JPS59114802A - Fluid cooling type resistor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a fluid-cooled resistor used to improve cooling efficiency and reliability of, for example, semiconductor conversion devices.

In recent years, the capacity of power semiconductor conversion devices and the like has increased significantly, and losses have increased accordingly. To cope with this increased loss, water, oil.

There is a method of improving cooling efficiency by using a refrigerant such as Freon. In this case, it is desirable to cool the resistor and the like as well as the semiconductor element using the same coolant.

A conventional resistor of this type is shown in FIG. 1. This resistor has a resistor 2 on the surface of a metal box 1.
is glued together. The metal box 1 allows cooling water to pass therethrough, and is made of dredged material that is resistant to corrosion against pure water. In addition, cooling water is introduced into the metal box 1,
A 1m, lb. cap for discharging is attached. Furthermore, #3 is provided at several locations inside the metal box 1 to prevent deformation due to water pressure.

The resistor 2 adhered to the surface of the box 1 is in the form of a plate that has been appropriately insulated, and has lead wires 4 and electrical terminals s? ci
I am. This lead wire 4 is made of a metal wire such as copper having low resistivity so as not to generate heat, and is brazed to a resistance wire (eg, chrome wire). Note that 6 in the figure is a mounting foot.

In the resistor configured in this way, the resistor 2 generates heat when electricity is supplied from the electric terminal 5.

On the other hand, cooling water flows in from the cap 1a, passes through the inside of the box 1, and flows out from the cap 1b. At this time, heat is exchanged with the resistor 2 through the wall surface of the box 1, and the resistor 2 is cooled.

However, in this resistor, since the resistor 2 is simply bonded to the box 1, it is in contact with the resistor 2, resulting in poor cooling efficiency. This increases the size of the device and tends to cause variations in the cooling of the resistors. Conventionally, a water channel was installed inside the box 1 to increase the cooling efficiency and cool the resistor 2 uniformly, but the cooling efficiency was not sufficient and there was a problem of large pressure loss. be.

Also, since the resistor 2 is pasted on the flat side of the box 1,
Poor adhesion and easy to peel off. Furthermore, since the lead wire 4 is brazed, there is a risk of corrosion due to flux or the like.

The present invention has been made in view of the above-mentioned problems, and its first purpose is to improve cooling efficiency, reduce the size of the device, achieve uniform cooling, reduce pressure loss, and improve the density of the resistor. The object is to obtain a fluid-cooled resistor that has good layer properties and can prevent corrosion of lead wires.

The invention will now be described with reference to an illustrative embodiment U.

As shown in FIGS. 2 to 5, the fluid-cooled resistor according to the present invention has a spiral groove 12 formed on the outer periphery of a gold pipe 11, and a resistor 13 wound around this groove 12. There is. The metal nozzle is one through which a cooling medium (water, oil, fluorocarbon, etc.) flows, and is made of a highly corrosion-resistant material such as copper, aluminum, or stainless steel, and has caps 11a at both ends.

11b. In addition, at the bottom of both ends are 24, J
There are 4. Although not shown, the outer periphery of the metal pipe 11 may be coated with an insulating thin film to improve insulation.

Further, as shown in FIG. 4, straight grooves 15 are formed on the inner surface of the metal #pi flJ to improve the cooling efficiency.

The resistor 13 wound around the metal tube 11 is constructed by applying a broken insulation film 17 to a resistance wire 16 (such as a chrome wire), and is wound while being embedded in the groove 12. The insulating coating 17 is formed of a heat-resistant resin such as silicone resin or polyamide resin alone, or a temporary base of this and an inorganic material such as glass or magnesia. Further, the resistor 13 is placed in the groove 12 by 1/! of the outer diameter or thickness! More embedded. Furthermore, although the resistor 13 is wound around one groove 12 in the illustrated example, it is also possible to provide two or more s12 and wind the resistor 13 around each of them and connect them in parallel or in series. .

The lead wire 18 of the resistor 12 is made by passing the end of the resistance wire 16 through a low resistivity metal pipe 19 (copper, aluminum, etc.) and connecting the pipe 19 and the resistance wire 16, as shown in FIG. It is constructed by pressure contacting at 21 or more locations and is connected to the electrical terminal 20. This electrical terminal 20 is constructed by pressure contact using a crimp terminal. Note that a heat-shrinkable tube 21 having heat resistance is applied to the opening f#18 in order to improve insulation properties.

