WO2013160932A1 - Method for joining collector of electronic component and device for same - Google Patents

Abstract

[Problem] To provide a method whereby laser welding of a collector is possible. [Solution] Provided is a method for laser welding of a collector of an electrode assembly (10), wherein the basal part (14a) and distal end part (14b) of a collector (14) are respectively compressed by being clamped between basal-side clamping bodies (20, 21) and distal-side clamping bodies (30, 31). At least the basal-side clamping bodies (20, 21) and/or the distal-side clamping bodies (30, 31) are displaced in the distance of separation thereof, and halted at a predetermined location. Between the basal-side clamping bodies (20, 21) and the distal-side clamping bodies (30, 31), a pressing member (40) is pressed against the collector (14), compressing a pressed portion (14c) of the collector (14). The pressed portion (14c) of the collector (14) is irradiated with a laser beam (50), forming a laser welded part (14y) in the irradiated portion of the pressed portion (14c).

Description

Method and apparatus for joining current collector part of electronic component

発 明 The present invention relates to a method and an apparatus for joining a current collecting portion in which a large number of electrode plates are laminated by laser welding in an electrode assembly of an electronic component such as a secondary battery such as a lithium ion battery or a capacitor.

Currently, secondary batteries such as large-capacity to small-capacity lithium-ion batteries are in the limelight as a power source for power engines and electronic devices as an environmental measure. Taking a lithium ion battery as an example, the positive electrode plate is a strip-shaped positive electrode current collector made of an aluminum foil with a positive electrode active material applied, and the negative electrode plate is made of copper foil. An electrode assembly produced by applying a negative electrode active material to a strip-shaped negative electrode current collector and winding a positive electrode plate and a negative electrode plate in a cylindrical shape with a separator interposed therebetween is a cylindrical battery. A battery element housed in a can or wound in a wound form is formed into a flat shape and housed in a square battery can or bag, filled with an electrolyte, and then closed.

In the current collector part of such an electrode assembly, a large number of current collectors of the same polarity (no positive electrode active material or negative electrode active material are applied to this part) are stacked and bonded by pressure bonding or ultrasonic welding. In addition, electrode terminals are joined to this portion (Patent Document 1).

Patent Document 1: Japanese Patent Application Laid-Open No. 2007-31126

Since the current collector is a portion that is joined to the electrode terminal and supplies a current to the outside, it is required to be surely integrated. On the other hand, as described above, pressure bonding or ultrasonic welding may cause uneven pressure bonding or welding unevenness. If there is a bonding failure in this part, it causes heat generation and leads to a trouble of the entire apparatus. Also, in ultrasonic welding, the current collectors in which a large number of electrode plates are stacked are rubbed together under pressure, and the adjacent electrode plates are welded together by frictional heat at that time, so fine powder is generated in the frictional part. Since this powder has electrical conductivity, it may cause an unexpected short circuit when it diffuses into the electronic component, causing troubles such as heat generation.

Therefore, we attempted laser welding on the current collector that is much better than crimping and ultrasonic welding in terms of dust-free and weldability. However, the current collector that composes the current collector is made of aluminum or copper. Since a large number of very thin foils are integrated, the heat capacity of each sheet is very small. Therefore, if the adjacent current collectors are not in close contact with each other, the heat cannot be diffused and the laser light can be emitted. When irradiated, the irradiated part was heated and evaporated, and a hole was instantly opened. In reality, laser welding was considered impossible.
The present invention has been made in view of such conventional problems, and an object of the present invention is to provide a method and apparatus for enabling laser welding of a current collector.

The inventive method according to claim 1 is:
An electrode assembly having a current collector (14) in which positive electrode plates (12) and negative electrode plates (13) are alternately stacked with separators (11) interposed therebetween, and current collectors (14d) of the same polarity are stacked ( 10), a laser welding method of the current collector (14),
The base (14a) of the current collector (14) is clamped by the base-side clamping body (20) (21), and the tip (14b) of the current collector (14) is clamped by the tip-side clamp (30) (31). After pressurization, at least one of the base side clamping body (20) (21) and the distal side clamping body (30) (31) is moved away from the other and stopped at a predetermined position,
Between the base side clamping body (20) (21) and the distal side clamping body (30) (31), the pressing member (40) is pressed against the current collecting part (14) to cover the current collecting part (14). Pressurize the pressing part (14c),
The pressed portion (14c) of the current collector (14) is irradiated with a laser beam (50) to form a laser welded portion (14y) at the irradiated portion of the pressed portion (14c).

As a result, the pressed portion (14c) of the current collector (14) is coated with a large number of current collectors (14d) constituting the current collector (14). If the gap (t) between them is eliminated and they are in close contact, and the pressed portion (14c) of the current collector (14) is irradiated with a laser beam (50) in this state, the adherent current collector (14d) seems to be integrated, heat transfer is instantaneously performed between adjacent current collectors (14d), and the total thickness (T) of the irradiated part is reduced without opening a hole in the irradiated part. A good weld is formed.

