Probe for secondary battery

Abstract

To reduce the contact resistance of a probe for a secondary battery and a secondary battery.SOLUTION: A probe 1 for a secondary battery is a probe for a secondary battery 50 including a first pole 51 and a second pole 52 in one side of the probe in an axial direction, the first pole being cylindrical, the first and second poles having different polarities, and the second pole being annular to surround the first pole 51. The probe 1 for the secondary battery has a through-hole 11a to avoid interference with the first pole 51, and includes an annular electrode 10 in contact with the second pole 52 and a second spring 22 for biasing the electrode 10 to the second pole 52.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The technology disclosed herein relates to a probe for a secondary battery. [Background technology]

[0002] There have been known test devices for inspecting secondary batteries, such as by testing their charge / discharge characteristics. For example, a device disclosed in Patent Document 1 charges and discharges a secondary battery according to the voltage between the positive and negative electrodes of the secondary battery. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2016-50800 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned secondary battery test, a probe is brought into contact with each of the positive and negative electrodes. A pin-shaped probe is usually used as a probe for a secondary battery. When a pin-shaped probe is used, the contact area between the positive or negative electrode and the probe is insufficient, and there is room for improvement. Furthermore, when the probe is tilted with respect to the secondary battery, there is a risk that the probe cannot be brought into sufficient contact with the positive or negative electrode. In particular, there is a secondary battery in which both the positive and negative electrodes are arranged on one end face in the axial direction. In such a secondary battery, one pole is arranged in a ring shape so as to surround the other pole. The width of the ring-shaped pole tends to be narrow, and the problem of contact with the probe described above becomes particularly large.

[0005] The technique disclosed herein has been made in view of the above points, and its object is to reduce the contact resistance between the probe and the secondary battery. [Means for solving the problem]

[0006] The secondary battery probe disclosed herein is a probe for a secondary battery having a first pole and a second pole formed in a ring shape to surround the first pole and having a polarity opposite to that of the first pole, disposed on one axial end face, the probe having a through hole to avoid interference with the first pole, and comprising: a ring-shaped electrode in contact with the second pole; and an elastic member to bias the electrode toward the second pole. Effect of the Invention

[0007] The secondary battery probe can reduce the contact resistance with the secondary battery. [Brief description of the drawings]

[0008] [Figure 1] FIG. 2 is a schematic perspective view showing a secondary battery probe separated from the secondary battery. [Diagram 2] FIG. 2 is a schematic perspective view showing a secondary battery probe in contact with a secondary battery. [Diagram 3] 10 is a bottom view of the electrode as viewed from the contact surface side of the contact, showing the attachment state of the contact and the terminal. FIG. [Figure 4] 4 is a side view of the electrode as viewed from the direction of arrow A in FIG. 3. [Diagram 5] 4 is a cross-sectional view showing a detailed configuration of a first electrode and a state where the first electrode is attached to a mounting base. FIG. [Figure 6] 4 is a cross-sectional view showing a detailed configuration of a second electrode and a state where the second electrode is attached to a mounting base. FIG. [Figure 7] 4 is a partial cross-sectional view showing a state in which a first electrode is in contact with a first pole. FIG. [Figure 8] 4 is a partial cross-sectional view showing a state in which a second electrode is in contact with a second electrode. FIG. [Figure 9] FIG. 13 is a schematic perspective view showing a secondary battery probe according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] Hereinafter, exemplary embodiments will be described in detail with reference to the drawings. Fig. 1 is a schematic perspective view showing a secondary battery probe 1 separated from a secondary battery 50. Fig. 2 is a schematic perspective view showing a secondary battery probe 1 in contact with a secondary battery 50.

[0010] As shown in Figs. 1 and 2, the secondary battery probe 1 is a probe for a secondary battery 50 having a first pole 51 and a second pole 52 formed in an annular shape so as to surround the first pole 51 and having a polarity different from that of the first pole 51, disposed on one end face in the axial direction. The secondary battery probe 1 has a through hole 11a for avoiding interference with the first pole 51, and includes an annular electrode 10 in contact with the second pole 52, and a second spring 22 for biasing the electrode 10 toward the second pole 52. The biasing direction of the second spring 22 is referred to as "biasing direction B". The second spring 22 is an example of an elastic member.

[0011] The secondary battery probe 1 is used, for example, in tests such as charge / discharge characteristic tests of a secondary battery 50. The annular electrode 10 is brought into contact with the annular second pole 52, and the electrode 10 is urged toward the second pole 52 by the second spring 22. In this way, the electrode 10 is electrically connected to the second pole 52. The electrode 10 is electrically connected via wiring to a measuring device (not shown) for testing the secondary battery 50. In other words, the electrode 10 electrically connects the second pole 52 to the measuring device by coming into contact with the second pole 52.

[0012] Examples of the secondary battery 50 include a sealed nickel-cadmium battery, a sealed nickel-hydrogen battery, a lithium-ion battery, a manganese dioxide lithium battery, and a lithium cobalt oxide carbon battery.

