JP2003240483A - Oil cooler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To temporarily fix an oil cooler easily and without being affected by thermal strain, before a brazing process. <P>SOLUTION: This oil cooler heat-exchanged between the first fluid and the second fluid, and assembled with a filter for removing a foreign matter in the first fluid is provided with a heat-exchanger core through which the first fluid and the second fluid flow, a core casing for storing the heat-exchanger core, and a top plate interposed between the core casing and the filter to seal the core casing and the filter. In the cooler, a cylindrical protrusion is extended toward the core casing in the central part of the top plate, a hole for penetrating the cylindrical protrusion is provided in the core casing, the top plate and the core casing are calking-fixed by bending the cylindrical protrusion toward the core casing after the cylindrical protrusion is engaged with the hole, and the top plate is brazedly joined thereafter to the core casing. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oil cooler for cooling oil such as vehicle engine oil and working oil (ATF) for automatic transmission.

[0002]

2. Description of the Related Art An oil cooler for a vehicle is fixed to, for example, a crankcase of an engine for heat exchange between oil and cooling water. An oil cooler is generally composed of a heat exchange core portion that exchanges heat between oil and cooling water, a core casing body that houses the heat exchange core portion, and a seat plate that closes the open bottom portion of the core casing body. Has been done. When an oil filter is attached to this oil cooler, between the oil filter and the oil cooler,
A top plate that also serves as a mounting bracket for mounting the oil filter on the oil cooler is inserted while sealing the gap to prevent engine oil from leaking. Even when the oil filter is not assembled to the oil cooler, the top plate is attached to the core casing to seal the upper portion of the core casing.

By the way, in order to join the top plate and the core casing by brazing, it is necessary to temporarily fix the top plate and the core casing. for that reason,
In the past, the top plate and core casing were temporarily fixed by spot welding.

However, in spot welding, the core casing is deformed by the heat generated during welding, or springback occurs in which the top plate tries to return to the radially outward direction after welding and tensile force is applied to the core casing. As a result, there is a problem that the core casing is distorted and the roundness of the core casing deteriorates, so that the core casing cannot be accurately fitted to the seat plate.

[0005]

In view of the above problems,
An object of the present invention is to provide an oil cooler that can be easily and temporarily fixed before the brazing process without being affected by thermal distortion.

[0006]

In order to solve the above problems, according to the oil cooler of the first aspect of the present invention, the first fluid and the second fluid are heat-exchanged, and at the same time, in the first fluid. In an oil cooler in which a filter for removing foreign matter is assembled, a heat exchange core through which a first fluid and a second fluid flow, a core casing for housing the heat exchange core, and a core casing and a filter for sealing the core casing and the filter. And a top plate inserted between the top plate and a cylindrical protrusion extending toward the core casing in the center of the top plate, and the core casing has a hole for allowing the cylindrical protrusion to penetrate therethrough. After the top plate and the core casing are fixed by caulking, the tubular projection is bent toward the core casing after fitting the part into the hole. Ring is brazed. As a result, the top plate of the oil cooler to which the oil filter is attached and the core casing are mechanically constrained, so the core casing does not undergo thermal deformation due to welding as in the past, and is easily and thermally affected. You can temporarily stop without.

According to the oil cooler of the second aspect, in the oil cooler for exchanging heat between the first fluid and the second fluid, the heat exchange core through which the first fluid and the second fluid flow and the heat exchange core are housed. And a top plate attached to the upper part of the core casing to seal the upper part of the core casing, and in the center of the top plate, a male screw part extends toward the core casing. Is formed with a female screw portion that is screwed to the male screw portion, and the top plate and the core casing are brazed after the female screw portion and the male screw portion of the top plate are screwed. Since the top plate and core casing of the oil cooler of the type that does not have an oil filter attached are mechanically restrained, the core casing does not undergo thermal deformation due to welding as in the past, and it is easy and free from the influence of thermal strain. It can be temporarily stopped.

According to the oil cooler of the third aspect, in the oil cooler for exchanging heat between the first fluid and the second fluid, the heat exchange core through which the first fluid and the second fluid flow and the heat exchange core are housed. A core casing, and a top plate attached to the upper part of the core casing to seal the core casing and the filter.A male screw portion extends toward the core casing at the center of the top plate, and Has a female screw portion that is screwed to the male screw portion, and the top plate and the core casing are brazed after the male screw portion and the female screw portion are screwed together. Thereby, the same effect as that of the second aspect is achieved.