Here, the front end side clamping body (31) may be a roller as shown in FIG. 1 or a curved body whose section perpendicular to the axis is convexly curved as shown in FIG. In such a way that the other tip side clamping body (30) can roll (a flat surface as shown in the figure, or a cylindrical curved surface arranged in parallel to the tip side clamping body (30), not shown) )

Further, `` the base part (14a) of the current collecting part (14) is the base side clamping body (20) (21) and the tip part (14b) of the current collecting part (14) is the tip side clamping body (30) (31) After pressing and pressing each of the at least one of the base side clamping body (20) (21) and the distal side clamping body (30) (31) is moved away from the other and stopped at a predetermined position. '' And when moving either the base-side clamping body (20) (21) or the distal-side clamping body (30) (31) in the separation direction with respect to the other, and when moving both in the separation direction, 12 includes the case where the tip side clamping body (30) is moved in the separating direction when the tip side clamping body (31) is constituted by a surface as shown in FIG. On the contrary, although not shown, the case where the base side clamping body (20) is moved in the separating direction with respect to the distal side clamping body (30) includes the base side clamping body (20) and the distal side clamping. This includes the case where the body (30) moves in the direction away from each other.

Further, the pressing portion (40) of the pressed portion (14c) of the current collector (14) is pressed by the base side holding bodies (20) and (21) and the front end side holding body (30) (see FIG. 10). If the clamping force of (31) is sufficient, it is possible to apply pressure only by the pressing member (40) without using the receiving surface (22), and otherwise press against the receiving surface (22). . In this case, both cases are included.

The invention method described in claim 2 is the method according to claim 1, wherein in the first aspect, “at least one of the base-side holding bodies (20) and (21) and the distal-side holding bodies (30) and (31) is moved away from the other”. After stopping at a predetermined position, the pressing member (40) is further applied to the current collector (14) between the base side holding bodies (20) (21) and the front end side holding bodies (21) (31). To bend the pressed part (14c) of the current collector (14) and irradiate the curved part (14c1) of the current collector (14) with a laser beam (50) from the convex curved surface side to the concave curved surface side. The laser welded part (14y) leading to is formed in the curved part (14c1) ".

By curving the current collector (14) by pressing the pressing member (40), a slight slip occurs between the adjacent current collectors (14d), and at the same time, the base side clamping body ( 20) (21) and the tip side clamping body (30) (31) are pushed out to generate tension. As a result, the air between the current collectors (14d) is pushed out by simple pressing, the degree of adhesion between the adjacent current collectors (14d) is improved, and better laser welding is realized.

According to a third aspect of the present invention, there is provided the method according to the first aspect, wherein “when at least one of the base side sandwiching bodies (20) and (21) and the distal end side sandwiching bodies (30) and (31) is moved in the separating direction relative to the other. Moreover, the moving side is characterized by exceeding the laser welded portion (14y) of the current collecting portion (14).

In this way, when the moving side presses the current collector (14) and crosses the laser weld (14y), the air between the adjacent current collectors (14d) in the most important welded part in welding is pushed out in the moving direction. Further, the degree of adhesion between the current collectors (14d) in this portion is further improved.

The invention described in claim 4 is a welding apparatus (A) for realizing the laser welding of claim 1. That is,
An electrode assembly having a current collector (14) in which positive electrode plates (12) and negative electrode plates (13) are alternately stacked with separators (11) interposed therebetween, and current collectors (14d) of the same polarity are integrated ( 10), the laser welding device (A) of the current collector (14),
A base side clamping body (20) (21) for clamping and pressurizing the base (14a) of the current collector (14);
A front end side clamping body (30) (31) that moves in the front end direction while holding and pressing the front end portion (14b) of the current collector (14) and stops at a predetermined position;
Between the base side clamping body (20) (21) and the tip side clamping body (30) (31), the current collector (14) is provided on the receiving surface (22) provided on the one clamping body (20) side. A pressing member (40) for pressing and pressing the current collector (14);
A laser emitting part (51) that irradiates the pressed part (14c) of the current collecting part (14) with a laser beam (50) to form a laser welded part (14y) in the irradiated part of the pressed part (14c). It is structured.

The invention described in claim 5 is characterized in that, in the laser welding apparatus (A) of claim 4, "the tip side clamping bodies (30) (31) are formed of rollers".

According to a sixth aspect of the present invention, in the laser welding apparatus (A) according to the fourth aspect, in the method of the fifth aspect, the “tip-side clamping body (30) is formed of a roller, and the tip-side clamping body ( 31) is a surface continuous with the receiving surface (22) ".