[0013] In this example, the secondary battery 50 is cylindrical. The first electrode 51 is a positive electrode, and the second electrode 52 is a negative electrode. The secondary battery 50 includes a case, a lid, a positive electrode plate, a negative electrode plate, a separator, an electrolyte, and a safety valve. The positive electrode plate and the negative electrode plate are housed in the case, isolated from each other by the separator. The case is cylindrical with a bottom. The case and the lid are fitted together with an insulator to form a sealed container. The sealed container is filled with an electrolyte. The safety valve is provided in the lid and releases the internal pressure when the internal pressure in the sealed container becomes high.

[0014] The lid includes a first pole 51. The case includes a second pole 52. The case is cylindrical with a bottom and opens on one side in the axial direction. The lid closes the opening of the case. The first pole 51 is disposed in the center of the lid. The outer peripheral edge of the case that defines the opening is the second pole 52. That is, the first pole 51 and the second pole 52 are disposed on one end face in the axial direction of the secondary battery 50. The first pole 51 is disposed in the center of the end face, and the second pole 52 is disposed on the outer peripheral edge of the end face.

[0015] Examples of charge / discharge characteristic tests for the secondary battery 50 include a capacity test, a high-rate discharge characteristic test, a low-temperature discharge characteristic test, an overcharge characteristic test, a capacity retention characteristic test, a long-term storage characteristic test, a durability characteristic test, a safety valve operation characteristic test, a vibration resistance characteristic test, and an impact resistance characteristic test.

[0016] The electrode 10 includes an annular, flat contact 11 that contacts the second pole 52, and a terminal 12 that is electrically connected to the contact 11. In this example, the electrode 10 includes two terminals 12.

[0017] The contact 11 is made of a conductive metal, for example, a gold-plated metal plate. The contact 11 has a through hole 11a in its center. The contact 11 is formed in a ring shape corresponding to the second pole 52. "Corresponding to the second pole 52" means that the contact 11 substantially covers the entire circumference of the second pole 52 when viewed in the biasing direction B. In this example, the contact 11 is formed in a ring shape. That is, the inner diameter of the contact 11 is smaller than the diameter of the second pole 52, and the outer diameter of the contact 11 is larger than the diameter of the second pole 52. In a plan view (i.e., when viewed in the biasing direction B), the contact 11 sufficiently covers the second pole 52.

[0018] The contact 11 includes a contact surface 11b that contacts the second pole 52, and an attachment surface 11c on the opposite side to the contact surface 11b. The contact surface 11b may have an uneven shape. The uneven shape is formed, for example, by providing mesh-like or lattice-like grooves. The uneven shape may also be formed by knurling or blasting. A removable mesh member may also be provided as the uneven shape.

[0019] The terminal 12 has a columnar overall shape. The terminal 12 is a terminal pin. The terminal 12 has an electrical contact disposed at one axial end. The terminal 12 is attached to the contact 11 with the contact in contact with the contact.

[0020] Fig. 3 is a bottom view of the electrode 10 viewed from the contact surface 11b side of the contact 11, showing the attached state of the contact 11 and the terminal 12. Fig. 4 is a side view of the electrode 10 viewed from the direction of the arrow A in Fig. 3. As shown in Figs. 3 and 4, the two terminals 12 are attached to the attachment surface 11c of the contact 11. The two terminals 12 are disposed at positions symmetrical with respect to the center 11p of the contact 11. In other words, the two terminals 12 are disposed at positions equidistant from each other in the circumferential direction with respect to the center 11p of the contact 11.

[0021] The terminal 12 is fixed to the contact 11 by a screw 16. Specifically, the screw 16 passes through the through hole 11d from the contact surface 11b side of the contact 11 and is screwed into the screw hole 12a in the end surface of the terminal 12. This electrically and mechanically connects the terminal 12 to the contact 11. The terminal 12 is attached to the mounting surface 11c so as to extend in a direction perpendicular to the mounting surface 11c. The head of the screw 16 is embedded in the counterbore of the through hole 11d of the contact 11, and the head of the screw 16 is located flush with the contact surface 11b or behind the contact surface 11b.

[0022] The terminal 12 is fixed by two screws 16. The two screws 16 are located on either side of a contact area with the second pole 52, which is indicated by a two-dot chain line in Fig. 3. This makes it possible to prevent the screws 16 from coming into contact with the second pole 52. Note that the terminal 12 may be fixed to the contact 11 by welding instead of the screws 16.

[0023] A wire is connected to the terminal 12. This wire is connected to a measuring device for testing the secondary battery 50. In other words, the contact 11 is electrically connected to the measuring device via the terminal 12 and the wire.

[0024] The secondary battery probe 1 is attached to the mounting base 31 as shown in Figs. 1 and 2. That is, the secondary battery probe 1 is used in a state where it is attached to the mounting base 31. The secondary battery 50 is placed between the mounting base 31 and the support base 32. At this time, the opposing direction of the mounting base 31 and the support base 32 coincides with the axial direction of the secondary battery 50. The axial end face of the secondary battery 50 on which the first pole 51 and the second pole 52 are arranged faces the mounting base 31, and the opposite axial end face of the secondary battery 50 contacts the support base 32.

