JP2021093328A - Load resistance device - Google Patents

Abstract

To provide a load resistance device capable of miniaturizing a whole of the device.SOLUTION: A load resistance device contains: a box-shaped housing; two end part electrodes which are respectively supported by an upper end and a lower end of the housing, and to which a positive electrode and a negative electrode of a charging battery are respectively connected; and a plurality of resistance body groups that includes a plurality of resistance bodies made of a plate-like metal electrically connected with each other in parallel, and is electrically connected in series between the two end part electrodes. Each resistance body is made of a stainless steel.SELECTED DRAWING: Figure 3

Description

The present invention relates to a load resistance device for performing a load test.

A secondary battery such as a lithium ion battery or a battery pack (combined battery) having a plurality of these secondary batteries is charged and repeatedly used, and is widely used as various power sources. As the capacity of secondary batteries has increased, external short-circuit tests, which are load tests, have become common as safety tests for secondary batteries.

The external short-circuit test is a test that assumes misuse or safe use when the secondary battery is short-circuited outside and ignites or explodes. The positive and negative terminals are connected to an external resistance device, and an excessive load current is applied. This is a test to confirm that the secondary battery does not ignite or explode.

FIG. 8 shows an example of a test circuit for performing an external short circuit test. This test circuit includes a secondary battery 100 as a test target, an external short-circuit test device 101, and a load resistance device 102. The external short-circuit test device 101 has an opening / closing means 103 for opening / closing the test circuit, and the secondary battery 100, the load resistance device 102, and the opening / closing means 103 are connected in series in the test circuit. The external short-circuit test is a test in which an external short-circuit is performed in advance on a fully charged secondary battery to confirm the safety function of the secondary battery and the safety of the external protection circuit of the secondary battery. For example, FIG. The standards shown in the table are known.

As an external short-circuit condition for this secondary battery, the load resistance value (external resistance) is defined as several mΩ to 100 mΩ. Therefore, in order to realize the specified load resistance value, for example, a load resistance device (hereinafter referred to as a hollow resistance load device) in which a plurality of enamel resistors having a relatively large size as resistance elements are mounted as shown in FIG. 102H is commonly used. Each of the enamel resistors has a structure in which a metal wire resistor between both terminals is wound around an insulator tube and fixed with an enamel coating, and is relatively large in size, external dimensions, heavy, and expensive. is there.

Hollow resistance load devices for external short-circuit tests combine multiple hollow resistors inside the housing to form the desired specified resistance value, so that the hollow resistance increases as the battery capacity of the secondary battery to be tested increases. Since the number of devices is increased, the device as a whole is a load resistance device that is expensive and heavy. Further, in the enamel resistance load device, as the number of enamel resistors increases, many blowers for air cooling of the enamel resistors are required, and the size of the device housing must be increased.

The present invention has been made to solve such a problem, and an example of the present invention is to provide a load resistance device in which the entire device can be miniaturized.

The load resistance device of the present invention is a load resistance device for performing a load test of a rechargeable battery.
With a box-shaped housing
Two end electrodes that are supported by the upper and lower ends of the housing and to which the positive and negative electrodes of the rechargeable battery are connected, respectively.
A group of resistors made of plate-shaped metal electrically connected in parallel with each other and electrically connected in series with each other between the two end electrodes.
Including
The resistor is characterized by being made of a stainless steel material.

According to the present invention, a plurality of strip-shaped or plate-shaped resistors made of stainless steel (hereinafter, also referred to as stainless steel plate resistors) are arranged in parallel and in series so as to form a target resistance value. The efficiency of the installation space of the resistor that generates heat in the housing of the load resistance device is improved, and the device housing can be miniaturized and realized at low cost.