According to a seventh aspect of the present invention, in the laser welding apparatus (A) according to the fourth to sixth aspects of the present invention, "the roller as the front end side clamping body (30) moves beyond the through hole (23)". And

If the front end side clamping body (30) is formed of a roller, the front end side clamping body (30) (31) is moved to the front end side while holding the current collector (14), or a planar front end side Smooth when rolling on the sandwiching body (31) and moving while pressing with rollers or surfaces and rollers from both sides, so the air between the current collectors (14d) adjacent in the moving direction of the rollers Can be driven out and the adhesion between the two can be increased. In particular, when the roller which is the front end side clamping body (30) moves beyond the through hole (23), it is possible to directly increase the adhesion degree of the most important laser welded portion (14y).

The invention described in claim 8 is another embodiment of claim 5, in the laser welding apparatus (A) of claim 4, wherein “the contact surface of the front end side clamping bodies (30), (31) is perpendicular to the axis”. A simple cross section is formed in a circular arc shape ”. In this case, unlike the roller, the front-side clamping body (30) (31) exhibits a certain amount of frictional resistance against the current collector (14d) on the surface layer of the current collector (14). Between the (20) (21) and the front-end sandwiching body (30) (31), it is possible to apply tension to the current collector (14) sandwiched between them, whereby the adjacent current collector (14d ) Can be further increased.

The invention described in claim 9 is the laser welding apparatus (A) according to any one of claims 4, 5 and 7, wherein the base side is aligned with the pressed portion (14c) of the current collector (14). A slit (67) for passing a laser beam (50) that reaches the receiving surface (22) of the press groove (63d) provided with a press groove (63d) in the sandwiching body (21) and pressed by the current collector (14) Is formed in the base side sandwiching body (21) '', and by providing a press groove (63d), the current collecting part (14) is pressed by the pressing member (40). 63d) is pushed in and curved, and the curved portion (14c1) is pressed from both sides to increase the close contact of the same portion (14c1), and the slit hole (67) Is open, so the laser weld (14y) will be formed in the integrated curved part (14c1), so that high quality laser welding can be applied to the current collector (14). I became.

A tenth aspect of the present invention is the laser welding apparatus (A) according to any of the fourth to ninth aspects, wherein the base side clamping body (21) is formed of a heat resistant transparent material. Thus, the laser beam (50) passes through the base side sandwiching body (21) as it is to form a welded portion (14y) in the pressed portion (14c). In this case, the slit hole (67) is unnecessary.

According to the present invention, the base part (14a) and the tip part (14b) of the current collector (14) are clamped by the base part side clamps (20) and (21) and the tip side clamps (30) and (31), respectively. Pressurized and pressed between them by pressing of the pressing member (40), so that the pressed part (14c) and the curved part (14c1) sandwiched at both ends are greatly compressed by this pressing and further bending. In the contact state where there is no gap (t) between the stacked current collectors (14d) constituting the current collector (14), in other words, they are integrated in the heat conduction surface although they are not physical It will be in the state. Therefore, even if the pressed part (14c) or the curved part (14c1) is irradiated with a laser beam (50), heat is smoothly transferred between the closely contacted current collectors (14d), and the holes are clear. In addition, since laser welding is performed in a pressurized state, fusion of the melted parts is promoted as if “forged”, and a more complete joint is achieved.

The perspective view of the welding apparatus which concerns on this invention. FIG. 2 is an enlarged perspective view of a main part of FIG. The front view before the operation | movement of this invention apparatus. The front view of the state which inserted the electrode assembly in this invention apparatus. The front view of the state which lowered | hung the upper side base clamping body of this invention apparatus. The principal part front view of the state which raised the lower base clamping body of this invention apparatus, and pressed the current collection part. The enlarged front view of the curved part of the current collection part of FIG. The partial expanded sectional view which shows the welding state of the curved part of the current collection part of FIG. The principal part front sectional view which shows the other press state of FIG. The principal part front sectional drawing of the other front end side clamping body of this invention apparatus. The other principal part front sectional drawing of the press member of this invention apparatus. The welding apparatus which concerns on this invention WHEREIN: The expansion part notch perspective view when the front end side clamping part is comprised by the plane. In the case of FIG. 12, the front view before an operation | movement in the case of a front end side clamping part being located ahead of a welding part. FIG. 14 is a front view after operation in the case of FIG. 13. The welding apparatus which concerns on this invention WHEREIN: The enlarged front view when an upper base clamping part is formed with a heat resistant transparent body. The perspective view of the current collection part of the assembly after welding.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A welding apparatus (A) according to the present invention includes an apparatus main body (60) to which a vertical rail (61) is attached, a lifting block (62) attached to the rail (61), and a lifting block (62). The device body (61) directly below the upper lifting mechanism (63) and the upper lifting mechanism (63) mounted on the lifting block (62), the ball screw driving part (61a) of the servo motor drive (not shown) to be moved 60), the lower elevating mechanism (70), which is mounted so as to be movable up and down, the laser emitting unit (51) disposed above the upper elevating mechanism (63), and the lower elevating mechanism (70). And an assembly supply base (90).

