JP2012156201A - Wiring material supply mechanism, and control method of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mechanism for supplying a wiring material with small-sized and mechanically simple facilities, while imparting constant tension to the material.SOLUTION: A wiring material supply mechanism 1 includes: wiring material feeding means 2 in which a wiring material is previously wound around; traction means 5 which grips the wiring material and pulls the material in a horizontal direction; direction converting means 4 which is placed between the wiring material feeding means and the traction means, and converts a direction of the wiring material to a pulled direction by the traction means; first driving means 6 which drives the wiring material feeding means; second driving means 7 which drives the traction means; and a control unit 8 which determines a circumferential length of the wiring material in the wiring material feeding means according to a length of the wiring material pulled out from the wiring material feeding means and a rotation angle of the wiring material feeding means, determines a winding radius of the wiring material according to the obtained circumferential length, and synchronously controls the first driving means and the second driving means so as to obtain a required torque according to the winding radius and a desired tension.

Description

  The present invention relates to a wiring material supply mechanism and a control method thereof, and is particularly suitable for manufacturing a solar cell string.

The solar power generation apparatus is configured by installing a plurality of solar cell modules as an installation unit and connecting them, and this solar cell module has a plurality of solar cells therein. That is, the solar cell module is formed by arranging a plurality of solar cell strings in which a plurality of solar cells each having an output of several watts per series are connected in series, and wiring and then EVA (ethylene vinyl acetate). It is manufactured by sealing with a filler mainly composed of a polymerized resin), a protective material, and a cover glass.
In this solar cell string, an electrode formed on the light receiving surface of a solar cell and an electrode formed on the back surface of an adjacent solar cell are electrically connected in series using a wiring material (also referred to as a tab lead). And this connection structure is applied to a plurality of solar cells.

  FIG. 9 is a front view showing a state in which units including a plurality of solar cells 110, 120, and 130 are connected by wiring members 140, 150, 160, and 170 to form a solar cell string, and FIG. It is the expanded sectional view seen from the front which shows a mode that the wiring materials 140 and 150 were attached.

  According to FIG. 9, in this example, the back surface of a certain cell and the surface of the cell located on the right side in the figure are connected by the wiring material, and the manner in which this is repeated is shown.

  Referring to FIG. 10, a solar battery cell is formed by laminating an N-type semiconductor N layer 112 and a P-type semiconductor P layer 111, and the light receiving surface side is an N layer 112. It collects electrons generated by light irradiation and extracts current. As shown in FIG. 10, an antireflection film 113 is formed on the light receiving surface, and finger electrodes 114 are formed at portions where the antireflection film 113 is linearly etched at equal intervals, and the finger electrodes 114 are formed on the antireflection film 113 and the finger electrodes 114. A bus bar 115 is formed by applying a conductive paste such as silver in a direction perpendicular to the electrodes in a straight line and firing and metallizing the paste. An aluminum sheet 116 is attached to the bottom surface of the P layer 111 on the back surface, and a bus bar 117 is formed on the bottom surface in the same manner as the surface. The role of these bus bars 115 and 117 is to interpose between silicon and aluminum and the wiring material, which cannot directly solder the wiring material, and to securely connect them.

  Pre-processed wiring members 140, 150, 160, 170 are soldered to the bus bar, and the connection state is such that the wiring member 150 attached to the bus bar 115 on the upper surface of a certain cell 110 is connected to the lower surface of the adjacent cell 120. It can be attached to the bus bar. A solar cell string is manufactured by repeating a predetermined number of such connections using the wiring material.

  In manufacturing a solar battery string, a wiring material is applied to a bus bar as an electrode provided at a predetermined position on a light receiving surface of a solar battery cell and an electrode provided at a predetermined position on the back surface of an adjacent solar battery cell. After the wiring material wound around the wiring material feeding means such as a bobbin (also referred to as a reel) is pulled out by a pulling means such as a chuck, After applying necessary processing such as correction to eliminate warping and bending by applying tensile force from both sides, forming to form a step in the position corresponding to the gap between two cells, cutting to cut to the required length, etc. It arrange | positions on the electrode of a battery cell and the adhering by soldering is performed.

