JPH09199516A - Conveyer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conveyer which can convey magnetic works at a high speed with a low vibration and a low noise and, further, facilitates the highly accurate positioning. SOLUTION: A conveyer has a nonmagnetic rail 1 having a guide surface 2 which guides the first surface of a work W so as to slide freely and a conveying belt 22 which has a conveying surface 22a brought into contact with the second surface of the work W and which moves freely along the rail 1. The belt 22 is driven to circulate by a driving means 12. A magnet 5 is provided so as to face the rail 1 with the belt 22 therebetween. The magnetic force of the magnet 5 has a force component which attracts the second surface of the work W tightly to the belt 22 and a force component which attracts the first surface of the work W to the rail 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transfer device, and more particularly to a transfer device suitable for transferring a magnetic work such as a lead frame.

[0002]

2. Description of the Related Art Conventionally, when a hoop material such as a lead frame is transported in a manufacturing process, it is not cut into a certain length,
It is customary to convey in a continuous state. The conventional transporting device has a reciprocating feed claw, and when feeding the hoop material, the feed claw is hooked in the hole of the hoop material and moved, and when the feed claw returns, the feed claw disengages from the hole of the hoop material and the hoop is moved. The material is kept in a stopped state. At this time, in order to prevent the hoop material from moving backward, an air cylinder, a one-way clutch or the like is used to press the hoop material. In order to obtain the stop position accuracy of the hoop material, it is necessary to suppress the bending and the vibration, and the hoop material is always given a tension by combining a brake sprocket and a tension roller.

[0003]

However, in the conventional conveying apparatus, as the distance from the feeding standard (feeding claw) of the hoop material is increased, the accumulative pitch dimension accuracy of the hoop material and the elongation of the hoop material due to heat cause a stop position. There was a drawback that the accuracy was likely to be adversely affected. Also, due to the reciprocating motion of the feed claw by the cam, the return operation time affects the takt time,
In addition, the higher the speed, the more severe the vibration and noise. Further, a device for preventing the hoop member from moving backward and a device for applying a tension are required, which has a drawback that the device becomes large.

By the way, as described in Japanese Utility Model Publication No. 7-35388, the lead frame is guided along the upper surface of the non-magnetic guide rail, and a non-magnetic guide member is provided on one side edge of the upper surface of the guide rail. A transfer guide device has been proposed in which magnets are provided and magnets are embedded inside the guide member at appropriate intervals. In this case, since the side edge of the lead frame is attracted by the magnetic force and comes into contact with the guide member, it is excellent in positional accuracy and is a device for preventing backward movement of the hoop material, a device for applying tension, etc. There is an advantage that is unnecessary.

However, also in this case, it is necessary to use a transfer means such as a feed claw for transferring the lead frame, and it is difficult to carry out high speed transfer with low vibration and low noise. Further, since the lead frame is in close contact with the guide member, a frictional resistance acts between the lead frame and the guide member, and a large load is partially applied to the lead frame when the transfer means engages with the lead frame and transfers the lead frame. However, the lead frame may be stretched or deformed.

Therefore, an object of the present invention is to provide a transfer device which can transfer a magnetic work at high speed with low vibration and low noise, and can perform high-precision positioning. Another object of the present invention is to provide a transfer device that can transfer a work without applying an excessive load.

[0007]

In order to achieve the above object, the present invention is an apparatus for conveying a magnetic work having two adjacent surfaces, and a guide for slidably guiding the first surface of the work. A non-magnetic rail having a surface, a transport surface that comes into contact with the second surface of the workpiece, and a non-magnetic transport body that is movable along the rail; a drive unit that drives the transport body to rotate; and the transport body. Is arranged at a position facing the rail with the space between them, and a component force for bringing the second surface of the work into close contact with the carrier,
And a magnet that generates a magnetic force having a component force that brings the first surface of the work into contact with the rail.

It is desirable that yokes be attached to both poles of the magnet and that the guide surface of the rail be located near the boundary between one pole of the magnet and the yoke. Further, it is preferable that the carrier is composed of a non-magnetic belt, and the driving means is composed of a pulley around the belt and a motor for driving the pulley. Furthermore, the present invention is suitable for conveying a thin long work such as a magnetic hoop material.