It is a perspective view which shows the front state which closed the door of the load resistance device of this Example. It is a perspective view which shows the state of the resistor group seen from the door opening by removing the door in front of the load resistance device of this Example. It is a functional block diagram explaining the load resistance apparatus 1 of the Example which concerns on this invention. It is a figure which shows the example of the type of the stainless steel material of the stainless steel plate resistor and the characteristic of the metal other than the stainless steel material in the load resistance apparatus of this Example. It is a schematic perspective view explaining an example of the process of manufacturing the stainless steel plate resistor (FIG. 5B) from the stainless steel plate (FIG. 5A) in the load resistance apparatus of this Example. It is a perspective view which shows the two states of a part of the unit of a resistor group in the vicinity of the end electrode of the upper stage inside the load resistance apparatus of this Example, respectively. It is a perspective view which shows the two states of a part of the unit of a resistor group in the vicinity of the lower end electrode inside the load resistance apparatus of this Example, respectively. It is a wiring diagram which shows an example of the test circuit for performing an external short circuit test. It is a table explaining the standard of an external short circuit test. It is a perspective view which shows the load resistance apparatus which mounts a plurality of relatively large enamel resistors as a resistance element.

Hereinafter, the load resistance device according to the embodiment of the present invention will be described with reference to the drawings. It should be noted that the present embodiment is an example of the present invention, and the present invention is not limited thereto.

FIG. 1 is a perspective view showing a front state in which the double door DR of the load resistance device 1 of the present embodiment is closed, and FIG. 2 is a view from the door opening with the front door DR of the load resistance device 1 removed. It is a perspective view which shows the state of the resistor group 2G, and FIG. 3 is a functional block diagram explaining the load resistance device 1.

As shown in FIG. 1, the load resistance device 1 has a box-shaped housing 10 having a rectangular parallelepiped outer shape. An intake port INL is provided on the lower side surface (lower side plate) of the housing 10, and an exhaust port OTL is provided on the upper surface. A metal net panel NP is attached to each of the intake port INL and the exhaust port OTL. As described above, the housing 10 is provided with a double door DR on the front surface. In the load resistance device 1, it is possible to access the internal device portion by opening the double door DR.

The upper part of the front surface of the housing 10, specifically the upper part of the double door DR, is equipped with a power receiving lamp LP that lights up when energized from a connected external short-circuit test device (not shown). Has been done.

As shown in FIGS. 2 and 3, the load resistance device 1 has a plurality of resistor groups 2G supported and housed inside the housing 10. Each of the resistors group 2G has a plurality of plate-shaped resistors 2 electrically connected in parallel with each other. That is, each of the resistors 2 has a strip shape. Each of the resistors 2 is made of a stainless steel plate (described later).

As shown in FIG. 2, in the load resistance device 1, 8 units (16 units in total) of the resistor group 2G instructed in each of the upper and lower two stages on the girder member 11 of the frame in the housing 10 are inside the housing 10. It is stored in. The two end electrodes 4 are supported by support metal fittings 12 on the upper and lower stages of the housing 10, and 16 units are connected in series between the two end electrodes 4.

As shown in FIG. 3, each of the plurality of resistor groups 2G has two relay electrodes 3 made of copper (Cu), and the plurality of resistors 2 are electrically parallel to each other between the two relay electrodes 3. It is connected to the. The plurality of resistor groups 2G are connected to each other via the electrical connection portion 3a of the two relay electrodes 3. That is, the plurality of resistor groups 2G are electrically connected in series with each other between the two end electrodes 4. The two end electrodes 4 are connected to the positive electrode and the negative electrode of the rechargeable battery of the external short-circuit test device 101, respectively.

As shown in FIG. 2, the opposite end (electrical connection portion) of the end electrode 4 of the upper and lower series 8 units is connected by a connecting plate 3aa made of copper, whereby a resistor group of 16 units is connected. 2G is electrically connected in series between the two end electrodes 4.

As shown in FIG. 2, the relay electrode 3 and the electrical connection portion 3a are fixed to the girder member 11 of the frame in the housing 10 via a plurality of support metal fittings 12. The relay electrodes 3 and the electrical connection portion 3a of the upper and lower U-shaped tubular members U1 and U2 also function as holding means for holding the stainless steel plate resistor 2. The support metal fitting 12 is insulated and fixed from the girder member 11 via an insulating bush such as a heat-resistant insulating insulator.

