Heat Exchanger

This application claims priority to Japanese Patent Application No. 2024-095925, filed on Jun. 13, 2024, the contents of which is hereby incorporated by reference in its entirety.

The present disclosure relates to heat exchangers.

In general, a heat exchanger in which two types of fluid flow paths are formed alternately by stacking a plurality of plates are known as a heat exchanger provided in a vehicle, etc. In such heat exchangers, the pressure loss is reduced by matching the in-plane direction of the plate rather than matching the direction in which the fluid flows in and out with the stacking direction. As a heat exchanger having an inflow and outflow direction of such fluid, it is proposed that a cooling water inlet and outlet are formed on the side of the outer peripheral wall of the cylindrical casing, and that a gap is secured between the outer peripheral wall of the casing and the outer perimeter of the core to allow cooling water to flow in the plate stacking direction of the core (see, for example, Patent Literature 1). In the heat exchanger described in Patent Literature 1, cooling water introduced into the interior of the casing from the outer wall is distributed longitudinally and then passed through the interior of the core to be derived from the outer wall.

The plurality of plates forming the core of the heat exchanger have through-holes, etc. formed for fluid to pass through, and in order for these to be in the desired state of connection, the in-plane deviation between the plates needs to be suppressed. However, in the heat exchanger described in Patent Literature 1, a core was formed by stacking a plurality of tubes consisting of a first plate and a second plate, making it difficult to stack the tubes accurately, and improvement in workability was desirable.

The present disclosure is made in light of the above-mentioned problems and is intended to provide a heat exchanger that can improve workability while reducing pressure loss.

To solve the above problem, a heat exchanger according to the present disclosure comprises a laminated body in which a flow path for a first fluid and a flow path for a second fluid are alternately formed in a stacking direction by alternatingly stacking a first plate and a second plate, a bottom tube-shaped case housing the laminated body and opening one side of the stacking direction, and a base plate provided on an open side of the case, the case having an inlet and outlet through which the first fluid passes in a sidewall portion extending along the stacking direction, the first plate and the second plate each having an outer circumferential flange portion protruding in the stacking direction from an outer circumferential edge, the outer circumferential flange portion being taper-joined to the outer circumferential flange portion of another plate adjacent to the protruding side, and between the first plate and the second plate adjacent to each other in the stacking direction, an opening portion that opens the gap between the plates to form a flow path for the first fluid and a closing portion that closes the gap between the plates to form a flow path for the second fluid are formed at a position facing the inlet or the outlet.

According to this aspect, since the case has an inlet and an outlet in the sidewall portion, the first fluid can flow in a direction that intersects the layering direction when flowing into the case and passing between the plates, reducing pressure loss. In addition, an outer circumferential flange portion is formed in the first plate and the second plate, and by taper fitting the outer circumferential flange portions in the plates adjacent to the stacking direction, the plates can be positioned in the in-plane direction, and the plates can be superimposed in a predetermined order to improve workability.

The case may have a first distribution channel formed extending in the stacking direction sequentially to the inlet or outlet, and at least a portion of the plurality of the first plate or the second plate may have an extension continuous to the outer circumferential flange portion to reduce the open area of the opening. According to this aspect, reducing the open area of the opening portion can limit the flow rate of the first fluid flowing into the flow path for the first fluid. When the first fluid flowing into the case from the inlet is dispensed in the stacking direction, the position closer to the inlet in the stacking direction is more likely to have a higher flow rate, and the position farther from the inlet is more likely to have a smaller flow rate. Limiting the flow rate, especially at a position close to the inlet, makes it easier to secure the flow rate even at a position far from the inlet, and can reduce the difference in flow rate between each position in the stacking direction.

The outer circumferential flange portion has fluid guide walls extending along the flow direction of the first fluid and the second fluid in the laminated body, and the fluid guide walls may be joined together in the first plate and the second plate adjacent to each other. According to this aspect, the outer circumferential flange portion can define a flow path of the fluid. That is, there is no need to define a flow path by the case or other member and the structure of the heat exchanger can be simplified.

The outer circumferential flange portion may be provided throughout the circumferential edge of the first plate and the second plate, except for positions opposite the first distribution channel. According to this aspect, fluid can flow into the flow path between the inlet and outlet more efficiently.

