JP3276738B2 - Intermittent transfer device for hoop-shaped lead frame - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for intermittently transferring a hoop-shaped lead frame used in the manufacture of a semiconductor component such as a transistor or a diode at an appropriate pitch in the longitudinal direction of the lead frame. It is.

[0002]

2. Description of the Related Art To intermittently transfer a hoop-shaped lead frame at an appropriate pitch in its longitudinal direction, FIG.
As shown in FIG. 5, a feed gear 2 fixed on a rotary shaft 1 meshes with a feed hole formed in the lead frame A in a line at a constant pitch along the longitudinal direction thereof. In general, the feed gear 2 is rotated by a pulse motor 3 connected to the rotating shaft 1 at an appropriate pitch interval.
When a load that stops the transfer is applied to the lead frame A due to, for example, being caught halfway during the transfer of the lead frame A, the feed gear 2
As a result, the lead frame A may be damaged.

Therefore, in a conventional transfer device, as shown in FIG. 5, the feed gear 2 is sandwiched between two friction plates 4 and 5, and the rotary shaft 1 is rotated.
After being rotatably fitted to the boss body 6 fitted to the boss body, it is pressed in the axial direction by the coil spring 7 fitted to the boss body 4,
By transmitting the rotation of the rotary shaft 1 to the feed gear 2 with a transmission torque only by the frictional force of the friction plates 4 and 5, a load (an external force) that impedes the transfer to the lead frame A during transfer. ) Acts, the feed gear 2 idles with respect to the rotating shaft 1 to avoid breakage of the lead frame A.

[0004]

Since the lead frame is very thin and very easily deformed, the torque transmitted from the pulse motor 3 to the feed gear 2 is several kgf / kg. However, setting the transmission torque due to the friction between the friction plates 4 and 5 to a small value of several kgf / cm or less as described above requires fine adjustment. Not only is it extremely difficult, but the frictional force of the two friction plates 4 and 5 changes due to the intrusion of dust and moisture in the atmosphere, the intrusion of oil, and the like, so that the above-described transmission torque can be obtained in a stable state. I could not do it.

[0005] In addition, in the above-described configuration using friction, the feed gear 2 is moved by the load applied to the transfer of the lead frame A.
When the motor idles, the phase between the teeth of the feed gear 2 and the pulse motor 3 is shifted, so that when the transfer of the lead frame A is started next, the phase shift must be corrected. Required a lot of trouble.

In addition, in the conventional apparatus, when an overload occurs in the transfer of the lead frame A, the rotation of the feed gear 2 is stopped, but the pulse motor 3 is kept rotating and the friction plates 4 and 4 are not rotated. 5 causes wear, so that not only the transmission torque fluctuates, but also its durability is low. It is a technical object of the present invention to provide an intermittent transfer device that solves these problems.

[0007]

In order to achieve this technical object, the present invention provides a feed gear meshing with a feed hole or the like in a hoop-shaped lead frame, a rotary shaft on which the feed gear is mounted, and a rotary shaft. A pulse motor that intermittently rotates a rotary shaft in a direction of transport of the hoop-shaped lead frame, wherein the feed gear is rotatably fitted to the rotary shaft, and the feed gear is When the feed gear rotates in the transfer direction of the lead frame, a stopper is provided so as to abut against a contact portion provided on the rotating shaft, and further, a stopper is provided between the feed gear and the rotating shaft. A spring means for urging the feed gear in such a direction that its stopper always contacts a contact portion of the rotary shaft, and a feed detecting means for the hoop-shaped lead frame. The this feed detecting means and the pulse motor, and the associated. "Say configured to stop the pulse motor by feeding failure detection signal in the feed detecting means.

[0008]

In this configuration, the feed gear rotatably fitted to the rotary shaft is urged by spring means so that the stopper of the feed gear always contacts the contact portion of the rotary shaft. Accordingly, the rotation of the rotating shaft rotated by the pulse motor is transmitted to the feed gear via the spring means.

In other words, the feed gear is rotated by the elastic force of the spring means following the rotation of the rotary shaft by the pulse motor. For this,
When a load larger than the elastic force of 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 transmission torque from the rotating shaft to the feed gear is stored in the spring means. In this state, the rotation of the feed gear is stopped, and only the rotating shaft is advanced and rotated, so that a force exceeding the elastic force of the spring means can be prevented from acting on the lead frame. On the other hand, when the feed of the lead frame is stopped by stopping the rotation of the feed gear, the rotation of the rotary shaft is stopped by stopping the pulse motor by the feed failure detection signal from the feed detecting means. .

When the overload acting on the hoop-shaped lead frame is released, the stopper of the feed gear is brought into contact with the rotary shaft by the elastic force stored in the spring means. It automatically returns to the original phase position where it comes into contact with this part.

[0011]

As described above, according to the present invention, the transmission of the rotation from the rotating shaft to the feed gear is obtained by the spring means, and the transmission torque by the spring means is set to a small value by the spring constant of the spring means. Not only is not affected by dust and humidity in the atmosphere, but also is not affected by oil, and obtains a predetermined transmission torque corresponding to the lead frame in a stable state. Therefore, it is possible to reliably prevent the lead frame from being damaged due to an overload for transferring the lead frame.

