JP2929278B2 - Wire feeder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire feeding device, and more particularly to a wire feeding device suitable for use in an automatic joining device for joining a fuse wire having a small diameter to a lead frame.

[0002]

2. Description of the Related Art FIG. 5 shows a conventional thermal fuse (JP-A-7-169381). This thermal fuse is used for communication, and 1 is a fusible alloy such as solder (hereinafter, referred to as a fuse).
Reference numeral 2 denotes a cylindrical body made of an insulator, and 3 denotes a lid-like terminal. In this fuse, a fuse wire 1 is diagonally stretched in a cylindrical body 2, and both ends thereof are protruded to the outside of the cylindrical body 2 and are bent along an outer wall surface.
The outer wall surface of the cylindrical body 2 and the terminal 3
The fuse wire 1 is sandwiched between the inner wall surfaces of the fuse wire 1 and connected to the terminal 3, or hot air is blown toward the solder placed in advance near the end of the fuse wire 1 so that the end of the fuse wire 1 is The part was hot-air soldered to the terminal 3.

As for a fuse wire having a relatively large diameter, a bonding method and apparatus disclosed in Japanese Patent Application Laid-Open No. 7-328780 are known. This bonding method and apparatus contact the fuse wire and the lead member, irradiate the laser beam to the contact portion, and at the moment the fuse wire is heated and melted, move the laser beam irradiation port to the lead member side by a predetermined distance. The lead member is heated by a laser beam, and the contact portion is gradually cooled and hardened while being heated at a low temperature by heat conduction from the lead member.

According to this method, the contact portion is not quenched, so that cracking and embrittlement can be prevented. Also, at the moment when the contact portion is heated and the fuse wire is melted, the lead member is moved by a predetermined distance. Pushing it to the side has the advantage of improving the joining strength because the so-called thinning (reduction in wire diameter) of the joining portion is prevented.

[0005]

However, in the above-mentioned conventional joining methods, the fuse lines are previously cut to a predetermined length, so that the handling is complicated and unsuitable for automation. In addition, the latter bonding method and apparatus, because the fuse wire is mechanically gripped by a clamp and transported, if the wire diameter is small, the wire diameter is reduced or broken when gripped, thereby lowering reliability, There is a problem that it is difficult to apply to a very small one such as a micro fuse.

The present invention has been made in order to solve the above-mentioned conventional problems, and an object of the present invention is to provide a stable and reliable continuous supply even if the wire diameter is small. The present invention provides a wire feeder that has been developed.

[0007]

In order to achieve the above object, a wire feeder according to the present invention comprises a spool on which a wire is wound, a sensor for detecting a wire fed from the spool, and a sensor for detecting the wire fed from the spool. Upon detection, a drive device that intermittently rotates the spool and feeds a predetermined amount of wire, a pair of clamps that hold the wire fed from the spool at a predetermined interval, and a wire through hole through which the wire passes. A pair of pneumatic tension applying means having a communication hole communicating with the wire rod through-hole, provided before and after the pair of clamps, respectively, and ejecting compressed air from the wire rod through-hole in a direction opposite to the clamp; the equipped, like the pair of clamp which is one of the clamp or with gripping the wire to alternately open and close to grip the free wire rod reciprocate In characterized by a predetermined amount of movement to the wire supply direction.

In the present invention, when the sensor detects the wire, the driving device rotates the spool. The spool is paid out by being intermittently rotated by the driving device. The pair of clamps alternately open and close to grip the wire. One of the clamps is reciprocally movable, grips the wire at the time of wire supply, and moves forward by a predetermined amount. The pneumatic tension applying means prevents loosening of the wire between the clamps by ejecting compressed air in a direction opposite to the clamp to apply tension to the wire.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on one embodiment shown in the drawings. FIG. 1 is a side sectional view showing an embodiment of an automatic fuse joining apparatus provided with a wire feeder according to the present invention, FIG. 2 is a side view showing a part of the wire feeder, and FIG. FIG. 4 is a plan view of the wire feeder, and FIG. 4 is a sectional view of the pneumatic tension applying means. In these drawings, in this embodiment, a fuse wire 1 having a low melting point (300 ° C.) is used as a wire, and the fuse wire 1 is joined to a lead frame 5 made of a material having a high melting point (1450 ° C.). An example applied to the automatic joining device 11 will be described.

