CN1319078C

CN1319078C - Precision shunt resistor and manufacturing method thereof

Info

Publication number: CN1319078C
Application number: CNB031387721A
Authority: CN
Inventors: 彭德龙; 陈冬
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-07-09
Filing date: 2003-07-09
Publication date: 2007-05-30
Anticipated expiration: 2023-07-09
Also published as: CN1545106A

Abstract

The present invention provides a precise shunt resistor and a manufacturing method thereof, which belongs to a base electrical apparatus element and a manufacturing method of the electronic field. The precise shunt resistor is composed of a resistance element and a busbar which is made of a red copper plate. The present invention is characterized in that a manganin plate of which the temperature coefficient is lower than 20 ppm is adopted to serve as the resistance element, a transition manganin-red copper alloy band which has a temperature coefficient lower than 50 ppm and is formed by the welding fusion of an electronic beam is arranged between the resistance element and the busbar, and an installing hole and a voltage output end are arranged on the busbar. The precise shunt resistor has the advantages of low temperature coefficient, high reliability, good heat stability, large accessible rated current, small size, convenient use, maximum material saving, etc. The manufacturing method has the advantages of less production working procedure, high production efficiency and convenient automation production, and simultaneously can effectively ensure that the manufactured precise shunt resistor has preferable heat stability and very high reliability.

Description

Accurate shunt resistor and production method thereof

Affiliated technical field

The invention belongs to a kind of basic electric elements in the electricity field and its production method, particularly a kind of accurate shunt resistor and production method thereof.

Technical background

Shunt resistor is widely used in also can be used as the critical piece of current sensor in the various instrument and meters that digital watt-hour meter, high-accuracy test instrumentation and all measure, take a sample, shunt electric current.The previous low conventional, electric-resistance device of resistance that adopts is made shunt resistor.Their shortcoming is that poor heat stability, precision are low, when passing through bigger electric current on the shunt resistor, on resistor, produce bigger heat, this heat can not distribute soon, thereby resistance can change a lot, cause poor stability, precision low, the supporting use of instrument, instrument that can not be higher with precision.For addressing these problems, the patent No. is the Chinese patent of " high-accuracy shunt resistor " for " 92218841.6 " title, a kind of shunt resistor of being made up of resistance wire, resistance wire lead-in wire, housing, inserts etc. has been proposed, its feature is to adopt the many resistance wires that temperature coefficient is lower, in parallel, be welded on and constitute the shunt resistance body on the bus-bar, put it into again in the housing, in housing, insert the filler of good heat dispersion performance, form the higher relatively shunt resistor of precision.This shunt resistor mainly is at the design of the temperature coefficient of shunt resistor, the resistance wire that constitutes resistive element is realized being connected by silver soldering with bus-bar, though the thermal stability than conventional, electric-resistance improves, but the shunt resistor of this structure exists that volume rated current big, that can pass through is less, thermal stability and reliability are still not high enough; The production method of this accurate shunt resistor of while, various, the main dependence of operation is hand-manipulated, production efficiency is lower.

Summary of the invention

The object of the present invention is to provide a kind ofly have that temperature coefficient is low, reliability is high, accurate shunt resistor that Heat stability is good, the rated current that can pass through are bigger and the method for this accurate shunt resistor of production that operation is less, production efficiency is high.

Purpose of the present invention adopts following technical scheme to finish: accurate shunt resistor, form by the bus-bar that resistive element and employing copper plate are made, its feature is that described resistive element adopts temperature coefficient to be lower than the copper-manganese plate of 20ppm, between resistive element and bus-bar, there is the temperature coefficient that forms by the electron beam welding fusion to be lower than transition copper-manganese-red copper alloy band of 50ppm, on bus-bar, has installing hole and voltage output end.Produce the method for this accurate shunt resistor, carry out as follows:

(1) select temperature coefficient to be lower than the copper-manganese band of 20ppm, the parallel both sides that are placed on the copper-manganese band of the red copper band that thickness is identical, put into vacuum electron beam welding machine, its abutment joint is carried out the vacuum electron beam welding, make the red copper of joint, transition copper-manganese-red copper alloy band that copper-manganese fusion formation temperature coefficient is lower than 50ppm, thereby make red copper-copper-manganese-red copper bimetal band;

(2) red copper-copper-manganese-red copper bimetal band is gone out accurate shunt resistor with mould punching.

