Heat Exchanger

This application claims priority to Japanese Patent Application No. JP2024-095924, filed on Jun. 13, 2024, the contents of which is hereby incorporated by reference in its entirety.

The present invention relates to a heat exchanger.

Conventionally, a heat exchanger in which a core formed by stacking multiple plates is housed in a casing has been proposed as an oil cooler to be installed on the cylinder block of an internal combustion engine (for example, see Patent Literature 1). In the heat exchanger described in Patent Literature 1, inlet and outlet ports for cooling water are formed on the side of the outer peripheral wall of the tubular casing, and a gap is ensured between the outer peripheral wall of the casing and the outer peripheral part of the core to allow cooling water to flow through in the plate stacking direction of the core. That is, cooling water introduced from the outer wall part into the interior of the casing is distributed in the vertical direction, then passes through the interior of the core, and is discharged from the outer wall part.

In a configuration such as that of the heat exchanger as described in Patent Literature 1, where pipes for the inlet and outlet ports of cooling water are provided on the side of the casing, and fluid introduced into the interior of the casing is distributed in the plate stacking direction, when attempting to reduce the size of the heat exchanger, the gap between the casing and the stacked core becomes smaller, the fluid resistance of the cooling water flowing through this gap increases, so reducing the pressure loss while also reducing the size remains a problem to be solved. Furthermore, when the distance between the pipes and the stacked core is shortened due to size reduction, cooling water does not flow readily to layers distant from the opening of the pipe in the up-down direction, reducing the heat exchange rate, so distributing to the core in layers distant in the up-down direction while reducing the size remains a problem to be solved.

The present invention was made in view of the aforementioned problems, it being an object of the present invention to provide a heat exchanger that makes it possible to reduce overall size while ensuring fluid distribution performance.

To solve the above problem, the heat exchanger according to the present invention is characterized in that it comprises a stacked body in which multiple plates are stacked to form a flow passage for a first fluid and a flow passage for a second fluid alternately in the stacking direction; a bottomed tubular case which houses said stacked body and which is open on one side in said stacking direction; and a base plate provided on the open side of said case; wherein said case has an inflow port and an outflow port through which said first fluid passes in a side wall part that extends in said stacking direction; the outer peripheral part of said stacked body is formed so as to lie along the inner surface of the side wall part of said case, and has a recessed part spaced away from the inner surface of said side wall part in the portion opposite said inflow port and the portion opposite said outflow port; and said recessed part forms a first distribution flow passage, through which said first fluid flows in said stacking direction, between the outer peripheral part of said stacked body and the inner surface of said side wall part.

According to this aspect, a recessed part is formed in the portion of the outer peripheral part of the stacked body opposite the inflow port and the portion opposite the outflow port, and a first distribution flow passage is formed by these recessed parts, eliminating the need to increase the size of the case relative to the stacked body. Here, although the distance in the in-plane direction through which the first fluid passes becomes shorter in a plate where recessed parts have been formed, requiring the stacked body to be made slightly larger to compensate for this, the recessed parts are formed locally, and since the outer peripheral part of the stacked body lies along the inner surface of the side wall part of the case, it becomes possible to suppress the increase in size of the stacked body. In this way, it becomes possible to reduce the overall size of the heat exchanger while ensuring the fluid distribution performance by means of the first distribution flow passage formed by the recessed parts.

The case may be formed in a rectangular shape when viewed from the stacking direction, and the inflow port and the outflow port may be arranged at locations adjacent to each of a pair of diagonally opposed corner parts along a pair of edges of the rectangular shape. According to this aspect, since the first fluid flows along the diagonal in the stacked body, the distance in the in-plane direction over which the first fluid passes can be made longer, making it easier to reduce the size of the stacked body, and as a result, making it easier to reduce the overall size of the heat exchanger.

The recessed parts may be formed by the plate being formed in a plate shape wherein the corner parts of the rectangular shape have been cut away. According to this aspect, the recessed parts can be easily formed, and increased complexity of the stacked body shape can be avoided.

