Abstract
A cooling member includes a heat-transfer member, a refrigerant introducing pipe and a covering material. The heat-transfer member has a surface with a groove opened to the surface of the heat-transfer member. The refrigerant introducing pipe is pressed into the groove. The covering material coats the surface of the heat-transfer member and the refrigerant introducing pipe.
Claims
1. A cooling member comprising: a heat-transfer member having a surface with a groove opened to the surface of the heat-transfer member, the heat transfer member being a plate; a refrigerant introducing pipe pressed into the groove, the groove having tabs extending toward each and formed to retain the pipe in the groove such that the heat transfer member partially overlies the refrigerant introducing pipe as viewed along a direction perpendicular to the surface of the heat transfer member, outer surfaces of the tabs being located on a same surface as a plane of the surface of the heat transfer member, and the refrigerant introducing pipe being in contact with the groove and inner surfaces of the tabs; and a covering material coating portions of the surface of the heat-transfer member adjacent the groove and an exposed portion of the refrigerant introducing pipe disposed in the groove such that the covering material is applied to joints between the heat-transfer member and the refrigerant introducing pipe to block the joints from atmosphere, and portions of the surface of the heat transfer member spaced from the groove being uncovered by the covering material.
2. The cooling member according to claim 1, wherein the covering material includes a coating material applied to the surface of the heat-transfer member and the refrigerant introducing pipe.
3. The cooling member according to claim 1, wherein the covering material includes a cover that covers the heat-transfer member.
4. The cooling member according to claim 1, wherein electric parts are mounted on one surface of a heat-conducting member, which is arranged and configured to make the surface of the heat-transfer member and the refrigerant introducing pipe closely fitted with each other on another surface of the heat-conducting member.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) FIG. 1 is a perspective view showing a cooling member and a main portion of a manufacturing device thereof according to Example 1 of the present invention;
(2) FIG. 2(a) is a side view illustrating dimensions of a punch and a heat-transfer member applied to the manufacturing device for a cooling member according to Example 1 of the present invention;
(3) FIG. 2(b) is a side view illustrating dimensions of a refrigerant introducing pipe deformed by the punch;
(4) FIGS. 3(a) to 3(c) are respectively a side view illustrating procedures of a manufacturing method to be carried out using the manufacturing device or the cooling member of the present invention;
(5) FIG. 3(d) is a cross-sectional view in a width direction in which the cooling member is fractured on A-A lines;
(6) FIG. 4(a) is a side view showing a process of operation of the manufacturing device for the cooling member according to Example 1 of the present invention;
(7) FIG. 4(b) is a side view showing a process of operation of a first variant of the manufacturing device for the cooling member;
(8) FIG. 5(a) is a cross-sectional view in a width direction showing a process of operation of a second variant of the manufacturing device for the cooling member according to Example 1 of the present invention;
(9) FIG. 5(b) is a cross-sectional view of a cooling member manufactured by the device;
(10) FIG. 6(a) is a cross-sectional view in a width direction showing a process of a third variant of the manufacturing device for the cooling member according to Example 1 of the present invention;
(11) FIG. 6(b) is a cross-sectional view of a cooling member manufactured by the device;
(12) FIG. 7(a) is a plan view of a cooling member according to Example 2 of the present invention;
(13) FIG. 7(b) is a cross-sectional view in a width direction in which the cooling member is fractured on A′-A′ line;
(14) FIG. 8 is a cross-sectional view showing a first variant of the cooling member according to Example 2 of the present invention;
(15) FIG. 9 is a graph showing changes of thermal resistance ratio caused by an acetic acid salt water spray test to be targeted for the cooling member shown in FIG. 8;
(16) FIG. 10 is a cross-sectional view showing a second variant of the cooling member according to Example 2 of the present invention;
(17) FIG. 11 is a cross-sectional view showing a third variant of the cooling member according to Example 2 of the present invention;
(18) FIG. 12 is a cross-sectional view showing a fourth variant of the cooling member according to Example 2 of the present invention;
(19) FIG. 13 is a side view showing a fifth variant of the cooling member according to Example 2 of the present invention;
(20) FIG. 14(a) is a cross-sectional view in a width direction showing a process of a manufacturing method for a cooling member according to embodiments of the present invention;
(21) FIG. 14(b) is a cross-sectional view of a cooling member manufactured by the method.
