Heat exchanger mounting structure

Abstract

An attachment structure in which a flange 2 of a heat exchanger and a casing 3 form a metal touch 12, wherein a liquid is prevented from leaking out from a hole edge section of a flow path hole 6.　A protruding step surface 8 is formed at the hole edge section of the flow path hole 6 in the flange 2 of the heat exchanger, the protruding step surface 8 projecting farther toward the casing 3 than does the surface of the metal touch 12. The flange 2 is thereby press-fitted firmly to the casing 3, and a liquid is thereby prevented from leaking out from the hole edge of the flow path hole 6.

Description

[Technical Field]

[0001] The present invention relates to a heat exchanger that is optimal for a vehicle oil cooler, and relates to a mounting structure for mounting the heat exchanger to a casing via a flange at its end. [Background technology]

[0002] Conventionally, a heat exchanger for an oil cooler is made by stacking many dish-shaped plates to form a core, placing a flange on the end of the core, and attaching the heat exchanger to the casing via an O-ring on the flange.The oil cooled by the heat exchanger is then returned to the casing. In this case, the oil inlet / outlet of the heat exchanger and the casing are sealed using a metal-to-metal contact, where polished flat surfaces come into contact with each other. Summary of the Invention [Problem to be solved by the invention]

[0003] In the mounting structure of a heat exchanger used as an oil cooler, if the flange and casing are sealed with a metal-to-metal seal, leakage may occur at the oil inlet and outlet depending on the finish accuracy of the sealing surface, resulting in a decrease in the heat exchange performance of the oil cooler. SUMMARY OF THE INVENTION It is therefore an object of the present invention to reliably prevent oil leakage from the flange of a heat exchanger serving as an oil cooler. [Means for solving the problem]

[0004] The present invention as set forth in claim 1 provides a heat exchanger mounting structure in which a flange 2 is provided at one end of a heat exchanger 1, and the flange 2 is connected to a surface of a casing 3, The flange (2) has a band area (4) formed of an annular flat surface on its surface, and an annular groove (5) is formed in the band area (4) to accommodate an O-ring (9) for sealing. At least one flow path hole 6 is formed inside the band region 4, and a case-side flow path hole 7 is provided in the casing 3 opposite the flow path hole 6, The surfaces of the casing 3 that contact the flange 2 are flush with each other, and the flange 2 and the casing 3 form a metal-to-metal contact 12 in the band region 4. The heat exchanger mounting structure is characterized in that the edge of the flow passage hole 6 of the flange 2 is formed into a convex stepped surface 8 that protrudes further toward the casing 3 than the surface of the metal touch 12. The present invention as set forth in claim 2 provides the heat exchanger mounting structure as set forth in claim 1, The band region 4 is a mounting structure for a heat exchanger in which an outer band 4a is formed on the outside of the annular groove 5 and an inner band 4b is formed on the inside, and the convex step surface 8 is provided including the inner band 4b. The present invention as set forth in claim 3 provides the heat exchanger mounting structure as set forth in claim 1 or claim 2, The projection step surface 8 is a mounting structure for a heat exchanger in which the projection step surface 8 has a distance of 0.02 mm to 0.3 mm from the surface of the metal touch 12 and a flatness of 0.1 mm or less. [Effects of the Invention]

[0005] In the invention described in claim 1, the flange 2 and the casing 3 form a metal contact 12, The edge of the flow passage hole 6 of the flange 2 is formed into a convex stepped surface 8 that protrudes further toward the casing 3 side than the surface of the metal touch 12 . This allows the flange 2 to be pressed against the casing 3 more strongly than the surface of the metal contact 12 by the amount of the convex step surface 8, preventing fluid from leaking out from the hole edge of the flow path hole 6. This improves heat exchange performance. In the invention described in claim 2, a convex stepped surface 8 is provided on the inner band 4b of the band region 4. This brings the stepped convex surface 8 closer to the O-ring 9, making it possible to more effectively prevent fluid leakage. In the invention described in claim 3, the convex step surface 8 is set to have a pitch of 0.02 mm or more and 0.3 mm or less with respect to the surface of the metal touch 12, and the flatness thereof is set to 0.1 mm or less. This makes it possible to provide a heat exchanger mounting structure that is free from fluid leakage and easy to manufacture. That is, within the above numerical range, there is no fluid leakage. [Brief explanation of the drawings]

