JP2019196850A - Cooling device, and power conversion device including cooling device - Google Patents

Abstract

To improve performance of a cooling device by a self-excited vibration heat pipe, to secure strength against vibration, and to improve manufacturability as the cooling device.SOLUTION: A cooling device includes, for example, a heat receiving plate provided with a heat generation source on one surface, and a self-excited vibration heat pipe disposed on a surface at an opposite side, of the heat receiving plate. The self-excited vibration heat pipe has a structure obtained by bending a plate having a flow channel filled with a working fluid, in a manner of being reciprocated in a plurality of times to a longitudinal direction in a state that liquid columns and air columns alternately exist, and the reciprocative bent structure has a shape in which a bending angle of the adjacent plates in one reciprocation is 180 degrees or more.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a cooling device to which a self-excited vibration heat pipe is applied, and is particularly suitable when applied to an electric vehicle such as a railway vehicle or an electric vehicle as a cooling device for a power conversion device.

  The self-excited vibration heat pipe is generally constituted by a small-diameter channel of the order of mm, and the working fluid is sealed in a state where liquid columns and air columns are alternately present due to surface tension. A plurality of heat receiving portions (high temperature portions) and heat radiating portions (low temperature portions) are alternately provided in the flow path, and pressure rise due to evaporation in the heat receiving portions and pressure drop due to condensation in the heat radiating portions are generated intermittently. As a result, the liquid column and the air column vibrate self-excitingly to transport heat.

  Unlike the conventional heat pipe, the self-excited vibration heat pipe does not require reflux due to gravity, and thus has an advantage that the installation posture is free and can be made smaller than the conventional heat pipe.

  In Patent Document 1, as a self-excited oscillating heat pipe used for a heat sink, a thin-walled plate that is bent and meandered in a heat-conducting manner between opposing plate surfaces in parallel portions of plates obtained by bending a belt-shaped thin plate into a serpentine bend A structure in which auxiliary fins made of ribbons are provided is described.

Japanese Patent No. 4363501

  The inventor of the present application diligently studied the practical application of a cooling device for a power conversion device such as a railway vehicle to which a self-excited vibration heat pipe was applied. As a result, the following knowledge was obtained.

  A power conversion device for controlling an electric motor that drives a railway vehicle or the like has a large heat loss due to the semiconductor element because the semiconductor element is switched to conduct a large current. When applying a self-excited vibration heat pipe to the cooling device to cool this power conversion device, the self-excited vibration heat pipe tends to improve in performance as the heat receiving area and the cooling area increase. It is necessary to increase the heat receiving area and the cooling area as much as possible even under limited dimensional constraints.

  In addition, since a power conversion device for controlling an electric motor that drives a railway vehicle or the like is generally installed under the floor of a railway vehicle or the like, a cooling device for the power conversion device is similarly applied to the railway vehicle. It is often installed under the floor. Exciting force of several tens to hundreds of Hz is applied to equipment installed under the floor of railway vehicles, etc. due to vibrations generated during running of railway vehicles, etc., so these equipments can withstand the exciting force. It is necessary to have strength to obtain.

  Furthermore, a generally known self-excited vibration heat pipe has a complicated structure including an internal flow path, and its manufacture is difficult. Therefore, it is necessary to provide a structure with good manufacturability.

  It is an object of the present invention to improve the performance of a cooling device using a self-excited vibration heat pipe, to secure strength against vibration, and to improve manufacturability as a cooling device.

  In order to solve the above-described problem, a cooling device according to the present invention includes, for example, a heat receiving plate having a heat source provided on one side and a self-excited vibration heat pipe provided on the opposite side of the heat receiving plate. The vibration heat pipe has a structure in which a plate provided with a flow path enclosing a working liquid in a state where liquid columns and air columns are alternately present is bent back and forth multiple times in the longitudinal direction, The structure that is folded back and forth is characterized in that the bending angle between adjacent plates after one round trip is larger than 180 degrees.