According to the oil cooler of the fourth aspect, in the oil cooler for exchanging heat between the first fluid and the second fluid, the heat exchange core through which the first fluid and the second fluid flow and the heat exchange core are housed. And a top plate attached to the top of the core casing to seal the top of the core casing.At least two protrusions extend from the surface of the top plate facing the core casing. , A recess for receiving at least two protrusions is formed, and the protrusion and the recess are fitted together, and then the protrusion is bent toward the core casing, whereby the top plate and the core casing are fixed by caulking. It is later brazed and joined. As a result, the same operational effects as those of claims 2 and 3 are achieved.

According to the oil cooler of the fifth aspect, in the oil cooler for exchanging heat between the first fluid and the second fluid, the heat exchange core through which the first fluid and the second fluid flow and the heat exchange core are housed. And a top plate attached to the upper part of the core casing to seal the upper part of the core casing, a female screw part is formed on the side part of the top plate, and a male screw is formed on the side part of the core casing. The upper plate and the core casing are brazed after the female screw portion and the male screw portion are screwed together. As a result, the top plate and the core casing of the oil cooler of the type in which the oil filter is attached or the type in which the oil filter is not attached are mechanically constrained, so that the core casing is not thermally deformed by welding as in the conventional case, It can be temporarily and easily fixed without being affected by thermal strain.

According to the oil cooler of the sixth aspect, in the oil cooler for exchanging heat between the first fluid and the second fluid, the heat exchange core through which the first fluid and the second fluid flow and the heat exchange core are housed. And a top plate attached to the top of the core casing to seal the top of the core casing, and the side parts of the top plate and the side parts of the core casing respectively have complementary fitting parts. When the fitting portion of the top plate and the fitting portion of the core casing are fitted, the top plate and the core casing are brazed and joined together. Thereby, the same effect as that of the fifth aspect is achieved.

[0012]

DETAILED DESCRIPTION OF THE INVENTION Embodiments of the present invention will be described below with reference to the accompanying drawings. First, the oil cooler of the first embodiment will be described. In the present embodiment, a type in which an oil cooler is assembled with an oil filter, that is, a filter-on type will be described as an example. FIG. 1 is a sectional view of an oil cooler of the present invention. In FIG. 1, reference numeral 100 generally indicates the oil cooler of the present invention. The oil cooler 100 is mounted on the wall surface of a crankcase 300 of a vehicle, and has oil (hereinafter simply referred to as oil) such as engine oil and working oil (ATF) for automatic transmission and engine cooling water (hereinafter simply referred to as oil). This is called "cooling water") and heats the oil to cool the oil.

The structure of the oil cooler 100 will be described in more detail below. As shown in FIG. 1, 110 is a heat exchange core (hereinafter, simply referred to as a core) for exchanging heat between oil and cooling water. The core 110 is made of a plurality of stainless steel materials press-molded into a predetermined shape. Plates 111, 112
Are laminated in the thickness direction of the plates 111 and 112.

Reference numeral 120 denotes a core casing. The core casing 120 is formed in a substantially cylindrical shape for accommodating the core 110, and has a stainless steel core casing main body 121 having an opening 123 at its axial end (lower side in the drawing). , And a disk-shaped seating surface plate 124 that closes the opening 123. Further, while the core 110, which is temporarily assembled by stacking the plates 111 and 112, is arranged inside the core casing body 121, the core 110 is pressed through the seat plate 124 while the core casing body 121 is being pressed.
By brazing the core 110 together with the seat plate 124, a closed space (core casing 120) for housing the core 110 is formed. At this time, it was formed (partitioned) by the plates 111 and 112.
The space 113 constitutes a passage through which oil flows, and among the spaces inside the core casing 120, a space 127 outside the space 113 (hereinafter referred to as the oil passage 113) is a passage through which cooling water flows (hereinafter referred to as a cooling water passage). (Referred to as 127)).

In this embodiment, the core casing body 121
An inflow port 122 through which cooling water flows in and an outflow port (not shown) through which cooling water that has finished heat exchange with the oil flows out are formed in the cylindrical wall portion of the. The oil passage 1
Inside 13 is provided an inner fin (not shown) that promotes heat exchange between oil and cooling water.