[0006] FIG. 1 shows the main part of the heat exchanger of the present invention, (A) being an exploded perspective view thereof, and (B) showing the attached state thereof before the bolts 11 are tightened. 2A and 2B are longitudinal cross-sectional views of the main part of the flange 2 of the mounting structure of the present invention, where (A) is a view taken along the arrows II-II in FIG. 3, and (B), (C), and (D) are enlarged views of parts B, C, and D in FIG. 2A. FIG. 3 is a plan view of the rear side of the flange 2 of the present invention. FIG. 4 is a plan view of the heat exchanger of the present invention. FIG. 5 is a cross-sectional view taken along the line VV in FIG. FIG. 6 is an explanatory diagram showing the heat exchanger attached to a casing 3 via a flange 2. DETAILED DESCRIPTION OF THE INVENTION

[0007] Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1A is a vertical cross-sectional view of a main part of the heat exchanger mounting structure of the present invention, and FIG. 1B is an enlarged partial view thereof, and FIG. 1B shows the state before the bolts 11 are fastened. 2A is a longitudinal cross-sectional view of the essential parts of the flange 2 of the present invention, and (B), (C), and (D) are enlarged views of parts B, C, and D of FIG. 2A. FIG. 3 is a plan view of the rear side of the flange 2 of the present invention. FIG. 4 is a plan view of the heat exchanger. FIG. 5 is a cross-sectional view taken along the arrows VV in FIG. 4. FIG. 6 is a schematic diagram of the mounting structure of the heat exchanger. As shown in Figure 6, this heat exchanger 1 has a core in which many dish-shaped plates are stacked. A flange 2 is disposed at the bottom end of the core, and this flange 2 is liquid-tightly connected to a casing 3 via an O-ring 9. The flange 2 of this heat exchanger seals the oil inlet and outlet with a single O-ring 9. Then, oil 15 is guided from the case-side flow passage hole 7 of the casing 3 through the flange 2 into the inside of the heat exchanger 1 . As shown in Fig. 5, the heat exchanger 1 has oil flow paths and cooling water flow paths stacked alternately. Oil 15 flowing in from the flow path holes 6 of the flange 2 flows in a serpentine manner through the oil flow paths of the heat exchanger 1. Heat is exchanged between the cooling water 14 shown in Fig. 4 and the oil 15 shown in Fig. 5. The cooled oil 15 is returned to the casing 3 through an oil outlet 17 shown in FIG. The present invention is characterized by the mounting structure between the flange 2 provided at the end of the heat exchanger 1 and the casing 3. In this example, a relatively thick base 19 is connected to the lowest plate of the core of the heat exchanger 1, and the heat exchanger 1 and flange 2 are connected via the base 19. The base 19 and flange 2 are joined together. 3, an annular groove 5 is formed on the underside of the flange 2 (the surface on the side connected to the casing 3). The annular groove 5 is provided within a banded region 4 formed in an annular shape. In the banded region 4, an outer band 4a is formed on the outside relative to the center of the flange 2, and an inner band 4b is formed on the inside. As shown in Figure 2(B), the outer band 4a protrudes slightly by a distance H1 toward the casing 3 beyond the plane of the lower surface of the flange 2. As a result, in Figure 1(B), the plane of the casing 3 and the surface of the metal contact 12 are formed. Here, the metal contact means that flat surfaces of metals come into contact with each other. 2(C), the inner band 4b is formed with a convex stepped surface 8 that protrudes slightly by a distance H2 toward the casing 3 beyond the outer bands 4a and 4b. The protrusion amount is 0.02 mm to 0.3 mm from the plane of the outer band 4a. The flatness of the convex stepped surface 8 is 0.1 mm or less. A flow path hole 6 is formed in the center of the convex stepped surface 8. For reference, the convex step surface 8 in Figure 2(D) protrudes by H3 toward the casing 3 side from the plane of the lower surface of the flange 2. This protrusion amount of H3 is approximately the same as the protrusion amount of H1 and H2 mentioned above combined. One or more bolt holes 10 are drilled in the flange 2, and bolts 11 are inserted into the bolt holes 10. The edge of the bolt holes 10 protrudes slightly in the same direction as the outer band 4a and inner band 4b. The amount of protrusion between the plane of the edge of the bolt holes 10 and the planes of the outer band 4a and inner band 4b is approximately flush with each other, except for the convex step surface 8. In alignment with the flow path hole 6 serving as an oil inlet, a case-side flow path hole 7 is provided in the casing 3. Furthermore, in alignment with the oil outlet 17 of the flange 2, a case-side outlet 17a is provided. Each portion of the connection surface 13 of the casing 3 with which the flange 2 comes into contact is formed flush, and the connection surface 13 faces the surface of the metal contact 12 of the flange 2. When the flange 2 is brought into contact with the casing 3 , the protruding stepped surface 8 comes into contact with the connecting surface 13 of the casing 3 . 1(B), when the flange 2 of the heat exchanger 1 is placed on the flush connecting surface 13 of the casing 3, the convex stepped surface 8 comes into contact with the connecting surface 13. When the bolt 11 is tightened in this state, the metal-to-metal contact 12 surface of the flange 2 and the connecting surface 13 of the casing 3 are pressed together, improving the sealing performance of the O-ring 9. The amount of pressure contact is the difference between the convex stepped surface 8 and the pair of band regions 4. As a result, the oil in the flow passage hole 6 is prevented from leaking to the outside. According to experiments, when the protrusion amount of the convex step surface 8 that protrudes slightly from the inner band 4b toward the casing 3 is set to 0.02 mm or more and 0.3 mm or less from the plane of the outer band 4a as the reference plane, and the flatness of the convex step surface 8 is set to 0.1 mm or less, and the oil flow rate is changed to low flow rate, medium flow rate, and high flow rate, the heat dissipation amount of the heat exchanger increases by 3.2% to 5.0%, and there is no oil leakage. Furthermore, when the above-described structure of the stepped convex surface 8 is adopted, the conventional press method can be used as is. [Industrial Applicability]