As shown in FIG. 2, the load resistance device 1 includes a blower 22 at the upper end of the inside for exhausting Joule heat generated from the stainless plate resistor 2. A blower 22 is provided for air cooling of the resistor (resistor group 2G) to suppress the temperature rise. The blower 22 may be arranged not only at the upper end inside the housing but also at the upper and lower ends. The exhaust amount of the blower 22 may be controlled by monitoring the exhaust temperature with a temperature sensor (not shown).

Further, a door sensor DS is provided on the upper edge of the door opening of the load resistance device 1 shown in FIG. 2, and an earth leakage breaker BK is provided on the right edge of the door opening.

As shown in FIG. 1, the door sensor DS has opened the door DR (access to the inside) when the power receiving lamp LP is lit and energized with the double door DR of the load resistance device 1 closed. Detecting what is possible) and transmitting a door open signal to the stop interlock circuit of an external short circuit tester (not shown).

The earth leakage breaker BK detects the on / off or electric leakage of the blower 22 or the like, and sends an off signal (blower stop signal) of the earth leakage breaker to an external short-circuit test device (not shown) via a control unit (not shown). Send to the stop interlock circuit.

Stop of the external short-circuit test device The interlock circuit automatically stops the test system in response to a predetermined signal from a protective device such as a door sensor DS or an earth leakage breaker BK.

[Stainless steel plate resistor]
FIG. 4 is a diagram showing Tables 1 and 2 showing examples of the types of stainless steel materials and the characteristics of metals other than stainless steel materials of the resistor 2 (stainless steel plate resistor) made of stainless steel plate in the load resistance device 1 of this embodiment. Is.

Table 1 shows the classification of stainless steel (SUS: Steel Use Stainless) by metal structure, such as "ferrite type", "austenitic type", "duplex type (austenitic ferrite type)", "martensite type", and "precipitation hardening type". The characteristics of "ferrite-based", "austenitic-based", and "two-phase-based" are shown. Table 2 shows the characteristics of "austenitic" SUS304 and other metals (aluminum, copper, iron).

As the metal material of the resistor, SUS304 is an advantageous material. This is because, as shown in FIG. 4, SUS304 has a larger volume resistivity than other metals, and the temperature change of the volume resistivity is smaller than that of other metals. Due to this characteristic, the plate material of SUS304 has a small change in resistance value even if it generates heat, and therefore is preferably used as a stable load resistance for the purpose of testing. Although SUS304 is inferior to other metals in terms of thermal conductivity, in the case of a plate-shaped flat heating element, the stainless steel plate resistor 2 functions as an air-cooled fin, so that there is no problem in cooling. Further, as the stainless steel plate resistor 2, a non-magnetic "austenitic" SUS is preferably used in addition to the SUS304.

Since the stainless steel plate resistor 2 has a low rate of change in volume resistivity, the resistance value does not change much even when the temperature rises. Further, the stainless plate resistor 2 is preferable from the viewpoint of space saving, cost reduction, and improvement of heat dissipation because it is easy to design and manufacture the shape of the resistor by cutting it out from a commercially available stainless steel plate based on the sheet resistance.

The design of the stainless plate resistor 2 includes the total energy during discharge, the temperature rise of the stainless plate resistor 2, the upper limit of the temperature rise, the rectangular shape of the stainless plate resistor 2, the sheet resistance of the raw material stainless steel plate, etc. It is done in consideration.

FIG. 5 is a schematic perspective view illustrating an example of a process of manufacturing the stainless steel plate resistor 2 (FIG. 5B) from the stainless steel plate (FIG. 5A) in the load resistance device 1 of the present embodiment.