(22) FIG. 15 is a view in which a refrigerant introducing pipe is in accordance with dimensions of a groove of a heat-transfer member applied to a method for manufacturing a cooling member according to embodiments of the present invention;
(23) FIG. 16 is a graph in which a half of a minor axis of a groove in a heat-transfer member applied to the method for manufacturing a cooling member according to embodiments of the present invention is indicated as a horizontal axis and a calculated value of the circumference of an inner circumferential surface is indicated as a vertical axis;
(24) FIG. 17 is a graph showing a dent ratio of a refrigerant introducing pipe deformed by the method for manufacturing a cooling member according to embodiments of the present invention in a horizontal axis and an increase ratio of pressure loss of refrigerant according to an increase in the dent ratio in a vertical axis;
(25) FIG. 18(a) is a cross-sectional view showing a fifth variant of a heat-transfer member applicable to the method for manufacturing a cooling member according to embodiments of the present invention;
(26) FIG. 18(b) is a cross-sectional view showing a sixth variant of a heat-transfer member applicable to the method for manufacturing a cooling member according to embodiments of the present invention;
(27) FIG. 19 is a perspective view illustrating procedures for a conventional method for manufacturing a cooling member;
(28) FIGS. 20(a) and 20(c) are respectively side views illustrating procedures for a conventional manufacturing method for a cooling member;
(29) FIG. 20(b) is a cross-sectional view taken on B-B lines;
(30) FIG. 20(d) is a cross-sectional view taken on C-C lines;
(31) FIG. 21(a) is a cross-sectional view showing an example of a conventional process for manufacturing a cooling member:
(32) FIG. 21(b) is a cross-sectional view showing an example of a cooling member manufactured by the process;
(33) FIG. 22(a) is a cross-sectional view showing a conventional process for manufacturing a cooling member:
(34) FIGS. 22(b) to 22(d) are respectively cross-sectional views of an example of a cooling member manufactured by the process.
DETAILED DESCRIPTION OF EMBODIMENT(S)
(35) The cooling member, the device and the method for manufacturing the cooling member according to the present invention will now be described in the following Examples 1 to 3.
EXAMPLE 1
(36) As shown in FIG. 1, a device 1 for manufacturing a cooling member comprises: a punch 7 wherein corners 3 are formed in a curved surface shape at both ends and a pressing surface 5 is a lower surface of the web of the punch 7; and a support 13 for supporting a heat-transfer member 9 in such a posture that a groove 11 is arranged at a position opposite to the pressing surface 5.
(37) The punch 7 is a cuboid in which two corners 3 are respectively located adjacent to the pressing surface 5. The wording “in a curbed surface state” of the corners 3 herein does not only mean that the surface is a spherical-like state but also means an aspheric surface-like state. Further, the punch 7 is to be attached to a ram of a press machine as a mold. Since a press machine is an obvious art, it is omitted in figures. The support 13 is a jig for positioning the heat-transfer 9 on a bed of the press machine and may fix the heat-transfer member 9 using bolts or the like.
(38) FIG. 2(a) shows a state that the punch 7 moves backward (rise) from the heat-transfer member 9. And FIG. 2(b) shows a state that the punch 7 moves closer to the heat-transfer member 9. As mentioned above, the two corners 3 of the punch 7 arranged at a position opposite to the heat-transfer member 9 are respectively positioned inwardly of edges 15 longitudinally located at both sides of the heat-transfer member 9. Dimension d shows a distance from a boundary between the corners 3 and the pressing surface 5 to the edges 15. A width x to be pressed which corresponds to longitudinal dimensions of the pressing surface 5 is set to be shorter than a full width L. The full width L is a distance where the edges 15 of both sides of the heat-transfer member 9 are spaced.
(39) Referring to a method for manufacturing a cooling member as below. As shown in FIG. 3(a), the punch 7 is moved backward from the heat-transfer member 9 to insert a refrigerant introducing pipe 17 into a groove 11 and then the punch 7 is moved forward. In this process, as shown in FIG. 3(b), first, the entire area of the pressing surface 5 of the punch 7 contacts the refrigerant introducing pipe 17. The refrigerant introducing pipe 17 is pressed to the pressing surface 5 by further moving the punch 7 forward to be plastically deformed into a flattened shape, the corners 3 gradually come in contact with a surface of the refrigerant introducing pipe 17. A force with which the corners 3 press the refrigerant introducing pipe 17 is dispersed in a longitudinal direction outwardly beyond the corners 3, resulting in no scratch on the surface of the refrigerant introducing pipe 17 by being excessively pressed by the corners 3. As mentioned above, it is possible to secure reliability and physical strength of the refrigerant introducing pipe 17 by keeping the surface of the refrigerant introducing pipe 17 smooth.