Accurate shunt resistor provided by the present invention, owing to adopted the copper-manganese plate to do resistive element, make the rated current of passing through increase greatly, because the temperature coefficient of copper-manganese plate is lower than 20ppm, the temperature coefficient that forms by the electron beam welding fusion between resistive element and bus-bar is lower than 50ppm transition copper-manganese-red copper alloy band, guaranteed that accurate shunt resistor has lower temperature coefficient, simultaneously, the reliability that makes bus-bar be connected with resistive element increases greatly, the electric current of importing from the installing hole of bus-bar, can flow through resistive element from bus-bar by the copper-manganese of the transition between resistive element and the bus-bar-red copper alloy band equably, significantly reduced the contact resistance between resistive element and the bus-bar, further improved thermal stability, and having dwindled the volume of shunt resistor, volume only is about 1/2 of a prior art, because installing hole directly is set on bus-bar, make shunt resistor and instrument, connection between the instrument, very simple.Simultaneously, owing to adopted this structure, also saved material widely.

Because the copper-manganese band of having selected temperature coefficient to be lower than 20ppm has guaranteed that the accurate shunt resistor of being produced has lower temperature coefficient, because the vacuum electron beam welding is to utilize the high energy strong current electron beam bombardment weldment abutment joint that produces in the vacuum electronic rifle, when high-velocity electrons and weldment bump, send its kinetic energy to weldment, this kinetic energy converts heat energy to rises butt weld district temperature, the weldment commissure fusion of butt joint is because electron beam energy is high, power density can reach 10 ⁹W/cm ²The beam spot diameter is little, the depth of fusion of weld seam is big with the ratio of weld width, can reach 20: 1, therefore, adopt the vacuum electron beam welding can obtain the unrivaled quality weld of any welding method, thereby make joint fusion formation temperature coefficient be lower than transition copper-manganese-red copper alloy band of 50ppm, make red copper-copper-manganese-red copper bimetal band, this bimetal band is become with mould punching: middle copper-manganese material is a resistive element again, the red copper material of its both sides is bus-bars, has the accurate shunt resistor of installing hole and voltage output end on bus-bar.Compared with prior art, this production method operation reduces more than 1/2, and production efficiency improves more than 20 times, can realize automated production, can guarantee effectively that the accurate shunt resistor of being produced has thermal stability and very high reliability preferably simultaneously.

Accurate shunt resistor provided by the present invention has reliability height, Heat stability is good, temperature coefficient rated current low, that can pass through is big, volume is little, easy to use, advantage such as economical with materials to greatest extent, the method of producing this accurate shunt resistor has the advantage that production process is few, production efficiency is high, be convenient to automated production, can guarantee effectively that the accurate shunt resistor of being produced has thermal stability and very high reliability preferably simultaneously.

Description of drawings

Fig. 1 is the structural representation of an embodiment of accurate shunt resistor provided by the present invention;

Fig. 2 is the top view of embodiment one;

Fig. 3 is the partial sectional view of Fig. 2;

Fig. 4 makes the used bimetal band that is formed through electron beam welding by copper belt and copper-manganese band of accurate shunt resistor;

Fig. 5 is the sectional view of bimetal band shown in Figure 4.

