JP6794509B2 - Shunt resistor - Google Patents

Description

The present invention relates to a shunt resistor used for current value detection.

The shunt resistor is connected in series to an electric circuit whose current value is to be detected, and is a member used when detecting the current value of the circuit by measuring the voltage values on both sides of the shunt resistor. It is widely used in various fields such as bus rings (bus bars) in rotary electric motors.

For example, in Patent Document 1 below, a thick film resistor is joined to the pair of electrode conductors so as to connect a pair of electrode conductors arranged opposite to each other on an insulating substrate, and the thick film resistor is formed by laser trimming. A method of manufacturing a shunt resistor having a desired resistance value by providing a slit has been proposed.

The method described in Patent Document 1 adjusts the resistance value to a desired value by changing the length, number, and pitch of the slits formed by laser trimming, but along the direction orthogonal to the plate surface. The slits are formed so as to open outward in a plan view, and therefore the strength of the slit forming portion, particularly the bending strength in the direction orthogonal to the plate surface, is weakened, and vibration that can be applied in the usage state is weakened. Or bending stress may cause breakage or damage. In particular, when the pitches of a plurality of slits are narrowed, the risk becomes high.

Further, when the slit is opened outward in a plan view, there is a problem that the edge portion of the slit is likely to come into contact with an external peripheral member, which is also likely to be damaged or damaged.
Further, there is a problem that shavings are generated when forming a slit by laser trimming, and it is necessary to remove the shavings in a subsequent process.

In Patent Document 2 below, a shunt resistor is manufactured by punching and forming a resistance value adjusting hole with a first punch and further punching and forming a shunt resistor so as to straddle the resistance value adjusting hole with a second punch. The method is described.

However, even in the shunt resistor manufactured by this method, the notch formed by the resistance value adjusting hole is open outward in a plan view, and therefore, the strength of the notch forming portion, particularly the plate surface, is formed. The bending strength in the orthogonal direction becomes weak, and there is a risk of damage or damage due to vibration or bending stress that may be applied in the used state.

Further, since the notch is open to the outside in a plan view, there is a problem that the edge portion of the notch is likely to come into contact with an external peripheral member, which is also likely to be damaged or damaged.
Further, there is a problem that a punched piece is generated when forming a hole punching for adjusting the resistance value by a punch, and it is necessary to remove the punched piece in a subsequent process.

Japanese Unexamined Patent Publication No. 10-032110 Japanese Unexamined Patent Publication No. 2011-11408

The present invention has been made in view of such a prior art, and it is easy to adjust to a desired resistance value without causing unnecessary substances such as shunting residue and punching pieces and without causing local strength deterioration. The purpose is to provide a shunt resistor that can be used.

The present invention is a shunt resistor including a pair of electrode plate materials separated from each other in the plate surface direction and a resistance alloy plate material connecting the pair of electrode plate materials in order to achieve the above object. The resistance alloy plate material has a ridge portion that forms a convex portion in a cross section along a direction orthogonal to the plate surface and extends from one of the pair of electrode plate materials in an energizing direction toward the other, and includes the ridge portion. Provided is a shunt resistor in which the entire resistance alloy plate material is located in a space sandwiched by the facing end faces of the pair of electrode plate materials.

Preferably, the resistance alloy plate may have a plurality of the ridges parallel to each other.

According to the shunt resistor according to the present invention, it is easy to adjust to a desired resistance value without causing unnecessary substances such as shavings and punched pieces and without causing local strength deterioration in the final form. be able to.

FIG. 1 is a plan view of a shunt resistor according to an embodiment of the present invention. FIG. 2 is a partially enlarged cross-sectional view of the shunt resistor along the line II-II in FIG. FIG. 3 is a partially enlarged cross-sectional view of the shunt resistor along the line III-III in FIG. FIG. 4 is a partially enlarged cross-sectional view corresponding to FIG. 3 of a modified example of the shunt resistor. FIG. 5 is a partially enlarged cross-sectional view corresponding to FIG. 3 of another modified example of the shunt resistor. FIG. 6 is a schematic perspective view showing one step of a method for manufacturing a shunt resistor according to an embodiment of the present invention. FIG. 7 is a schematic perspective view showing one step of the manufacturing method, which is performed after the step of FIG.

