JPH11274782A - Heat radiator utilizing heat pipe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a radiator utilizing a heat pipe which has a very high heating capacity, high performance and can be made compact and light in weight at a low manufacturing cost, and if a radiator tilts due to running of an automobile, when used e.g. for EV (an electric vehicle), the so-called dry out phenomenon does not occur, as working fluid always exists in an evaporator (heat receptor) and hence the radiation performance is very excellent. SOLUTION: The radiator 10 utilizing a heat pipe has a plate-like heat pipe 2, a flat bottom part 2a of which is adhered to the top face of a radiation board 1, on the lower face of which heating bodies 4 such as semiconductor elements are mounted. The heat pipe 2 is formed like a loop long sideways as seen from the front and has a hollow sealing working fluid, and a radiation fin 3 is inserted between the flat bottom 2a (evaporating part) and opposite flat top 2b (condensing part) of the heat pipe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat radiator using a heat pipe, and more particularly, to a heat radiator using a heat pipe used for cooling a semiconductor element such as a transistor and a thyristor and a heating element such as an integrated circuit (IC). About the vessel.

[0002]

2. Description of the Related Art Heretofore, a radiator for an electric vehicle (EV), for example, requires a large amount of heat radiation, and a heat radiator made of extruded aluminum is known.

[0003]

However, all of the conventional radiators do not have good heat radiation performance, and in order to satisfy the required performance, it is necessary to enlarge the heat radiation area and increase the heat radiation area. In this case, there is a problem that the weight of the radiator becomes very large and the cost becomes high.

In a radiator for an electric vehicle (EV), for example, if the radiator is flat, if the radiator is tilted due to the traveling of the vehicle, the heat receiving portion (evaporating portion) of the radiator is tilted. There is a problem that a so-called dry-out phenomenon occurs in which the working fluid does not exist at a high position and the heat radiation performance is reduced.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, to achieve a very large heat dissipation, a high performance, a compact size, a light weight, and a low manufacturing cost. For example, when the radiator is used as a radiator for an electric vehicle (EV), the working fluid is always present in the evaporating section (heat receiving section) even when the radiator is tilted due to the running of the car. An object of the present invention is to provide a radiator using a heat pipe, which does not cause any phenomenon and has excellent heat radiation performance.

[0006]

In order to achieve the above object, a heat radiator using a heat pipe according to the present invention is provided on an upper surface of a heat radiating substrate on which a heating element such as a semiconductor element is mounted on a lower surface, and has a horizontally long loop shape as viewed from the front. And a flat bottom portion of a plate-like heat pipe having a working fluid-filled hollow portion on substantially the entire surface is joined.

In the radiator, it is preferable that a radiation fin is interposed between the flat bottom of the loop heat pipe and the flat top opposed thereto.

[0008]

Embodiments of the present invention will now be described with reference to the drawings.

In this specification, front and rear, left and right are based on FIG. 2, the front is the front side of the drawing sheet of FIG. 2, the rear is the same back side, and the left is the left and right sides of the drawing. Means the right side. In this specification, the term aluminum is used to include its alloy.

Referring to FIGS. 1 and 2, a radiator (10) using a heat pipe according to the present invention is a radiating substrate made of aluminum to which a heating element (4) such as a semiconductor element is attached on a lower surface.
A plate-shaped heat pipe made of an aluminum roll-bonded material having an oval shape, that is, a horizontally long loop as viewed from the front, and a working fluid filled hollow portion (5) almost all over the top surface of (1).
The flat bottom (2a) of (2) is brazed. A radiation fin (3) made of aluminum corrugated fin is interposed between the flat bottom (2a) of the horizontally elongated heat pipe (2) and the flat top (2b) opposed thereto, The upper and lower ends of the radiating fin (3) are the upper surface of the flat bottom (2a) and the flat top (2b) of the horizontal loop heat pipe (2).
Is brazed to the lower surface.