The blockage portion may have a first blockage portion formed in the first plate and a second blockage portion formed in the second plate, the first blockage portion having a first wall-like portion extending opposite the protruding side and a first joint portion extending from a tip of the first wall-like portion towards the inlet or the outlet, the second blockage portion having a second wall-like portion extending toward the protruding side and a second joint extending from a tip of the second wall-like portion towards the inlet or outlet, and the first joint and the second joint may be superimposed and joined together. According to this aspect, it is easy to secure the joint area between the first joint portion and the second joint portion, and fluid leakage at the blockage portion may be suppressed.

The first blockage portion or the second blockage portion may have a cover portion that covers the other end from the side of the inlet continuously at one end of the first joint portion and the second joint portion. According to this aspect, it is inhibited that fluid flowing from the inlet directly towards the tip of the first joint portion or the second joint portion. This can reduce the pressure of the fluid applied to the joint portion between the first joint portion and the second joint portion and can reduce chemical degeneration of the joint portions and deformation or damage due to pressure.

According to the heat exchanger according to the present disclosure, workability can be improved while reducing pressure loss.

Embodiments of the present disclosure will be described below with reference to the drawings. As shown in, the heat exchangeraccording to an embodiment of the present disclosure comprises a laminated bodyin which a flow path for a first fluid (cooling water in the present embodiment) and a flow path for a second fluid (oil in the present embodiment) are alternately formed in the Z direction (stacking direction), a bottomed tubular casecontaining the laminated bodyand opening one side in the Z direction, and a base plateprovided on the open side of case. Casehas an inletand an outletthrough which the first fluid passes in the sidewall portionextending along the Z direction. The outer perimeterof the laminated bodyis formed along the inner surface of the sidewall portionof caseand has recess portionsthat are spaced from the inner surface of the sidewall portionat portions opposite the inletand the outlet. The recess portionforms a first distribution channelbetween the outer perimeterof the laminated bodyand the inner surface of the sidewall portionin which the first fluid flows along the Z direction.

In addition, the first plateand the second plateeach have an outer circumferential flange portionandprotruding in the Z direction from the outer circumferential edge, as illustrated in. The outer circumferential flange portionsandare taper-joined to the outer circumferential flange portionsandof other plates adjacent to the protruding side. Between the first plateand the second plateadjacent to each other in the Z direction, as shown in, at a position opposite the inletor the outlet, an opening portionB is formed which opens the space between the plates which serves as a flow path for the first fluid (cooling water), and a closing portionA is formed which closes the space between the plates which serves as a flow path for the second fluid (oil).

Caseis also rectangular and has a first fluid passing through the inletand outletand a step portionA formed around the inletor outletin the short side sidewall portionas a planar portion of the sidewall portion(see).

Here,is a perspective view illustrating the heat exchangeraccording to an embodiment of the present disclosure,is a perspective view illustrating the laminated bodyand the base plateof the heat exchanger,is a cross-sectional view through the outlet pipeof the heat exchanger,is a cross-sectional view passing through an inlet pipeof a heat exchanger,is an enlarged cross-sectional view illustrating a portion of,is an enlarged cross-sectional view illustrating a portion of,is a plan view illustrating the bottom plateof the laminated body,is a plan view illustrating the first plateof the laminated body,is a plan view illustrating the second plateof the laminated body,is a cross-sectional view passing through a second distribution channel (in this embodiment where the first fluid is cooling water and the second fluid is oil, a flow path that connects the oil flow paths in the stacking direction of the core among the oil flow paths formed alternately with the water paths)of the heat exchanger,is a side view illustrating the heat exchanger, andis a side view of the laminated bodyand base plate.

Heat exchangerare used in cooling water systems of automobiles (vehicles), for example. The automobile to which the heat exchangeris provided may have only an internal combustion engine as the driving source, may have an internal combustion engine and a motor, may have only a motor, and a heat exchangeris provided to cool the heating portion in each driving method. Cooling water is exemplified as the fluid used for cooling, and hydraulic oils and other oils are exemplified as the fluid to be cooled, but these fluids can be selected as appropriate according to the driving method of the automobile, the type of heating portion, the required cooling performance, etc. In the present embodiment, the fluid used for cooling is the first fluid and the fluid to be cooled is the second fluid, but in addition to the fluid used for cooling being the second fluid, it is also possible to use the fluid to be cooled as the first fluid. In the following description, the first fluid is cooling water and the second fluid is oil.