  According to the present invention, the cooling performance can be improved by expanding the heat receiving area and the cooling area of the self-excited vibration heat pipe. In addition, the strength against vibration of the self-excited vibration heat pipe can be ensured. Furthermore, since the dimensional tolerance required for bending the self-excited vibration heat pipe can be relaxed, the manufacturability is also improved.

It is sectional drawing at the time of mounting the power converter device provided with the cooling device which concerns on Example 1 on a rail vehicle. It is sectional drawing which looked at the power converter device provided with the cooling device which concerns on Example 1, and a power converter element from the advancing direction of a railcar etc. It is sectional drawing which shows the flow-path structure in the self-excited vibration heat pipe which comprises the cooling device which concerns on Example 1. FIG. It is AA sectional drawing of the self-excited vibration heat pipe shown in FIG. It is a perspective view which shows the state which bent the self-excited vibration heat pipe which concerns on Example 1. FIG. It is a perspective view which shows the state which isolate | separated the self-excited vibration heat pipe and heat receiving plate which concern on Example 1. FIG. It is a perspective view which shows the state which joined the self-excited vibration heat pipe and heat receiving plate which concern on Example 1. FIG. It is a perspective view which shows the state which bent the self-excited vibration heat pipe which concerns on Example 2. FIG. It is a perspective view which shows the state which decomposed | disassembled the self-excited vibration heat pipe and heat receiving plate which concern on Example 2. FIG. It is sectional drawing which looked at the power converter device provided with the cooling device which concerns on Example 2 from the advancing direction, such as a rail vehicle. It is sectional drawing which looked at the power converter device provided with the cooling device which concerns on Example 3 from the advancing direction, such as a rail vehicle.

  Hereinafter, Examples 1 to 3 of the present invention will be described with reference to the drawings as modes for carrying out the present invention.

FIG. 1 is a cross-sectional view when a power conversion device including a cooling device according to a first embodiment of the present invention is mounted on a railway vehicle.
The power conversion device 2 is installed under the floor of the railway vehicle 1. Inside the power conversion device 2, a plurality of semiconductor elements 3 and an electrical component group 4 constituting a power conversion circuit of the power conversion device 2 are installed. The semiconductor element 3 is attached to one side of the heat receiving plate 6 constituting the cooling device 5. A self-excited vibration heat pipe 7 that constitutes the cooling device 5 is installed on the opposite surface of the heat receiving plate 6. The cooling device 5 is supplied with traveling wind 8 generated when the railway vehicle 1 travels, and dissipates heat loss generated from the semiconductor element 3.

Next, the structure of the cooling device according to the first embodiment of the present invention will be described with reference to FIGS.
In each embodiment shown below, the cooling device according to the present invention is applied to a power conversion device for a railway vehicle, but the cooling device according to the present invention is limited to the power conversion device for a rail vehicle. However, the present invention can also be applied to power conversion devices for other uses (for example, for mobile objects such as automobiles and general industrial equipment).

FIG. 2 is a cross-sectional view of a power conversion device including the cooling device according to the first embodiment and a semiconductor element constituting the power conversion circuit as viewed from the traveling direction of a railcar or the like.
The cooling device 5 includes a heat receiving plate 6 and a self-excited vibration heat pipe 7. A plurality of semiconductor elements 3 are installed on one side of the heat receiving plate 6, and a self-excited vibration heat pipe 7 is installed on the other side.

First, the structure of the self-excited vibration heat pipe 7 will be described.
FIG. 3 is a cross-sectional view showing a flow path structure in a self-excited vibration heat pipe constituting the cooling device according to the first embodiment, and FIG. 4 is a cross-sectional view taken along line AA of the self-excited vibration heat pipe shown in FIG. .
The self-excited oscillating heat pipe 7 has a plate-like structure, and a plurality of rectangular cross-section channels 9 are formed in the plate in parallel and parallel to the longitudinal direction, as shown in FIG. The A predetermined amount of hydraulic fluid is sealed in the flow path 9. In addition, it is not restricted to the thing in which the several independent flow path 9 was formed in parallel parallel, The single or several flow path 9 may be arrange | positioned inside the plate by meandering. Moreover, the cross-sectional shape of the flow path 9 is not limited to a rectangle, and may be another shape such as a circle.