Two rails (61) are attached to the front surface side of the rail attachment portion (60a) of the main body (60) in parallel with the vertical direction, and the elevating block (62) is attached to be movable up and down. A ball screw drive unit (61a) is attached to the elevating block (62), and elevates the elevating block (62). The ball screw drive unit (61a) shown in the drawing is of a type driven by a servo motor, but of course, the present invention is not limited to this, and a cylinder drive type or other types can be used as appropriate.

The upper elevating mechanism (63) is a pair of upright plates (63a) attached vertically to the front surface of the elevating block (62), and an upper base sandwiched between the upright plates (63a) at the lower front end (21), an upper lever (64) pivotally attached to a pivot shaft (64b) on the outer surface of the standing plate (63a), and an upper side provided on the lifting block (62) side of the standing plate (63a) Upper coil spring (66) suspended between the tension adjustment section (65), the pin (64a) attached to the upper end of the upper lever (64) and the upper adjustment screw (65a) of the upper tension adjustment section (65) ), An upper lever shaft (64c) attached between the lower ends of the pair of upper levers (64), and an upper tip side clamping body (31) comprising a roller rotatably provided on the upper lever shaft (64c). It is configured.

The upper adjustment screw (65a) is screwed to an upper adjustment plate (65b) attached to the up / down block (62) side of the upright plate (63a) so as to be able to advance and retract. The upper coil spring (66) is suspended between the upper adjustment screw (65a) and the pin (64a) of the upper lever (64), and the upper lever (64) is moved toward the upper adjustment screw (65a). I'm pulling. The tension in the pulling direction of the upper lever (64) is adjusted by screwing and screwing the adjustment screw (65a) at the upper end of the upper lever (64). This is performed by contact with the upper stopper (67) provided on the adjustment screw (65a) side. The upper tension adjusting section (65) is constituted by the adjusting screw (65a) and the adjusting plate (65b).

The lower edge of the upright plate (63a) is formed with a relief groove (63c) with an open bottom surface for the upper end side clamping body (31) to enter and exit, and the bottom surface is opened in front of it adjacent to the relief groove (63c). The press groove (63d) is formed, and the ceiling surface of the press groove (63d) and the ceiling surface of the concave groove of the base side holding body (21) to be described later are the receiving surface (22).

The upper base clamping body (21) is a rectangular parallelepiped block, the lower surface of which is mounted flush with the lower edge of the upright plate (63a), and as shown in the above and FIG. 7, the press groove (63d) The lower surface is recessed over the entire length in the longitudinal direction so as to be continuous with the ceiling surface, and this portion becomes the receiving surface (22). A through hole (23) is formed in the longitudinal direction so as to be formed in a tapered groove constricted from the upper surface so as to open to the receiving surface (22). The length of the through hole (23) is formed so as to cover the entire width of the assembly (10). The opening width of the slit-like opening of the through hole (23) opening in the receiving surface (22) is formed to a width that allows a laser beam (50) described later to pass through.

Immediately below the upper lifting mechanism (63), a fixed block (71) protrudes from the front surface of the apparatus main body (60), and a lower lifting operation unit (72) is attached to the fixed block (71). . The lower elevating mechanism part (70) is guided by the guide (72a) projecting parallel and upward on both sides of the lower elevating operation part (72) so as to elevate, and the lower elevating operation part (72). The lower elevating mechanism part (70) is raised and lowered by the provided elevating mechanism part (72b). For the driving of the elevating mechanism part (72b), a combination of a screw mechanism and a servo motor, a cylinder mechanism or the like can be considered.

The lower elevating mechanism (70) is a lower block (73) to which a guide (72a) is attached, a lower side provided directly below the upper base side clamping body (21) on the upper surface of the lower block (73). The base side clamping body (20), the pressing member (40) attached to the upper surface of the lower block (73) along the back side of the lower base side clamping body (20), and the left and right sides of the lower block (73) The lower lever (74) whose central portion is pivotally attached to the pivot shaft (74b), the lower tension adjusting portion (75) provided on the back side of the lower block (73), the lower lever ( 74), a lower coil spring (76) suspended between a pin (74a) attached to the lower end of the lower tension adjusting portion (75) and a lower adjustment screw (75a), and a pair of lower levers (74) ) Between the upper ends of the lower lever shaft (74c) and a lower tip side clamping body (30) comprising a roller rotatably provided on the lower lever shaft (74c).