The heat exchangercomprises a flat rectangular case, as described below, with the thickness direction of case(the direction in which casehas an opening as described below) in the Z direction, with the long side direction of casein the XY plane, which is a plane orthogonal to the Z direction, and the short side direction in the Y direction. In addition, in the following, the side on which caseopens in the Z direction (the side on which base plateis provided, the bottom side in) is the lower side, the opposite side (the upper side in) is the upper side, and these may be simply referred to as the upper and lower sides, but the upper and lower sides in the Z direction are for convenience, and may not match the vertical direction upper and lower sides in the actual use state.

The heat exchangerfurther comprises an inlet pipeand an outlet pipein addition to the laminated body, caseand base plate. The heat exchangerhas two rotational symmetry with respect to the rotational axis extending in the Z direction as well as passing through the intersection points of diagonal lines Land Ldescribed below, and has a symmetrical shape between the inlet side and the outlet side. That is, when the heat exchangeris rotated 180° around this rotation axis, the shape before rotation matches the shape after rotation.

In the laminated body, the first plateand the second plateare alternately stacked in the Z direction to alternately configure the flow path for the first fluid (cooling water flow path) and the flow path for the second fluid (oil flow path) in the Z direction, and the laminated bodyfurther includes the bottom plateand the top plate, as also shown in. The laminated bodyis formed in a rectangular form as a whole by being stacked in the Z direction with each platetoextending along the XY plane (in-plane direction along the XY plane). The two virtual diagonals as seen from the Z direction of the laminated bodyare the first diagonal line Land the second diagonal line L, the pair of corners connected by the first diagonal line Lis the first corner portionA, and the pair of corners connected by the second diagonal line Lis the second corner portionB (see).

In the laminated body, a second plateis overlaid on the bottom plate(that is, opposite side of the base plate) and a first plateis overlaid thereon. The top plateis overlaid on the second plateand is shaped similarly to the first plateunless otherwise explained. A fin plateis provided on the upper side of the second plateand lower side of the first plateto form a flow path for the second fluid. In contrast, a flow path for a first fluid is formed between the upper side of the first plateand the lower side of the second plate. It should be noted that each plate comprising the laminated bodycan use, for example, a clad material of aluminum.

The bottom plate, unlike other plates, as shown in, does not have recess portions as described below and is formed in a rectangular plate. The bottom platehas a through holeformed in the second corner portionB, a plurality of convex portionsformed in the top surface, and an outer circumferential flange portionprojecting upward in the Z direction from the outer circumferential edge.

The first platehas a recess portionformed in the first corner portionA, a through holeformed in the second corner portionB, a plurality of convex portionsformed in the upper surface and convex on the upper side, an outer circumferential flange portionprojecting upward in the Z direction from the outer circumferential edge, and a first blockage portion(see) extending downward in the first corner portionA, as also shown in. The first plateis formed with a recess portiondue to the rectangular corners being formed in an ablated plate shape.

The second platehas a recess portionformed in the first corner portionA, a through holeformed in the second corner portionB, a plurality of convex portionsformed on the lower surface and convex on the lower side, an outer circumferential flange portionprojecting upward in the Z direction from the outer circumferential edge, and a second occlusion portion(see) extending upward in the first corner portionA, as also shown in. The second plateforms a recess portionbecause the rectangular corners are formed in an ablated plate.

As can be seen from, the top platehas a recess portion, a plurality of convex portions, and an outer circumferential flange portion, similar to the first plate(see), and although a portion of the rectangle is ablated in shape, it differs from the first platein that no through-holes are formed.

The circumferential flange portions,,, andare formed in portions of each plate peripheral edge excluding recess portions (that is, all but the positions opposite the first distribution channel), and are tapered portions with an incline relative to the Z direction such that they are outwardly facing upward (i.e., the area surrounded by the circumferential flange portion is greater) as they are protruding, particularly as shown in. This causes the circumferential flanges of the lower plate to taper mating and brazing together in the Z direction such that the circumferential flanges of the upper side plate are located outwardly relative to the circumferential flanges of the upper side adjacent plate. For example, the outer circumferential flange portionof the first plateis located outside the outer circumferential flange portionof the second plateadjacent to the upper side, and the outer circumferential flange portionof the second plateis located outside the outer circumferential flange portionof the first plateadjacent to the upper side.

By brazing the outer circumferential flanges together in this manner, a plurality of plates are assembled, resulting in a rectangular laminated bodyas a whole as shown in. The laminated bodymay be stacked and assembled in caseor may be housed in caseafter being assembled outside case.

