JPH07122579A - Intermittent conveying device for hoop-shaped - Google Patents

Abstract

PURPOSE:To simplify the structure and to simplify the setting of tension when a hooped-shaped lead frame is intermittently conveyed at the appropriate pitch interval in the longitudinal direction with a pulse motor under the tightened state, wherein the tension is applied on the part having the appropriate length in the lead frame. CONSTITUTION:A pair of feed gears 16 and 25 are intermeshed with a lead frame A, A pulse motor 11 is linked to a rotary shaft 10 in one feed gear 16 at the front side. A rotation transfer mechanism 15 is arranged between the pulse motor 11 or the rotary shaft 10 and a rotary shaft 12 of the other feed gear 25. The mechanism 15 rotates the rotary shaft 12 of the other feed gear 25 with the pulse motor 11 in the conveying direction of the lead frame A. The other feed gear 12 is rotatably coupled with the rotary shaft 12. Furthermore, a spring means is provided between the other feed gear 25 and the rotary shaft 12 so that the other feed gear 25 is energized in the reverse direction with respect to the conveying direction of the lead frame A for the rotary shaft 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention tensions a hoop-shaped lead frame used for manufacturing semiconductor parts such as transistors or diodes by applying a predetermined tension to a portion of the lead frame having an appropriate length. In this state, the present invention relates to a device for intermittently transferring in the longitudinal direction at appropriate pitch intervals.

[0002]

2. Description of the Related Art Generally, when a semiconductor part such as a transistor or a diode is manufactured using a hoop-shaped lead frame, a predetermined tension is applied to a portion of the lead frame having a proper length so as to be in a tense state. Then, the tensioned portion is intermittently transferred at appropriate intervals, and various processing steps such as die bonding of a semiconductor chip, wire bonding with a metal wire, and molding of a package mold portion are performed on the tensioned portion.

Conventionally, as described above, the lead frame is tensioned by applying a predetermined tension to a portion of the lead frame having an appropriate length.
When intermittently transferring in the longitudinal direction at an appropriate pitch, as shown in FIG. 5, the two feed gears 1 and 2 are inserted into the feed holes of the hoop-shaped lead frame A.
Of the two feed gears 1 and 2, which are meshed with each other at an appropriate distance L in the longitudinal direction of the lead frame A, one feed gear 1 located forward of the lead frame A in the transfer direction is pulsed. By intermittently rotating the motor 3 at an appropriate pitch, the lead frame A
While intermittently transferring in the longitudinal direction at an appropriate pitch,
The other feed gear 2 is rotated in a direction opposite to the transfer direction of the lead frame A by the torque motor 4 which rotates the other feed gear 2 only with a torque equal to or lower than a certain value and does not transmit the rotation with a torque higher than the constant torque. By rotating in the direction, a predetermined tension is applied to the portion of the lead frame A at the appropriate distance L.

[0004]

However, since this conventional intermittent transfer device uses two motors, that is, a pulse motor and a torque motor, not only the price of the intermittent transfer device is greatly increased, but also both motors are used. Since the tension is applied to the lead frame by the method, there is a problem that it is extremely difficult to adjust the tension.

Further, when a load (external force) acts on the lead frame A during the transfer so as to hinder the transfer, the lead frame A may be damaged by one of the feed gears 1. . On the other hand, conventionally, as shown in FIG. 6, the one feed gear 1 is used.
Is rotatably fitted to a boss body 8 fitted to a rotary shaft 7 connected to the pulse motor 1 with the feed gear 1 sandwiched between two friction plates 5 and 6, and then the boss body A coil spring 9 fitted in 8 is pressed in the axial direction so that the rotation of the rotary shaft 7 is transmitted to one of the feed gears 1 by a transmission torque only by the frictional force of the friction plates 5, 6. As a result, when a load (external force) that hinders the transfer is applied to the lead frame A during transfer, the one feed gear 1 idles with respect to the rotating shaft 7 to prevent damage to the lead frame A. I try to avoid it.