In the bearing surface plate 124 at the bottom of the core casing 120, the surface 131 (hereinafter referred to as the seal surface 131) and the crankcase 300 are the surfaces 131 on the side that contacts the wall surface of the crankcase 300 of the engine.
An O-ring groove 128 is formed in which an O-ring 130 that seals a gap with the wall surface of the O-ring is mounted.

On the other hand, on the upper surface of the core casing 120,
Oil filter 20 for removing (filtering) foreign substances in oil
0 (indicated by a dotted line) is assembled, and the filter 20 is provided between the oil filter 200 (hereinafter abbreviated as the filter 200) and the core casing 120.
The core casing 120 is brought into contact with the 0-side sealing surface 210.
A stainless top plate 140 that secures the airtightness (sealability) between the filter 200 and the filter 200 is provided.

Reference numeral 150 is a center bolt for fixing the oil cooler 100 and the oil filter 200 to the crankcase 300. As shown in FIG. 1, the upper end of the center bolt 150 is formed with a first male screw portion 151 that is screwed with a female screw portion (not shown) of the filter 200. Is the top plate 1
A radial projection 153 for contacting the upper surface of the crankcase 40 is formed, and a male screw portion 152 that engages with a female screw portion 303 formed in the second oil passage 302 of the crankcase 300 is formed at the lower end. There is. With this configuration,
Install the oil cooler 100 after brazing to the crankcase 30
After positioning by contacting with 0, the center bolt 150
By engaging the second male screw portion 152 and the crankcase 300 with each other, the protrusion 15 of the center bolt 150
3 presses and holds the core casing 120 and the top plate 140 against the crankcase 300, and the center bolt 15
The filter 200 is mounted on the crankcase 300 by screwing the first male screw part 151 of No. 0 and the filter 200 together.
Can be held at. Also, the center bolt 150
Has a hole penetrating in the longitudinal direction thereof, and when assembled, the top plate 140 and the core casing 1 are
20 through the filter 200 to the crankcase 30
An oil flow path extending to 0 is formed.

After the filter 200 is assembled to the crankcase 300, the surface 141 of the top plate 140 that comes into contact with the sealing surface 210 of the filter 200 becomes the sealing surface between the filter 200 and the oil cooler 100. The gap between the top plate 140 and the core casing 120 is sealed by brazing so that oil does not leak from the sealing surface.

The oil flows from the first oil passage 301 of the crankcase 300 into the oil passage 113 in the core casing 120 through the oil holes 125 provided in the seat plate 124. The top plate 1 flows in the oil passage 113 upwards and in the circumferential direction of the core casing 120 and exits from the hole 121a of the core casing 120.
It flows into the oil filter 200 through the hole 142 of 40. The oil filtered by the oil filter 200 passes through the center bolt 150 and the second oil of the crankcase 300.
It flows into the oil passage 302. On the other hand, the water that cools the oil flows into the core casing 120 from the inflow port 122, flows in the cooling water passage 127 in the circumferential direction of the core casing 120, cools the oil, and then flows from the outflow port (not shown) to the core. Exit the casing 120.

The temporary fixing method according to the present invention before brazing the core casing and the top plate together will be described in detail below. In the oil cooler of the present invention, the top plate and the core casing are fixed by mechanical restraint instead of spot welding as in the conventional case. FIG. 2 is a sectional view of the top plate 140 and the core casing 120 before temporary fixing according to the first embodiment of the present invention. As shown in FIG. 2, the top plate 140 of the present embodiment includes a peripheral edge portion 140a that matches the peripheral edge portion of the core casing 120, a cylindrical wall portion 140b extending vertically upward from the peripheral edge portion 140a, and an oil filter 200. Radius outside area portion 140c that contacts and radius inside area portion 140d that contacts the upper surface of the core casing.
And the outer radius area 140c and the inner radius area 140d
And a tapered transition 140e between them. Further, at the center of the radially inner region 140d of the top plate 140, a cylindrical protrusion 140f extends vertically downward. On the other hand, in the center of the upper surface of the core casing 120, a hole having substantially the same shape and size as the cylindrical protrusion 140f of the top plate 140 is formed. The transition portion 140e of the top plate 140 and the core casing 120
Holes 142 and 121a are formed in each of the upper surfaces of so as to form oil passages.