Through-holes may be formed in the plate at a different pair of corner parts from the corner parts at which the recessed parts are formed, and a second distribution flow passage through which the second fluid flows in said stacking direction may be formed by the through-holes. According to this aspect, the distribution flow passage for the second fluid is formed at a pair of corner parts, and the second fluid after distribution also flows along the diagonal. This makes it possible to make the distance in the in-plane direction over which the second fluid passes through the plate longer, making it easier to reduce the size of the stacked body, and as a result, making it easier to reduce the overall size of the heat exchanger. Furthermore, by arranging the recessed parts for allowing the first fluid to pass through and the through-holes for allowing the second fluid to pass through at different corner parts, the stacked body can be used in a spatially efficient manner, making it possible to reduce the overall size of the heat exchanger.

With the heat exchanger according to the present invention, it becomes possible to reduce overall size while ensuring fluid distribution performance.

An embodiment of the present invention will be described below with reference to the drawings. The heat exchangeraccording to an embodiment of the present invention, as shown in, comprises a stacked bodyin which multiple platestoare stacked to alternately form a flow passage for a first fluid (cooling water in the present embodiment) and a flow passage for a second fluid (oil in the present embodiment) in the Z direction (stacking direction); a bottomed tubular casethat houses the stacked bodyand is open on one side in the Z direction; and a base plateprovided on the open side of case. Casehas an inflow portand an outflow portthrough which a first fluid passes in a side wall partextending in the Z direction. The outer peripheral partof the stacked bodyis formed so as to lie along the inner surface of the side wall partof caseand has a recessed partthat is spaced away from the inner surface of the side wall partin a portion opposite the inflow portand in a portion opposite the outflow port. The recessed partsform a first distribution flow passage, through which the first fluid flows in the Z direction, between the outer peripheral partof the stacked bodyand the inner surface of the side wall part.

Furthermore, the first plateand the second plate, as shown in, each has an outer peripheral flange part,that protrudes from the outer peripheral edge in the Z direction. The outer peripheral flange parts,are positioned on the outer side relative to the outer peripheral flange parts,of another adjacent plate on the protruding side, and are connected by taper fitting and brazing. Between the first plateand the second plateadjacent to each other in the Z direction, as shown in, at locations opposite the inflow portor the outflow port, there are formed an opening partB that opens the space between the plates that forms a flow passage for the first fluid (cooling water), and a closing partA that closes the space between the plates that forms a flow passage for the second fluid (oil).

Furthermore, the casehas a rectangular parallelepiped shape, and has an inflow portand an outflow portthrough which the first fluid passes, and a stepped partA formed around, respectively, the inflow portor the outflow port, in the short-edge side wall partas a flat surface part of the side wall part(see).

Here,is a perspective view showing the heat exchangeraccording to an embodiment of the present invention,is a perspective view showing the stacked bodyand the base plateof the heat exchanger,is a cross-sectional view passing through the outlet pipeof the heat exchanger,is a cross-sectional view passing through the inlet pipeof the heat exchanger,is an enlarged cross-sectional view showing a portion ofin enlargement,is an enlarged cross-sectional view showing other parts ofin enlargement,is a plan view showing the lowermost plateof the stacked body,is a plan view showing the first plateof the stacked body,is a plan view showing the second plateof the stacked body,is a cross-sectional view passing through the second distribution flow passage (in the present embodiment, where the first fluid is cooling water and the second fluid is oil, this refers to the flow passage that provides a connection, in the stacking direction of the core, between the oil flow passages formed alternately with the water passages)of the heat exchanger,is a side view showing the heat exchanger, andis a side view of the stacked bodyand the base plate.

The heat exchangeris used by being incorporated into the cooling water system of, for example, an automobile (vehicle). The automobile in which the heat exchangeris provided may have only an internal combustion engine as a drive source, or may have both an internal combustion engine and a motor, or may have only a motor, and the heat exchangeris provided to cool the heat-generating parts in each drive system. While cooling water is exemplified as the fluid used for cooling and oil, such as hydraulic oil, is exemplified as the fluid to be cooled, these fluids can be selected as appropriate according to the automobile drive system, the type of heat-generating part, the required cooling performance, etc. Furthermore, in the present embodiment, the fluid used for cooling is referred to as the first fluid, and the fluid to be cooled is referred to as the second fluid, but it is also possible to use the fluid used for cooling as the second fluid and the fluid to be cooled as the first fluid. In the following description, it will be assumed that the first fluid is cooling water, and the second fluid is oil.