1 is the bus-bar of doing with red copper among Fig. 1, Fig. 2, Fig. 3, and 2 are the resistive element with the making of copper-manganese plate, and 3 is between bus-bar and the resistive element, and by the low-temperature coefficient transition manganin district that the electron beam welding fusion forms, 4 is installing hole, and 5 is voltage output end.Among Fig. 4, Fig. 51 for the red copper band of making bus-bar, 2 for making the copper-manganese band of resistive element, 3 low-temperature coefficient transition copper-manganese red copper alloy bands for red copper band and copper-manganese band are formed after the electron beam welding fusion.

Embodiment

The embodiment of accurate shunt resistor provided by the present invention and production method thereof is as follows: at first according to the resistance of shunt resistor, rated current is chosen the width and the thickness of copper-manganese band, the composition of copper-manganese is that Mn is 11%-13%, Ni is 2%-5%, remainder is Cu, temperature coefficient is lower than 20ppm, choose the red copper band identical again with the copper-manganese thickness of strip, with cleaning agent copper-manganese band and red copper band are carried out clean, remove surface and oil contaminant, with the parallel both sides that are placed on the copper-manganese band of red copper band, putting into vacuum electron beam welding machine, is 10 in vacuum degree ^-2-10 ^-4Pa, anode voltage is 30-150KV, electronic beam current is 10mA-1A, focal diameter is less than carrying out the vacuum electron beam welding under the condition of 1mm, the focal position of electronic beam current is at 1/3 place of distance weldment surface thickness of strip, make the red copper of joint, copper-manganese fusion formation temperature coefficient is lower than transition copper-manganese-red copper alloy band of 50ppm, make red copper-copper-manganese-red copper bimetal band, selecting die stamping to go out middle copper-manganese material by designing requirement then is resistive element, the red copper material of its both sides is bus-bars, on bus-bar, have the accurate shunt resistor of installing hole and voltage output end, also can adopt metal cutting to change the thickness of resistive element, thereby adjust resistance value.The composition of copper-manganese is Mn:12% in the embodiment of the invention, Ni:4%, Cu: surplus, temperature coefficient are 10ppm, thickness is 1.2mm, width is 5.2mm, and the thickness of copper belt is 1.2mm, and width is 17.5mm, surface and oil contaminant is removed with the cleaning agent cleaning in the two surface, with the parallel both sides that are placed on the copper-manganese band of red copper band, put into vacuum electron beam welding machine, be 10 in vacuum degree ^-3Pa, anode voltage are that 30-150KV, electronic beam current are that 100mA, focal diameter are less than carrying out the vacuum electron beam welding under the condition of 1mm, the focal position of electronic beam current is at 1/3 place of distance weldment surface thickness of strip, form the bimetal band of red copper-copper-manganese-red copper as shown in Figure 4, use die stamping then, form accurate shunt resistor, adopt metal cutting that the thickness of resistive element is adjusted into 0.7mm again, make accurate shunt resistor as shown in Figure 1, its temperature coefficient is lower than 50ppm, rated current is 40A, and volume only is 1/2 of a prior art.

Claims

1, a kind of accurate shunt resistor, form by the bus-bar that resistive element and employing copper plate are made, it is characterized in that described resistive element adopts temperature coefficient to be lower than the copper-manganese plate of 20ppm, has the temperature coefficient that forms by the electron beam welding fusion to be lower than transition copper-manganese-red copper alloy band of 50ppm between resistive element and bus-bar.

2, accurate shunt resistor according to claim 1 is characterized in that having installing hole and voltage output end on bus-bar.

3, a kind of method of accurate shunt resistor of production claim 1 is characterized in that this production method carries out as follows:

(1) select temperature coefficient to be lower than the copper-manganese band of 20ppm, the parallel both sides that are placed on the copper-manganese band of the red copper band that thickness is identical, put into vacuum electron beam welding machine, abutment joint to two kinds of bands carries out the vacuum electron beam welding, make the red copper of joint, transition copper-manganese-red copper alloy band that copper-manganese fusion formation temperature coefficient is lower than 50ppm, thereby make red copper-copper-manganese-red copper bimetal band;