[0025] The mounting base 31 supports the electrode 10 so as to be movable in a predetermined biasing direction B. More specifically, the mounting base 31 supports the terminal 12 so as to be movable in the biasing direction B. The mounting base 31 has a second mounting hole 31b into which the terminal 12 is inserted. The second mounting hole 31b penetrates the mounting base 31 in the biasing direction B. Since the electrode 10 has two terminals 12, the mounting base 31 also has two second mounting holes 31b. The terminal 12 is slidable in the biasing direction B within the second mounting holes 31b. With the terminal 12 attached to the mounting base 31, the contact 11 is disposed on the secondary battery 50 side relative to the mounting base 31, and the contact surface 11b is substantially perpendicular to the biasing direction B.

[0026] The second spring 22 is a coil spring. The second spring 22 is fitted around the terminal 12. The second spring 22 and the terminal 12 are detachable from each other. One end of the second spring 22 is engaged with the terminal 12. The other end of the second spring 22 is engaged with the mounting base 31.

[0027] 2, when the secondary battery probe 1 is installed on the secondary battery 50, the mounting base 31 is disposed close to the secondary battery 50 so as to compress and deform the second spring 22. This causes the second spring 22 to urge the terminal 12 toward the secondary battery 50 by its elastic force. Since the terminal 12 is attached to the contact 11, the contact 11 is urged toward the secondary battery 50. As a result, the contact surface 11b of the contact 11 properly contacts the second pole 52 of the secondary battery 50.

[0028] In this example, the secondary battery probe 1 includes two second springs 22. The two second springs 22 are arranged at positions symmetrical with respect to the center 11p of the contact 11. In other words, the two second springs 22 are arranged at positions equidistant from each other in the circumferential direction with respect to the center 11p of the contact 11. As a result, the elastic forces of the two second springs 22 act on the contact 11 at positions symmetrical with respect to the center 11p.

[0029] The secondary battery probe 1 may further include an electrode 15 and a first spring 21. The electrode 15 is an electrode separate from the electrode 10. The electrode 15 is an electrode that contacts a first pole 51 of a secondary battery 50. The first spring 21 biases the electrode 15 toward the first pole 51. That is, in the secondary battery probe 1, the probe for the first pole 51 and the probe for the second pole 52 are integrated. Hereinafter, the electrode 15 will also be referred to as the "first electrode 15" and the electrode 10 will also be referred to as the "second electrode 10".

[0030] The first electrode 15 is electrically connected via wiring to a measuring device for testing the secondary battery 50. That is, the first electrode 15 comes into contact with the first electrode 51, thereby electrically connecting the first electrode 51 to the measuring device.

[0031] In this example, the first electrode 15 has a configuration similar to that of the terminal 12. The first electrode 15 has a columnar overall shape. The first electrode 15 is a terminal pin. The first electrode 15 has an electrical contact arranged at one end in the axial direction. The first electrode 15 is supported by the mounting base 31 so as to be movable in the biasing direction B. The mounting base 31 has a first mounting hole 31a into which the first electrode 15 is inserted. The first mounting hole 31a penetrates the mounting base 31 in the biasing direction B. The first mounting hole 31a is arranged between the two second mounting holes 31b, more specifically, in the center of the two second mounting holes 31b. The first electrode 15 is slidable in the biasing direction B within the first mounting hole 31a. In a state in which the first electrode 15 is attached to the mounting base 31, the contact of the first electrode 15 is arranged on the secondary battery 50 side with respect to the mounting base 31. The first electrode 15 is arranged inside the through hole 11a of the contact 11. That is, the first electrode 15 is not in contact with the contact 11 , that is, the second electrode 10 .

[0032] The first spring 21 is a coil spring. The first spring 21 is fitted around the first electrode 15. The first spring 21 and the first electrode 15 are detachable. One end of the first spring 21 is engaged with the first electrode 15. The other end of the first spring 21 is engaged with the mounting base 31.

[0033] 2, when the secondary battery probe 1 is installed on the secondary battery 50, the mounting base 31 is disposed close to the secondary battery 50 so as to compress and deform the first spring 21. As a result, the first spring 21 urges the first electrode 15 toward the secondary battery 50 by its elastic force. As a result, the first electrode 15 is in proper contact with the first pole 51 of the secondary battery 50.

[0034] 5 is a cross-sectional view showing a detailed configuration of the first electrode 15 and a state where the first electrode 15 is attached to the mounting base 31. The first electrode 15 has a first pin 101, a second pin 102, and a bush 103. The first pin 101 is cylindrical. The second pin 102 is columnar. The bush 103 is cylindrical. The first pin 101 is slidably inserted into the bush 103. The second pin 102 is slidably inserted into the first pin 101. The first pin 101 and the second pin 102 are insulated from each other.

[0035] In this example, the first spring 21 is integrally assembled with the first electrode 15. The first electrode 15 and the first spring 21 configure a spring-type terminal pin. The first spring 21 is fitted around the outer periphery of the first pin 101.

[0036] Specifically, the bush 103 is made of an insulating material. The bush 103 supports the first pin 101 so as to be slidable in the biasing direction B.

[0037] The longitudinal direction of the first pin 101 coincides with the biasing direction B. The first pin 101 has a first end 101a which is one end in the longitudinal direction and a second end 101b which is the other end in the longitudinal direction. The first end 101a and the second end 101b each protrude from the bush 103. The first end 101a of the first pin 101 contacts the first pole 51 when testing the secondary battery 50. The second end 101b of the first pin 101 is connected to a measuring instrument via a wire (not shown).