The heat exchangercomprises a flat rectangular parallelepiped shaped caseas described later, where the thickness direction of case(the direction in which the casehas an opening, as described later) will be assumed to be the Z direction, and in the XY plane, which is a plane perpendicular to the Z direction, the long edge direction of casewill be assumed to be the X direction, and the short edge direction will be assumed to be the Y direction. Also, hereinafter, the side where the caseis open in the Z direction (the side where the base plateis provided, which is the downward side in) will be referred to as the downward side, and the opposite side (the upward side in) will be referred to as the upward side, and while these may be simply called up and down, referring to up and down with regard to the Z direction is done for the sake of convenience, and these do not necessarily have to match up and down with regard to the vertical direction during actual use.

In addition to the stacked body, the case, and the base plate, the heat exchangerfurther comprises an inlet pipeand an outlet pipe. The heat exchangerhas 2-fold rotational symmetry with respect to an axis of rotation that passes through the intersection of the diagonals L, L, described later, and extends in the Z direction, and the inflow side and outflow side have a symmetrical shape. That is, when the heat exchangeris rotated 180° about this axis of rotation, the shape after rotation matches the shape before rotation.

The stacked body, as also shown in, has a first plateand a second platealternately stacked in the Z direction to form the flow passage for the first fluid (cooling water flow passage) and the flow passage for the second fluid (oil flow passage) alternately in the Z direction, and further has a lowermost plateand an uppermost plate. The stacked bodyis formed on the whole in a rectangular parallelepiped shape by having each platetoextend along the XY plane (the direction along the XY plane will be referred to as the in-plane direction) and stacking the plates in the Z direction. When the stacked bodyis viewed from the Z direction, two virtual diagonals are defined as the first diagonal Land the second diagonal L, and a pair of corner parts connected by the first diagonal Lare defined as the first corner partsA, and a pair of corner parts connected by the second diagonal Lare defined as the second corner partsB (see).

In the stacked body, the second plateis stacked above the lowermost plate(i.e., on the opposite side from the base plateside), and the first plateis stacked above the second plate. The uppermost plateis stacked above the second plate, and has a similar shape to the first plateunless specified otherwise. A fin plateis provided on the upward side from the second plateand the downward side from the first plate, and a flow passage for the second fluid is formed. In contrast, a flow passage for the first fluid is formed between the upward side of the first plateand the downward side of the second plate. It should be noted that for each plate forming the stacked body, for example, aluminum clad material or the like can be used.

As shown in, the lowermost plate, unlike the other plates, does not have a recessed part as described later, and is formed in a rectangular plate shape. The lowermost platehas a through-holeformed in the second corner partB, multiple protruding partsformed on the upper surface, and an outer peripheral flange partprotruding upward in the Z direction from the outer peripheral edge.

As also shown in, the first platehas a recessed partformed in the first corner partsA, a through-holeformed in the second corner partsB, multiple protruding partsformed on the upper surface and protruding upward, an outer peripheral flange partprotruding upward in the Z direction from the outer peripheral edge, and a first closing part(see) extending downward in the first corner partsA. The first plateis formed in a plate shape with the corner parts of the rectangular shape cut away, thereby forming the recessed parts.

As shown also in, the second platehas a recessed partformed in the first corner partsA, a through-holeformed in the second corner partsB, multiple protruding partsformed on the bottom surface and protruding downward, an outer peripheral flange partprotruding upward in the Z direction from the outer peripheral edge, and a second closing part(see) extending upward at the first corner partsA. The second plateis formed in a plate shape with the corner parts of the rectangular shape cut away, thereby forming the recessed parts.

As can be understood from, the uppermost platehas, in the same manner as the first plate(see), a recessed part, multiple protruding parts, and an outer peripheral flange part, and has a shape in which a portion of the rectangular shape has been cut away, but differs from the first platein the aspect that a through-hole is not formed.