Further, according to the present invention, the pulse motor is automatically stopped in response to the stop of the transfer of the lead frame due to the overload of the transfer. Deformation can be avoided, and unlike the related art, there is no reduction in durability that occurs when the pulse motor continues to rotate.

[0013] In addition, according to the present invention, when the overload on the lead frame is released, the feed gear is automatically returned to the original phase position by the spring means. In addition, there is an effect that it is not necessary to correct a phase shift between the pulse motor and the feed gear.

[0014]

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

Reference numeral 12 denotes a feed gear meshed with the feed hole A1 in the hoop-shaped lead frame A, and the feed gear 12 is sandwiched between the flange plates 13 and 14 on the left and right sides. The rotation shaft 10
The pair of ball bearings 16 are rotatably fitted on the outer periphery of the boss body 15 fitted to the boss body 15. A ring member 17 is attached to one end of the boss member 15 fitted on the rotating shaft 10.
On the outer peripheral surface of the ring body 17, a contact pin 18, which is one embodiment as a contact portion in the present invention, is fitted so that the contact pin 18 is directed outward in the radial direction. One of the flange plates 13 and 14 that sandwiches the feed gear 12 while being implanted so as to protrude.
A stopper pin 19 is provided on the side of the stopper pin 3 so as to contact the contact pin 18 when the feed gear 12 rotates in the same direction as the feed direction C of the lead frame A with respect to the rotating shaft 10. , So as to protrude in the axial direction of the rotating shaft 10.

Further, the boss body 15 and the feed gear 12
Between the torsion spring 20 and the torsion spring 2 which is one embodiment of the spring means in the present invention.
0 is fixed to the boss body 15 and the other end 20b is fixed to the other flange plate 14 sandwiching the feed gear 12, respectively.
Is urged so that the stopper pin 19 of the feed gear 12 is always in contact with the contact pin 18 of the boss 13.

Further, the hoop-shaped lead frame A
A feed detection sensor 21 for detecting the intermittent feed of the lead frame A is provided above, and a detection signal from the feed detection sensor 21 is input to the control circuit 22;
By inputting the output from the control circuit 22 to the pulse motor 11, the pulse motor 11 is stopped by a feed failure detection signal from the feed detection sensor 21.

In this configuration, when the rotary shaft 10 is rotated in the direction of arrow B by the pulse motor 11, this rotation is transmitted to the feed gear 12 via the torsion spring 20, so that the feed gear 12 Since it rotates in the direction B, the hoop-shaped lead frame A meshing with the feed gear 12 can be intermittently transferred in the direction of arrow C at appropriate intervals.

During the transfer, an external force acts on the lead frame A so as to hinder the transfer. When the external force is larger than the elastic force of the torsion spring 20, the rotation of the feed gear 12 is reduced. Stop and rotate 10
Only the torsion spring 20 advances while rotating while deforming the torsion spring 20 against its elasticity.
Can prevent the force exceeding the elastic force of the torsion spring 20 from acting on the other hand. On the other hand, when the rotation of the feed gear 12 stops, the feed of the lead frame A stops. The rotation of the rotary shaft 10 is stopped by stopping the pulse motor 11 in response to the feed failure detection signal from the feed detection sensor 21.

When the external force acting on the hoop-shaped lead frame so as to hinder its transfer is released, the feed gear 12 is moved by the elastic force stored in the torsion spring 20. The stopper pin 19 of the feed gear 12 automatically returns to the original phase position where the stopper pin 19 contacts the contact pin 18 of the rotary shaft 10.

[Brief description of the drawings]

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

FIG. 2 is an enlarged sectional view taken along line II-II of FIG.

FIG. 3 is a left side view of FIG. 2;

FIG. 4 is a front view showing a conventional device.

FIG. 5 is a sectional view taken along line VV of FIG. 4;

[Explanation of symbols]

 A Lead frame A1 Feed hole 10 Rotary shaft 11 Pulse motor 12 Feed gear 13 Boss body 18 Contact pin 19 Stopper pin 20 Torsion spring 21 Feed detection sensor 22 Control circuit

Claims (1)

(57) [Claims] 1. A feed gear meshing with a feed hole or the like in a hoop-shaped lead frame, a rotating shaft to which the feed gear is attached, and intermittently rotating the rotating shaft in a direction of transport of the hoop-shaped lead frame. In the intermittent transfer device including a pulse motor, the feed gear is rotatably fitted to the rotary shaft, and the feed gear rotates on the feed gear when the feed gear rotates in the transfer direction of the lead frame. A stopper is provided so as to contact a contact portion provided on the shaft, and further, between the feed gear and the rotating shaft,
A spring means is provided for urging the feed gear in a direction in which the stopper always comes into contact with a contact portion of the rotary shaft, and a feed detecting means is provided for the hoop-shaped lead frame, and the feed detecting means is provided. Means for intermittently moving the hoop-shaped lead frame, wherein the means and the pulse motor are stopped so that the pulse motor is stopped by a feed failure detection signal from the feed detection means.