The fuse wire 1 has a wire diameter of 46 μm to 1 μm.
20 μm is used. The lead frame 5 is formed in a band shape as shown in FIG. 3 by a 42 alloy (iron / nickel alloy) having a thickness of 0.1 mm. Silver plating is applied in advance in order to make this possible. In the lead frame 5, perforations 6 are formed on both side edges 5b in the longitudinal direction, and a connecting portion 5c for connecting the both side edges 5b to a center portion in the width direction, and a front end facing the land portion 5a. Are formed in a tongue-shaped fuse small piece 5d. When used as a fuse, the small fuse piece 5d is cut and separated from the side edge 5b. Note that a slit 8 is formed between the connecting portion 5c and the small piece for fuse 5d.

The schematic structure of the automatic joining apparatus 11 will be described. This apparatus 11 has a portable housing 12 having casters 13. An unillustrated loader (not shown) in which a cassette for accommodating the lead frame 5 is loaded, and a lead frame 5 drawn out from the cassette in the loader, and a wire shaping device 15 And a wire feeder 16 to be described later for feeding the lead frame 1 to the joining station S. The transport direction of the lead frame 5 and the supply direction of the fuse wire 1 are orthogonal to each other.

In the wire shaping device 15, the center of the upper surface forms the joining station S, and the lead frame 5
The lower die 17 is installed with its back side up, in other words, the land 5a is directed downward, the upper die 18 for pressing the lead frame 5 against the upper surface of the lower die 17, and the fuse wire 1 The fuse wire 1 cut into the length and cut along with the upper die 18 is shaped into a predetermined shape (Ω shape), and each end of the fuse wire 1 is brought into contact with two opposing lead portions 5 a of the lead frame 5. A punch 19 and the like are provided. The punch 19 is slidably inserted into a punch hole provided in the lower die 17, and when the punch 19 is raised at the time of joining the fuse wire 1, cuts the fuse wire 1 and cuts the cut end to the land of the lead frame 5. The portion 5a is contacted from below.

In the chamber 14 of the housing 12, two laser beams having the same beam intensity and arranged above the wire shaping device 15 are simultaneously applied to two opposing lands 5a of the lead frame 5 from above. A laser irradiation device 20 for irradiating each end of the fuse 1 to the two lands 5a, a second transfer device (not shown) for transferring the lead frame 5 to which the fuse wire 1 is connected, and a second transfer device (not shown). A vertically movable unloader (not shown) loaded with an empty cassette for accommodating the lead frame 5 transported by the apparatus is provided.

As the laser irradiation device 20, for example, a YAG laser is used, and the back surface of the lead frame 5 is irradiated from above for a given time (about 1.5 sec or less) and heated. Thereby, each end of the fuse wire 1 is heated and melted by heat conduction from the heated lead frame 5, and is joined to the land 5 a of the lead frame 5. If the beam intensity of the laser beam is adjusted so that the heating temperature at this time is about 20 ° C. higher than the melting temperature of the fuse wire 1, the lead frame 5 itself does not melt. The reason why each end of the fuse wire 1 is simultaneously joined to the two lands 5a using two laser beams is as follows.
This is for shortening the joining time and improving the productivity.

It is to be noted that, in the lower chamber inside the housing 12,
A control circuit (not shown) for controlling the automatic joining apparatus 11 itself is housed. Further, the loader, the first transfer device, the wire shaping device 15, the laser irradiating device 20, the second transfer device, and the unloader are not directly related to the present invention, and thus detailed descriptions thereof are omitted.

Next, the structure of the wire feeder and the like are shown in FIGS.
It will be described in detail based on. The wire feeder 16 includes a horizontal base 30 that is long in the front-rear direction, and a mounting base 31 installed at the front end of the upper surface of the base 30, and a case 32 is mounted on the mounting base 31. Near the front of the inside of the case 32, a fuse wire supply spool 34 around which the fuse wire 1 is wound, a drive motor 35 for intermittently rotating the spool 34 and feeding out the fuse wire 1; Compressed air 3 is applied to the fuse wire 1 immediately after being fed out.
A nozzle 37 for blowing the fuse wire 6 from above, a rotatable roller 38 for guiding the fuse wire 1, a tension regulating member 40 for regulating the tension of the fuse wire 1 provided between the roller 38 and the spool 34, and a fuse. A sensor 41 for detecting the line 1 and the like are provided.