The outer peripheral flange parts,,,are formed in the portion of the outer peripheral edge of each plate excluding the recessed part (i.e., in the entire area excluding the location opposite the first distribution flow passage), and specially as shown in, they form a tapered part having an inclination with respect to the Z direction such that they are oriented outward toward the upper side which is the protruding side (i.e., such that the surface area surrounded by the outer peripheral flange part becomes larger). Accordingly, the outer peripheral flange part of the downward side plate is connected so as to be positioned on the outer side of the outer peripheral flange part of the adjacent plate on the upward side by taper fitting and brazing the adjacent outer peripheral flange parts in the Z direction to each other. For example, the outer peripheral flange partof the first plateis positioned on the outer side of the outer peripheral flange partof the second plateadjacent on the upward side, and the outer peripheral flange partof the second plateis positioned on the outer side of the outer peripheral flange partof the first plateadjacent on the upward side.

The multiple plates are assembled by taper fitting and brazing the outer peripheral flange parts together in this way, forming a stacked bodywith an overall rectangular parallelepiped shape as shown in. Moreover, the stacked bodymay be assembled by stacking the plates inside the case, or it may be assembled outside the caseand then housed inside the case.

Among the outer peripheral flange parts,,,, as shown in, the portions extending in the X direction become the fluid guide walls,,,. The first fluid and the second fluid flow along the diagonals L, Las described later, and the fluid guide walls,,,extending in the X direction, which is the long edge direction, have a relatively smaller inclination angle with respect to the flow direction of the first fluid and the second fluid. When the outer peripheral flange parts,,,are connected to each other, the fluid guide walls,,,also come to be connected to each other. This makes it possible for the first fluid and the second fluid to flow along the inner surface of the fluid guide walls,,,, preventing the fluid from flowing out into the casefrom both sides in the Y direction.

In the assembled stacked body, as the recessed parts,,overlap with each other, the recessed partis formed in a portion of the outer peripheral partof the stacked bodythat is closer to the first corner partA than to the central portion of the side wall part in the Y direction. A second distribution flow passagethrough which a second fluid can pass in the Z direction is formed by the through-holes,,overlapping with each other.

In the first plate, a flange part extending upward from around the through-holeis formed, and in the second plate, a flange part extending downward from around the through-holeis formed, and these flange parts are connected to each other (see). This ensures that the space between the upward side of the first plateand the downward side of the second plateis delimited from the second distribution flow passage, preventing the second fluid that passes through the second distribution flow passagefrom flowing into this space. In contrast, the space between the downward side of the first plateand the upward side of the second platecommunicates with the second distribution flow passage.

In the stacked body, due to the outer peripheral flange parts,,,being formed, the space between the plates is delimited from the external space (the space inside the case) except at the recessed part. At the recessed part, the first closing partand the second closing partare connected to form a closing partA, which delimits the space between the downward side of the first plateand the upward side of the second platefrom the external space, while an opening partB is formed between the upward side of the first plateand the downward side of the second plate, allowing this space to communicate with the external space (see). It should be noted that the closing partA is formed extending in the Y direction up to the position of the long edge of the plate between the through-holes,and the outer peripheral flange parts,(see).

The caseis formed in a bottomed tubular shape having a bottom plate partand a tubular side wall partcontinuous with the outer peripheral edge of the bottom plate part, and has a rectangular shape when viewed from the Z direction.

The bottom plate partis formed in a rectangular plate-shaped form along the XY plane, and the corner parts are connected by the first diagonal Land the second diagonal L. In the case, the pair of corner parts connected by the first diagonal Lare designated as the first corner partsA, and the pair of corner parts connected by the second diagonal Lare designated as the second corner partsB.

The side wall parthas a pair of long side wall partscorresponding to the long edges of the bottom plate part, a pair of short-edge side wall partscorresponding to the short edges, and a total of four curved partslocated between the long side wall partsand the short-edge side wall parts.

In each of the pair of short-edge side wall parts, there is formed an inflow portand an outflow portthrough which the first fluid passes. The inflow portand the outflow portare formed in the central portion of the short-edge side wall partin the Z direction, and are formed closer to the first corner partA than to the central portion in the Y direction. That is, the inflow portand the outflow portare arranged along the pair of short edges of the rectangular shape at positions adjacent to the respective diagonally opposed pair of first corner partsA when the caseis viewed from the Z direction.