Among the circumferential flange portions,,, and, the portion extending along the X direction becomes the fluid guide walls,,, and, as shown in. The first fluid and the second fluid flow along diagonal lines Land L, as described below, and the fluid guide walls,,, andextending along the long side direction X direction have relatively small angles of inclination with respect to the flow direction of the first fluid and the second fluid. When the outer circumferential flanges,,, andare joined together, the fluid guide walls,,, andare also joined together. This allows the first fluid and the second fluid to flow along the inner surface of the fluid guide wall,,, andso that no fluid flows from either side of the Y direction into case.

In the laminated bodyafter assembly, the recess portions,, andoverlap each other, and a recess portionis formed in the vicinity of the first corner portionA with respect to the central portion in the Y direction of the sidewall portion of the outer perimeterof the laminated body. The through holes,, andoverlap each other to form a second distribution channelthrough which the second fluid can pass along the Z direction.

In the first plate, a flange portion is formed extending from the perimeter of the through holetowards the upper side, and in the second plate, a flange portion is formed extending from the perimeter of the through-holetowards the lower side, where these flange portions are joined together (see). This allows the space between the upper side of the first plateand the lower side of the second plateto be compartmented with the second distribution channelso that the second fluid passing through the second distribution channeldoes not flow into this space. In contrast, the space between the lower side of the first plateand the upper side of the second plateis in communication with the second distribution channel.

The laminated bodyis partitioned with space between the plates and outer space (space within case) other than the recess portionsbecause the outer circumferential flange portions,,, andare formed. In the recess portion, the space between the lower side of the first plateand the upper side of the second plateis partitioned from the outer space by the first blockage portionand the second blockage portionare joined to form the blockage portionA, and an opening portionB is formed between the upper side of the first plateand the lower side of the second plate, which is in communication with the outer space (see). The blockage portionA is formed between the through holesandand the circumferential flangesandextending in the Y direction to the position of the long side of the plate (see, and).

Caseis formed in a bottom cylinder with a bottom plate portionand a cylindrical sidewall portioncontinuous on the outer perimeter of the bottom plate portion, and is rectangular in view of the Z direction.

The bottom plate portionis formed in a rectangular plate along the XY plane, with corners connected by the first diagonal line Land the second diagonal line Ldescribed above. In case, the pair of corners connected by first diagonal line Lis set as first corner portionA, and the pair of corners connected by second diagonal line Lis set as second corner portionB.

The sidewall portionhas a pair of long side sidewall portioncorresponding to a long side of the bottom plate, a pair of short side sidewall portioncorresponding to a short side, and a total of four curved surfaceslocated between the long side sidewall portionand short side sidewall portion.

Each of the pair of short side sidewall portionis formed with an inletand an outletthrough which the first fluid passes. The inletand outletare formed in the short side sidewall portionat a central portion in the Z direction and closer to the first corner portionA than the central portion in the Y direction. That is, the inletand the outletare positioned adjacent to each of the diagonal pairs of first corner portionA of the pair of short sides of a rectangular shape when caseis viewed from the Z direction.

Each of the pair of short side sidewall portion, which are planar portions of the sidewalls, has a step portionA formed around the inletor outletas shown in. Specifically, the step portionA is formed in a straight line extending along the Z direction at a position sandwiching the inletor outletfrom the Y direction as viewed from the X direction. The rectangular region surrounded by the two lines, the line portion that virtualizes the top ends of the two lines, and the line portion that virtualizes the bottom ends, becomes the inner regionB in which the inletor outletis disposed. The region sandwiching the inner regionB from the Y direction in the short side sidewall portionbecomes the outer regionC.

The step portionA has a step in an orientation in which the inner regionB protrudes outwardly of casethan the outer regionC. The short side sidewall portionhas a constant wall thickness between the inner regionB and the outer regionC, that is, in the inner regionB, the inner and outer dimensions of caseare enlarged.

The sidewall portionhas an enlarged magnification portionat the lower edge that is the open side of case. The bottom plateis larger in external dimensions than the other plates and a magnification portionis provided for mounting the bottom plate. The magnification of the magnification portion(step height relative to other parts) is equal to the step height of the step portionA. This allows the inner regionB and the magnification portionto be smoothly connected, and the inner regionB and the magnification portionextend along the same plane.

The base plateis formed in a flat plate and is provided to block the opening of case. The base plateis formed with a pair of through holesfor passage of the second fluid and a plurality of mounting holes for attachment to other equipment. With the laminated bodyhoused in caseand the base plateattached to case, the through holeand the second distribution channelare in communication. In the present embodiment, the second fluid flow path and through holein other equipment shall be connected directly, but a pipe or the like may be attached relative to the base plateto introduce and derive fluid.