The nozzle 37 gives a slack as shown in FIG. 2 by blowing the compressed air 36 onto the fuse wire 1 from above, thereby preventing the fuse wire 1 from breaking. That is, the fuse wire 1 has a very small wire diameter of about 46 μm to 120 μm, so that the fuse wire 1 is broken by a slight force. for that reason,
When supplying the fuse wire 1 to the wire shaping device 15,
It is necessary to prevent the portion between the spool 34 and the roller 38 from being tensioned and applying a large tension. In this case, if the slack is given by a mechanical means, an external force will be applied to the fuse wire 1 as a result, and there is a possibility that the fuse wire 1 may be disconnected. However, if the compressed air is used, the fuse wire 1 may be loosened without contact. Because it is possible, there is no disconnection.

The roller 38 is disposed close to the inside of a wire outlet 42 provided at the lower part of the back plate constituting the case 32.

The tension regulating member 40 has a groove 40a into which the fuse wire 1 is inserted by branching the lower end into a forked shape. (Vertical direction) and upward movement.

The sensor 41 is preferably a proximity sensor using a magnetic field such as a high-frequency oscillation type or a differential coil, and is disposed between the roller 38 and the tension regulating member 40. The fuse wire 1 immediately after being unwound from the spool 34 is held in a relaxed state as shown by a solid line in FIG. In this state, the sensor 41 cannot detect the fuse wire 1, and when the fuse wire 1 is supplied to the wire shaping device 15 by a predetermined amount (length), the fuse wire 1 ′ between the spool 34 and the roller 38 becomes As shown by a two-dot chain line, the sensor 41 is detected by the sensor 41 because the user enters a region where the sensor 41 can be detected by tension. When the sensor 41 detects the fuse wire 1, the drive motor 35 is driven by a drive signal from the control unit based on the detection signal, whereby the spool 34 is intermittently rotated,
The fuse wire 1 is extended by a predetermined amount.

At the rear end of the upper surface of the base 30, a fuse wire 1 fed from a wire outlet 42 of the case 34 is provided.
Clamps 50A, 50B for holding the fuse wire 1 substantially horizontally at a predetermined interval, and two pneumatic tension applying means 51A, 51B provided before and after these clamps, respectively, for applying tension to the fuse wire 1. I have.

The two clamps 50A and 50B are alternately opened and closed by a solenoid 52, and at the same time, one of the clamps 50A and 50B is reciprocated to grip the fuse wire 1 and intermittently feed the fuse wire 1 by a predetermined amount. In this case, of the two clamps 50A and 50B, for example, the clamp 50A located forward is fixed on the base 30. On the other hand, the clamp 50B located rearward is provided on the guide rail 53 so as to be movable in the front-rear direction. 1 is sent to the wire shaping device 15. At this time, the front clamp 50A is held in the open state and does not hold the fuse wire 1. When a predetermined amount of the fuse wire 1 is supplied, the clamp 50B is opened to release the gripping state of the fuse wire 1, and the clamp 50B is retracted by the reverse rotation of the drive motor 54 and moved back to the original position. At this time, the clamp 50A on the front side is closed to hold the fuse wire 1. Thus, the clamps 50A, 50
B alternately opens and closes, and the clamp 50B reciprocates, so that the fuse wire 1 can be intermittently supplied to the wire shaping device 15 by a fixed amount. In the present embodiment, the front clamp 50A is fixed and the rear clamp 50B is provided so as to be reciprocable. On the contrary, the front clamp 50A is provided so as to be reciprocable and the rear clamp 50B is fixed. You may.