  By the way, if sagging of the wiring material occurs when the wiring material is pulled out, the wiring material may come off from the bobbin, which significantly reduces the manufacturing efficiency. In order to prevent such a sag, a technique is conventionally known in which a tension applying means such as a tension pulley is used to pull out the wiring member while applying a certain tension (see Patent Document 1).

  The tension pulley suspends the drawn wiring material in a U shape, engages a pulley that can move up and down at the lower end of the tension pulley, and applies a constant tension to the wiring material by the downward force due to its own weight. This prevents slack in the wiring material.

JP 2009-81317 A

  However, the sagging prevention mechanism for the wiring material as described in Patent Document 1 needs to form a U-shaped wiring material suspension as described above, and in addition to the tension pulley, there are a plurality of routing pulleys, bending pulleys, and the like. Pulley is required. Therefore, these installation spaces are required in the apparatus, resulting in a problem that the apparatus becomes large, the mechanical structure is complicated, and the number of maintenance is increased.

  The present invention has been made in view of such a situation, and provides a wiring material supply mechanism having a small and simple mechanism capable of supplying a wiring material while applying a constant tension, and a control method thereof. For the purpose.

In order to solve the above problems, the wiring material supply mechanism in the present invention is:
Wiring material supply means around which the wiring material is wound, pulling means for pulling out the wiring material, direction changing means for changing the direction of the wiring material, driving means for driving the wiring material supply means, and driving the pulling means A driving unit that controls the driving unit on the wiring material feeding unit side and the driving unit on the traction unit side,
It is characterized by providing.

In addition, the method for controlling the wiring material supply mechanism according to the present invention includes:
A step of inputting a tension applied to the wiring material to the control unit, a step of the control unit detecting a drawing length of the wiring material, and a step of detecting a rotation angle of the wiring material feeding means by the control unit; The control unit calculates a circumferential value of the wiring material from the value of the lead length and the rotation angle, and the control unit calculates a winding radius of the wiring material from the circumferential value; A step of calculating torque from the tension input in the step and the diameter calculated in the step;
It is characterized by providing.

  According to the present invention, two means that are synchronously controlled without using a plurality of rollers and pulleys and a wiring material suspension as in the prior art as a means for applying a constant tension to the wiring material drawn by the traction means. Since it is a servo motor (driving means), it is possible to achieve a reduction in size due to simplification of the structure, a reliable operation and easy maintenance of the wiring material.

  In addition, the control method of the wiring material supply mechanism is characterized in that the two servo motors are controlled synchronously so as to give a desired tension to the wiring material, and the same effect as the wiring material supply mechanism is obtained. It is what you play.

It is a top view which shows the schematic whole structure of one Example of the solar cell string manufacturing apparatus with which the wiring material supply mechanism concerning this invention is applied. It is a front view which shows typically the principal part of the solar cell string manufacturing apparatus concerning this invention shown in FIG. It is the schematic of the wiring material supply mechanism which concerns on one Embodiment of this invention. It is a side view which shows the detailed structure of the wiring material supply mechanism in FIG. It is a top view which shows the structure of the chuck | zipper which grabs and pulls the drawn | out | reduced wiring material. It is a front view of the same structure as FIG. It is a flowchart of the wiring material supply mechanism control method which concerns on one Embodiment of this invention. It is explanatory drawing which illustrates each element required for torque calculation calculation. It is a side view which shows the structure of a solar cell string. It is sectional drawing which shows the mode of the connection of the layer structure of one cell which comprises a solar cell string, and a wiring material.

  Hereinafter, embodiments of a wiring material supply mechanism and a control method thereof according to the present invention will be specifically described with reference to the drawings.

  FIG. 1 is a plan view showing a schematic overall configuration of an example of a solar cell string manufacturing apparatus 100 to which a wiring material supply mechanism according to the present invention is applied.

  The solar cell string manufacturing apparatus 100 includes a solar cell supply unit 10 that supplies solar cells, a wiring material supply and molding unit 20, a holding unit 30 that holds the molded wiring material, and a connection between the wiring material and the solar cells. The wiring material attaching part 40 which performs this, and the conveyance part 50 etc. which convey the supplied photovoltaic cell to a wiring material attaching part are provided.

