JP2020087751A - Terminal welding device - Google Patents

Abstract

To provide a terminal welding device capable of obtaining a value close to contact resistance Ra between the top surface of a protruding portion of an external terminal connection portion and an electrode terminal portion of a battery to a good extent before resistance welding.SOLUTION: A terminal welding device 100 includes a first electrode rod 110 that is brought into contact with an electrode terminal portion 15 of a battery 10, a second electrode rod 115 that is brought into contact with a peripheral portion 23d of an external terminal connecting portion 23 of an external terminal member 20 and presses the peripheral portion 23d to bring the top surface 23cn of a protruding portion 23c into contact with the electrode terminal portion 15, a first resistance measuring probe 120 brought into contact with the electrode terminal portion 15, a second resistance measuring probe 125 brought into contact with a base end surface 23cm of the protruding portion 23c, and a resistance detection unit 160 that detects an inter-probe resistance value Rk between the first resistance measuring probe 120 and the second resistance measuring probe 125.SELECTED DRAWING: Figure 3

Description

The present invention relates to an external terminal member having an external terminal connecting portion including a projecting portion and a peripheral portion, a top surface of the projecting portion is brought into contact with one electrode terminal portion of a battery to connect the external terminal connecting portion to the electrode terminal. The present invention relates to a terminal welding device for resistance welding to a portion.

There is known a battery module in which an external terminal connecting portion of an external terminal member is welded to a positive or negative electrode terminal portion of a battery. For example, Patent Document 1 describes such a battery module. In this patent document 1, a disc-shaped welded portion (external terminal connection portion) of a bus bar (external terminal member) and one connection terminal portion (electrode terminal portion) of a cylindrical battery are welded by the following method. ing.

That is, the disk-shaped welded portion (external terminal connecting portion) of the bus bar (external terminal member) is formed in a shape in which the central protruding portion projects more than the peripheral portion surrounding the circumference thereof in an annular shape. Then, of the pair of electrode rods of the terminal welding device, one electrode rod is brought into contact with the connection terminal portion (electrode terminal portion) of the cylindrical battery, and the other electrode rod is welded to the bus bar (external terminal member). It is pressed against the (external terminal connection part), and the top surface of the projection of the welded part (external terminal connection part) is brought into contact with the connection terminal part (electrode terminal part) of the cylindrical battery (see FIG. 10 of Patent Document 1 and the like). ). Then, a welding current is passed between the one electrode rod and the other electrode rod, and the welded portion (external terminal connection portion) of the bus bar (external terminal member) is connected to the connection terminal portion (electrode terminal portion) of the cylindrical battery. Resistance welding.

JP, 2017-174521, A

However, due to variations in the shape of the protrusion of the welded portion (external terminal connection) and variations in the pressing force that presses this protrusion against the connection terminal (electrode terminal) of the cylindrical battery, the top surface of the protrusion and the cylinder The contact resistance with the connection terminal (electrode terminal) of the battery is different. Therefore, if resistance welding is performed without considering the magnitude of this contact resistance, welding variations occur. That is, if this contact resistance is too small, the amount of heat generated at the contact portion between the top surface of the protrusion and the connection terminal portion (electrode terminal portion) during resistance welding is too small to perform sufficient welding. On the other hand, if the contact resistance is too large, the amount of heat generated at the contact portion during resistance welding may be too large and the weld portion may melt and break.

The present invention has been made in view of the above situation, and prior to resistance welding the external terminal connecting portion of the external terminal member to one electrode terminal portion of the battery, the top surface of the protruding portion of the external terminal connecting portion is formed. The present invention provides a terminal welding device that can obtain a value close to the contact resistance Ra between the battery and the electrode terminal of the battery with good accuracy.