(40) As shown in FIG. 2(b), operation for moving the punch 7 forward is stopped when a deformation quantity p of the refrigerant introducing pipe 17 reaches a desired size to move the punch 7 backward to the position shown in FIG. 2(a). The refrigerant introducing pipe 17 is closely fitted with the inner surface of the groove 11 in the process so far. And as shown in FIG. 3(c), curbed surfaces of curvature radius R substantially identical to the corners 3 of the punch 7 are formed in the refrigerant introducing pipe 17. Further, no unnecessary bending force is applied to the refrigerant introducing pipe 17 projecting from the edges 15 because a reaction force for plastically deforming the aforementioned refrigerant introducing pipe 17 is completely received between the corners 3 of the punch 7 and the edges 15 of the heat-transfer member 9. Accordingly, it is possible to assemble a cooling member 19 which is accurate in dimension and direction of the refrigerant introducing pipe 17 projecting from the edges 15.
(41) In the cooling member 19, a region 23 to be pressed is formed in the refrigerant introducing pipe 17 by the shrinkage of the refrigerant introducing pipe 17 in a direction where the refrigerant introducing pipe 17 is pressed to the punch 7 of a press machine. Moreover, in the refrigerant introducing pipe 17, curbed surface portions 25 in the shape of gradually shrinking in a direction where the refrigerant introducing pipe 17 are pressed to the press machine with a move to the region 23 to be pressed from the edges 15 of the heat-transfer member 9. Gradually shrinking means herein that the refrigerant introducing pipe 17 is mostly plastically deformed into the shape of a curbed surface of the curvature radius R in accordance with the corners 3 of the punch 7.
(42) The curvature radius R is preferably greater than a thickness t of the refrigerant introducing pipe 17 from a viewpoint of avoiding the concentration of stress on a portion where the refrigerant introducing pipe 17 has been deformed. Further, when the curvature radius R is greater than a diameter φ of the refrigerant introducing pipe 17, the deformation quantity of the refrigerant introducing pipe 17 runs short between the corners 3 of the punch 7 and the edges 15 of the heat-transfer member 9. As a result, a contact force between the inner surface of the groove 11 and the refrigerant introducing pipe 17 becomes weaker, so that heat-transfer performance therebetween is lost. It is, therefore, preferable to set in such a manner that the curvature radius R of the corners 3 is t<R<φ.
(43) Since the corners 3 of the punch 7 get closer to the edges 15 of the heat-transfer member 9 so as to set the dimension d small, resulting in a stronger tendency to apply a bending force based on the reaction force of the aforementioned plastic deformation to the refrigerant introducing pipe 17, the dimension d is preferably set greater than the deformation quantity p of the refrigerant introducing pipe 17. Since the width x to be pressed of the pressing surface 5 is restricted when the dimension d is set to be twice as great as the diameter φ of the refrigerant introducing pipe 17, heat-transfer performance between the inner surface of the groove 11 and the refrigerant introducing pipe 17 is lost. Accordingly, the dimension d is preferably set in such a manner that p<d<2φ.
(44) As FIG. 3(d) shows, when the aforementioned conditions that p<d<2φ are satisfied, an arc-like clearance 21 remains between the inner surface of the groove 11 near the edge 15 and the refrigerant introducing pipe 17 in the stage that the cooling member 19 is assembled. Even when an external force is applied to the refrigerant introducing pipe 17 in a bending direction, it is possible to secure the physical strength of the refrigerant introducing pipe 17 and reduce time and costs for performing R processing on respective heat-transfer members like conventional ones because it is possible to prevent the concentration of the stress near the boundary between the refrigerant introducing pipe 17 and the edges 15.