A raw material stainless steel sheet having sheet resistance Rs (volume resistivity ρ, length L, width W, plate thickness D, (L> W> D)) is, for example, an electricity with a target design load resistance value (for example, R = 8 mΩ). Create based on resistance value). Then, for example, in order to obtain a stainless steel plate resistor 2 having the same shape, the steel plate is equally divided into vertical L / m and horizontal W / n by a shearing machine such as a laser processing machine or a shirring machine, and a plurality of (m × n). It is subdivided into stainless steel plate resistors 2 (length l, width w, plate thickness d, (l = L / m> w = W / n> D), respectively) so that they can be stored in the apparatus housing. If n groups of stainless steel plate resistors 2 (that is, one unit that is a group of resistors 2G) are arranged in the width direction and electrically connected in parallel, and the m units 2G are electrically connected in series. A load resistance device having a target load resistance value can be obtained. For example, as shown in FIG. 3, six groups of stainless steel plate resistors 2 are arranged in the width direction and electrically connected in parallel to form a resistor group 2G. If 16 units of the resistor group 2G are electrically connected in series as one unit, a load resistance device having a predetermined load resistance value can be obtained.

The relationship between the electrical resistance value R of a rectangular parallelepiped stainless steel plate and its dimensions (the length of the long side of the rectangular parallelepiped is L, the width is W, and the plate thickness is D) and the sheet resistance Rs is
R = (ρ · L) / (d · W) = Rs · L / W
Is. If the sheet resistance Rs of a stainless steel sheet having a plate thickness D is known, the actual length of the stainless steel sheet can be obtained by substituting the value of the width W of the stainless steel sheet and the value of the length L of the stainless steel sheet into the above relational expression. The electric resistance value R in the direction can be calculated.

[Divided arrangement of stainless steel plate resistors in the load resistance device]
6 and 7 are perspective views showing two states of a part of the unit of the resistor group 2G in the vicinity of the upper and lower end electrodes 4 inside the load resistance device 1, respectively.

As shown in FIG. 6, the six stainless steel plate resistors 2 of the upper resistor group 2G are arranged so that their long sides are separated from each other and parallel to each other and both ends are aligned, and both ends of each stainless steel plate resistor 2 are arranged. The portions are bolted to the side surfaces of the relay electrodes 3 of two parallel plate-shaped copper plates. Each of the resistors 2 has a strip shape, and in each of the resistor groups 2G, the resistors 2 are arranged in a row along the short direction of the strip shape.

The stainless steel plate resistor 2 is supported by the relay electrode 3 by being physically fixed by bolting. The physical fixation may be a close fitting or the like. Since the stainless steel material of the stainless plate resistor 2 has an ionization tendency similar to that of copper (Cu) when applied to the ionization column, it does not hinder contact corrosion.

As described above, the plurality of resistors 2 are arranged in a row along the lateral side of each of the plurality of resistors 2 in each of the plurality of resistor groups 2G, and the two relay electrodes 3 are arranged. Each connects the longitudinal ends of the plurality of resistors 2 in each of the plurality of resistor groups 2G. The plurality of resistor groups 2G are arranged so as to overlap each other along the direction perpendicular to the plate surface of the resistor 2.

The relay electrode 3 is a part of U-shaped tubular members U1 and U2 made of copper integrally formed with a pair of relay electrodes adjacent to each other by the electrical connection portion 3a. In the upper U-shaped tubular member U1, the upper ends of the six stainless steel plate resistors 2 are arranged on the opposite side surfaces of the relay electrode 3 so as to face the adjacent six stainless steel plate resistors 2. In the lower U-shaped tubular member U2, the lower ends of the six stainless steel plate resistors 2 are arranged on the opposite side surfaces of the relay electrode 3 so as to sandwich the relay electrode 3 together with the adjacent six stainless steel plate resistors 2. Will be done. That is, the relay electrodes 3 of the adjacent resistor groups 2G among the plurality of resistor groups 2G form a U-shaped tubular member U1 or U2 integrally connected by the electrical connection portion 3a.

Eight units of the resistor group 2G, in which six stainless steel plate resistors 2 are electrically connected in parallel, are electrically connected in series by the relay electrodes 3 of the upper and lower U-shaped tubular members U1 and U2 and the electrical connection portion 3a.

A heat radiating plate HS made of copper is fixed to the electrical connection portion 3a of the lower U-shaped tubular member U2. The lower heat dissipation plate HS ensures the same heat dissipation effect as the electrical connection portion 3a of the upper U-shaped tubular member U1.