FIG. 5 is a perspective view showing a state where the self-excited vibration heat pipe is bent as the structural shape of the self-excited vibration heat pipe used in the present invention.
The structure of the self-excited vibration heat pipe used in the present invention is formed by bending the self-excited vibration heat pipe 7 shown in FIG. At that time, the self-excited vibration heat pipe 7 has a structure in which the adjacent plates reciprocated once are folded back and forth a plurality of times at a bending angle larger than 180 degrees. is not. That is, the interval between adjacent plates that have made one reciprocation changes continuously in the longitudinal direction and is not constant.
Furthermore, the bent portion of the adjacent plates that have made one reciprocal contact with each other, and the gap formed between the adjacent plates for one reciprocation is viewed from the short direction (the arrow direction shown in FIG. 5). The shape is almost triangular. Here, the short direction (the arrow direction shown in FIG. 5) is the traveling direction of the railway vehicle or the like, that is, the traveling wind direction.

FIG. 6 is a perspective view showing a state where the self-excited vibration heat pipe and the heat receiving plate are separated, and FIG. 7 is a perspective view showing a state where the self-excited vibration heat pipe and the heat receiving plate are joined.
As shown in FIG. 6, a recess 10 is formed in the heat receiving plate 6, and a joining member 11 such as a brazing material or solder is installed in the recess 10. In addition, as shown in FIG. 7, a self-excited vibration heat pipe 7 that is bent back and forth a plurality of times is installed in the recess 10. At that time, the joining member 11 is melted by heating the joining member 11, and the joining member 11 is then solidified by lowering the temperature, whereby the heat receiving plate 6 and the self-excited vibration heat pipe 7 are joined to each other. 11 is joined.
Note that one end or both ends of the self-excited vibration heat pipe 7 are arranged on the opposite side of the place where the heat receiving plate 6 is joined. In the first embodiment shown in FIG. 7, both end portions of the self-excited vibration heat pipe 7 are disposed on the opposite side from the place where the heat receiving plate 6 is joined. This arrangement is due in part to facilitating the work of sealing the working fluid into the internal flow path 9.

  On the other hand, as shown in FIG. 2, a sealing member 12 such as a resin is poured into the recess 10 and the joint between the heat receiving plate 6 and the self-excited vibration heat pipe 7 is covered and hardened. Bonding with the vibration heat pipe 7 can be strengthened.

  Furthermore, like the self-excited vibration heat pipe 7 shown in FIG. 2, the adjacent bent portions may be joined back and forth on the side not joined to the heat receiving plate 6 by joining means such as welding or soldering. (In FIG. 2, it shows as the welding part 13).

Here, the function and effect of the first embodiment will be described.
As the self-excited vibration heat pipe 7 has a larger area of the heating unit that receives heat and the heat radiation unit that radiates heat to the outside air, the cooling performance is improved. In the present invention, in the self-excited vibration heat pipe 7, the part joined to the heat receiving plate 6 is a heating part, and the other part exposed to traveling wind is a heat radiating part.

  In the first embodiment, when the self-excited vibration heat pipe 7 is folded back and forth a plurality of times in the longitudinal direction, the adjacent plates for one round-trip are bent at a bending angle larger than 180 degrees, thereby the adjacent plates. Since they are not parallel to each other, the heat radiating portion of the self-excited vibration heat pipe 7 is not perpendicular to the heat receiving plate 6 but is arranged obliquely. Thereby, the area of a heat radiating part is expanded and the cooling performance is improved as compared with a case where the self-excited vibration heat pipe 7 is bent in parallel.