(45) In the case where work for coating the refrigerant introducing pipe 17 shown in FIG. 3(c) with a coating material, the coating material is introduced to the whole circumference of the refrigerant introducing pipe 17 along the clearance 21 by making the boundary between the refrigerant introducing pipe 17 and the edges 15 indicating as reference numeral 23 lightly in contact with the coating material (capillarity). Additionally, it is possible to easily perform this work from a surface side of the cooling member 19, so that it is possible to efficiently coat a desired portion in the cooling member 19 with the coating material.
(46) And the heat-transfer member 9 may be directly positioned on a bed of the press machine so that the bed can play a role of a support 13. For instance, it is not essential that one punch 7 has two corners 3 and one punch or a plurality of punches having one corner may be attached to a ram of the press machine. The shape of the heat-transfer member 9 is not limited to a rectangular plate but may be disk-shaped.
(47) As shown in FIG. 4(a), there is a possibility that a reaction force of plastically deforming the refrigerant introducing pipe 17 with a press machine may cause an upward warping on the refrigerant introducing pipe 17. Therefore, as shown in FIG. 4(b), back-up portions 27 extending from both ends in a direction along the refrigerant introducing pipe 17 are provided on the punch 7 to hit the back-up portions 27 against the refrigerant introducing pipe 17 upwardly depending on the material of the refrigerant introducing pipe 17 and a speed of moving the punch 7 forward. This restricts the warping of the refrigerant introducing pipe 17 and makes it possible to assemble the cooling member 19 that is accurate in dimension and direction of the refrigerant introducing pipe 17 projecting from the edges 15.
(48) Furthermore, while explanation has been given as described above provided that the pressing surface 5 of the punch 7 is in the flat shape, as shown in FIG. 5(a), the pressing surface 5 may be in a convex shape projecting against the groove 11. In this case, the cross section of the region 23 to be pressed in the refrigerant introducing pipe 17 turns into a concave shape as shown in FIG. 5(b) when pressing the pressing surface 5 to the refrigerant introducing pipe 17 inserted into the groove 11. Alternatively, as shown in FIG. 6(a), the pressing surface 5 may be concave-shaped against the groove 11. In this case, the cross section of the region 23 to be pressed turns into a convex shape as shown in FIG. 6(b) when pressing the pressing surface 5 to the refrigerant introducing pipe 17.
EXAMPLE 2
(49) Same names will be subsequently used for elements already mentioned in Example 1 regardless of embodiments shown in the following drawings or whether or not shown in figures.
(50) As shown in FIG. 7(a), in a cooling member 101, a refrigerant introducing pipe 107 is pressed into grooves 105 of a heat-transfer member 103 and a surface 111 of the heat-transfer member 103 and the refrigerant introducing pipe 107 are covered with covering materials 113. As shown in FIG. 7(b), a heat-conducting member 117 composed of an aluminum plate is attached to electric parts 115 to connect the heat-transfer member 103 to the electric parts 115 through the heat-conducting member 117. However, the heat-conducting member 117 may be omitted and the heat-transfer member 103 may be directly connected to the electric parts 115.
(51) The heat-transfer member 103 is an aluminum plate and openings of the grooves 105 are opened on the surface 111 of the heat-transfer member 103. The covering materials 113 are coating materials applied to dotted regions of the refrigerant introducing pipe 107 in the figure. Such regions are not limited at all, but it is enough that at least the coating materials may be applied to joints 119 between the heat-transfer member 103 and the refrigerant introducing pipe 107.
(52) Additionally, films or adhesive tapes to be adhered to the aforementioned regions may be applied as the covering materials 113. Alternatively, plate materials 121 shown in FIG. 8 may be applied.
(53) In the cooling member 101, the joints 119 between the heat-transfer member 103 and the refrigerant introducing pipe 107 are blocked from the peripheral atmosphere by the covering materials 113. Thus, it is possible to prevent moisture from entering the joints 119 even when the heat-transfer member 103 and the refrigerant introducing pipe 107 build up condensation. And even when the heat-transfer member 103 and the refrigerant introducing pipe 107 contact poisonous gas or are under the environment in which salt is splashed, it is possible to prevent poisonous gas or salt from entering the joints 119 using the covering materials 113. This makes it possible to prevent the heat-transfer member 103 and the refrigerant introducing pipe 107 from corrosion.
(54) In addition, the cooling member 101 is capable of securing preferable heat transfer between the heat-transfer member 103 and the refrigerant introducing pipe 107 as below and allowing performance of the electric parts 115 to properly exert.
