Heat Exchanger

The present application claims priority to Japanese Patent Application No. JP 2024-095926 filed on Jun. 13, 2024, the contents of which are 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 an inlet pipe and outlet pipe are connected to these inlet and outlet ports.

When a heat exchanger is incorporated into a vehicle or the like, the space for the heat exchanger is set in consideration of the relationship with other components. As described in Patent Literature 1, by providing inlet and outlet ports for fluid in the outer peripheral wall (i.e., the side wall part) of the casing, and connecting pipes extending in a direction perpendicular to the stacking direction of the plates, the overall height (stacking direction dimension) of the heat exchanger becomes smaller and is flattened. Here, with a tubular casing, the space utilization efficiency may become lower, and due to layout considerations, in some cases the use of a rectangular-shaped casing has been desired.

However, when forming inlet and outlet ports for fluid in the side wall part of a rectangular-shaped casing and connecting pipes thereto, the rigidity of the flat-shaped side wall part tends to decrease, so there is the possibility that deformation would occur during manufacturing or use. That is, when achieving improvement in space utilization efficiency while flattening, there have been situations where it was difficult to ensure the rigidity of the casing.

The present invention was made in view of the aforementioned problem, and it is an object of the present invention to provide a heat exchanger that makes it possible to improve the rigidity of the case.

To solve the aforementioned 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 and rectangular parallelepiped shaped 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 flat surface part of a side wall part that extends in said stacking direction, and a stepped part formed around said inflow port or said outflow port.

According to this aspect, since stepped parts surround the inflow port and the outflow port in the flat surface part, even when using a rectangular parallelepiped shaped case and providing the inflow port and the outflow port in the side wall part to achieve space utilization efficiency, the rigidity of the case can be improved. For example, since the pipes are attached to the inflow port or outflow port by brazing, when an external force acts from the outer side in a direction that would topple the pipes, it is possible to avoid stress concentration at the base where the pipes are attached. Furthermore, in cases where the diameter of the pipes is made larger to lower the flow path resistance or the like, the bonding surface area of the brazed pipes increases, increasing the joint strength of the pipes, so when an external force acts on the pipes, a major deformation force acts on the flat surface part to which the pipes are attached, but deformation of flat surface part to which the pipes are attached is suppressed by the stepped parts.

The aforementioned stepped parts may have a level difference with a direction such that the inner side region thereof protrudes more toward the outer side of the case than the outer side region.

According to this aspect, the internal space of the case is enlarged at the position where the inflow port and outflow port are formed. As a result, it becomes possible to enlarge the flow passage for when a first fluid that has flowed into the interior of the case through the inflow port flows in the stacking direction, or when the first fluid heading from the stacked body toward the outflow port flows in the stacking direction.

The side wall part may also have an enlarged part with enlarged internal dimensions and external dimensions, in an edge part on the open side of the case, wherein the inner side region and the enlarged part extend along the same plane. According to this aspect, rigidity of the open side of the case can be improved by means of the enlarged part. Furthermore, the shape can be simplified as compared to a configuration in which the stepped part and the enlarged part are located on different planes.

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. According to this aspect, since relative rigidity can be ensured more easily at locations adjacent to the corner parts within the flat surface part and since the inflow port and outflow port are formed at such locations, decrease in rigidity of the case due to forming of the inflow port and outflow port can be suppressed.

With the heat exchanger according to the present invention, rigidity of the case can be improved.

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, 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 another portion 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 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 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, 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 L1, L2, 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 L1 and the second diagonal L2, and a pair of corner parts connected by the first diagonal L1 are defined as the first corner partsA, and a pair of corner parts connected by the second diagonal L2 are 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 especially 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 parts 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 case, or it may be assembled outside caseand then housed inside 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 L1, L2 as 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 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 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).

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 shape along the XY plane, and the corner parts are connected by the first diagonal L1 and the second diagonal L2. In case, the pair of corner parts connected by the first diagonal L1 are designated as the first corner partsA, and the pair of corner parts connected by the second diagonal L2 are 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 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 upper 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 region that sandwiches the inner side regionB from the Y direction in the short-edge side wall partbecomes 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 caseand the base plateis attached to 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 q 15 mm). It is preferable that the protrusion amount of the inlet pipeand the outlet pipeinto 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 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 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 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 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.