Hereinafter, an embodiment of the shunt resistor according to the present invention will be described with reference to the accompanying drawings.
FIG. 1 shows a plan view of the shunt resistor 1 according to the present embodiment.
Further, FIGS. 2 and 3 show partially enlarged cross-sectional views of the shunt resistor 1 along the lines II-II and III-III in FIG. 1, respectively.

As shown in FIGS. 1 and 2, the shunt resistor 1 is a resistance alloy plate material connecting a pair of electrode plate materials 10 and 10 separated from each other in the plate surface direction and the pair of electrode plate materials 10 and 10. It has 20 and.

The electrode plate material 10 is formed of a conductive member 10A, and for example, a Cu metal plate material is preferably used.
As shown in FIGS. 1 and 2, the pair of electrode plates 10 and 10 are provided with a pair of detection terminals 15 and 15 so as to be located in the vicinity of the resistance alloy plate 20 connecting the two. ing.
Reference numeral 18 in FIGS. 1 and 2 is a through hole for fastening used for fixing the shunt resistor 1 at a predetermined position.

In the resistance alloy plate material 20, the pair of electrode plate materials 10 and 10 are mechanically and electrically connected, and the resistance value is adjusted so that the pair of electrode plate materials 10 and 10 have a desired resistance value. Is a member on which
As the resistance alloy plate material 20, for example, Cu—Mn-based alloys, Ni—Cr-based alloys, and Cu—Ni-based alloys are preferably used.

As shown in FIGS. 1 and 3, in the shunt resistor 1, a ridge portion 30 is provided on the surface of the resistance alloy plate material 20, and the recess 35 is formed in the ridge portion 30 to form the recess 35. The resistance value between the pair of electrode members 10 and 10 is adjusted to be a desired resistance value.

The ridge portion 30 forms a convex portion in a cross section along a direction orthogonal to the plate surface, and extends along an energization direction X from one of the pair of electrode plate materials 10 and 10 toward the other.
In the present embodiment, the ridge portion 30 has three ridge portions 30 (1), 30 (2), and 30 (3) which are parallel to each other.
By providing a plurality of the ridges 30 in this way, the surface area of the resistance alloy plate 20 can be increased and the heat dissipation can be improved.

As the resistance alloy plate material 20, an alloy member 20A such as a Cu—Mn alloy, a Ni—Cr alloy, or a Cu—Ni alloy is preferably used, and the alloy member 20A is subjected to wire drawing or rolling. As a result, the ridge portion 30 is formed.

The recess 35 reduces the area of the energized region defined by the cross section along the direction orthogonal to the plate surface, and the resistance value of the resistance alloy plate 20 increases according to the area reduction of the energized region. ..

Therefore, by adjusting whether or not the recess 35 is formed in the ridge portion 30 and, if the recess 35 is formed, the size (depth) thereof, the pair of electrode plate materials 10, 10 Increasing the resistance value between them from the initial resistance value (the resistance value between the pair of electrode plate materials 10 and 10 in the state before forming the recess 35 in the ridge portion 30 of the resistance alloy plate material 20) to the desired resistance value. Can be done.

In the illustrated form, as described above, the resistance alloy plate material 20 is formed with three ridges 30 (1), 30 (2), and 30 (3), which are located in the center in the width direction. A recess 35a having a depth of Da (see FIG. 3) is formed in the portion 30 (2), and a recess 35b having a depth Db (see FIG. 3) shallower than Da in the ridge portion 30 (1) on one side in the width direction. Is formed, and the recess 35 is not formed in the ridge portion 30 (3) on the other side in the width direction.

By adjusting the depth of the recess 35 formed in the ridge portion 30 in this way, the cross-sectional area of the resistance alloy plate material 20 that defines the area of the energized region is adjusted, whereby the pair of electrode plate materials 10 The resistance value between 10 can be increased to a desired resistance value.

In the present embodiment, the ridge portion 30 (2) is formed with a recess 35a having a depth of Da, and the ridge portion 30 (1) is formed with a recess 35b having a depth Db. As long as the resistance value between the members 10 and 10 can be increased to a desired resistance value, the quantity and size (depth) of the recess 35 formed in the ridge portion 30 can be changed.