The lower adjustment plate (75b) is attached to the elevating block (62) side of the left and right outer surfaces of the lower block (73), and the adjustment screw (75a) is screwed so as to be able to advance and retreat, and the tension of the lower coil spring (76) is increased. It can be changed. Restriction of the pulling direction of the lower lever (74) is performed by a lower stopper (77) provided on the adjustment screw (75a) side of the lower lever of the lower lever (74). The lower tension adjusting section (75) is configured by the adjusting screw (75a) and the adjusting plate (75b).

Insert the tip-end clamping body (30) (31) between the upper and lower lever shafts (64c) (74c) using, for example, a bearing so that the forward / reverse rotation is smooth as described above. Alternatively, using a sleeve with a different friction coefficient depending on the rotation direction, when moving in a direction away from the base side clamping body (20) (21), it rotates smoothly and reverse When trying to rotate in the direction, it may be rotated in the reverse direction with a certain amount of frictional force (that is, in the direction close to the base side sandwiching bodies (20) and (21)). In addition, a small one-way clutch or ratchet, etc. is provided between the upper and lower lever shafts (64c) (74c) and the tip side clamping bodies (30) (31) to rotate in the reverse direction (ie, the base You may make it stop the rotation in the direction which adjoins the side clamping body (20) (21). When stopping reverse rotation, in order to prevent damage to the current collector (14), a certain amount of force is placed between the front end side clamping body (30) (31) and the current collector (14) sandwiched. It is preferable that slip occurs. This is the same in the case of the embodiment shown in FIGS.

The lower base side sandwiching body (20) is a rectangular parallelepiped block provided facing the compatibility plate (63a) and the upper base side sandwiching body (21), and is erected from the lower block (73). Fixed to the upper ends of the pair of front and rear guide pins (24), and further, a compression coil spring (25) is attached to the guide pins (24), and the lower base side clamping body (20) is moved upward with a predetermined force. The pressure is applied. The guide pin (24) is slidably inserted into the guide hole (73a) of the lower block (73), and the pin head (24a) at the lower end of the guide pin (24) contacts the lower surface of the guide hole (73a). Yes. Therefore, the lower base side clamping body (20) is always held in a state of floating from the lower block (73).

The pressing member (40) is an L-shaped or plate-shaped member that fits into a concave groove continuous with the pressing groove (63d) of the upper base side clamping body (21), and its receiving surface through the current collecting section (14). Press (22). The lateral length is at least the same lateral length as that of the lower base side sandwiching body (20), is arranged below the through hole (23), and is fixed to the upper surface of the lower block (73). As shown in FIG. 3, the upper end is provided below the upper surface of the lower base side clamping body (20) that is pressed and biased upward and located at the uppermost position (top dead center). In the present embodiment, the pressing member (40) is fixed to the upper surface of the lower block (73). However, of course, the pressing member (40) is not limited to this, and as shown in FIG. 11, similar to the lower base side sandwiching body (20). Using the guide pin (40a) and the compression coil spring (40b), the guide pin (40a) inserted in the guide hole (40c) drilled in the lower block (73) can be moved in the vertical direction and compressed. The coil spring (40b) may be pressed and biased upward. As a result, when pressed, it is pushed down to the receiving surface (22) via the curved portion (14c1) of the current collector (14), and presses the curved portion (14c1) of the current collector (14) with a constant force.

The pressing surface of the pressing member (40) is formed in a semicircular cross section over the entire length, irradiated with a laser beam (50) during welding, and the molten welded portion (14y) of the current collector (14) is kept at a constant pressure. Since it will be contact-pressed, it is desirable that it is excellent in heat resistance and heat conductivity. For example, a material used for a spot welding electrode material such as a copper-tungsten alloy, a chromium copper alloy, alumina-dispersed copper, or molybdenum, or a member such as ceramic is used for this portion. The same material or steel is used for the upper base side clamping body (21).

The laser emitting part (51) is supported by an arm (not shown) on the elevating block (62) and moves along the through hole (23), and the laser beam is emitted from its tip like a continuous wave laser device. (50) is emitted continuously while moving toward the through hole (23) or intermittently like a pulsed laser device. In the case of pulse oscillation, the nuggets formed in the welded portion (14y) are usually connected to each other.

The assembly supply base (90) is disposed in front of the lower lifting mechanism (70), supplies the unprocessed assembly (10) toward the lower lifting mechanism (70), and after the processing is completed, the assembly It has the function of picking up (10) and supplying a new raw assembly (10).