In each of the pair of short-edge side wall partswhich are flat surface parts within the side wall part, as shown in, stepped partsA are formed around the inflow portor the outflow port. Specifically, the stepped partsA are formed in a linear shape extending in the Z direction at positions that sandwich the inflow portor the outflow portfrom the Y direction when viewed from the X direction. The rectangular-shaped area surrounded by these two straight lines, a line segment that virtually connects the top end parts of the two straight lines, and a line segment that virtually connects the lower end parts of the two straight lines, becomes the inner side regionB where the inflow portor the outflow portis arranged. The regions that sandwich the inner side regionB from the Y direction in the short-edge side wall partbecome the outer side regionC.

The stepped partsA have a level difference in the direction in which the inner side regionB protrudes toward the outer side of casemore than the outer side regionC. The thickness of the short-edge side wall partis fixed in both the inner side regionB and the outer side regionC, that is, in the inner side regionB, the internal dimensions and external dimensions of caseare enlarged.

The side wall parthas an enlarged part, in which the internal dimensions and external dimensions are enlarged, at the edge part on the downward side, which is the open side of case. The lowermost platehas larger external dimensions than the other plates, and the enlarged partis provided for installing the lowermost plate. The amount of enlargement (height of level difference relative to the other portion) of the enlarged partis equal to the height of level difference of the stepped partsA. As a result, the inner side regionB and the enlarged partare smoothly connected, and the inner side regionB and the enlarged partextend along the same plane.

The base plateis formed in a flat plate shape and is provided to block the opening of case. In the base plate, there is formed a pair of through-holesfor the second fluid to pass through, and multiple mounting holes for mounting on other equipment. In the state where the stacked bodyis housed in the caseand the base plateis attached to the case, the through-holeand the second distribution flow passagecommunicate with each other. In the present embodiment, the flow passage of the second fluid in other equipment is directly connected to the through-hole, but a pipe or the like may be attached to the base platefor introducing and discharging the fluid.

The inlet pipeand the outlet pipeare tubular members through which the first fluid passes, and are connected by brazing in a liquid-tight manner to the inflow portand the outflow port, respectively. The outside diameter of the inlet pipeand the outlet pipeis substantially the same as the inside diameter of the inflow portand the outflow port, respectively. In order to lower the fluid resistance, the inside diameter of the inlet pipeand the outlet pipeis made a relatively large diameter (approximately φ 15 mm). It is preferable that the protrusion amount of the inlet pipeand the outlet pipeinto the casebe small, but the detailed structure of this and the structure for connection are not particularly limited.

In the heat exchangeras described above, for example, through heating in a state where the stacked bodyhas been housed in the case, the brazing material provided on the surface of various parts of the stacked bodymelts, and as it cools, the brazing material solidifies to connect the various parts. Specifically, the outer peripheral flange parts of adjacent plates are connected to each other, and the bottom surface or upper surface of the plate and the tip ends of the protruding parts of the plate are connected. Furthermore, the inner surface (bottom surface) of the bottom plate partof caseand the uppermost plateare also connected in a similar manner.

Here, the relationship between the parts of caseand the stacked body, and the flow of fluid will be described. The external dimensions of the rectangular parallelepiped shaped stacked bodyare either substantially equal to or slightly smaller than the internal dimensions of the rectangular tubular side wall part. That is, the outer peripheral partof the stacked body, except for the recessed part, lies along the inner surface of the side wall part. Furthermore, since the inflow portand the outflow portare provided in the vicinity of the first corner partsA, and the recessed partsare provided in the vicinity of the first corner partsA, the recessed partsare provided at the portion opposite to the inflow portand the portion opposite to the outflow port, respectively.

Thus, between the caseand the stacked body, at the recessed parts, a gap is formed between the outer peripheral partand the inner surface of the side wall part, and this gap forms the first distribution flow passage. As described above, since the opening partB is formed between the upward side of the first plateand the downward side of the second plate, the first distribution flow passageand the space between the upward side of the first plateand the downward side of the second platecommunicate with each other.

The first fluid is introduced into the casethrough the inlet pipeand is discharged through the outlet pipe. The first fluid introduced to the inflow portby the inlet pipearrives at the first distribution flow passage. In the first distribution flow passage, the first fluid can flow in the Z direction, and can flow into the space between the upward side of the first plateand the downward side of the second plate. That is, the first fluid is distributed in the Z direction and flows into the multiple spaces between the upward side of each first plateand the downward side of each second plate.