  Further, when the self-excited vibration heat pipe 7 is reciprocated and adjacent bent portions are in contact with each other, the area joined to the heat receiving plate 6 is expanded, that is, the area of the heating portion of the self-excited vibration heat pipe 7 is expanded. As a result, the cooling performance is improved.

  Furthermore, since the self-excited vibration heat pipe 7 is bent as described above, the shape of the gap formed between the adjacent plates for one reciprocation becomes a triangular shape when viewed from the short side. The heating part which becomes the base of the triangle is poured into the recess 10 of the heat receiving plate 6 and a sealing member 12 such as a resin is poured and hardened. At the same time, the bent portions of the adjacent plates that have reciprocated once in a portion that is not joined to the heat receiving plate 6 are joined by a joining means such as welding. Thereby, the self-excited vibration heat pipe 7 has a shape in which deformation is difficult to occur, and the strength against vibration can be improved as compared with the case where the self-excited vibration heat pipe 7 is bent in parallel.

  In the second embodiment, the bending pitch of the self-excited vibration heat pipe 7 is reduced as compared with the first embodiment. Hereinafter, the difference from the first embodiment will be mainly described.

FIG. 8 is a perspective view showing a state where the self-excited vibration heat pipe according to the second embodiment is bent, and FIG. 9 is a perspective view showing a state where the self-excited vibration heat pipe and the heat receiving plate according to the second embodiment are disassembled. is there.
In the second embodiment, since the bending pitch is reduced in order to increase the heat radiation area of the self-excited vibration heat pipe 7, the bent portion is configured by only a curved surface, unlike the first embodiment, as shown in FIG. It will be. As a result, the gap formed by the one reciprocating adjacent plates of the self-excited vibration heat pipe 7 according to the second embodiment is substantially drop-shaped when viewed from the short direction (the arrow direction shown in FIG. 8). Therefore, there is a concern that the bent area is insufficient when the bent portion is bonded to the heat receiving plate 6.
Therefore, as shown in FIG. 9, a groove portion 14 having a shape along the curved surface of the bent portion of the self-excited vibration heat pipe 7 is installed in the recess 10 of the heat receiving plate 6. Further, a joining member 11 (using a brazing material, solder or the like as in the first embodiment) is installed in the groove portion 14 and joined to the self-excited vibration heat pipe 7.

  By setting it as such a shape, the junction area of the self-excited vibration heat pipe 7 and the heat receiving plate 6 is expanded, that is, the area of the heating portion of the self-excited vibration heat pipe 7 is expanded, and the cooling performance is improved. Further, when the self-excited vibration heat pipe 7 is joined to the heat receiving plate 6, when an external force is applied from the opposite side of the heat receiving plate 6 to press the self-excited vibration heat pipe 7 against the heat receiving plate 6, the groove portion 14 is self-excited vibration heat. In addition to the role of positioning the pipe 7, the self-excited vibration heat pipe 7 is deformed so as to follow the shape of the groove 14. Thereby, since the dimensional tolerance at the time of bending the self-excited vibration heat pipe 7 can be relieved, manufacturability improves.

  FIG. 10 is a cross-sectional view of a power conversion apparatus such as a railway vehicle provided with a cooling device including a self-excited vibration heat pipe and a heat receiving plate according to the second embodiment when viewed from the traveling direction of the railway vehicle. Similar to the first embodiment, the adjacent bent portions may be joined together like the welded portion 13 by reciprocating once on the side not joined to the heat receiving plate 6.

  Example 3 is different from Example 1 and Example 2 in that the method of joining the bent portions of the self-excited vibration heat pipe 7 is changed. Hereinafter, the difference from the first embodiment and the second embodiment will be mainly described.

  FIG. 11: is sectional drawing which looked at power converters, such as a rail vehicle provided with the cooling device concerning Example 3, from the advancing direction of a rail vehicle. In the third embodiment, a reinforcing member 15 is installed on the side opposite to the heat receiving plate 6, and the bent portions of the self-excited vibration heat pipe 7 on the side opposite to the heat receiving plate 6 are joined by the reinforcing member 15. Further, when the self-excited vibration heat pipe 7 has a small bending pitch as shown in the second embodiment, the curved surface of the bent portion of the self-excited vibration heat pipe 7 is also formed on the joint surface on the reinforcing member 15 side. You may provide the groove part of the shape which follows.