As shown in FIG. 2, the top plate 140
The cylindrical protrusion 140f of the hole 1 of the core casing 120
After the top plate 140 and the core casing 120 are positioned before being temporarily fixed in the state of being fitted in the 29, the cylindrical protrusion 140f is curved outward in the radial direction from the lower side of the core casing 120 by a spreader jig (not shown). As shown in FIG. 1, the top plate 14
0 and the core casing 120 are fixed by crimping, and the top plate 140 and the core casing 120 are temporarily fixed.
Since the method of assembling the top plate and the core casing is a mechanical restraint method that does not cause thermal deformation in this way, the oil cooler can be easily assembled without being affected by thermal distortion.

Next, a second embodiment will be described. In the first embodiment, the filter-on type oil cooler in which the oil filter is attached to the oil cooler has been described as an example, but in the present embodiment, a filterless type oil cooler in which the oil filter is not attached to the oil cooler is taken as an example. explain. FIG. 3 is a sectional view of a top plate and a core casing according to a second embodiment of the present invention. Note that FIG.
Shows only the top plate, the core casing and the center bolt, and the other components are almost the same as those of the first embodiment. The top plate 140 of the present embodiment includes a peripheral edge portion 140a that matches the peripheral edge portion of the core casing 120, a cylindrical wall portion 140b that extends vertically upward from the peripheral edge portion 140a, and a flat portion 140c. At the center of the flat portion 140c, the center bolt 150
A hole 140g for allowing a to pass therethrough is provided. On the surface of the flat portion 140c facing the core casing 120, the cylindrical member 140d is spot-welded at a position surrounding the hole 140g. This cylindrical member 140f
A plurality of holes 142 for oil passages are formed in the side surface of the, and a male screw portion is formed on the outer periphery of the tip of the cylindrical member 140f. On the other hand, a hole 129 is opened in the center of the core casing 120, and a female screw portion corresponding to the male screw portion of the cylindrical member 140f of the top plate 140 is formed in the hole 129.

With this structure, when temporarily fixed, the male screw portion of the cylindrical member 140f of the top plate 140 is screwed to the female screw portion of the hole 129 of the core casing 120, as shown in FIG. The top plate 140 and the core casing 120 are temporarily and easily fixed without being affected by thermal strain. After the top plate 140 and the core casing 120 are brazed and joined together, the center bolt 150a is passed through the core 110 and the seat plate 124, and the bolt 150a is fastened to the crankcase 300, thereby fixing the oil cooler 100 to the crankcase 300. can do. The oil that has undergone heat exchange and exits from the hole 121a of the core casing 120 passes through the hole 142 on the side surface of the cylindrical member 140f, passes through the space formed between the cylindrical protrusion 140f and the center bolt 150a, and is cranked. It is returned to the case 300.

Next, a third embodiment will be described. The oil cooler of this embodiment is a filter-on type as in the first embodiment. In this embodiment, the top plate 140 and the core casing 120 are temporarily fixed by screwing. FIG. 4 is a sectional view of the top plate 140 and the core casing 120 according to the third embodiment of the present invention. The configuration of the components other than the top plate and the core casing is almost the same as that of the first embodiment, and therefore the top plate 1 is shown in FIG.
Only 40 and core casing 120 are shown.

The top plate 140 of this embodiment has a peripheral edge portion 140a which matches the peripheral edge portion of the core casing 120.
And the cylindrical wall portion 1 extending vertically upward from the peripheral edge portion 140a.
40b and the flat portion 14 that contacts the oil filter 200
0c, a radially inner area portion 140d that contacts the upper surface of the core casing, a flat portion 140c, and a radially inner area portion 140.
transition section 140e having a tapered shape between d and transition section 140e
And a cylindrical protrusion 140f that extends vertically downward from. A male screw portion is formed on the outer circumference of the cylindrical protrusion 140f. On the other hand, a hole 129 is opened in the center of the upper surface of the core casing 120, and a female screw portion corresponding to the male screw portion of the cylindrical protrusion 140 f of the top plate 140 is formed in this hole 129. With such a configuration, at the time of temporary fixing, the male screw portion of the cylindrical protrusion 140f of the top plate 140 is screwed to the female screw portion of the hole 129 of the core casing 120, and as shown in FIG. 140 and core casing 1
20 is temporarily and easily fixed without being affected by thermal strain.