Referring to FIGS. 2 and 3, the plate-shaped heat pipe (2) is made of two aluminum plates (1
1) (12) are superimposed on each other, and a frame-shaped peripheral joint portion (13) is provided on the peripheral edge thereof. A swelling part (15) is provided, and a large number of substantially square and rectangular aluminum plate joints (14) are arranged in a zigzag pattern on the inner part surrounded by the surrounding swelling part (15) for working fluid circulation as viewed from a plane. And an inner bulging portion (16) connected to the peripheral bulging portion (15) and having a net-like pattern as viewed from a plane.

The plate-shaped heat pipe (2) is formed by printing an anti-compression material (not shown) on one of the two aluminum plates (11) and (12) in a predetermined shape, and attaching the other surface to the other surface. After press-fitting the plates, fluid pressure is introduced into the non-pressed portion between the two plates (11) and (12) to cause them to bulge, and the peripheral bulges (15) and the inner bulges inside ( It is made by the so-called roll bonding method by forming 16). Peripheral bulge (1
5) and inside of the inside bulge (16), there is a hollow part filled with working fluid.
(5) and (5) are provided.

In the drawing, the bulging portions (15) and (16) are formed by a so-called one-sided bulging tube.
(15) and (16) may be formed by a so-called double-sided expanded tube.

Here, the plate-shaped heat pipe (2) is formed by bending a plate-shaped heat pipe (2) shown in FIG. It has a horizontally long loop shape. At the flat bottom (2a) of the plate-shaped heat pipe (2) and the flat top (2b) opposite to it, a number of relatively small aluminum plate joints (14a) that are approximately square when viewed from the plane are staggered. Bulges of these parts (16a)
Have a net-like pattern finer than a plane.

On the other hand, at the bent middle portions (2c) (2c) on both left and right sides of the plate-shaped heat pipe (2), a large number of rectangular aluminum plate joints (14b) long in the left-right direction are arranged in parallel. The bulging portions (16b) of these portions are provided with a parallel pattern that is long in the left-right direction, so that the portions near the left and right ends of the plate-like heat pipe (2) are easily bent. It has been done. Also, plate heat pipe
When viewed from the plane of (2), the four corners and the front and rear side edges of the center have approximately two small aluminum plate joints (14a).
Rectangular aluminum plate joint with double size (14
c) are provided to realize the staggered arrangement of the mesh pattern.

At the center of the front edge of the plate-shaped heat pipe (2),
A working fluid injection part (17) is provided which is connected to the frame-shaped peripheral bulging part (15), opened at the front end of the plate-shaped heat pipe (2), and sealed after the working fluid is sealed.

When the working fluid is injected from the injection section (17), the injection section (17) faces upward and the plate-shaped heat pipe is turned on.
(2) is set up, and while injecting the working fluid from the injection part (17),
Instead, the internal air may be discharged.

The flat bottom portion (2a) of the plate-shaped heat pipe (2) formed into a loop shape as described above serves as a heat receiving portion for receiving heat generated from the heating element (4) such as a semiconductor element, that is, a working fluid evaporator. Part, the flat top (2b) opposite to this is the working fluid condensing part, and the left and right bent middle part (2c) (2c) connecting both
Is a so-called heat insulating part.

Screw holes are provided at required places on the lower surface of the heat dissipation board (1).
The heating element (4), such as a transistor or a thyristor, such as a semiconductor element, is pressed against the lower surface of the heat dissipation board (1) and attached with the required number of mounting screws (7). Things.

In the radiator (10) using the heat pipe, heat generated from the heating element (4) such as a transistor or a semiconductor element such as a thyristor attached to the lower surface of the radiating board (1) is transferred to the radiating board (1). ) Is quickly transmitted to the working fluid sealed in the hollow portion (5) inside the bulging portion (16a) at the flat bottom portion (2a) which is the heat receiving portion of the loop heat pipe (2), The working fluid is heated and evaporated. The vapor of the working fluid that has been heated and evaporated here rises in the hollow portions (5) and (5) of the bent middle portions (2c) and (2c) as heat pipe heat insulating portions on both the left and right sides, and the loop heat Pipe (2)
To the flat top (2b), where it radiates heat and is cooled, forming condensate. The condensate of the working fluid descends from the flat top (2b) through the bent middle portions (2c) and (2c) on the left and right sides and returns to the flat bottom (2a) where it is heated and evaporated again. And recirculated.