[0038] A male thread is formed on the outer peripheral surface of the first pin 101 near the second end 101b. Two nuts 104 are screwed onto the male thread of the first pin 101. The two nuts 104 are so-called double nuts. The nuts 104 come into contact with the bush 103, thereby restricting the movement of the first pin 101 toward the first end 101a. The nuts 104 function to prevent the first pin 101 from coming out of the bush 103. By removing the nuts 104 from the first pin 101, the first electrode 15 can be disassembled, and the first electrode 15, the first spring 21, and the mounting base 31 can be separated.

[0039] A step is formed on the outer circumferential surface of the first pin 101 near the first end 101a. The portion of the first pin 101 closer to the first end 101a than the step is thicker. The first spring 21 is disposed between the step of the first pin 101 and the bush 103 when the first pin 101 is inserted into the bush 103. One end of the first spring 21 is engaged with the step of the first pin 101. The other end of the first spring 21 is engaged with the bush 103.

[0040] At this time, the first spring 21 is compressed and exerts an elastic force in the expanding direction. The first pin 101, i.e., the first electrode 15, is urged by the first spring 21 toward the first end 101a in the urging direction B. However, the movement of the first pin 101 is restricted at a position where the nut 104 contacts the bush 103. When an external force acts on the first pin 101 toward the second end 101b in the urging direction B, the first pin 101 moves toward the second end 101b against the elastic force of the first spring 21.

[0041] A first internal bush 301 and a second internal bush 302 are disposed inside the first pin 101. The first internal bush 301 and the second internal bush 302 are formed of an insulator. The first internal bush 301 is disposed inside the first pin 101 near the first end 101a. The entire first internal bush 301 is housed inside the first pin 101. The second internal bush 302 is disposed inside the first pin 101 at the second end 102b. The second internal bush 302 partially protrudes from the first pin 101.

[0042] The second pin 102 is slidably inserted into the first inner bush 301 and the second inner bush 302. A first end 102a, which is one end of the second pin 102, protrudes from a first end 101a of the first pin 101. A second end 102b, which is the other end of the second pin 102, protrudes from a second end 101b of the first pin 101. The first end 102a of the second pin 102 comes into contact with the first pole 51 when testing the secondary battery 50. The second end 102b of the second pin 102 is connected to a measuring device via a wiring (not shown).

[0043] A step is formed on the outer circumferential surface of the second pin 102 near the second end 102b. The portion of the second pin 102 closer to the second end 102b than the step is thicker. The step of the second pin 102 comes into contact with the second internal bush 302, thereby restricting the movement of the second pin 102 toward the first end 102a. In other words, the second internal bush 302 also functions to prevent the second pin 102 from coming out.

[0044] A collar 303 is fixed to the outer circumferential surface of a portion of the second pin 102 that is located inside the first pin 101. The collar 303 is made of an insulating material. The collar 303 is located inside the first pin 101, between the first inner bush 301 and the second inner bush 302. The collar 303 slides against the inner circumferential surface of the first pin 101.

[0045] An internal spring 401 is fitted around the outer periphery of the second pin 102. The internal spring 401 is a coil spring. The internal spring 401 is disposed between the second internal bush 302 and the collar 303. At this time, the internal spring 401 is compressed and exerts an elastic force in the extension direction. The second pin 102 is biased toward the first end 102a in the biasing direction B by the internal spring 401. However, the movement of the second pin 102 is restricted at a position where the step of the second pin 102 contacts the second internal bush 302. When an external force acts on the second pin 102 toward the second end 102b in the biasing direction B, the second pin 102 moves toward the second end 102b against the elastic force of the internal spring 401.

[0046] First spring 21, by being incorporated into first electrode 15, biases first pin 101 in biasing direction B. This allows first pin 101 to be elastically displaceable in biasing direction B, and to stably contact first pole 51 with a predetermined contact pressure.

[0047] The bushing 103 is inserted into the first mounting hole 31a of the mounting base 31. One end of the bushing 103 is engaged with the first surface 31c of the mounting base 31. The other end of the bushing 103 is screwed into the nut 33 on the second surface 31d side of the mounting base 31. In this way, the bushing 103 is fixed to the first mounting hole 31a of the mounting base 31. With the bushing 103 attached to the mounting base 31, the first end 101a of the first pin 101, the first end 102a of the second pin 102, and the first spring 21 are disposed on the first surface 31c side of the mounting base 31.

[0048] FIG. 6 is a cross-sectional view showing the detailed configuration of the second electrode 10 and the state of attachment to the mounting base 31. The terminal 12 has a configuration similar to that of the first electrode 15. That is, the terminal 12 has a first pin 101, a second pin 102, and a bush 103. In this example, the second spring 22 is integrally built into the terminal 12. The terminal 12 and the second spring 22 form a spring-type terminal pin. The second spring 22 is fitted onto the outer periphery of the first pin 101. The first pin 101 is inserted into the bush 103 in a state in which it is biased by the second spring 22 toward the first end 101a in the biasing direction B. The second pin 102 is inserted into the first pin 101 in a state in which it is biased by the internal spring 401 toward the first end 102a in the biasing direction B.