One aspect of the present invention for solving the above-mentioned problem is that, in the external terminal member having the external terminal connecting portion that is protruded from the peripheral portion in which the central protruding portion surrounds the periphery thereof, the top surface of the protruding portion is A terminal welding device for resistance welding the external terminal connection portion to the electrode terminal portion by abutting on one electrode terminal portion of a battery, the first electrode rod being in contact with the electrode terminal portion and conducting. A second contacting part of the external terminal connecting part is brought into contact with the peripheral part to conduct electricity, and the peripheral part is pressed against the electrode terminal part side so that the top surface of the protruding part abuts on the electrode terminal part. An electrode rod, a first resistance measuring probe that comes into contact with the electrode terminal portion to conduct electricity, and a first resistance probe that comes into contact with and comes into contact with a base end surface of the protrusion of the external terminal connection portion opposite to the top surface. It is a terminal welding device provided with a 2 resistance measurement probe and a resistance detection part which detects inter-probe resistance value Rk between the 1st resistance measurement probe and the 2nd resistance measurement probe.

In the above-mentioned terminal welding device, in addition to a pair of electrode rods (first electrode rod and second electrode rod) for resistance welding, a pair of resistance measurement probes (first resistance measurement probe and second resistance measurement probe) described above. And a resistance detector. With these, the resistance value Rk between the probes between the resistance measuring probes can be detected before the resistance welding of the external terminal connecting portion of the external terminal member to the electrode terminal portion of the battery, so that the top surface of the protruding portion of the external terminal connecting portion can be detected. It is possible to acquire a value close to the contact resistance Ra between the battery and the electrode terminal of the battery. In particular, in the above-described terminal welding device, the second resistance measuring probe is installed in the vicinity of the contact portion between the top surface of the protruding portion of the external terminal connecting portion and the electrode terminal portion of the battery, specifically, the top of the protruding portion. The base end face opposite to the face is brought into contact. Accordingly, the distance from the second resistance measuring probe to the contact portion between the top surface of the protrusion and the electrode terminal portion can be shortened, and the conductor resistance can be reduced, and the second resistance measuring probe can be stably contacted. A value closer to the contact resistance Ra can be stably obtained as the inter-probe resistance value Rk.

FIG. 3 is a partial top view of the battery module according to the embodiment. It is an AA partial sectional view in FIG. 1 of the battery module according to the embodiment. It is explanatory drawing which shows the terminal welding apparatus which concerns on embodiment. It is a flow chart of a resistance welding process using a terminal welding device concerning an embodiment. FIG. 7 is an explanatory diagram showing a manner of detecting an inter-probe resistance value Rk between a pair of resistance measurement probes according to the embodiment. FIG. 6 is an explanatory view showing a manner of resistance welding an external terminal connecting portion of an external terminal member to a negative electrode terminal portion of a battery according to the embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 and 2 are a partial top view and a partial cross-sectional view of a battery module 1 according to this embodiment. In addition, in the cylindrical battery 10 of FIG. 2 and FIGS. 5 and 6 described later, the inside of the battery is omitted and only the cross section of the battery case 11 is shown. Moreover, below, the vertical direction BH, the horizontal direction CH, and the height direction DH of the battery module 1 are set and demonstrated as the direction shown in FIG.1 and FIG.2.

The battery module 1 is a vehicle-mounted battery module mounted in a vehicle such as a hybrid car, a plug-in hybrid car, an electric vehicle, or the like. The battery module 1 is formed by connecting a plurality of cylindrical batteries (hereinafter, also simply referred to as “batteries”) 10 in parallel with each other. In addition to the batteries 10, a battery holding member (not shown) that holds the batteries 10, a battery The negative electrode side external terminal member 20 that connects the negative electrode terminal portions (electrode terminal portions) 15 of the battery 10 and the positive electrode side external terminal member (not shown) that connects the positive electrode terminal portions (the electrode terminal portions, not shown) of the battery 10 to each other. ) Etc.

Among them, the battery 10 is a cylindrical (cylindrical) and sealed type lithium ion secondary battery (specifically, 18650 type lithium ion secondary battery). The battery 10 has a cylindrical battery case 11 made of metal (carbon steel in the present embodiment), in which a belt-shaped positive electrode plate and a belt-shaped negative electrode plate are superposed on each other via a pair of belt-shaped separators. The electrode body (not shown) wound around is housed together with the non-aqueous electrolytic solution (not shown).
At one end (downward in FIG. 2) of the battery 10 in the axial direction (the direction orthogonal to the paper surface in FIG. 1, vertical direction in FIG. 2), the battery 10 is connected to the positive electrode plate of the electrode body to conduct electricity. A convex positive electrode terminal portion (not shown) is provided. On the other hand, the bottom surface portion of the battery case 11 located at the other end (upper side in FIG. 2) in the axial direction of the battery 10 is a disk-shaped negative electrode terminal portion 15 that is connected to the negative electrode plate of the electrode body to conduct electricity inside the battery. Is.