Next, a fourth embodiment will be described. The oil cooler of this embodiment is a filterless type. As shown in FIG. 5, the top plate of the present embodiment includes a peripheral edge portion 140a that matches the peripheral edge portion of the core casing 120,
Cylindrical wall 140 extending vertically upward from the peripheral edge 140a
b and a flat portion 140c. Flat part 140c
Has a hole 14 through which the center bolt 150a passes.
0 g is provided. Further, on the surface of the flat portion 140c facing the core casing 120, the cylindrical protruding member 1
40f is spot welded at a position surrounding the hole. This cylindrical protrusion member 140f is, for example, four long branch portions 14
4 and four short branches 146, these long branches 14
4 and short branches 146 are arranged alternately. On the other hand, a hole 129 is formed in the center of the flat portion of the core casing 120, and the periphery of the hole 129 is, as shown in FIG.
A concave portion 129a corresponding to the cross-sectional shape of the long branch portion 144 of the cylindrical protruding member 140f of the top plate 140 is formed. In addition, a hole 140g through which the center bolt 150 penetrates is formed in the center of the top plate 140 as in the second embodiment.

With this structure, the long branch portion 144 of the top plate 140 is fixed to the core casing 12 before temporary fixing.
0 in the recess 129a of the hole 129, and the short branch portion 146 of the top plate 140 is positioned so as to be in contact with the surface region of the core casing 120 between the recesses 129a, and the expansion jig is inserted from the lower side of the core casing 120. The long branch portion 144 is curved outwardly by a radius (not shown) to expand the mouth. Thus, as shown in FIG. 5, the top plate 140 and the core casing 120 are caulked and fixed,
The top plate 140 and the core casing 120 are temporarily fixed.

Next, a fifth embodiment will be described. Figure 7
FIG. 8 is a sectional view of a top plate and a core casing according to a fifth embodiment of the present invention. FIG. 7 shows a filter-on type top plate. The top plate 140 and the core casing 120 of this embodiment have substantially the same configuration as that of the first embodiment, but the configurations of the outer peripheral edge portion and the inner peripheral edge of the top plate 140 and the core casing 120 are different from those of the first embodiment. There is. Top plate 140 of this embodiment
The central portion of the core casing 120 is flat, and the top plate 140 and the core casing 120 are provided with holes 140g and 129 for the center bolt 150 to pass through. On the other hand, at the outer peripheral edge, an internal thread portion is formed on the inner surface of the top plate 140, and the outer surface of the core casing 120 is formed on the outer surface of the top plate 140.
A male screw portion corresponding to the female screw portion is formed. With such a structure, as shown in FIG.
The female screw portion of the top plate 140 is attached to the core casing 12
The top plate 140 and the core casing 120 are temporarily and easily fixed without being affected by thermal strain by screwing the male screw portion of No. 0.

The top plate 1 having the structure of this embodiment is also used.
The 40 and the core casing 120 can also be applied to a filterless type oil cooler. In this case, the top plate has the shape shown in FIGS. 3 and 5.

Finally, a sixth embodiment will be described. In this embodiment, the configurations of the top plate and the core casing are almost the same as those of the fifth embodiment, except that the threaded portion in the fifth embodiment is replaced with a fitting portion. Therefore, the present embodiment can be applied to both the filter-on type and the filterless type. FIG. 9 is a partial sectional view of the oil cooler of the sixth embodiment. As shown in FIG. 9, a convex portion extends over the entire circumference on the inner side surface of the top plate 140, and a concave portion corresponding to the convex portion on the top plate 140 extends over the entire circumference on the outer surface of the core casing 120. . With such a configuration, at the time of temporary fixing, the protrusions of the top plate 140 and the recesses of the core casing 120 are fitted to each other as shown in FIG. 9, so that the top plate 140 and the core casing 120 can be easily and thermally affected by heat distortion. It is temporarily stopped without receiving it.

Further, as a modification of the sixth embodiment, the top plate 140 and the core casing 120 may have opposite convex and concave portions. That is, as shown in FIG. 10, the inner surface of the top plate 140 has a recess extending over the entire circumference, and the outer surface of the core casing 120 has a projection corresponding to the recess of the top plate 140 extending over the entire circumference. There is.

In the above embodiment, an example in which the oil cooler is mounted on the crankcase of the vehicle has been described, but it goes without saying that the oil cooler may be mounted on the cylinder block or the transmission body.