For example, as shown in FIG. 4, the recess 35c is formed only in one of the plurality of ridges 30 (1), 30 (2), and 30 (3) (for example, 30 (2)). The depth of the recess 35c can be adjusted so that the resistance value between the pair of electrode members 10 and 10 rises to a desired resistance value.

Alternatively, as shown in FIG. 5, recesses 35d having the same depth are formed in all of the plurality of ridges 30 (1), 30 (2), and 30 (3), and the pair of electrode members 10, 10 It is also possible to adjust the depth of the recess 35d so that the resistance value between them rises to a desired resistance value.

From the viewpoint of adjusting the area of the energized region in the resistance alloy plate 20 by the recesses 35, the alloy member 20A includes the ridges 30 in a state of being connected between the pair of electrode members 10 and 10. The entire alloy member 20A is formed so as to be arranged in the space 90 (see FIG. 6 below) sandwiched by the facing end faces 15 and 15 of the pair of electrode members 10 and 10.
According to such a configuration, the area of the energized region can be adjusted with high sensitivity by the size (depth) of the recess 35.

Hereinafter, a method for manufacturing the shunt resistor 1 according to the present embodiment will be described.
In the manufacturing method, as shown in FIG. 6, a pair of conductive members 10A and 10A forming the pair of electrode plate members 10 and 10 and an alloy member 20A forming the resistance alloy plate member 20 are prepared, and the alloy member It has a step of connecting the pair of conductive members 10A and 10A by 20A to form a resistor pre-assembly.

Here, the ridge portion 30 is formed on the surface of the alloy member 20A in advance by wire drawing or rolling.
Further, in the alloy member 20A, the pair of conductive members 10A and 10A (the pair of electrode members 10A and 10A) are connected by the alloy member 20A. It is assumed that the resistance value (initial resistance value) between the pair of electrode plate materials 10, 10) has a resistance value that is smaller than the desired resistance value desired in the completed state of the shunt resistor 1.

As described above, preferably, in a state where the pair of electrode members 10 and 10 are connected by the alloy member 20A, the entire alloy member 20A including the ridge portion 30 faces the pair of electrode members 10 and 10. Specifically, the upper end of the ridge portion 30 is said to be arranged in the space 90 sandwiched by the end faces 15 and 15 in a state where the pair of electrode members 10 and 10 are connected by the alloy member 20A. It is located flush with the upper surfaces 11 and 11 of the pair of electrode members 10 and 10 or below the upper surfaces 11 and 11, and the bottom surface 22 of the alloy member 20A is flush with the bottom surfaces 12 and 12 of the pair of electrode members 10 and 10. One or above the bottom surfaces 12 and 12, the side surface 23 of the alloy member 20A is located flush with the corresponding side surfaces 13 and 13 of the pair of electrode members 10 and 10 or inward of the side surfaces 13 and 13. As such, the alloy member can be formed.

Next, the manufacturing method includes a step of measuring the resistance value between the pair of conductive members 10A and 10A (the pair of electrode plate members 10, 10) in the resistor preassembly as an initial resistance value, and an initial resistance. It has a step of calculating the difference between the value and the desired resistance value as the resistance value to be adjusted.

The manufacturing method is configured such that the resistance value is increased by the resistance value to be adjusted from the initial resistance value by forming the recess 35 in the ridge portion 30 of the alloy member 20A (the resistance alloy plate material 20). Has been done.

Specifically, the manufacturing method determines the size and quantity of the recess 35 to be formed in the ridge 30 so that the resistance value of the resistance alloy plate 20 increases by the resistance value to be adjusted. It has a determination step and a recess forming step of forming recesses 35 having a size and a quantity determined by the recess determination step in the ridge portion 30.

Here, the rising resistance value information regarding how much the resistance value of the alloy member 20A (the resistance alloy plate material 20) rises depending on the size (depth) of the recess 35 formed by the recess forming member 50 is experimentally conducted in advance. It is known by the above.

Therefore, in the recess determination step, the quantity and size (depth) of the recess 35 to be formed in the ridge 30 are determined based on the resistance value to be adjusted and the rising resistance value information. ..