In each of the batteries 10 constituting the battery module 1, the negative electrode terminal portion 15 faces the upper DS in the height direction DH, and the positive electrode terminal portion (not shown) faces the lower DK in the height direction DH so as to be parallel to each other. And they are arranged in the same height. Then, the negative electrode terminal portion 15 of each battery 10 is connected (welded) to an external terminal member 20 on the negative electrode side, which will be described later, so that the negative electrode terminal portions 15 are electrically connected to each other. On the other hand, the positive electrode terminal portion of each battery 10 is connected (welded) to a positive electrode side external terminal member (not shown) having substantially the same configuration as the negative electrode side external terminal member 20, whereby the positive electrode terminal portions are connected to each other. They are in conduction with each other.

Next, the external terminal member 20 on the negative electrode side will be described. The external terminal member 20 is formed by press punching a metal plate material (copper plate material in this embodiment), and has a plate shape as a whole. Specifically, the external terminal member 20 has a plate-shaped external terminal body portion 21 in which circular through holes 21h are provided at positions corresponding to the respective batteries 10. In each of the through holes 21h of the external terminal body portion 21, a disk-shaped external terminal connection portion 23 and a belt-shaped connection portion 25 that connects the external terminal connection portion 23 and the external terminal body portion 21 are respectively provided. It is provided.

The external terminal main body portion 21 is arranged above the negative electrode terminal portion 15 of each battery 10 so as to cover each battery 10 constituting the battery module 1 from the upper DS, and the external terminal member 20 is connected from the upper DS to the external terminal member 20. When viewed in a plan view (see FIG. 1), the negative electrode terminal portion 15 of each battery 10 is located inside the through hole 21h in the radial direction.
The connecting portion 25 extends in a band shape radially inward and obliquely downward DK from the peripheral edge of the through hole 21h of the external terminal main body portion 21, and the external terminal connecting portion 23 is provided at the tip of the connecting portion 25.
The external terminal connecting portion 23 is disk-shaped, and has a shape in which a central protruding portion 23c protrudes downward DK from a peripheral portion 23d surrounding the periphery thereof in an annular shape. The protruding portion 23c of the external terminal connecting portion 23 and the negative electrode terminal portion 15 of the battery 10 are resistance-welded as described later, and a welded portion (welding nugget) 30 between the protruding portion 23c and the negative electrode terminal portion 15 is formed. ing.

Next, a method for manufacturing the battery module 1 will be described (see FIGS. 3 to 6). First, a plurality of batteries 10 are prepared, and the negative electrode terminal portions 15 of the respective batteries 10 are directed to the upper side DS and the positive electrode terminal portions are directed to the lower side DK, respectively. It is held by a holding member (not shown).

Next, the external terminal member 20 on the negative electrode side is prepared, and the protruding portions 23c of the external terminal connection portions 23 of the external terminal member 20 are resistance-welded to the negative electrode terminal portions 15 of the held batteries 10, respectively. This welding is performed using the terminal welding device 100 schematically shown in FIG. This terminal welding device 100 includes a pair of electrode rods (first electrode rod 110 and second cylindrical electrode rod 115) through which a welding current YA flows, and a pair of resistance measuring probes (first resistance measuring probe 120 and second resistance measuring probe). 125), a variable current source 130, a constant current source 140, a voltmeter 145, a personal computer (PC) 150, and the like. In the present embodiment, the constant current source 140, the voltmeter 145, and the PC 150 constitute the resistance detection unit 160 described above.

Of these, the first electrode rod 110 is a solid round rod extending in the height direction DH. The first electrode rod 110 is configured to be movable in the height direction DH by a moving mechanism (not shown), is inserted into the through hole 21h of the external terminal member 20 from the upper DS, and the tip of the first electrode rod 110 is inserted. The portion 110s contacts the negative electrode terminal portion 15 of the battery 10 and becomes conductive.