However, since the frictional force generated by the friction plates 5 and 6 changes due to the intrusion of dust and water in the atmosphere, the intrusion of oil, etc., the transmission torque cannot be obtained in a stable state. Moreover, when one of the feed gears 1 idles due to the load on the transfer of the lead frame A, the phase between the teeth of the one feed gear 1 and the pulse motor 3 shifts. However, there is a problem that the phase shift must be corrected when starting the process, which requires a great deal of trouble.

A first technical object of the present invention is to provide an intermittent transfer device which solves the former problem described above, and an intermittent transfer device which solves the former problem and the latter problem described above. This is a second technical problem.

[0008]

In order to achieve the first technical object, "Claim 1" in the present invention states that "two feed gears that mesh with feed holes and the like in a hoop-shaped lead frame are provided. , The lead frame is arranged at a portion spaced apart along the longitudinal direction of the lead frame, and the rotary shaft of one of the feed gears located forward of the lead frame in the transfer direction is rotated by the rotary shaft. In an intermittent transfer device in which a shaft is connected to a pulse motor that intermittently rotates in the transfer direction of the lead frame, between the pulse motor or the rotary shaft connected to the pulse motor and the rotary shaft in the other feed gear. In, a rotation transmission mechanism in which the rotation shaft of the other feed gear is rotated in the transfer direction of the lead frame by a pulse motor is arranged, and the other feed gear is The lead frame is rotatably fitted to the rotary shaft of the other feed gear, and the other feed gear is transferred between the other feed gear and the rotary shaft of the lead frame with respect to the rotary shaft. A spring means for urging in the opposite direction is provided. "

In order to achieve the second technical object, "Claim 2" of the present invention is that "two feed gears meshing with feed holes and the like in a hoop-shaped lead frame are provided in the lead frame. Of the two feed gears, which are located at an appropriate distance from each other in the longitudinal direction of the lead frame, are attached to the rotary shaft of one of the feed gears located forward of the lead frame transfer direction. In an intermittent transfer device formed by connecting a pulse motor that intermittently rotates in a frame transfer direction, the pulse motor or the rotary shaft connected to the pulse motor and the rotary shaft of the other feed gear are connected to each other. A rotation transmission mechanism is provided in which the rotation shaft of the feed gear is rotated by a pulse motor in the transfer direction of the lead frame. It is rotatably fitted to the rotary shaft of the spiral gear, and the other feed gear is installed between the other feed gear and its rotary shaft in the direction opposite to the lead frame transfer direction with respect to the rotary shaft. While the spring means for biasing in the direction is provided, the one feed gear is rotatably fitted to its rotation shaft, and the one feed gear is connected to the one feed gear of the lead frame. A stopper is provided so as to abut on the abutment portion provided on the rotary shaft when the feed gear rotates, and one feed gear is provided between the one feed gear and the rotary shaft. Spring means is provided for urging the stopper so as to always contact the contact portion of the rotating shaft, while the feed detecting means is provided for the hoop-shaped lead frame. With pulse motor And to the configuration referred to as feed in defect detection signal related to stop the pulse motor. "In the feed detecting means.

[0010]

[Working] According to the structure described in "Claim 1", the portion of the hoop-shaped lead frame between the feed gears is provided between the other feed gear of the feed gears and its rotary shaft. The elastic force of the provided spring means applies tension to maintain the tensioned state.

In this state, one feed gear is intermittently rotated by the pulse motor, and at the same time, this intermittent rotation is transmitted to the rotary shaft of the other feed gear via the rotation transmission mechanism. Therefore, the hoop-shaped lead frame can be intermittently transferred at an appropriate pitch interval by the pulse motor in a state where the portion between the feed gears of the lead frame is tensioned.