The outer circumferential surface of the metal pipe 11 around which the resistor 13 is wound is covered with a heat-shrinkable tube 22 that provides heat resistance, thereby increasing the closeness of the metal pipe 11 and providing resistance. In addition, in the illustrated embodiment, the inner surface of the metal pipe 11 has linear striations 15, but spiral strips, cooling fins, etc. They may be provided, or they may not be provided.

This resistor is energized from the magnetic terminal 20, and the resistor 1
3 has a fever. On the other hand, the cooling medium flows in from the cap 11a and flows through the gold JA pipe 11. At this time, the heat of the resistor 13 conducted through the metal motherboard 11 is received and removed.
It is led out from the base 11b.

However, since the lever resistor is wound with the resistor 13 embedded in the groove 12, the resistor 13 is made of gold M
Cooling efficiency is high due to surface contact. Therefore, the device can be made smaller and the temperature can be equalized.

In addition, since the cooling medium flows through the metal nozzle 11,
The cooling passage is straight, reducing pressure loss. Furthermore, gold J
The A-made pipe 11 has a higher pressure resistance than a box body, and there is no need to provide a beam or the like. Further, since the opening sill 18 is made by pressure welding, there is a high risk of corrosion such as 7 lux.

Since more than 1/2 of the resistor 13 is embedded in the TL-groove 12, the magnetic clasp generated by changes in the current flowing through the resistor 13 generates eddy current in the metal pipe 11, which is consumed as eddy current loss. Ru. Therefore, it is possible to achieve low inductivity, and this effect is particularly significant as the frequency becomes higher.

This was confirmed from a series of experiments in which the relationship between frequency and inductance was investigated using this resistor. The results are shown in FIG. The plot (・) in the figure is the one using a grooved copper pipe of 20+a+φ as the metal pipe (product of the present invention) ◇ Also, the plot 0 is the one using the grooved copper pipe of 20+a+φ as the metal pipe.
This is the one using mφ grooveless copper pipe (comparison). Plot (c) is the one using a 20-diameter epoxy pipe (comparative example).

As described above, according to the present invention, by bringing the resistor into surface contact, the cooling efficiency is increased and the size is reduced.

It has the following effects: uniform heating, low pressure loss, prevention of lead wire corrosion, and low inductivity.

[Brief explanation of drawings]

FIG. 1(a) is a front view of a conventional fluid-cooled resistor for a semiconductor converter, FIG. 1(b) is a side view, and FIGS. 2 to 7 show one embodiment of the present invention. The figure is a front view of the resistor, the third
The figure is a side view of the same side, Figure 4 is a sectional view taken along line IV-IV in Figure 2, Figure 5 is a sectional view taken along line v--■ in Figure 3, and Figure 6 is a sectional view of the lead wire of the resistor. 7 is a diagram showing the frequency characteristics of inductance along with a comparative example. 11...Metal pipe, 1lapHb...Bag, 1
2... Brocade, 13... Resistor, 14... Mounting foot, 1
5... Straight groove, 16... Resistor, 12... Insulating coating, 18... Lead wire, 19... Low resistivity metal knob, 20... Electrical terminal, 21 ... Heat shrink tube, 22 ... Heat shrink tube. Figure 4 Figure 5 Figure 614 Figure 7

Claims (6)

[Claims] (1) Metal A through which the cooling medium flows? A fluid-cooled resistor is a fluid-cooled resistor in which a spiral groove is formed on the outer periphery of a coil, and a resistor having an insulating film formed on the surface of a resistance wire is wound around the groove. (2) The fluid-cooled resistor according to claim 1, wherein the insulating rupture film is formed of a heat-resistant resin or a composite of a heat-resistant resin and a heat-resistant unstructured material. (3) The fluid-cooled resistor according to claim 1, wherein the metal #pipe has grooves or cooling fins on its inner surface. (4) The fluid-cooled type according to claim 1, wherein the resistor is embedded and wound in a layer formed on the outer periphery of a shiny metal tube to a depth of more than 1/2 of the diameter or thickness of the resistor. Resistor. (5) The lead wire of the resistor is a fluid according to claim 1, in which the end of the resistance wire penetrates a low resistivity metal pipe, and the pipe and the resistance wire are pressed together at two or more places. Cooled resistor. (6) Claim 1, which is made by coating a heat-resistant heat-shrinkable tube on the entire outer periphery of a metal pipe around which a resistor is wound.
Fluid-cooled resistor as described in .