On the other hand, the second tubular electrode rod 115 is a hollow round rod (cylindrical) extending in the height direction DH. The second cylindrical electrode rod 115 is configured to be movable in the height direction DH by a moving mechanism (not shown), and is inserted into the through hole 21h of the external terminal member 20 from the upper side DS to form the second cylindrical electrode. The tip portion 115s of the rod 115 abuts on the entire circumference of the annular terminal portion 23d of the external terminal connecting portion 23 of the external terminal member 20 to conduct electricity. In addition, the tip portion 115s of the second tubular electrode rod 115 presses the peripheral portion 23d toward the negative electrode terminal portion 15 side (downward DK) of the battery 10 and the top surface 23cn of the protruding portion 23c of the external terminal connection portion 23. Is brought into contact with the negative electrode terminal portion 15.

The first electrode rod 110 and the second tubular electrode rod 115 are connected to a variable current source 130 capable of changing the current value Ia. On the other hand, the variable current source 130 is connected to the PC 150, and in accordance with an instruction from the PC 150, a current value Ia described later is provided in the welding current path EA between the first electrode rod 110 and the second cylindrical electrode rod 115. Of the welding current YA.

The first resistance measuring probe 120 has a needle shape extending in the height direction DH. The first resistance measuring probe 120 is arranged between the first electrode rod 110 and the second tubular electrode rod 115 arranged in the lateral direction CH (almost in the middle), and is moved in the height direction DH by a moving mechanism (not shown). It is configured to be movable. The first resistance measuring probe 120 is inserted into the through hole 21h of the external terminal member 20 from the upper side DS, and the tip portion 120s comes into contact with the negative electrode terminal portion 15 of the battery 10 to conduct electricity.

The second resistance measuring probe 125 has a needle shape extending in the height direction DH similar to the first resistance measuring probe 120. The second resistance measuring probe 125 is coaxially inserted into the second cylindrical electrode rod 115 having a cylindrical shape, and is movable in the height direction DH by a moving mechanism (not shown). The tip portion 125s of the second resistance measuring probe 125 is brought into contact with the center of the base end surface 23cm (the surface opposite to the top surface 23cn) of the protruding portion 23c of the external terminal connecting portion 23 to conduct electricity.

The first resistance measuring probe 120 and the second resistance measuring probe 125 are connected to the constant current source 140 and the voltmeter 145. On the other hand, the constant current source 140 and the voltmeter 145 are connected to the PC 150, and the inspection current between the first resistance measurement probe 120 and the second resistance measurement probe 125 from the constant current source 140 is instructed by the PC 150. A test current YK having a constant magnitude (current value Ik) can be passed through the path EK, and the voltage value Vk between the first resistance measuring probe 120 and the second resistance measuring probe 125 detected by the voltmeter 145 is detected. Is output to the PC 150.

Further, the PC 150 calculates the inter-probe resistance value Rk between the pair of resistance measurement probes 120 and 125 from the current value Ik of the inspection current YK and the voltage value Vk, and the inter-probe resistance value Rk=(voltage value Vk)/( It is calculated by the current value Ik). Since the circuit resistance of the terminal welding device 100 including the first resistance measuring probe 120 and the second resistance measuring probe 125 is extremely small, it is ignored in this embodiment.

Further, in the PC 150, the contact resistance Ra between the top surface 23cn of the protruding portion 23c of the external terminal connecting portion 23 and the negative electrode terminal portion 15 of the battery 10 is obtained from the inter-probe resistance value Rk. In the present embodiment, the conductor resistance Rb of the protruding portion 23c of the external terminal connecting portion 23 and the negative electrode terminal portion 15 of the battery 10 which form the inspection current path EK is substantially constant, and therefore, using a predetermined value obtained by an experiment in advance, The contact resistance Ra is calculated from the contact resistance Ra=inter-probe resistance value Rk (obtained value)-conductor resistance Rb (predetermined value).
In the present embodiment, since the conductor resistance Rb is only about 1/100 of the average value of the contact resistance Ra, the conductor resistance Rb is ignored, and the contact resistance Ra=inter-probe resistance value Rk is set between the probes. The resistance value Rk can be directly used as the contact resistance Ra.