Electronic parts such as secondary batteries and capacitors are basically composed of a positive electrode plate (12), a separator (11), and a negative electrode plate (13), and a positive electrode plate (12) and a negative electrode plate on both sides of the separator (11). An electrode assembly (10) formed by laminating a large number of unit bodies arranged with (13) is used as its main component. For example, as an example of the assembly (10), the current collector (14d) of the positive electrode plate (12) is extended from one end of the separator (11) around the separator (11), The current collector (14d) of the negative electrode plate (13) is extended from the other end of (11), and the current collector (14d) of these positive electrode plate (12) or negative electrode plate (13) The laminate of the positive or negative electrode active material is a current collector part (14), and this part is welded. When the current collector (14) is not pressurized in the laminated state, a gap (t) having a thickness of the separator (11) and the active material is formed between the adjacent current collectors (14d).

Next, the operation of the device (A) will be described. As shown in FIG. 3, the electrode assembly (10) is arranged on the assembly supply base (90) with one of the current collectors (14) facing the apparatus main body (60). At this time, the upper elevating mechanism part (63) and the lower elevating mechanism part (70) are standing by in a vertically opened position (home position) (FIGS. 1 and 3).

The electrode assembly (10) on the assembly supply base (90) is conveyed toward the apparatus main body (60), and the current collector (14) is sent between the base side clamping bodies (20) and (21). Stop. At this time, the base side clamping body (20) of the lower lifting mechanism section (70) is set flush with the assembly supply base (90), and the lowermost electrode plate of the current collector section (14) fed in (14) may be placed on the base side clamping body (20), or the upper surface of the base side clamping body (20) is set slightly lower than the assembly supply base (90), and the current collector ( 14), the lower lifting mechanism (70) is slightly raised at the stage where the lower lifting mechanism (14) is moved to the lowermost current collector (14d) of the lower lifting mechanism (70). (20) may be contact-supported. In any case, at this time, the lower tip side clamping body (30) is in contact with or slightly separated from the lowermost current collector (14d) (FIG. 4).

After that, the ball screw driving section (61a) is actuated to lower the elevating block (62), and the front end side clamping body (31) first contacts the uppermost current collector (14d). When the elevating block (62) is further lowered, the current collector (14) is pushed downward by the tip side clamping body (31) and bends downward, and the upper lever (64) gradually falls while extending the upper coil spring (66). . Subsequently, after the upper base side clamping body (21) contacts the uppermost current collector (14d) of the current collector (14), the current collector (14) is pushed down by a certain amount to collect current from above and below. The entire width of the part (14) is lightly sandwiched between the base side clamping bodies (20) and (21). Since the upper tip side clamping body (31) is set so as to slightly protrude below the upper base side clamping body (21), the tip end portion (14b) of the current collector (14) as described above. ) Is pushed down slightly, and thereafter, the tip end portion (14b) is lightly sandwiched from above and below by the upper and lower tip side clamping bodies (30) and (31). At this time, the current collector (14) is pushed down by the upper tip side clamping body (31) and is slightly bent downward (FIG. 5). When the lower lifting mechanism (70) is lifted in the next step, the amount of push down is pressed by the same amount to some extent without the upper and lower tip side clamping bodies (30) (31) being biased around the current collector (14). It is set to a possible amount.

Finally, the lower elevating mechanism (70) is greatly raised, and first, the base (14a) of the current collector (14) is strongly clamped by the upper and lower base-side clamping bodies (20) (21). At this time, the lower base side clamping body (20) is supported by the guide pin (24) so as to be vertically movable, and is pressed and biased upward by the compression coil spring (25). The compression coil spring (25) is bent by the rise of (70), and the base (14a) of the current collector (14) is clamped with a predetermined force by the spring force. Then, as the lower elevating mechanism (70) rises, the lower tip side clamping body (31) comes into contact with the current collector (14) from below, and then the tip portion (14b) is sandwiched from above and below.

In the embodiment of FIG. 6, the tip side holding bodies (30) and (31) sandwiching the tip part (14b) slightly apart from the base part (14a) of the current collector part (14) from above and below are the lower lifting mechanism part ( The upper and lower levers (64) and (74) are rotated with the rise of (70), and at the same time, are moved toward the apparatus main body (60) side while strengthening the clamping with respect to the tip (14b). By the movement of the front end side clamping body (30) (31), the front end part (14b) becomes like a roller hung from the upper and lower front end side clamping bodies (30) (31), and the adjacent current collector (14d ) Is pushed out to improve the adhesion between the two.

Here, the initial clamping position of the distal side clamping bodies (30), (31) may be closer to the distal side than the through hole (23) of the receiving surface (22) as shown in FIG. The figure shows the case where the roller-shaped front end side clamping body (30) rolls relative to the flat front end side clamping body (31). It is possible to replace it with the upper and lower distal end side sandwiching bodies (30) and (31) as shown in FIG. 6). The side clamping bodies (30) and (31) can roll the current collector (14) beyond the through hole (23) which is the target part of laser welding, and can increase the adhesion of the target part of laser welding. . At this time, the pressing member (40) is in a state before contacting the current collector (14).