[0049] More specifically, the bush 103 supports the first pin 101 so as to be slidable in the biasing direction B. A first end 101a and a second end 101b of the first pin 101 each protrude from the bush 103. Two nuts 104 are screwed onto a male thread of the first pin 101 near the second end 101b. By removing the nuts 104 from the first pin 101, the terminal 12 can be disassembled, and the second electrode 10, the second spring 22, and the mounting base 31 can be separated.

[0050] The second spring 22 is disposed on the outer periphery of the first pin 101 between the step of the first pin 101 and the bush 103. One end of the second spring 22 is engaged with the step of the first pin 101. The other end of the second spring 22 is engaged with the bush 103. At this time, the second spring 22 is compressed and exerts an elastic force in the extension direction. The first pin 101, i.e., the terminal 12, is urged toward the first end 101a in the urging direction B by the second spring 22. However, the movement of the first pin 101 is restricted at the position where the nut 104 contacts the bush 103. When an external force acts on the first pin 101 toward the second end 101b in the urging direction B, the first pin 101 moves toward the second end 101b against the elastic force of the second spring 22.

[0051] The second pin 102 is slidably inserted into the first inner bush 301 and the second inner bush 302 inside the first pin 101. A first end 102a, which is one end of the second pin 102, protrudes from the first end 101a of the first pin 101. In FIG. 6, the second pin 102 is elastically displaced, and the first end 102a is flush with the first end 101a. A second end 102b, which is the other end of the second pin 102, protrudes from the second end 101b of the first pin 101.

[0052] An internal spring 401 is fitted around the outer periphery of the second pin 102. The internal spring 401 is disposed between the second internal bush 302 and the collar 303. At this time, the internal spring 401 is compressed and exerts an elastic force in the extension direction. The second pin 102 is biased by the internal spring 401 toward the first end 102a in the biasing direction B. However, the movement of the second pin 102 is restricted at a position where the step of the second pin 102 contacts the second internal bush 302. When an external force acts on the second pin 102 toward the second end 102b in the biasing direction B, the second pin 102 moves toward the second end 102b against the elastic force of the internal spring 401.

[0053] Unlike the first electrode 15, the contact 11 is attached to the terminal 12. A screw hole 12a is formed in the end face of the first end 101a of the first pin 101 (see FIG. 4). The contact 11 is attached to the first end 101a of the first pin 101 via a screw 16. In this way, the first pin 101 is electrically and mechanically connected to the contact 11. Usually, the first end 102a of the second pin 102 protrudes from the first end 101a of the first pin 101 by the bias of the internal spring 401. By attaching the contact 11 to the first end 101a of the first pin 101, the second pin 102 is pushed toward the second end 102b in the bias direction B. In other words, in a state in which the contact 11 is attached to the first pin 101, the second pin 102 is pressed against the contact 11 by the elastic force of the internal spring 401. In this manner, the second pin 102 is electrically and mechanically connected to the contact 11 .

[0054] In this way, by being incorporated into the terminal 12, the second spring 22 urges the first pin 101 in the urging direction B. This allows the first pin 101 to be elastically displaced in the urging direction B. Furthermore, since the contact 11 is attached to the first pin 101 of the terminal 12, the second spring 22 urges the contact 11 in the urging direction B via the first pin 101. This allows the contact 11 to be elastically displaced in the urging direction B.

[0055] The bushing 103 is inserted into the second mounting hole 31b of the mounting base 31. One end of the bushing 103 is engaged with the first surface 31c of the mounting base 31. The other end of the bushing 103 is screwed into the nut 33 on the second surface 31d side of the mounting base 31. In this way, the bushing 103 is fixed to the second mounting hole 31b of the mounting base 31. With the bushing 103 attached to the mounting base 31, the first end 101a of the first pin 101, the first end 102a of the second pin 102, the contact 11, and the second spring 22 are disposed on the first surface 31c side of the mounting base 31.

[0056] Next, a description will be given of an example of use of the secondary battery probe 1. Fig. 7 is a partial cross-sectional view showing a state in which the first electrode 15 is in contact with the first pole 51. Fig. 8 is a partial cross-sectional view showing a state in which the second electrode 10 is in contact with the second pole 52.

[0057] First, the secondary battery 50 is placed on the support base 32. At this time, the end face of the secondary battery 50 on which the first electrode 51 and the second electrode 52 are not placed is in contact with the support base 32.

[0058] In this state, the mounting base 31 to which the secondary battery probe 1 is attached is brought close to the end surface of the secondary battery 50 on which the first pole 51 and the second pole 52 are arranged. The movement direction of the mounting base 31, i.e., the secondary battery probe 1, is substantially the same as the biasing direction B. Eventually, the first electrode 15, specifically the first pin 101 and the second pin 102, come into contact with the first pole 51 of the secondary battery 50, and the second electrode 10, specifically the contact 11, comes into contact with the second pole 52 of the secondary battery 50. Even after the first electrode 15 and the second electrode 10 come into contact with the first pole 51 and the second pole 52, respectively, the mounting base 31 is moved toward the secondary battery 50, and the first spring 21 and the second spring 22 are compressed.