Further, in the PC 150, the contact resistance Ra is set so that the heat generation amount Q generated at the contact portion between the top surface 23cn of the protrusion 23c of the external terminal connection portion 23 and the negative electrode terminal portion 15 of the battery 10 in resistance welding becomes a predetermined heat generation amount. Based on, the current value Ia of the welding current YA flowing in the welding current path EA between the pair of electrode rods 110 and 115 is determined. The heat generation amount Q can be expressed by the following formula, where t is the energization time.
Calorific value Q=(contact resistance Ra)×(current value Ia) ² ×(energization time t)
A predetermined value is used for the heat generation amount Q and the energization time t, and the current value Ia of the welding current YA is calculated by this formula. Further, the PC 150 controls the variable current source 130 so that the welding current YA having the current value Ia flows in the welding current path EA between the pair of electrode rods 110 and 115.

Next, a resistance welding process of resistance welding the external terminal connecting portion 23 of the external terminal member 20 and the negative electrode terminal portion 15 of the battery 10 using the terminal welding device 100 will be described (see FIGS. 3 to 6 ). First, the external terminal member 20 is aligned and arranged on the upper DS of each battery 10 held by a battery holding member (not shown).

Then, in step S1 (see FIG. 4), the pair of electrode rods 110, 115 and the pair of resistance measuring probes 120, 125 of the terminal welding apparatus 100 are moved downward DK and brought into contact with respective predetermined positions. Specifically, the pair of electrode rods 110, 115 and the pair of resistance measuring probes 120, 125 are moved downward DK and inserted into the through hole 21h of the external terminal member 20. Of these, the tip portion 110 s of the first electrode rod 110 is brought into contact with the negative electrode terminal portion 15 of the battery 10. Further, the tip end portion 115s of the second tubular electrode rod 115 is brought into contact with the peripheral portion 23d of the external terminal connecting portion 23 of the external terminal member 20 over the entire circumference, and further, the peripheral portion 23d is pressed downward DK. The top surface 23cn of the protruding portion 23c of the external terminal connecting portion 23 is brought into contact with the negative electrode terminal portion 15.

Further, the tip portion 120 s of the first resistance measuring probe 120 is brought into contact with the negative electrode terminal portion 15 of the battery 10 at approximately the middle of the pair of electrode rods 110 and 115. Further, the tip portion 125 s of the second resistance measuring probe 125 inserted into the second cylindrical electrode rod 115 is brought into contact with the center of the base end surface 23 cm of the protruding portion 23 c of the external terminal connecting portion 23.
Note that the above-mentioned contact state of the pair of electrode rods 110, 115 and the pair of resistance measuring probes 120, 125 is maintained until the resistance welding is completed.

Then, in step S2, the inter-probe resistance value Rk between the pair of resistance measurement probes 120 and 125 is detected. Specifically, the inspection current YK having a constant magnitude (current value Ik) is passed from the constant current source 140 between the pair of resistance measurement probes 120 and 125 (see FIG. 5). On the other hand, the voltage value Vk generated between the pair of resistance measuring probes 120 and 125 is measured by the voltmeter 145 and output to the PC 150. The PC 150 calculates the inter-probe resistance value Rk from the inter-probe resistance value Rk=(voltage value Vk)/(current value Ik).

Then, in step S3, the contact resistance Ra between the top surface 23cn of the protruding portion 23c of the external terminal connection portion 23 and the negative electrode terminal portion 15 of the battery 10 is calculated. Specifically, in the PC 150, the contact resistance Ra between the top surface 23cn of the protruding portion 23c and the negative electrode terminal portion 15 is calculated from the contact resistance Ra=probe resistance Rk−conductor resistance Rb (predetermined value).
Then, in step S4, the current value Ia of the welding current YA is determined. Specifically, in the PC 150, the heat generation amount Q=(contact resistance) so that the heat generation amount Q generated at the contact portion between the top surface 23cn of the protrusion 23c and the negative electrode terminal portion 15 during resistance welding becomes a predetermined heat generation amount. The current value Ia of the welding current YA is calculated by Ra)×(current value Ia) ² ×(energization time t).