(55) That is, the cooling member 101 shown in FIG. 7(a) is used as a sample of an example and a comparative sample in which covering materials are removed from the similar cooling member is prepared. Acetic acid salt water is then sprayed toward respective joints 119 of respective samples in the example and the comparative sample to measure thermal resistance ratio of the heat-transfer member 103 and the refrigerant introducing pipe 107 every time a certain time passes. This result is indicated in a graph in FIG. 9 in which spray time for spraying acetic acid salt water is indicated as a horizontal axis and thermal resistance ratio is indicated as a vertical axis. While a solid line S in FIG. 9 indicates that the thermal resistance ratio has little increased in the sample of the example, a dotted line C indicates that the thermal resistance ratio of the comparative sample has increased as a spray time passes.
(56) It is possible to achieve effects of the cooling member 101 as described above whether or not the covering materials are films, adhesive tapes, coating materials or the plate material 121. Particularly, in the case where coating materials are selected as the covering materials 113, it is possible to easily achieve the aforementioned effects by simply applying the coating materials to the surface 111 of the heat-transfer member 103 and the refrigerant introducing pipe 107 quickly.
(57) As shown in FIG. 10, a cooling member 123 is similar to the aforementioned cooling member 101 except that a cover 125 for covering the heat-transfer member 103 and the refrigerant introducing pipe 107 is applied as a covering material. In the cover 125, the heat-transfer member 103 is buried inside a channel portion 124 to arrange a pair of flanges 126 extending from both sides of the channel portion 124 at a position opposite to the heat-conducting member 117. The flanges 126 of the cover 125 may be fixed to the heat-conducting member 117 with an adhesive or may be fastened with screws or the like. Further, it is preferable that the heat-conducting member 117 and the pair of flanges 126 are airtightly joined to each other and a sealing material may intervene therebetween and the like.
(58) Since it is easy to remove the cover 125 from the heat-transfer member 103 as a merit of the cooling member 123, it is possible to efficiently separate the cover 125 and the heat-transfer member 103 to perform recycling. Furthermore, the material of the cover 125 may be a metal or a synthetic resin and thus a substance having a physical strength higher than the coating material may be applied. The cover 125 has, therefore, a merit of being insusceptible to damage, even when receiving an external force or an impact, and not carelessly dropping out of the heat-transfer member 103.
(59) As shown in FIG. 11, the heat-conducting member 117 is utilized as a covering material in a cooling member 127, so that the number of parts is few and the manufacturing costs are less expensive because neither the aforementioned coating materials nor the cover is needed. In this case, electric parts 115 are mounted on one surface 129 of the heat-conducting member 117 and the surface 111 of the heat-transfer member 103 and the refrigerant introducing pipe 107 are closely fitted with other surface 131 of the heat-conducting member 117.
(60) As shown in FIG. 12, the heat-transfer member 103 and the refrigerant introducing pipe 107 may be housed in the cover 125 in the state that the surface 111 of the heat-transfer member 103 and the refrigerant introducing pipe 107 are closely fitted with the other surface 131 of the heat-conducting member 117. As mentioned above, the clearance 21 shown in FIG. 3(d) remains in the cooling member. Sealing materials 132 shown in FIG. 13 may be inserted into such a clearance to prevent water and dirt or the like from entering between the heat-transfer member 103 and the refrigerant introducing pipe 107.
EXAMPLE 3
(61) Embodiments of a cooling member and a method for manufacturing the same according to the present invention will now be described. FIG. 14(a) shows a heat-transfer member 207 in which an opening 203 of a groove 201 is opened to a surface 205, a punch 211 having a flat pressing surface 209 arranged at a position opposite to the groove 201, and a refrigerant introducing pipe 213 inserted into the groove 201. Curved surface-shaped corners are longitudinally formed at ends of the punch 211 in the same manner as Example 1.
(62) As shown in FIG. 15, a center of curvature O of an inner circumferential surface 217 of the groove 201 is positioned inward the opening 203. Two corner portions 219 and 221 are the locations where the inner circumferential surface 217 warping in the shape of an ellipse is adjacent to an inner side 223 of the opening 203. The circumference of the inner circumferential surface 217 means herein the length of the inner circumferential surface 217 from the corner portion 219 to the corner portion 221. However, in Example 3, a thickness E from the corner portion 219 to the surface 205 and a thickness E from the corner portion 221 to the surface 205 are added. Accordingly, when the circumference of the inner circumferential surface 217 is L, A+L+2E<πG and the groove 201 satisfies with the conditions that the length (A+L) that the circumference of the inner circumferential surface 217 is added to the width A of the opening 203 is shorter than an outer circumference (πG) of the refrigerant introducing pipe 213.
