the outer tube 1 on one end side in the longitudinal direction (flow path direction) of the tube 2, and the connection pipe 6 is connected to the outer tube 1 on the other end side in the longitudinal direction of the tube 2. Each connection pipe 5, 6 is communicated with the inside of the outer tube 1. The connection pipes 5 and 6 are used for supplying and discharging the second fluid.

  The inside of the outer tube 1 is a second fluid circulation space S. The outer tube 1 is formed with a bulging portion 1a bulging outwardly at the intermediate portion between the fixed regions α, particularly on the surface facing the narrow surface of each tube 2, as the distribution space S. A large volume is secured.

  Next, with particular reference to FIG. 8, the positioning and fixing between the outer tube 1 and each tube 2 will be described. First, each tube 2 is formed with an inclined portion 2b that gradually increases in diameter toward the open end at both ends (only the inclined portion 2b at one end is shown in FIG. 8 but the other end). The configuration is the same as in FIG. The inclined portion 2b is formed on the inner side than the fixed region α. The inclined portion 2b is a portion that is gradually connected to a flat widened portion 2c (corresponding to the fixing region α) that is adopted to fix the tube 2 to the outer tube 1 in a close state.

  On the other hand, an inward projection 1b is formed on the outer tube 1 at a position corresponding to the inclined portion 2b. The inward projection 1b has a convex shape curved in a substantially arc shape. That is, the inward protrusion 1a extends from the fixed region α side toward the tube 2 gradually, then curves, and gradually extends away from the tube 2 toward the bulging portion 1a. The inwardly protruding portion 1 b (the most protruding portion) of the outer tube 1 is in contact with the inclined portion 2 b of each tube 2. Such inward protruding portions 1b are formed so as to be continuous in the stacking direction of the tubes 2 as shown in FIG.

  By the presence of the inclined portion 2b and the inwardly protruding portion 1b as described above at the both end portions of each tube 2, each tube 2 is reliably in the longitudinal direction of each tube 2 with respect to the outer tube 1. It is positioned (relative displacement in the longitudinal direction of each tube 2 with respect to the outer tube 1 is regulated). That is, within the range of the dimensional tolerance of each member, the inclined portion 2b and the inward protruding portion 1b abut on one end side of the tube 2, and the inclined portion 2b and the inward protruding portion 1b on either end side. However, this is a tolerance range, and is sufficient in terms of restricting the position of each tube 2 in the longitudinal direction with respect to the outer tube 1. As a result, the outer tube 1 and each tube 2 in the fixing region α can be fixed at a desired position with high accuracy. Since the inward protruding portions 1b are formed so as to be continuous in the stacking direction of the tubes 2, it is preferable to ensure the state in which the inclined portions 2b and the inward protruding portions 1b are brought close to or in contact with each other. In addition, the outer tube 1 having the inward projection 2b can be easily formed, which is preferable in terms of cost. Of course, the inwardly protruding portion 1b is formed by effectively utilizing the extended region of the bulging portion 1a (the connecting region between the bulging portion 1a and other portions). Formation becomes easy. In addition, the regulation of the width direction of the outer tube 1 and each tube 2 in the fixed region α (the direction orthogonal to the stacking direction of the tubes 2) is such that the width of the expanded portion 2c of each tube 2 corresponds to that of the outer tube 1 corresponding thereto. It is established by directly regulating by the U-shaped opposing wall surface.

  Since the inward protruding portion 1b (inclined portion 2b) is located inward of the fixed region α, when the fixed region α is viewed from the longitudinal end of each tube 2, the fixed region a is visually observed. It can be easily confirmed, and there is no part that becomes an obstacle when the brazing material is applied, it does not hinder the application of the brazing material, and it is extremely preferable for preventing the occurrence of improper fixing. .

  The heat exchanger H as described above is connected to the EGR passage that connects the exhaust passage and the intake passage of the engine using the connection members 3 and 4. That is, the exhaust gas from the exhaust passage is introduced into each tube 2 from, for example, the connection member 3, flows through each tube 2, and is then discharged from the connection member 4.

  On the other hand, the connection pipes 5 and 6 are connected to a cooling passage through which, for example, cooling water as a cooling medium is circulated. That is, the cooling water is introduced from the connection pipe 5 into the outer pipe 1 (the distribution space S), flows through the outer pipe 1, and then is discharged from the connection pipe 6. Of course, the cooling water also flows through the gaps between the tubes 2.

  Between the cooling water flowing in the outer pipe 1 and the exhaust gas flowing in each tube 2, heat is exchanged through each tube 2 to cool the exhaust gas. In Patent Document 1, there are convex portions for positioning each tube 2 in a portion corresponding to the bulging portion 1a of the outer tube 1, but in the present invention, such convex portions for positioning do not exist. For this reason, the cooling water flowing in the outer tube 1 flows smoothly without receiving a large resistance or the flow is stagnant, which is preferable in improving the efficiency of heat exchange.

  Although the embodiment has been described above, the present invention is not limited to the embodiment, and can be appropriately changed within the scope described in the scope of claims. For example, the invention includes the following cases. . The heat exchanger H according to the present invention is not limited to the EGR cooler, and can be applied as various uses such as an intercooler for cooling intake air supercharged in an engine with a supercharger. . The first fluid and the second fluid can be appropriately selected depending on the use of the heat exchanger and the like. The inward projection 1b may be formed completely independently from the bulge 1a. Of course, the object of the present invention is not limited to what is explicitly stated, but also implicitly includes providing what is substantially preferred or expressed as an advantage.

  According to the present invention, it is possible to provide a heat exchanger that satisfies both the improvement of heat exchange efficiency and the prevention of improper fixing.

H: heat exchanger α: fixed region 1: outer tube 1a: bulging portion 1b: inward projection portion 2: tube 2A: inner space 2b: inclined portion 2c: expanding portion 3, 4: connecting member (first fluid Supply / discharge)
5, 6: Connection pipe (for supply and discharge for the second fluid)

Claims (3)

An outer tube having a rectangular cross section and a plurality of tubes each having a flat inner space;
The plurality of tubes are disposed in the outer tube in a stacked state so as to ensure a clearance for circulation between each other,
Both ends of each tube are expanded and fixed in a state of being in close contact with the outer tube at the expanded site,
Between the outer tube and each tube, between both ends of each tube, a circulation space is formed,
A heat exchanger configured to exchange heat through the tube between the first fluid flowing in the tube and the second fluid flowing in the circulation space and the gap for circulation;
In each end portion of each tube, an inclined portion is formed to expand toward the open end side on the inner side of the fixed portion with respect to the outer tube,
Inward protrusions are formed at both ends of the outer tube to abut against the inclined portion and restrict relative displacement of the tubes relative to the outer tube in the longitudinal direction.
A heat exchanger characterized by that. In claim 1,
In the outer pipe, a bulging portion is formed to bulge outwardly and secure a large distribution space,
The inward projection is formed in an extension region of the bulging portion,
A heat exchanger characterized by that. In claim 1 or claim 2,
The inward projection is formed continuously in the stacking direction of the plurality of tubes in a stacked state.

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