The radiator (10) is provided with a corrugated radiating fin (3) in a space inside the loop heat pipe (2).
Is mounted in a fitting manner, and is usually used as an air-cooled radiator (10) for sending cooling air by forced air blowing.

By the action of the loop heat pipe (2) of the radiator (10), the heat caught by the heat radiating board (1) is quickly transmitted to the working fluid inside, and this is transferred to the heat pipe.
The heat is quickly released to the outside through the wall of (2) and the corrugated fins (3), so that the amount of heat dissipation can be sufficiently increased, and the temperature distribution becomes uniform as a whole of the radiator, and The performance is greatly improved, resulting in high performance.

Also, a loop-shaped heat pipe of the radiator (10)
The radiator (10) is compact because the corrugated fins (3) are housed inside (2), and the hollow part (5) exists inside the loop heat pipe (2). As a result, the radiator (10) as a whole becomes extremely lightweight,
Lightening can be achieved.

The radiator (10) is a loop heat pipe.
(2), for example, when the radiator (10) is used as a radiator for an electric vehicle (EV), even if the radiator is tilted by running of the vehicle, the loop-shaped heat pipe (2) is used. ) Of the flat bottom (2a), that is, the evaporating part (heat receiving part) is always lower and the working fluid is present, and therefore, the heat radiation performance is extremely excellent without causing a dry-out phenomenon. .

According to the illustrated embodiment, both the flat bottom portion (2a) of the loop heat pipe (2) and the bulging portion (16a) of the flat top portion (2b) opposed thereto are flat. Since the net-like pattern is bird-like, the flat bottom (2a) and flat top (2b) have bulges (16
In the hollow part (5) of (a), the working fluid passage is formed in a zigzag shape, and the liquid or vapor of the working fluid mixes very well, and heat absorption from the heating element (4) such as a semiconductor element or In addition, the absorbed heat is released very smoothly.

A radiator (10) according to the present invention comprises a flat bottom (2a) of a loop-shaped heat pipe (2) and a flat top opposed thereto, as viewed from the front, joined to a heat radiating board (1).
The heat transfer performance is improved by the interposition of the corrugated heat radiation fins (3) between the heat pipes (2b) and the heat radiation performance is further increased by the synergistic effect with the heat pipe (2). Since the upper and lower surfaces of the fins (3) are brazed to both the flat bottom (2a) and the flat top (2b) of the loop heat pipe (2), the fin efficiency is very good and the heat dissipation is improved. The performance is greatly improved.

In addition, the radiator (10) includes a radiating board (1)
And a loop-shaped heat pipe (2) joined to it, and a corrugated heat-radiating fin (3) housed inside the heat pipe (2). On the other hand, a compact design is possible.

FIG. 4 shows a modified example of the corrugated fin (3) used in the heat pipe utilizing radiator (10) of the present invention. Here, the difference from the above embodiment lies in the cross-sectional shape of the corrugated fins (3). That is, the radiation fins (3) of this modified example are configured such that the bent portions (3a) (3a) at the upper and lower ends project to the left and right sides, respectively, and the bent portions (3a) (3a) adjacent to each other. The ends of the overhanging portions are abutted with each other, and the upper surface of the upper bent portion (3a) and the lower surface of the lower bent portion (3a) have a large area, respectively, and the wide area of the upper and lower bent portions (3a) (3a) is large. The upper and lower surfaces having a loop heat pipe (2)
Are joined to the flat top (2b) and the flat bottom (2a).

Therefore, according to the radiation fins (3) of the radiator (10) of this modification, the radiation area can be increased even with the same pitch, the heat transfer efficiency is increased, and the radiation performance is greatly improved. In particular, when used as an air-cooled radiator (10) by forced air blowing, a uniform flow velocity can be obtained in the radiating fins (3), pressure loss can be reduced, and heat radiation performance can be significantly improved. improves. Furthermore, even with the same pitch, the brazing area of the radiation fins (3) can be increased, so that the strength of the radiator (10) increases, and it is extremely resistant to vibration and has excellent durability. Is what it is.