(63) TABLE-US-00001 TABLE 1 Symbol Dimensions [mm] Designation A 9.7 ± 0.1 Width of opening B 10.7 ± 0.1 Major axis C 3.95 Half of minor axis D 5.61 Height of intersection point E 0.44 Thickness F 5.95 ± 0.1 Depth G 5.92 ± 0.08 Diameter
(64) Table 1 shows dimensions of A to G. All of the unit of dimensions mentioned below is [mm]. Referring now to the procedures to calculate the dimensions of A to G using a case where the diameter of the refrigerant introducing pipe 213 includes a margin of errors ±0.08 when the diameter is 9.52 as an example. First, it is set that A=9.7±0.1 in such a manner that a width A of the opening 203 may be not smaller than the maximum value of 9.60 of the diameter of the refrigerant introducing pipe 213. The maximum value Amax of the width A in the opening 203=9.8. The minimum value Bmin=10.6 is calculated based on the following equation so that an over hang quantity, in which the difference between the maximum value Amax and the minimum value Bmin of a full width B of the inner circumferential surface 217 that is a major axis of an ellipse is divided by 2, may be at least 0.4 (about 4% of A). When the margin of errors at the time of the formation of the groove 201 in the heat-transfer member 207 is estimated to be ±0.1, the value of B may be determined at 10.7±0.1.
(65)
(66) Subsequently, assuming that a thickness E=0.44, a calculated value of the circumference of the inner circumferential surface 217 at the time when the minor axis of an ellipse in contact with both corner portions 219 and 221 is obtained. FIG. 16 is a graph in which a half of a minor axis corresponding to a half of a minor axis of an ellipse is indicated as a horizontal axis and a calculated value of the circumference of the inner circumferential surface 217 is indicated as a vertical axis. Since the minimum value of the outer circumstance (πG) of the refrigerant introducing pipe 213 is approximately 29.7, conditions in which the circumference of the inner circumferential surface 217 is shorter than the minimum value are that the half of the minor axis of the ellipse is not more than the value divided by a broken line in FIG. 16. For example, when πG<29, c<4.
(67) The method for manufacturing a cooling member 215 is as below. Referring now to FIG. 14(a) and FIG. 14(b) unless otherwise limited. First, the refrigerant introducing pipe 213 inserted into the groove 201 of the heat-transfer member 207 is pressed into the groove 201 with the punch 211 so that the refrigerant introducing pipe 213 to be plastically deformed may be closely fitted with the inner circumferential surface 217 of the groove 201. At this point, the refrigerant introducing pipe 213 partially projects from the opening 203 of the groove 201. This is because a portion of the refrigerant introducing pipe 213 projects from the surface 205 of the heat-transfer member 207 by the length to which the circumference of the inner circumferential surface 217 is added to is shorter than the outer circumference of the refrigerant introducing pipe 213. Additionally, the center of curvature O of the groove 201 is located inwardly of the opening 203 in the heat-transfer member 207. Accordingly, as mentioned above, at the point when the refrigerant introducing pipe 213 is closely fitted with the inner circumferential surface 217 of the groove 201, the width of the refrigerant introducing pipe 213 becomes greater than the opening 203, which leads to restrict the separation of the refrigerant introducing pipe 213 from the heat-transfer member 207. This completes the join between the heat-transfer member 207 and the refrigerant introducing pipe 213.
(68) Therefore, according to the method described above, there is no possibility of a clearance remaining between the heat-transfer member 207 and the refrigerant introducing pipe 213 at the point when the heat-transfer member 207 is joined to the refrigerant introducing pipe 213 in a state that the refrigerant introducing pipe 213 projects from the surface 205 of the heat-transfer member 207, even when an dimensional error is respectively included in the outer circumference of the refrigerant introducing pipe 213 and the circumference of the inner circumferential surface 217 in the groove 201. This enables the cooling member 215 to materialize preferable heat transfer from the heat-transfer member 207 to a curved portion 225 of the refrigerant introducing pipe 213. The curbed portion 225 is a portion where the refrigerant introducing pipe 213 has been plastically deformed into an ellipse that is in the same shape as the inner circumferential surface 217 of the groove 201 by being fitted with the inner circumferential surface 217. Further, the cross section of the inner circumferential surface 217 is an ellipse in which the direction of the major axis is conformed to the width direction of the opening 203, so that it is possible to firmly hold the refrigerant introducing pipe 213 on the heat-transfer ember 207 relative to an external force in a deviation direction to be applied to the refrigerant introducing pipe 213.