[0059] In detail, when the mounting base 31 approaches the secondary battery 50, in the first electrode 15, the second pin 102 comes into contact with the first pole 51, and then the second pin 102 is pushed into the first pin 101 against the elastic force of the internal spring 401. Then, as shown in FIG. 7, the first pin 101 comes into contact with the first pole 51, and both the first pin 101 and the second pin 102 come into contact with the first pole 51. From this state, the mounting base 31 moves further toward the secondary battery 50 against the elastic force of the first spring 21. The first spring 21 is further compressed. Thus, the first electrode 15, in contact with the first pole 51, is urged toward the secondary battery 50 in the urging direction B by the elastic force of the first spring 21.

[0060] In the second electrode 10, after the contact 11 comes into contact with the second pole 52, as shown in FIG. 8, the mounting base 31 moves further toward the secondary battery 50 against the elastic force of the second spring 22. The second spring 22 is further compressed. Thus, the second electrode 10, in a state of contacting the second pole 52, is urged toward the secondary battery 50 in the urging direction B by the elastic force of the second spring 22. Note that the first pole 51 is located inside the through hole 11a of the contact 11 as shown in FIG. 2. In other words, the contact 11 does not come into contact with the first pole 51.

[0061] After the secondary battery probe 1 is installed on the secondary battery 50, a test of the secondary battery 50 is performed. For example, the current of the secondary battery 50 is charged and discharged via the first pins 101 of the first electrode 15 and the second electrode 10, and the voltage of the secondary battery 50 is measured via the second pins 102 of the first electrode 15 and the second electrode 10. Such a test using the secondary battery probe 1 is a test based on a so-called four-terminal measurement method. For example, the first pin 101 is a pin for applying a current. The second pin 102 is a pin for measuring a voltage.

[0062] In a capacity test as an example of a charge / discharge characteristic test, first, a constant current is applied to the secondary battery 50 via the first electrode 15 and the second electrode 10 for a predetermined time to charge the secondary battery 50. After the charging is completed, the secondary battery 50 is left for one hour. Then, the secondary battery 50 starts to be discharged. Specifically, the secondary battery 50 is continuously discharged via the first electrode 15 and the second electrode 10 at a constant current until a predetermined discharge end voltage is reached. After the start of the discharge, the time until the predetermined discharge end voltage is reached is recorded.

[0063] According to the thus configured secondary battery probe 1, the second electrode 10 is formed in a ring shape corresponding to the second pole 52. That is, the second electrode 10 sufficiently covers the ring-shaped second pole 52. As a result, the second electrode 10 contacts the second pole 52 over a large part of its circumferential direction, preferably over the entire circumference. This increases the contact area between the second electrode 10 and the second pole 52. At this time, by forming the second electrode 10 in a ring shape having the through hole 11a, it is possible to avoid contact between the second electrode 10 and the first pole 51. That is, the second electrode 10 can increase the contact area with the second pole 52 while avoiding contact with the first pole 51.

[0064] Furthermore, since the second spring 22 biases the second electrode 10 toward the second pole 52, the contact pressure of the second electrode 10 with the second pole 52 can be improved. This allows the second electrode 10 to stably contact the second pole 52. In addition, even if the secondary battery 50 and the second electrode 10 are inclined relative to each other, the second spring 22 elastically displaces the second electrode 10, thereby maintaining contact between the second electrode 10 and the second pole 52.

[0065] These reduce the contact resistance between the secondary battery probe 1 and the secondary battery 50. Since the contact resistance between the secondary battery probe 1 and the secondary battery 50 can be reduced, it becomes possible for the secondary battery probe 1 to apply a large current to the secondary battery 50 while suppressing heat generation at the contact portion between the secondary battery probe 1 and the secondary battery 50.

[0066] In addition, the secondary battery probe 1 has a plurality of second springs 22 (two in this example), and the plurality of second springs 22 are arranged at positions symmetrical with respect to the center 11p of the contact 11, i.e., at positions equidistant in the circumferential direction with respect to the center 11p of the contact 11. This allows the contact 11 to be biased uniformly in the circumferential direction. As a result, the second electrode 10 can be brought into contact with the second pole 52 more stably.

[0067] In addition, the second pole 52 of the secondary battery 50 is formed in an annular shape in the same plane. By forming the contact 11 in an annular and flat shape, the contact 11 can be brought into contact with the annular second pole 52 over almost the entire circumference.

[0068] Since the contact surface 11b of the contact 11 has an uneven shape, the contact surface 11b of the contact 11 can contact the second pole 52 at multiple points, compared to when the contact surface is smooth. For example, when the second pole 52 is formed in a ridge shape, if the contact surface of the contact 11 is smooth, the contact 11 can only contact the ridge line of the second pole 52. In contrast, the contact surface 11b having an uneven shape can contact not only the ridge line of the second pole 52, but also parts other than the ridge line. This can further increase the contact area between the second electrode 10 and the second pole 52.

[0069] Since the second spring 22 and the second electrode 10 are detachable, the second electrode 10 can be easily replaced when it becomes worn out.