Since the other points of this modified example are the same as those of the embodiment of the present invention, the same parts are denoted by the same reference numerals in the drawings.

In the above description, the plate-shaped heat pipe
(2) is to form not only an aluminum roll bond material, but also, for example, a concave groove of a predetermined shape in one of two aluminum plates by pressing, and fit the other plate to this surface. What was formed by what is called a press method which forms the hollow part for working fluid distribution by brazing may be used. Plate heat pipe (2)
May be made of not only aluminum but also copper and other metals.

A bulge around the plate-shaped heat pipe (2)
A large number of aluminum plate joints (14) provided in a staggered arrangement on the inner part surrounded by (15) have a substantially square and a substantially rectangular shape when viewed from a plane, but they also have other shapes when viewed from a plane. Polygons such as triangular and pentagonal, or circular,
The shape may be an ellipse or the like.

[0033]

As described above, the heat radiator using a heat pipe according to the present invention is formed on the upper surface of a heat radiating substrate on which a heating element such as a semiconductor element is mounted on the lower surface, has a horizontally long loop shape as viewed from the front, and has substantially the entire working fluid. The flat bottom portion of the plate-shaped heat pipe having the enclosed hollow portion is joined, and according to the radiator of the present invention, when a heating element such as a semiconductor element is attached to the lower surface of the radiator substrate, the radiator is caught by the radiator substrate. The heat is quickly transmitted to the working fluid in the hollow portion of the bulging portion of the flat bottom of the plate-shaped heat pipe and quickly released, so that the amount of heat radiation can be sufficiently increased and the temperature distribution can be reduced. The heat sink is uniform, the heat dissipation performance is greatly improved, the performance is high, and the heat dissipation board and the horizontal loop-shaped plate-shaped heat pipe joined to it are used. It is very compact. In addition, the plate-shaped heat pipe is provided with a working fluid-filled hollow on almost the entire surface, which can reduce the weight. In addition, the plate-shaped heat pipe can be easily manufactured from aluminum roll bond material, aluminum pressed plate, etc. Therefore, the manufacturing cost of the radiator can be reduced.

Further, since the radiator of the present invention includes the loop heat pipe, for example,
When used as a radiator for a V (electric vehicle), even when the radiator is tilted due to the running of the vehicle, the flat bottom of the loop heat pipe, that is, the evaporating section (heat receiving section) is always lower and the working fluid Therefore, there is an effect that the heat radiation performance is extremely excellent without causing a dry-out phenomenon.

In the radiator according to the present invention, the heat transfer performance is improved by radiating fins between the flat bottom and the flat top of the loop-shaped heat pipe joined to the heat radiating substrate. In addition, the heat radiation performance is further increased, and the fin efficiency is very excellent, so that the heat radiation performance is greatly improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a product of the present invention.

FIG. 2 is an enlarged sectional view of a main part of the product of the present invention.

FIG. 3 is a developed bottom view of the plate-shaped heat pipe used in the product of the present invention.

FIG. 4 is an enlarged sectional view of a main part of a product of the present invention showing a modification of a corrugated radiating fin.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 radiator substrate 2 plate heat pipe 2 a flat bottom 2 b flat top 3 radiating fin 4 heating element such as semiconductor element 5 working fluid filled hollow section 10 radiator using heat pipe

Claims (2)

[Claims] 1. A plate formed in a horizontal loop shape as viewed from the front and having a working fluid-filled hollow portion (5) almost entirely on the upper surface of a heat dissipation substrate (1) on which a heating element (4) such as a semiconductor element is mounted on the lower surface. A heat pipe-based radiator in which a flat bottom (2a) of a heat pipe (2) is joined. 2. A flat bottom of the loop heat pipe (2).
The radiator according to claim 1, wherein a radiating fin (3) is interposed between (2a) and the flat top portion (2b) opposed thereto.