Next, in step S5, resistance welding is performed at the determined current value Ia. Specifically, the PC 150 controls the variable current source 130 so as to control the welding current path EA between the pair of electrode rods 110 and 115 (the negative electrode terminal portion 15 and the first external terminal connecting portion 23 in contact therewith). A welding current YA having a determined current value Ia is passed through a current path from a portion where the electrode rod 110 is in contact to a portion where the second cylindrical electrode rod 115 is in contact with the external terminal connecting portion 23. The protrusion 23c is resistance-welded to the negative electrode terminal portion 15 of the battery 10 to form a welded portion 30 between the protrusion 23c and the negative electrode terminal portion 15. By performing resistance welding with the current value Ia of the welding current YA set to an appropriate value in this manner, the amount of heat generated Q at the contact portion between the top surface 23cn of the protrusion 23c and the negative electrode terminal portion 15 during resistance welding. Therefore, even if the contact resistance Ra between the top surface 23cn of the protrusion 23c and the negative electrode terminal portion 15 varies, the welding variation can be suppressed.

After the welding is completed, in step S6, the pair of electrode rods 110, 115 and the pair of resistance measuring probes 120, 125 are moved to the upper DS and returned to their original positions.
After that, the resistance welding process described above is repeatedly performed so that the protruding portions 23c of the external terminal connecting portions 23 of the external terminal members 20 are respectively connected to the negative electrode terminal portions 15 of all the batteries 10 constituting the battery module 1. Weld. As a result, the negative electrode terminal portions 15 of the batteries 10 are electrically connected to each other via the external terminal member 20.

Next, an external terminal member (not shown) on the positive electrode side is prepared, and the external terminal member and the positive electrode terminal portion (not shown) of each battery 10 are connected (welded). Thus, the battery module 1 in which the batteries 10 are connected in parallel with each other is completed.

In the terminal welding device 100 described above, in addition to the pair of electrode rods (the first electrode rod 110 and the second tubular electrode rod 115) that perform resistance welding, the pair of resistance measuring probes (the first resistance measuring probe 120 and the second resistance). The measurement probe 125) and the resistance detection unit 160 are provided. With these, the probe-to-probe resistance value Rk between the resistance measuring probes 120 and 125 can be detected before the external terminal connecting portion 23 of the external terminal member 20 is resistance-welded to the negative electrode terminal portion 15 of the battery 10. A value close to the contact resistance Ra between the top surface 23cn of the protruding portion 23c of the portion 23 and the negative electrode terminal portion 15 of the battery 10 can be acquired.

In particular, in the terminal welding device 100, the second resistance measuring probe 125 is provided in the immediate vicinity of the contact portion between the top surface 23cn of the protruding portion 23c of the external terminal connecting portion 23 and the negative electrode terminal portion 15 of the battery 10, specifically, The protrusion 23c is brought into contact with the base end surface 23cm. Accordingly, the distance from the tip portion 125s of the second resistance measurement probe 125 to the contact portion between the top surface 23cn of the protrusion 23c and the negative electrode terminal portion 15 can be shortened, and the conductor resistance can be reduced, and the second resistance measurement probe 125 can be used. Since the tip portion 125s of the probe can be stably contacted, a value closer to the contact resistance Ra can be stably acquired as the inter-probe resistance value Rk.

Further, in the present embodiment, the first resistance measuring probe 120 is also brought close to the contact portion between the top surface 23cn of the protruding portion 23c and the negative electrode terminal portion 15. Specifically, the first resistance measuring probe 120 is arranged between the pair of electrode rods 110 and 115. Accordingly, the distance from the tip portion 120s of the first resistance measuring probe 120 to the contact portion between the top surface 23cn of the protruding portion 23c and the negative electrode terminal portion 15 is short, and the conductor resistance can be reduced. Further, a value close to the contact resistance Ra can be acquired.