  The separately manufactured solar battery cell 12 is transported to the take-out position of the solar battery cell by the transport path 11. The solar cells 12 that have reached a predetermined take-out position are taken out by the cell transfer robot 51, first inspected by the cell inspection unit 52, and then non-defective products are soldered by the flux application unit 54 by the index table 53. Flux application is performed, and the solar cell is sent to the soldering unit 43 by another cell transfer robot 56. In this embodiment, two lines forming the solar cell string are provided. The solar cell string completed by soldering is stocked in a stock part 44 of a finished product between the two lines 41 and 42 forming the string.

  On the other hand, the solar cells determined to be defective by the cell inspection unit 52 are sent by the cell transfer robot 51 to a reject unit 55 that accumulates defective products that are not used.

  In this embodiment, two sets of the wiring material supply and molding unit 20 and the holding unit 30 are provided corresponding to the two string forming lines 41 and 42.

  FIG. 2 is a front view schematically showing main parts of one embodiment of the solar cell string manufacturing apparatus 100 shown in FIG. Here, an example of an apparatus capable of supplying three wiring members is shown.

  As the wiring material used here, the following materials are generally used.

  The material of the wiring material is a pure copper conductive material coated with solder (Sn—Pb) or lead-free type solder (Sn—Ag—Cu), and the size is 1.2 to 2.5 mm in width. The thickness is 0.18 to 0.28 mm. The length of one-time feeding is 157 mm as a 6-inch cell, the tip is located 5 to 10 mm inside from the cell edge, the cell-to-cell distance is 1.5 to 30 mm, and the cell-to-cell distance is short Since the angle becomes steeper, the distance is about 300 mm to 350 mm for connecting two cells.

  First, in the wiring material supply and molding unit 20, the long wiring material is wound around the bobbins 21, 22, and 23, and the end of the wiring material is gripped by the chuck 61 through the drawing direction changing roller 201. The end of the material is drawn out to reach the position of the downstream end A of the wiring material forming table 24.

  After this drawing, the lock member 27 descends to lock the upstream side of the wiring material, and the chuck 61 moves slightly in the pulling direction, so that the wiring material is corrected to be free from warping or bending. Next, of the pair of forming members 25 (lower mold) and 26 (upper mold), the upper mold 26 is lowered, and a wiring member is sandwiched between the upper mold 26 and the lower mold 25 to provide an inclined surface between cells. In this way, the wiring material is molded. After forming the wiring material, the lock member 27 and the upper mold 26 are raised, the wiring material is pulled out by the chuck 61 by the required length, and the wiring material is locked by the lowering of the lock member 28, and then the cutter 29 is moved up and down. Move from and cut the wiring material. Note that the difference in height between the upper end portion and the lower end portion of the molded tab lead is equal to the thickness of the solar battery cell.

  The tip portion of the formed and cut wiring material is moved by the chuck 61 to the downstream end C on the holding member 31 of the holding portion 30, and at this time, the rear end portion of the wiring material is moved to the upstream end B of the holding member 31. It is supposed to be located. The holding member 31 is for temporarily placing the tab lead so as to maintain the correct position and posture before connecting the cells.

  In FIG. 2, two holding members 31 are shown in the upper and lower directions, but the same thing after a lapse of time is arranged in time series from top to bottom.

  In other words, the wiring material placed on the holding member 31 in the above figure is held at the tip portion by another chuck 62 and conveyed onto the wiring material mounting portion 40 so as to be positioned on the upper surface of the solar battery cell. In order to support the rear end portion during conveyance, as shown in the lower diagram showing the holding portion 30, a further chuck 63 is used at a gripping point D immediately before the holding member 31 is detached. The rear end portion of the wiring material is gripped, and gripped by these two chucks 62 and 63 and transferred to the wiring material mounting portion 40.

  In this way, the string forming line 41 is formed in the wiring material attaching portion 40.

  FIG. 3 is a schematic diagram showing a basic configuration of the wiring material supply mechanism 1 according to the present invention, and this wiring material supply mechanism 1 forms a part of the wiring material supply and forming unit 20 in FIG.