(69) Furthermore, according to the method described above, it is possible to prevent the refrigerant introducing pipe 213 from bending by force by setting a force to press the refrigerant introducing pipe 213 with the punch 211 so that the refrigerant introducing pipe 213 may project from the surface 205 until the refrigerant introducing pipe 213 partially projects from the groove 201, which leads to form a plane portion 227 on the refrigerant introducing pipe 213. The plane portion 227 is a portion where the refrigerant introducing pipe 213 has been plastically deformed into a flat shape which is in the same shape as the pressing surface 209 of the punch 211.
(70) FIG. 17 is a graph in which a horizontal axis represents a dent ratio obtained by dividing a dent amount Δt of the plane portion 227 by the major axis B (full width of the inner circumferential surface 217) and a vertical axis represents a ratio of increasing pressure loss in a refrigerant flowing in the refrigerant introducing pipe 213 as the dent ratio increases as an increase ratio of pressure loss. It will be understood from FIG. 17, it is necessary to limit the dent ratio to 0.3 or smaller to make the increase ratio of pressure loss to 3 or smaller. To materialize this, a force of the punch 211 to press the refrigerant introducing pipe 213 is so adjusted that a height t of the plane portion 227 projecting from the surface 205 of the heat-transfer member 207 may be smaller than the thickness of the refrigerant introducing pipe 213.
(71) The dimensional difference between the major axis of the ellipse and the width of the opening 203 is greater than the case in which the cross section of the inner circumferential surface 217 is in the shape of a conventional arc because the direction of the major axis of the aforementioned ellipse coincides with the width direction of the opening 203 in the cooling member 215. Accordingly, that is advantageous to increase an over hang quantity in the stage of forming the groove 201 in the cooling member 215, resulting in reinforcement of the joining between the heat-transfer member 207 and the refrigerant introducing pipe 213. Additionally, it is possible to improve the physical strength of the opening 203 in the heat-transfer member 207 by setting the thickness E at 0.44 in the aforementioned example.
(72) In order to recycle the cooling member 215, it is necessary to separate the refrigerant introducing pipe 213 in which the curbed portion 225 and the plane portion 227 are formed to sort out the refrigerant introducing pipe 213 and the heat-transfer member 207. In this case, it is possible to return the cross section of the refrigerant introducing pipe 213 to a circle to easily remove the refrigerant introducing pipe 213 from the opening 203 of the groove 201 by supplying inside the refrigerant introducing pipe 213 with compressed air so as to expand the refrigerant introducing pipe 213.
(73) It is to be understood that the present invention may also be carried out in aspects to which various improvements, modifications or variations are added based on knowledge of a skilled person in the art without departing from the spirit and scope of the invention. Typically, the cross section of the inner circumferential surface 217 is not limited to an ellipse, but may be in the shape of a parabola having conformed to the direction of a geometric central axis to the width direction of the opening 203. As shown in FIG. 18(a), the cross section of the inner circumferential surface 217 may be in an oval shape in which the major axis coincides with the width direction of the opening 203. Alternatively, the inner circumferential surface 217 of the groove 201 may be in the shape that an arc portion 319 and a linear bottom surface 321 are combined together. As shown in FIG. 18(b), the inner circumferential surface 217 has two or more centers of curvature O.
(74) Even when an external force in a deviation direction is applied to the refrigerant introducing pipe 213 being closely fitted with the inner circumferential surface 217 of the groove 201, the aforementioned cooling member having the heat-transfer member 207 is capable of preventing the refrigerant introducing pipe 213 from rotating relative to the heat-transfer member 207 without heavily depending on a frictional force between the heat-transfer member 207 and the inner circumferential surface 217.
(75) The present invention is a useful technology to manufacture a cooling member for cooling electric parts to produce heat, such as power modules or the like.