The inlet pipeand the outlet pipeare cylindrical members through which the first fluid passes, and are liquid tightly brazed connected to each of the inletand outlet. The inlet pipeand the outlet pipehave an outer diameter that is approximately the same as the inner diameter of each of the inletand outlet. In order to reduce the fluid resistance, the inner diameter of the inlet pipeand the outlet pipeis relatively large (about ø15 mm). The inlet pipeand the outlet pipepreferably have a small amount of protrusion into case, but are not particularly limited in terms of the detailed structure or the structure for the connection.

In the heat exchangeras described above, for example, by heating with the laminated bodycontained in case, the wax material provided on the surface of each part of the laminated bodymelts and cools, solidifying the wax material and joining each part. Specifically, the outer circumferential flanges of adjacent plates are joined together with the bottom or top surface of the plate and the tip of the convex portion of the plate. The inner surface (lower surface) of the bottom plate portionof caseand the top plateare also joined in the same manner.

The relationship between each part of caseand the laminated bodyand the flow of fluid will now be described. The external dimensions of the rectangular tubular sidewall portionare approximately equal or slightly smaller than the internal dimensions of the rectangular laminated body. That is, the laminated body, except for the recess portion, has its outer perimeteralong the inner surface of the sidewall portion. Also, since the inletand outletare provided in the vicinity of the first corner portionA and the recess portionis provided in the vicinity of the first corner portionA, the recess portionis provided in each of the portions opposite the inletand the portion opposite the outlet.

In this way, a gap is formed between caseand the laminated bodyat the recess portionbetween the outer perimeterand the inner surface of the sidewall portion, which is the first distribution channel. As described above, an opening portionB is formed between the upper side of the first plateand the lower side of the second plate, so that the space between the first distribution channeland the upper side of the first plateand the lower side of the second plateis in communication.

The first fluid is introduced from the inlet pipeinto caseand derived from the outlet pipe. The first fluid introduced into the inletby the inlet pipereaches the first distribution channel. In the first distribution channel, the first fluid can flow along the Z direction and into the space between the upper side of the first plateand the lower side of the second plate. That is, the first fluid is dispensed in the Z direction and flows into each of the plurality of spaces between the upper side of the first plateand the lower side of the second plate.

In the laminated body, the first fluid flows from one of the pair of first corner portionsA towards the other to reach the first distribution channelon the outletside. The first fluid flowing from each of the spaces between the upper side of the first plateand the lower side of the second plateinto the first distribution channelon the outletside flows along the Z direction towards the outlet. That is, the dispensed first fluid is again aggregated. The first fluid is then derived from the outletby the outlet pipe.

The second fluid is introduced and derived into the laminated bodywith one of the pair of through holesas an inlet and the other as an outlet. The second fluid flowing from one of the pair of through holesinto the second dispensing channelcan flow along the Z direction and can flow into the space between the lower side of the first plateand the upper side of the second plate. That is, the second fluid is dispensed in the Z direction and flows into each of the plurality of spaces between the lower side of the first plateand the upper side of the second plate.

In the laminated body, the second fluid flows from one of the pair of second corner portionsB towards the other to reach the other second distribution channel. The second fluid flowing from each of the spaces between the lower side of the first plateand the upper side of the second plateinto the other second distribution channelflows along the Z direction towards the other through hole. That is, the dispensed second fluid is again aggregated. The second fluid is then derived externally from the other through hole.

Preferably, when the first fluid and the second fluid flow as described above, the direction of flow in the X direction is opposite to each other. That is, the second fluid is preferably introduced into casefrom the through holethat is closer to the outletin the X direction of the pair of through holes. Depending on conditions such as fluid type and flow rate, the first fluid and the second fluid may flow in the same direction in the X direction.

Next, details of the structure of the portion of the laminated bodyopposite the inletor outletwill be described. The first blockage portionis formed throughout the recess portionand has a first wall-like portionA extending towards the lower side opposite the protruding side and a first joint portionB extending along the XY plane from the tip of the first wall-like portionA towards the inletor outlet(see). The second blockage portionis formed throughout the recess portionand has a second wall-like portionA extending upwardly, a second joint portionB extending along the XY plane from the tip of the second wall-like portionA towards the inletor outlet, and a cover portionC continuous to the tip of the second joint portionB.