  The wiring material supply mechanism 1 is a bobbin in which the wiring material is wound in advance and feeds the wiring material 3 by rotation. The wiring material feeding means 2 (on the bobbins 21, 22, and 23 in FIG. Equivalent), and direction changing means 4 (corresponding to the drawing direction changing roller 201 in FIG. 2), which is a single pulley or roller that changes the moving direction of the wiring member 3 drawn in the diagonally downward direction a to the horizontal direction, There is a pulling means 5 (corresponding to the chuck 61 in FIG. 2) including a chuck or the like that is arranged on the downstream side and pulls in the horizontal direction b by gripping or adsorbing the end of the wiring member. The wiring material feeding means 2 is driven by a driving means 6 that is a servo motor that performs a rotating operation, and the traction means 5 is driven by a driving means 7 that is a servo motor that performs a horizontal movement operation. These driving means 6 and 7 are controlled by a control unit 8 comprising a servo amplifier and a controller, respectively. Further, in order to draw out the wiring material horizontally, the height of the portion of the direction changing means 4 in contact with the wiring material is equal to the height of the traction means 5.

  FIG. 4 is a side view showing the details of the wiring material feeding means 2 as viewed from the wiring material feeding destination side. Here, a solar cell string of a type in which solar cells are connected by three wiring materials is formed. A mechanism for pulling out three wiring members simultaneously is shown.

  As shown in FIG. 4, servomotors 231, 232, and 233 corresponding to the driving means 6 of FIG. 3 are attached to the support plate 200 so that their height positions are different. The lengths of the bearings 241, 242, and 243 connected to the shaft are longer as they are provided at the lower portion, and the lateral positions from which the wiring members are drawn are different.

  Blocks 251, 252 and 253 are attached to the bearings 241, 242 and 243, and shafts 221, 222 and 223 are fixed to the blocks 251, 252 and 253, respectively. Further, these shafts 221, 222, and 223 are attached so as to pass through holes provided in the central portions of the bobbins 211, 212, 213, and blocks 251, 252, It is fixed by being clamped between 253.

  Although not clearly shown in FIG. 4, wiring materials are wound around the bobbins 211, 212, and 213, respectively, and the servo motors 231, 232, and 233 are subjected to weak rotational torque in a direction opposite to the wiring material pulling direction. In the applied state, the tip of the wiring material is gripped, and the wiring material is pulled by applying a torque larger than the rotational torque of the servo motors 231, 232, 233 by the driving means 7, so that tension is applied to the wiring material. It can be pulled out. This control will be described later.

  5 and 6 show the detailed structure of the traction means 5, FIG. 5 is a plan view, and FIG. 6 is a front view.

  Referring to FIGS. 5 and 6, the driving means 7 in FIG. 3 corresponds to the servo motor 511, and a ball screw 521 is connected to the rotation shaft of the servo motor, and is rotated by the rotation of the servo motor. Since the ball screw 521 is engaged with a block 531 having a thread that engages with the thread valley, the block 531 moves in the left-right direction in the figure in accordance with the forward rotation and reverse rotation of the servo motor 511.

  A bracket 541 is fixed to the block 531, and three chucks 551, 552, and 553 are arranged in the bracket 541 in a horizontal direction in a positional relationship corresponding to the horizontal position of the bobbin.

  Therefore, after the chucks 551 to 553 are set so as to grip the tip of the wiring material, the servo motor 511 is commanded to drive the block 531 in the right direction in the figure by the control unit 8, thereby The material is pulled to the right.

  On the other hand, in the wiring material feeding means 2, after the feeding of the wiring material 3 is started by driving of the driving means 7, the wiring material 3 is always tensioned so as not to cause the wiring material to sag. For this reason, the force by which the driving unit 6 rotates the wiring material feeding unit 2 in the feeding direction needs to be smaller than the traction force by the driving unit 7 or in the reverse direction.

  Next, a method for controlling each element in FIG. 3 will be described.

  FIG. 7 is a flowchart showing an embodiment of control in the wiring material supply mechanism according to the present invention. Here, the description will be given focusing on the supply of one wiring material among the three wiring material supply mechanisms mentioned in the other drawings, but the same control is performed for the other wiring materials.