[Brief description of drawings]

FIG. 1 is a sectional view of an oil cooler according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a top plate and a core casing before temporary fixing according to the first embodiment of the present invention.

FIG. 3 is a sectional view of a top plate and a core casing according to a second embodiment of the present invention.

FIG. 4 is a sectional view of a top plate and a core casing according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a top plate and a core casing according to a fourth embodiment of the present invention.

FIG. 6 is a partial cross-sectional view of a top plate according to a fourth embodiment of the present invention.

FIG. 7 is a sectional view of a top plate and a core casing according to a fifth embodiment of the present invention.

FIG. 8 is a partial sectional view of a top plate and a core casing according to a fifth embodiment of the present invention.

FIG. 9 is a sectional view of a top plate and a core casing according to a sixth embodiment of the present invention.

FIG. 10 is a view showing a modification of the top plate and the core casing of the sixth embodiment of the present invention.

[Explanation of symbols]

100 ... Oil cooler 110 ... Heat exchange core 120 ... Core casing 129 ... Core casing hole 140 ... Top plate 140f ... Cylindrical protrusion 200 ... Oil filter

Claims (6)

[Claims] 1. An oil cooler in which a filter for heat exchange between a first fluid and a second fluid and for removing foreign matters in the first fluid is assembled, and a heat exchange core in which the first fluid and the second fluid flow. A core casing accommodating the heat exchange core; and a top plate interposed between the core casing and the filter for sealing the core casing and the filter, the top plate being provided with a top plate at the center thereof. The tubular projection extends toward the core casing, and the core casing has a hole for penetrating the tubular projection, and after the tubular projection is fitted into the hole, the tubular projection is moved to the core. By bending toward the casing, the top plate and the core casing are caulked and fixed, and then the top plate and the core casing are brazed. Oil cooler, characterized in that it is joined. 2. An oil cooler for exchanging heat between a first fluid and a second fluid, a heat exchange core through which the first fluid and the second fluid flow, a core casing for housing the heat exchange core, and the core casing. And a top plate attached to the upper part of the core casing to seal the upper part of the core casing, a male screw portion extending toward the core casing in the center of the top plate, and A female screw portion that is screwed to the male screw portion is formed, and the top plate and the core casing are brazed after the female screw portion and the male screw portion of the top plate are screwed to each other. And oil cooler. 3. An oil cooler that exchanges heat between a first fluid and a second fluid, a heat exchange core through which the first fluid and the second fluid flow, a core casing that houses the heat exchange core, and the core casing. And a top plate attached to the upper part of the core casing to seal the filter, a male screw portion extending toward the core casing in the center of the top plate, and the central casing of the core casing An oil is formed by forming a female screw portion which is screwed to the male screw portion, and the top plate and the core casing are brazed after the male screw portion and the female screw portion are screwed to each other. Cooler. 4. An oil cooler for exchanging heat between a first fluid and a second fluid, a heat exchange core through which the first fluid and the second fluid flow, a core casing for housing the heat exchange core, and the core casing. A top plate attached to the top of the core casing to seal the top of the core casing, at least two protrusions extending from a surface of the top plate facing the core casing, the core casing having at least the A recess for receiving the two protrusions is formed, and after the protrusion and the recess are fitted to each other, the protrusion is bent toward the core casing, whereby the top plate and the core casing are caulked. An oil cooler characterized by being brazed after being fixed. 5. An oil cooler for exchanging heat between a first fluid and a second fluid, a heat exchange core through which the first fluid and the second fluid flow, a core casing for housing the heat exchange core, and the core casing. A top plate attached to the upper part of the core casing to seal the upper part of the core casing, a female screw part is formed on a side part of the top plate, and a male screw part is formed on a side part of the core casing. An oil cooler characterized in that the top plate and the core casing are brazed after the female screw portion and the male screw portion are screwed together. 6. An oil cooler for exchanging heat between a first fluid and a second fluid, a heat exchange core through which the first fluid and the second fluid flow, a core casing for housing the heat exchange core, and the core casing. And a top plate attached to the top of the core casing to seal the top of the core casing, and the side portion of the top plate and the side portion of the core casing are respectively formed with complementary fitting portions. An oil cooler characterized in that the top plate and the core casing are brazed after the fitting portion of the top plate and the fitting portion of the core casing are fitted to each other.