As shown in FIG. 7, the six stainless steel plate resistors 2 of the lower resistor group 2G are also arranged so that their long sides are separated from each other and parallel to each other and both ends are aligned, and both ends of each stainless steel plate resistor 2 are arranged. The portions are bolted to the side surfaces of the two parallel plate-shaped relay electrodes 3. Also in the lower resistor group 2G shown in FIG. 7, the relay electrodes 3 of the U-shaped tubular members U1 and U2 and the electrical connection portion 3a electrically connect six stainless plate resistors 2 in parallel as in FIG. Eight units of the resistor group 2G are electrically connected in series. However, the positions of the U-shaped tubular members U1 and U2 are upside down from those in the upper row shown in FIG.

According to this embodiment, the following effects can be obtained by using a stainless steel plate resistor as the resistance element. Since the stainless steel plate resistor has high heat dissipation efficiency as a heat dissipation plate, it is easy for the entire device to dissipate heat (the number of blowers can be reduced). Since the stainless steel plate resistor has stable temperature resistivity characteristics, it is easy to design the target resistance value. Since stainless steel is a general-purpose material, equipment material costs can be realized at low cost. Since the stainless steel plate resistor is plate-shaped, it is easy to assemble the device. Since the stainless steel plate resistor is plate-shaped, it is possible to realize a load resistance device for high power that is lighter and more maintainable than the enamel resistance load device. In particular, by selecting a stainless steel type (SUS304 or the like) as the metal of the resistance material, the stability of the load resistance value, the weather resistance such as corrosion resistance, and the cost merit are superior to the enamel resistance load device.

In addition to the external short-circuit test of the secondary battery, the load resistance device of the above embodiment includes a fuel cell evaluation test, a battery capacity test, a generator periodic evaluation test, an emergency generator periodic test, and a power surplus. It can be used as a device for performing load tests such as a thermal conversion test system for electric power, a life test of a switch, and a life test of a relay.

1 Load resistance device 2 Stainless steel plate resistor 2G Resistor group 3 Relay electrode 3a Electrical connection part 10 Housing 11 Girder material 12 Support bracket 22 Blower U1, U2 U-shaped tubular member HS Heat dissipation plate

The load resistance device of the present invention is a load resistance device for performing a load test of a rechargeable battery.
With a box-shaped housing
The housing being respectively supported on the stage and a lower stage on the, and two end electrodes which positive and negative electrodes of the rechargeable battery in each of which is connected,
A group of resistors made of plate-shaped metal electrically connected in parallel with each other and electrically connected in series with each other between the two end electrodes.
Including
The resistor is characterized by being made of a stainless steel material.

Claims (6)

A load resistance device for performing load tests on rechargeable batteries.
With a box-shaped housing
Two end electrodes that are supported by the upper and lower ends of the housing and to which the positive and negative electrodes of the rechargeable battery are connected, respectively.
A group of resistors made of plate-shaped metal electrically connected in parallel with each other and electrically connected in series with each other between the two end electrodes.
Including
A load resistance device characterized in that the resistor is made of a stainless steel material. Each of the plurality of resistor groups has two relay electrodes made of metal, and the plurality of resistors are electrically connected between the two relay electrodes, and the plurality of resistor groups are described as described above. The load resistance device according to claim 1, wherein the load resistance device is connected to each other via two relay electrodes. Each of the plurality of resistors has a strip shape, and the plurality of resistors are arranged in a row in each of the plurality of resistor groups along the lateral direction of each of the plurality of resistors. The second aspect of claim 2, wherein each of the two relay electrodes connects the ends of the plurality of resistors in the longitudinal direction in each of the plurality of resistors. Load resistance device. The plurality of resistor groups are arranged so as to overlap each other along a direction perpendicular to the plate surface of each of the plurality of resistors, and relay electrodes of adjacent resistor groups among the plurality of resistor groups. The load resistance device according to claim 3, wherein the U-shaped tubular members are integrally connected to each other by an electrical connection portion. The load resistance device according to claim 4, wherein a heat radiating plate is fixed to the electrical connection portion of the U-shaped tubular member. The load resistance device according to any one of claims 1 to 5, further comprising a blower provided in the housing and blowing air toward the plurality of resistors.

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