  Here, although the torque required to obtain the given tension is obtained, it is necessary to accurately obtain the winding radius of the remaining wiring material in the wiring material feeding means 2. Since this cannot be obtained directly, the length corresponding to one round is obtained and the winding radius is obtained.

  First, the planned tension applied to the wiring member 3 is input by an operator and stored in a memory (not shown) in the control unit 8 (step S1). This tension is an empirically selected value that can surely prevent sagging from the material, hardness, width, thickness, etc. of the wiring material used, and does not cause a problem-related deformation.

  Next, the driving unit 6 is rotated in the direction in which the wiring member 3 is pulled out, the wiring member 3 is pulled out, and the tip is gripped by the chuck 551 of the pulling unit 5. This is done manually or automatically. After the tip of the wiring member 3 is securely gripped by the chuck 551, the drive means 7 that is a servomotor is driven to pull the pulling means 5 in the b direction. At this time, when the wiring material is pulled, the wiring material feeding means 2 rotates accordingly and the wiring material is pulled out. However, when the resistance at the time of the first pulling is large, the driving means 6 causes the wiring material feeding means 2 to pull out. Can be driven in the feeding direction. Since it is desirable to apply an appropriate tension to the wiring member after the start of feeding, the driving means 6 applies a rotational force that is weaker than the traction force of the driving means 7 or a braking force is applied. It is preferable to apply a rotational force in the reverse direction. Since the rotational speed of the driving means 7 is constantly monitored by the control unit 8, the drawing length of the wiring material is detected from this rotational speed (step S2).

  The controller 8 detects the rotation angle of the wiring material supply means 2 from the rotation speed of the drive means 6 (step S3).

  Since the remaining winding diameter and outer circumference length (circumference) vary depending on the amount of the wiring material drawn, the length (circumference value) of one round on the wiring material feeding means 2 is directly determined from the drawing length. Since it cannot be detected, the wiring wound around the wiring material feeding means 2 is calculated from the length of the drawn wiring material obtained in steps 2 and 3 and the rotation angle of the wiring material feeding means 2 by the following formula. A circumferential value of the material is obtained (step S4).

ただし、ｃ：配線材の円周値
Ｌ：配線材３の引き出し長さ（ステップＳ２で検出）
θ：配線材繰り出し手段２の回転角度（ステップＳ３で検出）である。 That is,

Where c: Circumference value of the wiring material
L: Pull-out length of the wiring material 3 (detected in step S2)
θ is the rotation angle of the wiring material feeding means 2 (detected in step S3).

  Next, in order to make the tension applied to the wiring material constant, it is necessary to apply a torque corresponding to the distance (winding radius) from the center of the bobbin to the outer peripheral surface of the wiring material. For this reason, the distance from the center of the bobbin to the outer peripheral surface of the wiring material is calculated by the following equation using the circumferential value c of the wiring material obtained in step S4.

として求まる(ステップＳ５)。 That is, if r is the winding radius of the wiring material, c = 2πr,

(Step S5).

  FIG. 8 shows a state in which the wiring member 3 is pulled out by the length L by rotating by the angle θ when the wiring member feeding means 2 has the winding radius r of the wiring member 3. It shows that the circumferential length c of the material is obtained, and the radius r is also obtained by the equation (2).

  However, when the bobbin rotates a plurality of times, the winding radius also changes, so the winding radius obtained here is an average value.

  Next, the control unit 8 calculates the torque N applied to the wiring material from the tension input in S1 and the diameter calculated in S5 (step S6).

From the required tension F given in step S1 and the winding radius r of the wiring material obtained in step S5.
N = r · F (3)
As required.

  The torque N obtained in this way is a torque N1 for rotating the bobbin by the driving means 7 in the a direction and a torque N2 for rotating the bobbin by the driving means 6 in the direction opposite to the a direction (a value including a sign indicating the direction). However, since these are torques in the reverse direction, they are differences in absolute value. Therefore, the torque N2 gives a braking force to the wiring member, and thereby a certain tension is applied. However, as described above, this tension needs to be smaller than a value Nmax that causes deformation such as elongation of the wiring material.

Therefore, the torque N satisfies the following relationship.
N = N1 + N2 = r · F <Nmax (4)

Since the torque N1 by the chuck side driving means 7 can take any value, the bobbin side torque N2 can be calculated from the equation (4).
N2 = N-N1 (5)
It becomes.