  By configuring the cooling device in such a shape, the self-excited vibration heat pipe 7 is shaped so as not to be deformed, and the strength against vibration is improved.

  Although not shown, corrugated fins are provided between adjacent plates of the self-excited vibration heat pipes according to each embodiment, for example, as auxiliary fins in Patent Document 1 to further improve the cooling performance. Improvements may be made.

1: railway vehicle, 2: power converter, 3: semiconductor element, 4: electrical component group, 5: cooling device,
6: heat receiving plate, 7: self-excited vibration heat pipe, 8: direction of traveling wind, 9: flow path, 10: depression,
11: Joining member, 12: Sealing member, 13: Welded part, 14: Groove part, 15: Reinforcing member

Claims (10)

A heat receiving plate provided with a heat source on one side;
A self-excited vibration heat pipe provided on the opposite surface of the heat receiving plate,
The self-excited vibration heat pipe has a structure in which a plate in which a working fluid is sealed in a state where liquid columns and air columns exist alternately is bent back and forth multiple times in the longitudinal direction. And the structure bent in the said reciprocation is a cooling device characterized by the bending angle of adjacent plates which carried out one reciprocation being larger than 180 degree | times. A heat receiving plate provided with a heat source on one side;
A self-excited vibration heat pipe provided on the opposite surface of the heat receiving plate,
The self-excited vibration heat pipe has a structure in which a plate in which a working fluid is sealed in a state where liquid columns and air columns exist alternately is bent back and forth multiple times in the longitudinal direction. And the structure bent in the said reciprocation is the cooling device characterized by the space | interval of the adjacent plates which carried out one reciprocation changing continuously in a longitudinal direction, and the shape which is not constant. A heat receiving plate provided with a heat source on one side;
A self-excited vibration heat pipe provided on the opposite surface of the heat receiving plate,
The self-excited oscillating heat pipe has a plate in which a working fluid is sealed in a state where liquid columns and air columns are alternately present, and a plate in which a flow path is enclosed is bent a plurality of times in the longitudinal direction, and is reciprocated once. The bent portions of the adjacent plates are in contact with each other, and the gap formed between the adjacent plates that have reciprocated once is substantially triangular or substantially drop-shaped when viewed from the short side direction. And cooling device. The cooling device according to any one of claims 1 to 3,
The heat receiving plate has a recess, and the cooling device has a structure in which the heat receiving plate and the self-excited vibration heat pipe installed in the recess are bonded using a bonding member. The cooling device according to claim 4,
The cooling device, wherein the heat receiving plate and the self-excited vibration heat pipe are bonded to each other using the bonding member, and the depression is covered with a sealing member. The cooling device according to claim 4 or 5, wherein
The said hollow has a groove part which is a shape along the curved surface of the bending part of the structure which the said self-excited vibration heat pipe bent in the said multiple times reciprocation. The cooling device according to any one of claims 1 to 6,
The cooling device characterized in that the bent portions located on the opposite side of the heat receiving plate in the bent portions of the one-way adjacent plates of the self-excited vibration heat pipe are joined to each other. . The cooling device according to any one of claims 1 to 7,
The cooling device according to claim 1, wherein one or both ends of the plate constituting the self-excited vibration heat pipe are arranged on the opposite side of the heat receiving plate. It is a power converter device provided with the cooling device according to any one of claims 1 to 8,
A power conversion apparatus comprising a semiconductor element constituting a power conversion circuit as the heat generation source on the one surface of the heat receiving plate. The power conversion device according to claim 9, which is mounted on an electric vehicle,
The power converter according to claim 1, wherein a short direction of the self-excited vibration heat pipe is a traveling direction of the electric vehicle.

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