BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a conceptual diagram of a water-cooled system with a water-cooled heat sink of the disclosure;
FIGS. 2A and 2B are a plan view and a side view of a heat transfer channel plate of the water-cooled heat sink in the water-cooled system of FIG. 1;
FIGS. 3A and 3B are a plan view and a side view of the other heat transfer channel plate of the water-cooled heat sink;
FIG. 4 is a sectional view taken along line IV-IV of FIGS. 2 and 3 in a state where heat transfer channel plates of these figures are stacked;
FIG. 5 is a partially enlarged sectional view of FIG. 4, showing details of a cross-sectional shape of a cooling-water channel;
FIG. 6 is an enlarged sectional view corresponding FIG. 5, showing another shape of the cooling-water channel;
FIG. 7 is an enlarged sectional view corresponding FIG. 5, showing still another shape of the cooling-water channel; and
FIG. 8 is an enlarged sectional view corresponding FIG. 5, showing a further shape of the cooling-water channel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
FIG. 1 is a conceptual diagram of a water-cooled system with a water-cooled heat sink 10 according to the disclosure. The water-cooled heat sink 10 is made of a heat-conductive metallic material, and has a continuous coolant channel 11 inside, and both ends of the coolant channel 11 are connected to an inlet hole (inlet end) 12 and an outlet hole (outlet end) 13 that face the external surface of the water-cooled heat sink 10. The inlet hole 12 communicates with a discharge port 16 of a liquid pump 15 via a suction communication passage 14, and the outlet hole 13 communicates with a suction port 18 of the liquid pump 15 via a discharge communication passage 17. The discharge communication passage 17 is provided with a heat-radiating unit 19 composed of a radiator 19a and a cooling fan 19b. A CPU 20, illustrated as a heat generating source, is in thermal contact with the water-cooled heat sink 10. When the liquid pump 15 is driven, a coolant enters the coolant channel 11 of the water-cooled heat sink 10 from the discharge port 16, the suction communication passage 14, and the inlet hole 12. The coolant that has taken heat away from the CPU 20 and thereby has risen in temperature is cooled by the heat-radiating unit 19 in the course of return from the outlet hole 13, the discharge communication passage 17, and the suction port 18 to the liquid pump 15.
The water-cooled heat sink 10, as shown in FIGS. 2 to 4, includes a first heat transfer channel plate 101 and a second heat transfer channel plate 102 that are stacked and coupled together, and an inlet/outlet block 103 having the inlet hole 12. The outlet hole 13 is fixed to the first heat transfer channel plate 101. As shown in FIG. 2, a continuous recess 11a is formed in a facing surface of the first heat transfer channel plate 101 that faces the second heat transfer channel plate 102. Here, the facing surface is open. The continuous recess 11a is formed such that it reaches a central portion of the first heat transfer channel plate 101 spirally from the inlet hole 12, and is again guided spirally to the outside of the first heat transfer channel plate 101 and reaches the outlet hole 13. The continuous recess 11a, as shown in FIGS. 4 and 5, is formed in a rectangular cross-sectional shape. There are some alternatives in the planar shape of the continuous recess 11a. The illustrated example is an example of the spiral planar shape that is effective for securing a sufficient effective length within a limited space.
As shown in FIG. 3, a continuous protrusion 11b, which is fitted into the continuous recess 11a, is formed in the facing surface of the second heat transfer channel plate 102 that faces the first heat transfer channel plate 101. As shown in FIGS. 4 and 5, the continuous protrusion 11b has a rectangular cross-section smaller than the continuous recess 11a, the first heat transfer channel plate 101 and the second heat transfer channel plate 102 are stacked together, thereby forming a U-shaped coolant channel 11 in cooperation with the continuous recess 11a in a state of being fixed with fixing bolts 104. A seal member or an adhesive can be interposed in a portion excluding the recess 11a between the first heat transfer channel plate 101 and the second heat transfer channel plate 102. Otherwise, joining (laser welding, diffusion joining) between metallic portions may be performed.
As such, the coolant channel 11 is composed of the continuous recess 11a including a simple rectangular groove, and the continuous protrusion 11b that is fitted into the continuous recess 11a with a gap therebetween, and is formed only by stacking the first heat transfer channel plate 101 and the second heat transfer channel plate 102 on each other. Accordingly, the machinability of the water-cooled heat sink is excellent. In addition, the first heat transfer channel plate 101 or the second heat transfer channel plate 102 are further split into two pieces, for example by separately forming continuous protrusions.
Further, when the coolant channel 11 is constituted by the continuous recess 11a and the continuous protrusion 11b, the heat radiation performance of the water-cooled heat sink is also excellent. Supposing the second heat transfer channel plate 102 is composed of a flat surface 11c (FIG. 5) that blocks the continuous recess 11a, the heat transfer area on the side of the second heat transfer channel plate 102 corresponds to a width s on the open side of the continuous recess 11a. In contrast, if the continuous protrusion 11b is formed in the second heat transfer channel plate 102, the heat transfer area on the side of the second heat transfer channel plate 102 increases twice (2×) as long as the protrusion length x of the continuous protrusion 11b towards the continuous recess 11a. For this reason, the cooling water that flows through the coolant channel 11 can effectively take away the heat on the side of the second heat transfer channel plate 102. The CPU 20 may be brought into direct thermal contact with the second heat transfer channel plate 102, and may be brought into indirect thermal contact therewith via heat-conductive grease, etc.
FIGS. 6 to 8 show other shapes of the continuous recess 11a and the continuous protrusion 11b (accordingly, coolant channel 11). FIG. 6 shows an example in which both the continuous recess 11a and the continuous protrusion 11b have a triangular (equilaterally triangular) shape, FIG. 7 shows an example in which both the continuous recess 11a and the continuous protrusion 11b have a semicircular cross-sectional shape, and FIG. 8 shows an example in which both the continuous recess 11a and the continuous protrusion 11b have an oblong cross-sectional shape (have a semicircular part outside a parallel part). These embodiments can also improve heat transfer performance similarly. Particularly, the triangular shape of FIG. 6 can enhance heat transfer performance compared with the rectangular shape. Depending on the size of the continuous protrusion 11b′ as indicated by a chain line in FIG. 5, a slit that 11b′ that increases heat transfer area can be formed.
Patent Application
20080029251