  Since there are an infinite number of combinations of N1 and N2 that satisfy such a relationship, the torque distribution in the two drive means 6 and 7 is referred to, for example, a look-up table in order to obtain the calculated torque N in the control unit 8. The driving means 6 and 7 are stopped when the rotation torque command for the two driving means 6 and 7 is synchronized and the specified length is extracted.

  Further, as apparent from the equation (3), the value of N changes when the winding radius changes.

  Thus, in the control method of the wiring material supply mechanism of the present invention, the torque absolute values of the two servomotors that are synchronously controlled as a constant tension applying means without using a plurality of rollers including a conventional tension pulley are used. It is characterized by the difference in values. The wiring material supply mechanism is characterized by including a component that performs such control.

  Further, as shown in FIGS. 4 and 5, the wiring material supply mechanism 1 includes a wiring material feeding means 2, a pulling means 5, a direction changing means 4, a driving means 6, and a driving means 7. When a plurality of bobbins are provided, the bobbin positions are different from each other. Therefore, it is necessary to determine a torque for each wiring material by the control unit 8 and to give control values to the wiring material feeding means 2 and the traction means 5.

  With the above-described method, the wiring member is pulled out with a predetermined tension applied in advance, so that the wiring member can be pulled out stably with a simple configuration.

DESCRIPTION OF SYMBOLS 1 Wiring material supply mechanism 2 Wiring material supply means 3 Wiring material 4 Direction change means 5 Pulling means 6 Driving means of wiring material supply means 7 Driving means of pulling means 8 Control part 10 Solar cell supply part 20 Wiring material supply and forming part 21, 22, 23, 211, 212, 213 Bobbin 24 Wiring material forming base 25, 26 Forming member 27, 28 Locking member 29 Cutter 30 Holding part 31 Holding member 40 Wiring material attaching part 41, 42 String forming line 50 Conveying part 61 , 62, 63.551, 552, 553 Chuck
201 Pull-out direction changing rollers 231, 232, 233 Servo motor 511 Servo motor 521 Ball screw

Claims (5)

A wiring material feeding means in which the wiring material is wound in advance;
Towing means for gripping the wiring material and pulling in the horizontal direction;
A direction changing means that is between the wiring material feeding means and the traction means and changes the direction of the wiring material to a traction direction by the traction means;
First driving means for driving the wiring material feeding means;
Second driving means for driving the traction means;
The circumferential length of the wiring material in the wiring material feeding means is obtained from the length of the wiring material drawn out from the wiring material feeding means and the rotation angle of the wiring material feeding means, and the winding of the wiring material is calculated from this circumferential length. A control unit that obtains a radius and synchronously controls the first drive unit and the second drive unit so as to obtain a necessary torque from the winding radius and a desired tension;
A wiring material supply mechanism comprising:   The said pulling means is provided with the block which moves horizontally with the ball screw driven by rotation of a servomotor, and the mechanism which hold | grips the said wiring material attached to this block, The Claim 1 characterized by the above-mentioned. Wiring material supply mechanism.   2. The wiring material supply mechanism according to claim 1, wherein the first driving unit is driven in a direction opposite to a feeding direction of the wiring material, and the second driving unit is driven in a feeding direction of the wiring material. .   The wiring material feeding means, the pulling means, the direction changing means, the first driving means, and the second driving means are provided in a plurality of sets corresponding to the number of wiring materials supplied simultaneously. The wiring material supply mechanism according to claim 1, wherein the wiring material supply mechanism is controlled by the control unit. A control method of a wiring material supply mechanism for pulling out the wiring material while maintaining a predetermined tension by a pulling means from a wiring material feeding means in which the wiring material is wound in advance.
The wiring material circumferential length and winding radius at that time from the pulling length when the wiring material drawn out from the wiring material feeding means is gripped and pulled in the horizontal direction by the pulling means and the rotation angle of the wiring material feeding means Seeking
Find the required torque from the product of this winding radius and the required tension,
A driving method of a wiring material supply mechanism, wherein the first driving means of the wiring material feeding means and the second driving means of the traction means are controlled in synchronism so as to generate the necessary torque.

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