Furthermore, in the terminal welding device 100, in resistance welding, the heat generation amount Q generated at the contact portion between the top surface 23cn of the protruding portion 23c of the external terminal connection portion 23 and the negative electrode terminal portion 15 of the battery 10 becomes a predetermined heat generation amount, The current value Ia of the welding current YA is changed based on the magnitude of the contact resistance Ra. By performing resistance welding with the current value Ia of the welding current YA set to an appropriate value in this manner, the heat generation amount Q generated at the contact portion between the top surface 23cn of the protrusion 23c and the negative electrode terminal portion 15 during resistance welding is reduced. Since it can be kept constant, even if the contact resistance Ra between the top surface 23cn of the protruding portion 23c and the negative electrode terminal portion 15 varies, welding variation can be suppressed.

Although the present invention has been described above according to the embodiment, it goes without saying that the present invention is not limited to the embodiment and can be appropriately modified and applied without departing from the scope of the invention.
For example, in the embodiment, the terminal welding device 100 of the present invention is used in the step of resistance welding the external terminal connecting portion 23 of the external terminal member 20 to the negative electrode terminal portion 15 of the battery 10, but the present invention is not limited to this. Absent. The terminal welding device 100 may be used in the step of resistance welding the external terminal connecting portion of the external terminal member to the positive electrode terminal portion of the battery 10.

Further, in the method of using the terminal welding apparatus 100 of the embodiment, the current value Ia of the welding current YA is determined in step S4 based on the magnitude of the contact resistance Ra obtained in step S3, and the current value Ia is determined in step S5. By performing the resistance welding in the above, variations in welding were suppressed, but the present invention is not limited to this. As another method of using the terminal welding device 100, for example, when the contact resistance Ra obtained in step S3 is larger or smaller than a predetermined range, after temporarily moving the electrode rods 110 and 115 to the upper DS, The electrode rods 110 and 115 are again moved to the lower DK to re-contact with the negative electrode terminal portion 15 and the external terminal connecting portion 23. After that, steps S2 and S3 are performed again to obtain the contact resistance Ra, and after confirming that the contact resistance Ra falls within a predetermined range, resistance welding with a predetermined current value can be performed. By making the contact resistance Ra between the top surface 23cn of the protruding portion 23c and the negative electrode terminal portion 15 uniform in this way, welding variations can also be suppressed.

1 Battery Module 10 Cylindrical Battery (Battery)
15 Negative electrode terminal (electrode terminal)
20 External Terminal Member 23 External Terminal Connection 23c Projection 23cn Top 23cm (of Projection) Base End 23d (Projection) Peripheral 25 Connection 30 Weld (Welding Nugget)
100 terminal welding device 110 first electrode rod (electrode rod)
115 Second cylindrical electrode rod (electrode rod)
120 First resistance measurement probe (resistance measurement probe)
125 Second resistance measurement probe (resistance measurement probe)
130 Variable Current Source 140 Constant Current Source 145 Voltmeter 150 Personal Computer (PC)
160 Resistance Detector YK Inspection Current YA Welding Current Ik (Inspection Current) Current Value Ia (Welding Current) Current Value Vk (Between Resistance Measuring Probes) Voltage Value EK Inspection Current Path EA Welding Current Path Rk (Inspection Current Path) ) Resistance value between probes Ra (contact between the top surface of the protruding portion of the external terminal connection portion and the negative electrode terminal of the battery) Rb (resistance of the inspection current path) Conductor resistance Q Heat generation amount t Energization time

Claims (1)

Of the external terminal member having an external terminal connecting portion projecting more than the peripheral portion in which the central projecting portion surrounds the circumference thereof annularly, the top surface of the projecting portion is brought into contact with one of the electrode terminal portions of the battery, A terminal welding device for resistance welding the external terminal connecting portion to the electrode terminal portion,
A first electrode rod that is in contact with the electrode terminal portion and is electrically connected;
A second electrode that abuts on the peripheral portion of the external terminal connecting portion to conduct electricity, and presses the peripheral portion toward the electrode terminal portion side so that the top surface of the protruding portion abuts on the electrode terminal portion. With a stick
A first resistance measuring probe that is in contact with the electrode terminal portion and is conductive;
A second resistance measuring probe that is in contact with a base end surface of the protruding portion of the external terminal connecting portion that is opposite to the top surface and that is conductive;
A terminal welding device, comprising: a resistance detection unit that detects an inter-probe resistance value Rk between the first resistance measurement probe and the second resistance measurement probe.

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