In addition, when a frictional force is generated as described above between the front end side clamping bodies (30) and (31) and the front end portion (14b) of the current collector (14), particularly in the case of FIG. The upper and lower tip side clamping bodies (30) and (31) move to the tip side while holding the clamped state, so that tension is applied between the clamping parts of the current collector (14), and the degree of adhesion is further increased. I can do it.

Then, as the lower elevating mechanism (70) further rises, the upper and lower levers (64) (74) gradually rotate toward the device main body (60), and the tension is applied between the sandwiched parts of the current collector (14). Then, the pressing member (40) comes into contact, and subsequently, the portion to be clamped is pushed toward the receiving surface (22). The sandwiched portion of the pushed current collector (14) is gradually curved, and the ridgeline at the apex is pressed against the receiving surface (22). When the portion is pressed against the receiving surface (22) with a predetermined pressure, the lower lifting mechanism (70) stops. The stop command for the lower lifting mechanism (70) is, for example, based on a command from a pressure sensor (not shown). In this case, when the pressing member (40) has a structure as shown in FIG. 11, a constant pressure can be applied without a pressure sensor. As shown in FIG. 6, the tip end (14b) has a lower tip side clamping body (30) on the inner side of the upper tip side clamping body (31) due to the difference in inclination between the upper and lower levers (64) and (74). 9 and the distal end portion (14b) is bent downward. As shown in FIG. 9, the tilt of the upper and lower levers (64) and (74) is substantially equal, and the distal end holding member (30 ) (31) may pinch the tip (14b) and be pulled in a straight line.

The laser beam (50) from the laser emitting part (51) to the curved part (14c1) of the current collecting part (14) from the through hole (23) in the state where the pressing of the sandwiched part of the current collecting part (14) is completed in this way Irradiate. The laser emitting portion (51) moves along the through hole (23) and forms a welded portion (14y) from the convex curved surface side to the concave curved surface side in the curved portion (14c1). As described above, since the welded portion (14y) is laser-welded in an integrated state in which a compressive force is applied between the receiving surface (22) and the pressing member (40) as described above, the current collecting portion (14) is closely attached. Heat is smoothly transferred between the electric bodies (14d), and the welded portion in a semi-molten state is subjected to the same action as so-called forging, and is welded in a good state without any holes.

The shape of the heel welded portion (14y) can be obtained arbitrarily by controlling the movement locus of the laser beam (50). For example, as shown in FIG. 16 (a), one welded portion (14y) over the entire width of the current collecting portion (14), or two or more parallel lines as shown in FIG. 16 (b). As shown in the figure (c), the welded part (14b) constituted, a welded part (14b) connected with a circle, as shown in the figure (d), various kinds of parts such as a welded part (14b) in a broken line shape Things are obtained. As the laser beam (50), various types such as a continuous oscillation system (CW) and a pulse oscillation system can be used.

When the laser welding is finished, the lower lifting mechanism (70) and the lifting block (62) are raised and lowered to return to the home position, the processed electrode assembly (10) is removed, and a new raw electrode assembly is removed. Solid (10) will be supplied.

In addition, in the above case, the roller is used for the front end side sandwiching bodies (30) and (31). However, as shown in FIG. 10, the contact surface of the front end side sandwiching bodies (30) and (31) seems to be cut off from the cylindrical outer surface. The cross section may be formed in a circular arc shape, in other words, a spatula shape. In this case, the front end side clamping bodies (30) and (31) exhibit a certain degree of frictional resistance against the current collector (14d) on the surface layer of the current collector (14). As a result, it is possible to apply tension to the current collector (14) between the base-side sandwiching bodies (20) (21) and the tip-side sandwiching bodies (30) (31). The degree of adhesion between (14d) can be further increased.

FIGS. 12 to 14 show another embodiment of the present invention in which the distal end side clamping body (31) is constituted by a surface. In the illustrated embodiment, the “surface” is a flat surface, but includes a “curved surface” in which the lower roller-shaped front end side clamping body (30) contacts the entire surface. Further, as described above, the lower roller-shaped front end side holding body (30) is positioned forwardly beyond the through hole (23) by a distance (S), and the lever (74) is moved rearward by the rotational movement. It is preferable to move backward through the hole (23).

FIG. 15 is another embodiment of the upper base side sandwiching body (20), and the base side sandwiching body (21) may be formed of a heat-resistant transparent material such as quartz glass or pyrex glass. In this case, since the laser beam (50) passes through the heat-resistant transparent material as it is, it is not necessary to provide a through hole (23). As a result, the tip of the pressing member (40) can directly press the pressed portion (14c) toward the heat-resistant transparent material, so that the integration effect is enhanced. In this case, if the heat-resistant transparent material is cooled, adhesion of the welded portion (14y) to the heat-resistant transparent material is prevented.