[0070] Since the second spring 22 is coaxially fitted into the terminal 12, the second spring 22 can be integrated with the terminal 12, and the space required for providing the second spring 22 can be reduced. Furthermore, the terminal 12 functions as a guide for the second spring 22, which is a coil spring. This allows the elastic force of the second spring 22 to be applied to the second electrode 10 in a stable manner.

[0071] Furthermore, the second spring 22 is incorporated into the terminal 12 as a spring-type terminal pin. In other words, the spring of the spring-type terminal pin is utilized as the second spring 22 to bias the contact 11. In other words, by utilizing the spring of the spring-type terminal pin for maintaining stable contact, the configuration of the second electrode 10 can be simplified.

[0072] Similarly, the first electrode 15 is biased toward the first pole 51 by the first spring 21, so that the contact pressure of the first electrode 15 with the first pole 51 is improved. This allows the first electrode 15 to stably contact the first pole 51. In addition, even if the secondary battery 50 and the first electrode 15 are inclined relative to each other, the first electrode 15 is elastically displaced by the first spring 21, so that the contact between the first electrode 15 and the first pole 51 is maintained.

[0073] <<Variation>> 9 is a schematic perspective view showing a secondary battery probe 1A according to a modified example. The secondary battery probe 1A differs from the secondary battery probe 1 in the configuration of the electrodes. The following description will focus on the configuration of the secondary battery probe 1A that differs from the secondary battery probe 1. Note that in the secondary battery probe 1A, the same reference numerals as those in the secondary battery probe 1 have the same configuration as the secondary battery probe 1, and therefore description thereof will be omitted.

[0074] The electrode 10A (hereinafter also referred to as the "second electrode 10A") of the secondary battery probe 1A has a contact 11. The second electrode 10A does not have the terminal 12 of the secondary battery probe 1. A wiring 17 is electrically connected directly to the contact 11 of the second electrode 10A. The wiring 17 is connected to a measuring instrument (not shown). The wiring 17 may include, for example, a wiring for applying a current and a wiring for measuring a voltage. Thus, the second electrode 10A is annular and flat.

[0075] The second spring 22 is disposed between the second electrode 10A and the mounting base 31 without the intermediation of the terminal 12. The second spring 22 and the second electrode 10A may be detachable from each other.

[0076] The secondary battery probe 1A, like the secondary battery probe 1, further includes a first electrode 15 for the first pole 51 and a first spring 21.

[0077] According to such a secondary battery probe 1A, since the second electrode 10A is annular and flat, when the second electrode 10A is brought into contact with the second pole 52, the second electrode 10A can be brought into contact so as to cover substantially the entire circumference of the second pole 52. As a result, the contact area of ​​the second electrode 10A with the second pole 52 can be increased.

[0078] Furthermore, the electrical connection of the contacts 11 is realized by a direct connection of the wiring 17. The second springs 22 are disposed on the contacts 11 regardless of the electrical connection of the contacts 11. Therefore, the mechanical connection of the contacts 11 by the second springs 22 and the electrical connection of the contacts 11 by the wiring 17 can be maintained separately.

[0079] Incidentally, the description of other configurations, operations and effects will be omitted, but the description of the secondary battery probe 1 can be used to describe the secondary battery probe 1A.

[0080] Other Embodiments As described above, the above embodiment has been described as an example of the technology disclosed in this application. However, the technology in this disclosure is not limited to this, and can be applied to embodiments in which modifications, replacements, additions, omissions, etc. are appropriately performed. In addition, it is also possible to combine the components described in the above embodiment to form a new embodiment. In addition, among the components described in the attached drawings and detailed description, not only components essential for solving the problem but also components that are not essential for solving the problem in order to exemplify the technology may be included. Therefore, the fact that these non-essential components are described in the attached drawings and detailed description should not immediately be taken to mean that these non-essential components are essential.

[0081] For example, in the secondary battery 50, the first electrode 51 may be a negative electrode and the second electrode 52 may be a positive electrode. The secondary battery 50 may be in the shape of a square tube instead of a cylindrical tube.

[0082] The secondary battery probe 1, 1A may not include the first electrode 15 and the first spring 21 for the first pole 51. In other words, the secondary battery probe 1, 1A may include only the second electrode 10, 10A and the second spring 22 for the second pole 52.

[0083] The elastic member that biases the electrodes is not limited to a coil spring such as the second spring 22, and may be rubber, a leaf spring, etc. Similarly, the first spring 21 is not limited to a coil spring, and may be rubber, a leaf spring, etc.

[0084] In the secondary battery probe 1, the second spring 22 is integrally assembled with the terminal 12, but is not limited thereto. For example, the second spring 22 may be disposed without being fitted into the terminal 12. By separating the second spring 22 from the terminal 12, maintenance of the second spring 22 and the terminal 12 can be performed separately, making maintenance easier. For example, the second springs 22 and the terminals 12 may be disposed alternately and at equal intervals in the circumferential direction with respect to the center 11p of the contact 11.

[0085] The secondary battery probe 1 includes two terminals 12, but the number of terminals 12 may be one or three or more. The multiple terminals 12 are preferably disposed at equal intervals in the circumferential direction with respect to the center 11p of the contact 11.