Further, when it is configured as in "Claim 2",
One of the feed gears is rotated by a pulse motor by a spring means so that the stopper of the one feed gear is constantly urged to abut against the abutment portion of the rotary shaft. Is transmitted to the one feed gear via the spring means. In other words, the one feed gear follows the rotation of the rotary shaft by the pulse motor and is rotated by the elastic force of the spring means. Therefore, when a load larger than the elastic force in the spring means acts on the transfer of the hoop-shaped lead frame in a direction that hinders the transfer of the lead frame, the torque transmitted from the rotary shaft to one of the feed gears is In the state of being stored in the spring means, the rotation of the one feed gear is stopped and only the rotating shaft advances and rotates, so that a force exceeding the elastic force of the spring means acts on the lead frame. On the other hand, when the feed of the lead frame is stopped by stopping the rotation of the one feed gear, the pulse motor is stopped by the feed failure detection signal in the feed detecting means. The rotation of the rotary shaft is stopped.

When the overload acting on the hoop-shaped lead frame is released, the stopper of the one feed gear is stopped by the elastic force stored in the spring means of the one feed gear. It automatically returns to the original phase position where it abuts against the abutment portion on the rotary shaft.

[0014]

As described above, according to the present invention, one pulse motor is used to intermittently transfer the hoop-shaped lead frame at an appropriate pitch while keeping a portion of the lead frame having an appropriate length in a tensioned state. Can be done by
Since the conventional torque motor is not required, the cost of the transfer device can be greatly reduced, and moreover, tension is applied to the lead frame by the spring means provided for the other feed gear of both feed gears. Therefore, there is an effect that the tension can be arbitrarily set by the spring means and can be easily adjusted.

According to the second aspect, in addition to the above effects, the transmission torque from the pulse motor to one of the feed gears is transferred to the one of the feed gears by the spring means provided for the one feed gear. Since it is possible to set a stable value without being affected by dust and humidity, it is possible to reliably prevent damage to the lead frame due to overload on the transfer of the lead frame, and release the overload on the lead frame. Then, since the one feed gear is automatically returned to the original phase position by the spring means, it is not necessary to correct the phase shift between the pulse motor and the one feed gear. Have.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to the drawings of FIGS. In the figure, reference numeral 10 indicates a rotary shaft arranged in a direction perpendicular to the longitudinal direction of the hoop-shaped lead frame A. The rotary shaft 10 is rotatable by a bearing (not shown) with respect to a machine base (not shown). And a pulse motor 11 for intermittently rotating the rotary shaft 10 in the direction of arrow B at an appropriate pitch at one end thereof.
Are connected.

Further, reference numeral 12 denotes a rotary shaft which is arranged at a portion appropriately separated from the rotary shaft 10 by a distance L in the direction opposite to the transfer direction of the lead frame A.
It is rotatably supported by a bearing 12a with respect to a machine base (not shown). The power transmission wheel 13 on one of the rotary shafts 10 and 12 and the rotary shaft 1 on the other side.
By winding an endless belt 15 for rotation transmission such as a toothed belt or a chain between the power transmission wheel 14 on the upper and the lower shaft 2, the rotary shafts 10 and 12 are connected to the lead frame by the intermittent rotation of the pulse motor 11. It is configured to rotate intermittently at an appropriate pitch in the transfer direction C of A.

A feed gear 16 that meshes with the feed hole A1 in the hoop-shaped lead frame A is attached to one of the rotary shafts 10 and 12, and the feed gear 16 is provided on both left and right flange plates 17. , 18 is rotatably fitted to the outer circumference of a boss body 19 fitted to the rotary shaft 10 by a pair of ball bearings 20, and a ring body is attached to one end of the boss body 19. 21 is fitted, and a contact pin 22 which is one embodiment as a contact portion in the present invention is attached to the outer peripheral surface of the ring body 21.
Is planted so that the contact pin 22 projects outward in the radial direction, while the feed plate 16 is sandwiched between the flange plates 17 and 18, the side face of one of the flange plates 17 is sandwiched with the feed plate. When the gear 16 rotates with respect to the rotating shaft 10 in the same direction as the feed direction C of the lead frame A, the stopper pin 23 that comes into contact with the contact pin 22 is provided in the axial direction of the rotating shaft 10. Plant so that it projects.