[0008] The present invention can be used as a heat exchanger for a transmission or engine of a vehicle or the like, and is particularly suitable for use as an oil cooler therefor. [Explanation of symbols]

[0009] 1 heat exchanger 2 flanges 3 Casing 4 Band Area 4a outer band 4b Inner belt 5 Annular groove 6 Flow passage holes 7 Case side flow passage hole 8 Convex stepped surface 9 O-ring 9a Claw part 10 bolt holes 11 volts 12 Metal Touch 13 Connection surface 14 Cooling water 15 Oil 17 Oil outlet 17a Case side outlet 18 Bypass 19 base

Claims

1. A heat exchanger mounting structure in which a flange (2) is provided at one end of a heat exchanger (1), and the flange (2) is connected to a surface of a casing (3), The flange (2) has a band area (4) made of an annular flat surface on its surface, and an annular groove (5) is formed in the band area (4) to accommodate an O-ring (9) for sealing. At least one flow path hole (6) is formed inside the band region (4), and a case-side flow path hole (7) is provided in the casing (3) opposite the flow path hole (6); The surfaces of the casing (3) that contact the flange (2) are flush with each other, and the flange (2) and the casing (3) form a metal-to-metal contact (12) in the band region (4). The edge of the flow passage hole (6) of the flange (2) is formed as a convex stepped surface (8) that protrudes toward the casing (3) beyond the surface of the metal contact (12), The band region (4) has an outer band (4a) formed outside the annular groove (5) and an inner band (4b) formed inside the annular groove (5), and the convex stepped surface (8) is provided including the inner band (4b).

2. The heat exchanger mounting structure according to claim 1, The convex step surface (8) has a flatness of 0.02 mm or more and 0.3 mm or less relative to the surface of the metal touch (12), and the flatness is 0.1 mm or less. Here, the metal touch refers to contact between flat metal surfaces.

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