[0086] The number of second springs 22 may be one or three or more. The multiple second springs 22 are preferably arranged at equal intervals in the circumferential direction with respect to the center 11p of the contact 11. This allows the second springs 22 to uniformly urge the contact 11 in the circumferential direction. As a result, the stability of the contact 11 with the second pole 52 is improved. Alternatively, the second spring 22 may be a coil spring having a diameter larger than the through hole 11a of the contact 11 and arranged substantially coaxially with the contact 11. In this case, one second spring 22 can press the entire contact 11 in the circumferential direction.

[0087] The shape of the contact 11 is not limited to a circular ring shape, and may be any ring shape that corresponds to the second pole 52. For example, the contact 11 may be a polygonal ring shape.

[0088] Although the contact 11 is flat, the contact 11 may be cylindrical. In this case, at least a portion of the contact 11 that contacts the second pole 52 may be a truncated cone that expands in diameter. This allows the second pole 52 to easily contact the inner peripheral surface of the cylindrical contact 11.

[0089] The terminal 12 is not limited to the above-mentioned configuration. For example, the terminal 12 may have the first pin 101 and may not have the second pin 102. In this case, a test may be performed by a so-called two-terminal measurement method.

[0090] The techniques disclosed herein can be summarized as follows:

[0091] [1] The secondary battery probe 1, 1A is a probe for a secondary battery 50 having a first pole 51 and a second pole 52 formed in a ring shape to surround the first pole 51 and having a polarity different from that of the first pole 51, disposed on one axial end face, and has a through hole 11a to avoid interference with the first pole 51, and is equipped with a ring-shaped electrode 10, 10A in contact with the second pole 52, and a second spring 22 (elastic member) that urges the electrode 10, 10A toward the second pole 52.

[0092] According to this configuration, for example, when the secondary battery probe 1, 1A is brought into contact with the secondary battery 50 to test the secondary battery 50, the electrode 10, 10A is formed in a ring shape corresponding to the second pole 52, so that the contact area with the second pole 52 can be enlarged. Furthermore, since the electrode 10, 10A has the through hole 11a, it can contact the second pole 52 while avoiding contact with the first pole 51. In addition, since the second spring 22 biases the electrode 10, 10A toward the second pole 52, it is possible to stabilize the contact of the electrode 10, 10A with the second pole 52. For example, even if the electrode 10, 10A is slightly tilted with respect to the secondary battery 50, the electrode 10, 10A is displaced by the elastic deformation of the second spring 22, so that the contact with the second pole 52 is maintained. As a result, the contact resistance between the secondary battery probe 1, 1A and the secondary battery 50 can be reduced.

[0093] [2] In the secondary battery probe 1A described in [1], the electrodes 10 and 10A are flat.

[0094] This configuration can further increase the contact area between the electrodes 10, 10A and the second pole 52. More specifically, the second pole 52 of the secondary battery 50 extends in an annular shape within one plane. By making the electrodes 10, 10A flat, they can be in contact with the second pole 52 over substantially the entire circumference.

[0095] [3] In the secondary battery probe 1, 1A described in [1] or [2], the electrode 10, 10A has a contact surface 11b that contacts the second pole 52, and the contact surface 11b has an uneven shape.

[0096] According to this configuration, the contact surfaces 11b of the electrodes 10, 10A have an uneven shape, so that the contact surfaces 11b of the electrodes 10, 10A can be brought into contact with the second electrode 52 at multiple points compared to when the contact surfaces 11b of the electrodes 10, 10A are smooth, thereby further increasing the contact area between the electrodes 10, 10A and the second electrode 52.

[0097] [4] In the secondary battery probe 1, 1A according to any one of [1] to [3], the second spring 22 and the electrode 10, 10A are detachable.

[0098] According to this configuration, when the electrodes 10, 10A become worn, the electrodes 10, 10A can be detached from the second spring 22, and the electrodes 10, 10A can be easily maintained.

[0099] [5] In the secondary battery probe 1 described in any one of [1] to [4], the electrode 10 includes an annular, flat contact 11 that contacts the second pole 52, and a terminal 12 electrically connected to the contact 11.

[0100] According to this configuration, the terminal 12 can also be used as a guide for the second spring 22. [Explanation of symbols]

[0101] 1,1A secondary battery probe 10,10A electrode 11 Contact 11a Through hole 11b Contact surface 12 Terminals 22 Second spring (elastic member) 50 Secondary battery 51 1st pole 52 2nd pole

Claims

1. A probe for a secondary battery, the probe comprising: a first electrode; a second electrode formed in an annular shape so as to surround the first electrode and having a polarity different from that of the first electrode, the second electrode being disposed on one end surface in an axial direction; a ring-shaped electrode having a through hole for avoiding interference with the first pole and in contact with the second pole; a resilient member that urges the electrode toward the second pole.

2. The secondary battery probe according to claim 1 , The electrode is a flat plate-shaped secondary battery probe.

3. The secondary battery probe according to claim 2, The electrode has a contact surface that contacts the second pole, The contact surface of the secondary battery probe has an uneven shape.

4. The secondary battery probe according to any one of claims 1 to 3, The elastic member and the electrode are detachable from each other.

5. The secondary battery probe according to claim 1 , The electrode is a secondary battery probe including an annular, flat contact that contacts the second pole, and a terminal that is electrically connected to the contact.

Images