Further, the boss 19 and the feed gear 16
Between the torsion spring 24 and the torsion spring 24, which is one embodiment of the spring means in the present invention.
One end 24a of the No. 4 is provided to the boss body 19 and the other end 24b is provided to be engaged with the other flange plate 18 sandwiching the feed gear 16, respectively.
Is urged so that the stopper pin 23 of the feed gear 16 always contacts the contact pin 22 of the boss body 19.

On the other hand, a feed gear 25 that meshes with the feed hole A1 in the hoop-shaped lead frame A is attached to the other rotary shaft 12 of the rotary shafts 10 and 12, and the feed gear 25 is provided on both left and right flange plates 26. , 27, the outer circumference of the boss body 28 fitted to the rotary shaft 12 is rotatably fitted by a pair of ball bearings 29, and a ring body is attached to one end of the boss body 28. 30 is fitted, and a contact pin 31 is attached to the outer peripheral surface of the ring body 30.
While the contact pin 31 is planted so as to project outward in the radial direction, the feed gear 25 is provided on the side surface of one of the flange plates 26, 27 for sandwiching the feed gear 25. When the rotating shaft 12 rotates in the same direction as the feed direction C of the lead frame A, a stopper pin 32 that abuts against the abutting pin 31 projects in the axial direction of the rotating shaft 12. To plant.

Further, the boss body 28 and the feed gear 25
Between the torsion spring 33 and the torsion spring 33, which is one embodiment of the spring means in the present invention.
One end 33a of the No. 3 is provided on the boss body 28, and the other end 33b is provided on the other flange plate 27 sandwiching the feed gear 25, respectively.
Is urged to rotate in the direction opposite to the feed direction C of the lead frame A. At this time, if the feed gear 25 is not meshed with the lead frame A, the feed gear 25
The stopper pin 32 in is contacted with the contact pin 31 in the boss body 28. The spring constant of the torsion spring 33 for the other feed gear 25 is set to be smaller than the spring constant of the torsion spring 24 for the one feed gear 16.

A feed detection sensor 34 for detecting the intermittent feed of the lead frame A is provided above the hoop-shaped lead frame A, and a detection signal from the feed detection sensor 34 is sent to the control circuit 35. By inputting the output from the control circuit 35 to the pulse motor 11, the pulse motor 11 is stopped by the feed failure detection signal from the feed detection sensor 34.

In this structure, when the hoop-shaped lead frame A is meshed with both feed gears 16 and 15,
By rotating the other feed gear 25 of the two feed gears 16 and 25 in the opposite direction against the torsion spring 33 thereof, the stopper pin 32 is moved from the contact pin 31 to an appropriate dimension S.
And the lead frame A is meshed with the other feed gear 25 in this state,
A tension is applied to the lead frame A by the elastic force of the torsion spring 33 that melts in the other feed gear 25.

When the pulse motor 11 is started, the rotation of the rotary shaft 10 connected to the pulse motor 11 is transmitted to the one feed gear 16 via the torsion spring 24, so that the one feed motor 16 is rotated. Gear 16 is arrow B
This intermittent rotation is transmitted to the rotary shaft 12 of the other feed gear 25 through the endless belt 15 for rotation transmission at the same time as the rotation of the hoop-shaped lead frame A. With the portion of the frame A between the feed gears 16 and 25 being strained, the pulse motor 1
By means of 1, it is possible to intermittently transfer at an appropriate pitch interval.

During the intermittent transfer, an external force acts on the lead frame A so as to hinder the transfer, and this external force is larger than the elastic force of the torsion spring 24 of the one feed gear 16. At this time, the rotation of the one feed gear 16 is stopped, and only the rotation shaft 10 of the feed gear 16 is advanced and rotated while deforming the torsion spring 24 against the elasticity thereof. Therefore, it is possible to prevent a force exceeding the elastic force of the torsion spring 24 from acting, and on the other hand, when the rotation of the one feed gear 16 is stopped, the feed of the lead frame A is stopped. , Feed detection sensor 3
The rotation of the rotary shaft 10 is stopped when the pulse motor 11 is stopped by the feed failure detection signal in 4.