The pneumatic tension applying means 51A, 5
1B, as shown in FIG. 4, a block-shaped main body 60 having a wire through hole 61 through which the fuse wire 1 penetrates and a communication hole 62 communicating with the wire through hole 61 at the center in the longitudinal direction. 62 is connected to a supply source 63 of compressed air via a pipe 64. The main body 60
Is provided with switching means 65 for switching the injection direction of the compressed air supplied to the wire rod through-hole 61 through the communication hole 62.

In this case, two tension applying means 51
A and 51B respectively inject the compressed air in the opposite direction to the clamps 50A and 50B, thereby forming the wire 1
Is given a predetermined tension. That is, the tension applying means 51A disposed in the front injects the compressed air supplied to the wire through hole 61 in the direction of the spool 34, and the tension applying means 51B disposed in the rear applies the fuse wire 1 to the wire shaping device. In this case, two tension applying means 51A and 51 are provided.
A predetermined tension is applied to the fuse line 1 between B. When the tension is applied in this manner, the fuse wire 1 is not loosened, so that when the clamps 50A and 50B are alternately opened and closed to grip the fuse wire 1, the fuse wire 1 can be satisfactorily gripped. 15 can be reliably supplied.

According to such an automatic joining apparatus 11, since the fuse wire 1 and the lead frame 5 can be automatically supplied to the joining station S, the joining of the fuse wire 1 can be automated and the productivity can be improved. Can be improved. Further, the wire feeder 16 can intermittently feed the fuse wire 1 from the spool 34 in a continuous manner by a predetermined amount, so that the wire feeder 16 is suitable for the wire feed of the automatic joining device 11. Further, since only the pair of clamps 50A and 50B are in direct contact with the fuse wire 1, the fuse wire 1 can be supplied satisfactorily regardless of the wire diameter, and the tension is applied to the fuse wire 1 by mechanical means. Since no wire is added, the wire diameter does not decrease, and the rated capacity does not fluctuate or break.

In the above-described embodiment, an example in which the fuse wire 1 is used as a wire material has been described. However, the present invention is not limited to this, and even if a solder-plated copper wire or the like is used. Good. The wire may be a ribbon.

[0027]

As described above, in the wire feeder according to the present invention, since the wire fed from the spool is blown with compressed air to be loosened, the mechanical tension is not applied to the wire and the wire diameter is reduced. Can be prevented, disconnection, and the like can be prevented. In addition, since the wire is intermittently fed out by a predetermined length in a continuous state from the spool, it is suitable for use in an automatic fuse joining device or the like.
In addition, since the portion directly in contact with the wire is only a pair of clamps that are alternately opened and closed and gripped, the wire can be supplied regardless of the wire diameter. In addition, since the tension is applied by the pneumatic tension applying means, gripping by the clamp is also reliable.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an embodiment of an automatic fuse joining apparatus provided with a wire feeder according to the present invention.

FIG. 2 is a side view showing a part of the wire feeder in a cutaway manner.

FIG. 3 is a plan view of the wire feeder.

FIG. 4 is a sectional view of a pneumatic tension applying means.

FIG. 5 is a schematic configuration diagram of a conventional fuse.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Fuse wire, 5 ... Lead frame, 5a ... Land part, 11 ... Automatic joining device, 12 ... Housing, 15 ... Wire shaping device, 16 ... Wire feeding device, 20 ... Laser irradiation device, 3
4 ... Spool, 35 ... Drive motor, 37 ... Nozzle, 41
... Sensor, 50A, 50B ... Clamp, 51A, 51
B: pneumatic tension applying means, 61: wire through hole, 6
2. Communication hole.

Claims (1)

(57) [Claims] A spool for winding a wire; a sensor for detecting a wire fed from the spool; a driving device for intermittently rotating the spool when the sensor detects the wire to feed the wire by a predetermined amount; A pair of clamps for holding the wire fed from the spool at a predetermined interval, a wire through hole through which the wire passes, and a communication hole communicating with the wire through hole, before and after the pair of clamps A pair of pneumatic tension applying means for respectively ejecting compressed air from the wire through-hole in a direction opposite to the clamp, wherein the pair of clamps alternately open and close to grip the wire and A wire feeder characterized in that one clamp is reciprocally movable and moves a predetermined amount in a wire feed direction while holding the wire.