For example, the rising resistance value information is the size (depth) of the recess 35 formed in the first ridge portion (for example, the ridge portion 30 (2)) of the plurality of ridges 30 and the rising resistance value. Relationship and the size of the recess 35 sequentially formed in the remaining ridges in a state where the recess 35 having the upper limit size (depth) is formed in the first ridge (for example, the ridge 30 (2)). It may include the relationship between (depth) and rising resistance.

In this case, in the recess determination step, the size (depth) of the recess 35 to be formed in the first ridge portion 30 and the recess 35 to be formed in the residual ridge portion 30 if necessary. Determine the size (depth).

Instead of this, the rising resistance value information is the size (depth) and rising resistance of the recess 35 when forming the recess 35 of the same size (depth) in each of the plurality of ridges 30. It may include a relationship with a value.
In this case, the recess determination step determines the size (depth) of the recess 35 formed in each of the plurality of ridges 30.

In the recess forming step, the recess 35 having the quantity and size (depth) determined by the recess determining step is formed in the ridge portion 30.

In the present embodiment, in the recess forming step, the recess 35 is formed by the recess forming member 50 (see FIG. 7) that is pushed in the direction orthogonal to the ridge portion 30.
In this case, the size (depth) of the recess 35 is adjusted by adjusting the pushing distance of the recess forming member 50.

According to the manufacturing method, the shunt resistor 1 having a desired resistance value is provided without causing unnecessary substances such as shavings and punched pieces to be generated during the manufacturing process and without causing local strength deterioration in the final form. It can be easily manufactured.

That is, a shunt resistor having a desired resistance value by forming slits that open outward in a plan view along a direction orthogonal to the plate surface by laser trimming and adjusting the pitch, number and / or length of the slits. In the conventional configuration in which the shunt resistor is manufactured, the strength of the slit forming portion, particularly the bending strength in the direction orthogonal to the plate surface, becomes weak, which causes breakage or damage due to vibration or bending stress that can be applied in the usage state of the shunt resistor. There is a risk of becoming.
Further, since the slit is open outward in a plan view, there is a problem that the edge portion of the slit easily comes into contact with an external peripheral member, which also causes damage or damage.
Further, there is a problem that shavings are generated when forming a slit by laser trimming, and it is necessary to remove the shavings in a subsequent process.

Further, a shunt resistor having a desired resistance value is formed by punching and forming a resistance value adjusting hole with a first punch and further punching and forming a shunt resistor so as to straddle the resistance value adjusting hole with a second punch. Even in other conventional configurations for manufacturing a vessel, since the notch formed by the resistance value adjusting hole opens outward in a plan view, the strength of the notch forming portion, particularly the direction orthogonal to the plate surface. The bending strength to the shunt resistor is weakened, and there is a risk of breakage or damage due to vibration or bending stress that may be applied during use of the shunt resistor.
Further, there is a problem that the edge portion of the notch easily comes into contact with an external peripheral member, which also causes damage or damage.
Further, when the resistance value adjusting hole is formed by the punch, a punched piece is generated, and there is a problem that the punched piece needs to be removed in a subsequent process.

According to the manufacturing method, it is possible to easily manufacture a shunt resistor having a desired resistance value while preventing such inconveniences in the prior art.

Further, in the shunt resistor 1, the adjusted resistance value is ensured by confirming the size (depth) and / or the quantity of the recess 35 formed in the ridge portion 30 of the resistance alloy plate material 20. Can be recognized.
Therefore, when the initial resistance value is known, the resistance value of the shunt resistor 1 can be reliably recognized by checking the size (depth) and / or the quantity of the recess 35.

1 Shunt resistor 10 Electrode plate 15 Opposing end face 20 Resistance alloy plate 20A Alloy member 30 Ridge 35 Recess 90 Space

Claims (2)

A shunt resistor including a pair of electrode plates separated from each other in the plate surface direction and a resistance alloy plate material connecting the pair of electrode plates.
The resistance alloy plate material has a convex portion formed in a cross section along a direction orthogonal to the plate surface and has a ridge portion extending from one of the pair of electrode plate materials in the energizing direction toward the other.
A shunt resistor characterized in that the entire resistance alloy plate material including the ridges is located in a space sandwiched by facing end faces of the pair of electrode plate materials. The shunt resistor according to claim 1, wherein the resistance alloy plate material has a plurality of the ridges parallel to each other.

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