When the external force acting on the hoop-shaped lead frame A to hinder the transfer thereof is released, the one feed gear 16 is rotated by the torsion spring 24.
The stopper pin 23 of the feed gear 16 is automatically returned to the original phase position in which the stopper pin 23 of the feed gear 16 contacts the contact pin 22 of the rotary shaft 10 by the elastic force stored in.

The rotation of the other feed gear 25 may be directly transmitted from the pulse motor 11, and the rotation of the other feed gear 25 may be transmitted to the rotation shaft 12. The endless belt 15 for rotation transmission, such as a toothed belt or a chain, is provided as in the above embodiment.
It goes without saying that other rotation transmission mechanism such as a gear train may be used instead of the above.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment of the present invention.

FIG. 2 is a side view taken along line II-II of FIG.

FIG. 3 is an enlarged sectional view taken along line III-III in FIG.

FIG. 4 is an enlarged sectional view taken along line IV-IV of FIG.

FIG. 5 is a perspective view showing a conventional device.

6 is a sectional view taken along line VI-VI of FIG.

[Explanation of symbols]

 A Lead frame A1 Feed hole 10 One rotation shaft 11 Pulse motor 12 Other rotation shaft 16 One feed gear 19 Boss body 22 Boss body 22 Contact pin 23 Stopper pin 24 Torsion spring 15 Endless band for rotation transmission 25 Other feed gear 28 Boss body 33 Torsion spring 34 Feed detection sensor 35 Control circuit

Claims (2)

[Claims] 1. Two feed gears, which mesh with feed holes or the like in a hoop-shaped lead frame, are arranged at positions that are appropriately spaced along the longitudinal direction of the lead frame,
Of these two feed gears, a rotary shaft of one feed gear located forward of the lead frame transfer direction is connected to a pulse motor that intermittently rotates the rotary shaft in the lead frame transfer direction. In the intermittent transfer device, between the pulse motor or the rotary shaft connected thereto and the rotary shaft of the other feed gear, the rotary shaft of the other feed gear is rotated in the lead frame transfer direction by the pulse motor. The rotation transmission mechanism is arranged so that the other feed gear is rotatably fitted to the rotation shaft of the other feed gear, and the other feed gear and its rotation shaft are A hoop shape characterized in that a spring means for urging the other feed gear in the opposite direction to the rotation axis of the feed gear is provided in the meantime. Intermittent transfer device over lead frame. 2. Two feed gears, which mesh with feed holes or the like in a hoop-shaped lead frame, are arranged at positions that are appropriately spaced along the longitudinal direction of the lead frame,
Of these two feed gears, a rotary shaft of one feed gear located forward of the lead frame transfer direction is connected to a pulse motor that intermittently rotates the rotary shaft in the lead frame transfer direction. In the intermittent transfer device, between the pulse motor or the rotary shaft connected thereto and the rotary shaft of the other feed gear, the rotary shaft of the other feed gear is rotated in the lead frame transfer direction by the pulse motor. The rotation transmission mechanism is arranged so that the other feed gear is rotatably fitted to the rotation shaft of the other feed gear, and the other feed gear and its rotation shaft are A spring means for urging the other feed gear in the opposite direction to the rotation direction of the lead frame is provided between the one feed gear and the other feed gear. , The rotary shaft is rotatably fitted to the one feed gear, and when the one feed gear rotates in the transfer direction of the lead frame, the one feed gear contacts the contact portion provided on the rotary shaft. A stopper is provided so as to hit, and one feed gear is urged between this one feed gear and its rotary shaft in the direction in which the stopper always contacts the contact part on the rotary shaft. While the spring means is provided, the feed detection means is provided for the hoop-shaped lead frame, and the feed detection means and the pulse motor are stopped by the feed failure detection signal from the feed detection means. An intermittent transfer device for a hoop-shaped lead frame, characterized in that