In the stacked body, the first fluid flows from one of the pair of first corner partsA toward the other, and arrives at the first distribution flow passageon the outflow portside. The first fluid that has flowed into the first distribution flow passageon the outflow portside from the spaces between the upward side of each first plateand the downward side of each second plateflows in the Z direction so as to head toward the outflow port. That is, the distributed first fluid is again collected. Then, the first fluid is discharged from the outflow portby means of the outlet pipe.

The second fluid is introduced into and discharged from the stacked body, with one of the pair of through-holesserving as an inflow port and the other as an outflow port. The second fluid that has flowed into the second distribution flow passagefrom one of the pair of through-holescan flow in the Z direction, and can flow into the spaces between the downward side of each first plateand the upward side of each second plate. That is, the second fluid is distributed in the Z direction and flows into the multiple spaces between the downward side of each first plateand the upward side of each second plate.

In the stacked body, the second fluid flows from one of the pair of second corner partsB toward the other, and arrives at the other second distribution flow passage. The second fluid that has flowed into the other second distribution flow passagefrom the spaces between the downward side of each first plateand the upward side of each second plateflows in the Z direction so as to head toward the other through-hole. That is, the distributed second fluid is again collected. Then, the second fluid is discharged to the outside from the other through-hole.

As described above, when the first fluid and the second fluid flow, it is preferable that the directions of flow with respect to the X direction be opposite to each other. That is, it is preferable that the second fluid be introduced into the casefrom the through-holeamong the pair of through-holesthat is nearer to the outflow portin the X direction. Depending on conditions such as the type of fluid and flow rate, the first fluid and the second fluid may be made to flow in the same direction with respect to the X direction.

Next, a detailed description of the structure of the portion of the stacked bodythat is opposite to the inflow portor the outflow portwill be provided. The first closing partis formed extending across the entire recessed part, and has a first wall-like partA that extends to the downward side, which is the side opposite to the protruding side, and a first joining partB that extends from the tip end of the first wall-like partA toward the inflow portor the outflow portalong the XY plane (see). The second closing partis formed across the entire recessed part, and has a second wall-like partA that extends toward the upward side, a second joining partB that extends along the XY plane from the tip end of the second wall-like partA toward the inflow portor the outflow port, and a cover partC that is continuous with the tip end of the second joining partB.

The first joining partB and the second joining partB are overlapped and joined to each other. The cover partC extends so as to rise toward the upward side, and covers the tip end of the first joining partB from the side of the inflow portor the outflow port. That is, the joint location between the first joining partB and the second joining partB is covered by the cover partC. The first joining partB and the second joining partB are connected by brazing, and the joint location is provided so as to extend in the Y direction to the position of the long edge of the plate even between the through-holes,and the outer peripheral flange parts,. Furthermore, the outer peripheral flange parts,are also formed at positions opposite to the through-holes,on the short edge sides of the plate. That is, in the vicinity of the through-holes,, the plates,are joined by brazing not only at the outer peripheral flange parts,but also at the first and second joining partsB,B. This enhances the liquid-tight reliability of the plate joining part in the vicinity of the long edge of the plates,. The cover partC is formed only at positions along the recessed parts,(see). The outer peripheral flange parts,are provided at positions opposite to the through-holes,on the short edge sides of the plate in order to concentrate the flow of the first fluid in the vicinity of the first distribution passage.

Thus, with the heat exchangeraccording to an embodiment of the present invention, the recessed partsare formed in portions of the outer peripheral part of the stacked bodythat are opposite to the inflow portand the outflow port, and the first distribution flow passageis formed by these recessed parts, thereby avoiding the need to increase the size of caserelative to the stacked body. Here, since the distance in the XY plane over which the first fluid passes becomes shorter as a result of forming the recessed parts, it is necessary to make the stacked bodyslightly larger to compensate for this, but the recessed partsare formed locally, and since the outer peripheral part of the stacked bodylies along the inner surface of the side wall partof case, it is possible to avoid increasing the size of the stacked body. In this way, it becomes possible to reduce the overall size of the heat exchangerwhile ensuring the fluid distribution performance by means of the first distribution flow passageformed by the recessed parts.