In the above embodiment, the base side sandwiching bodies (20) and (21) are in a fixed state, and the distal end side sandwiching bodies (30) and (31) are moved rearward. The base side clamping body (20) (21) may move forward while the distal side clamping body (30) (31) is fixed, or the base side clamping body (20) (21) may move forward. In addition, the front end side clamping bodies (30) and (31) may be moved rearward.

Further, in the above embodiment, the case where the current collecting part (14) is pressed and integrated with the receiving surface (22) by the pressing member (40) has been shown, but the base part (14a) of the current collecting part (14) and When the distal end portion (14b) is sandwiched between the base side clamping body (20) (21) and the distal side clamping body (30) (31), the base side clamping body (20) (21) and the distal side clamping body (30) When the clamping force between the base (14a) and the tip (14b) of (31) is sufficiently large and the friction between them is sufficient, in other words, when the holding force is sufficient, the receiving surface (22) is provided. Instead, the pressing member (40) may be pressed alone to apply pressure to the portion, and the pressed portion (14c) may be integrated. In this case, when the pressing force is sufficiently strong, the pressed portion (14c) is curved.

(A) Laser welding equipment (10) Electrode assembly (11) Separator (12) Positive electrode plate (13) Negative electrode plate (14) Current collector (14a) Base (14b) Tip (14c) Pressed part (14c1) Curved part (14d) Current collector (20) (21) Base side clamping body (22) Receiving surface (23) Through hole (30) (31) Tip side clamping body (40) Pressing member (50) Laser beam (51) Laser emission part

Claims (10)

In the electrode assembly having a current collector in which positive and negative electrodes are alternately stacked with separators and the electrode plates of the same polarity are integrated, the method of laser welding the current collector,
After clamping and pressing the base of the current collector with the base-side clamp and the tip of the current collector with the tip-side clamp, at least one of the base-side clamp and the tip-side clamp is separated from the other To stop at a predetermined position,
Between the base side clamping body and the tip side clamping body, press the pressing member against the current collecting part to pressurize the pressed part of the current collecting part,
A method of joining a current collecting portion of an electronic component, comprising irradiating the pressed portion of the current collecting portion with a laser beam to form a laser welded portion on the irradiated portion of the pressed portion. After at least one of the base side clamping body and the distal side clamping body is moved away from the other and stopped at a predetermined position, a current collector is further interposed between the base side clamping body and the distal side clamping body. Press the pressing member against the part to bend the pressed part of the current collecting part, and irradiate the curved part of the current collecting part with a laser beam to form the laser welding part from the convex curved surface side to the concave curved surface side at the curved part The method for joining the current collector part of the electronic component according to claim 1. 3. The electron according to claim 1, wherein when moving at least one of the base-side sandwiching body and the tip-side sandwiching body in a direction away from the other, the moving side exceeds the laser welded portion of the current collector. The method of joining the current collector of the part. A laser welding apparatus for the current collector part in an electrode assembly having a current collector part in which positive and negative electrode plates are alternately stacked with separators sandwiched, and electrode plates of the same polarity are integrated,
A base side clamping body that clamps and presses the base of the current collector;
A front end side clamping body that moves in the front end direction while holding and pressing the front end portion of the current collector and stops at a predetermined position;
Between the base side sandwiching body and the front end side sandwiching body, a pressing member that presses the current collector against the receiving surface provided on the one sandwiching body side and presses the current collector,
An apparatus for joining a current collecting portion of an electronic component, comprising: a laser emitting portion for irradiating the pressed portion of the current collecting portion with a laser beam to form a laser welding portion on the irradiated portion of the pressed portion. 5. The electronic device current collector joining device according to claim 4, wherein the front end side clamping body is formed of a roller. The electronic device current collector joining device according to claim 4, wherein the front end side clamping body is formed of a roller, and the front end side clamping body is a surface continuous with the receiving surface. The apparatus for joining a current collecting part of an electronic component according to any one of claims 4 to 6, wherein the roller which is the front end side clamping body moves beyond the through hole. The electronic device current collector joining device according to any one of claims 4 to 7, wherein the contact surface of the front end side sandwiching body is formed in an arc shape in a cross section perpendicular to the axis. A press groove is provided in the base side clamping body so as to coincide with the pressed portion of the current collector, and a slit hole for passing a laser beam reaching the receiving surface of the press groove where the current collector is pressed is formed in the base side clamping body. 9. The joining device for a current collector part of an electronic component according to claim 4, wherein the electronic device current collector part is joined. 10. The joining device for a current collector part of an electronic component according to claim 4, wherein the base side clamping body is formed of a heat resistant transparent material.

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