When the carrier is moved along the rail by the driving means, the second surface of the work is brought into close contact with the carrier surface of the carrier by the magnet, so that the work moves integrally with the carrier. At this time, since the first surface of the work is slidably guided by the guide surface of the rail, the work is conveyed while maintaining a stable posture. Since the work moves while being in close contact with the transfer body during transfer, the load is not concentrated on a part of the work. Therefore, the work can be conveyed without applying an unreasonable load, and the work can be prevented from being deformed or bent.

When the carrier is suddenly stopped, the work may be displaced due to inertial force. However, in the present invention, the second surface of the work is magnetically adhered to the carrier, so that the work is suddenly stopped. However, it is possible to stop the work without causing positional displacement. Further, a device for preventing the hoop material from moving backward and a device for applying tension are unnecessary, and the device becomes compact. Since the carrier of the present invention is orbitally driven and does not require a returning operation,
High-speed transportation is possible, and vibration and noise do not become severe even if the speed is increased.

Incidentally, the carrier in the present invention may be a continuous body that revolves, and may be a belt or a turntable having a cylindrical peripheral surface. The transport surface of the transport body does not need to be a smooth surface and may have irregularities. Further, in order that the magnetic force of the magnet penetrates the carrier and efficiently acts on the work, it is desirable that the carrier be made of a thin shape and made of a material having a high magnetic permeability. The two adjacent surfaces of the work do not have to be surfaces perpendicular to each other, and one of the surfaces may be a curved surface. The magnetic force of the magnet has a component force for bringing the second surface of the workpiece into close contact with the carrier and a component force for bringing the first surface of the workpiece into contact with the rail, but in order to minimize sliding friction between the workpiece and the rail, It is desirable to determine the position of the magnet so that the component force for bringing the second surface of the workpiece into close contact with the carrier is larger than the component force for bringing the first surface of the workpiece into contact with the rail.

[0012]

1 to 7 show a first embodiment of the present invention, in which a carrier is a lead frame W as a work.
It is used to transport The lead frame W of this embodiment is cut into a constant length as shown in FIGS. The lead frame W is formed by punching out a thin magnetic metal plate, has a tie bar b having a feed hole a at one side edge in the longitudinal direction, and protrudes in a substantially orthogonal direction from the tie bar b at the other side edge. Multiple terminals c
Are integrally formed.

This carrying device is equipped with a rail 1 which slidably supports the side surface (first surface) of the tie bar b of the lead frame W. The rail 1 is made of a non-magnetic material such as stainless steel, aluminum or resin, and its upper surface (guide surface) 2
To reduce the frictional resistance with the lead frame W,
A fluororesin coating or the like is appropriately applied. The rail 1 is fixed by screws 4 to the front surface of a rail base 3 made of a non-magnetic material as shown in FIG. On the rail base 3, permanent magnets 5 having yokes 6 and 7 made of magnetic materials attached to both N and S poles are arranged, and fixed to the rail base 3 by nonmagnetic magnet holders 8 provided at appropriate intervals. There is. Although the yokes 6 and 7 are long members having substantially the same length as the rail base 3, the permanent magnets 5 need not be long magnets like the yokes 6 and 7, and may be arranged intermittently. The magnet holder 8 is fixed to the rail base 3 with screws 9.

Both ends of the rail base 3 are horizontally supported by support bases 10 and 11 as shown in FIGS. A drive motor 12 such as a servo motor or a pulse motor is fixed to one support base 10. The rotating shaft 13 of the motor 12 is connected to a drive pulley 15 via a coupling 14. The other support 1
1 is a slide table 1 which can be slid horizontally.
6 is provided, and a tension pulley 18, which also functions as a driven pulley, is rotatably attached to the slide table 16 via a support shaft 17. A tension adjusting bolt 20 is screwed into a bracket 19 fixed to the upper portion of the support base 11, and a tension spring 21 is arranged between the bolt 20 and the slide table 16. Therefore, the tension pulley 18 is biased in the opposite direction to the driving pulley 15 by the spring force of the tension spring 21, and the spring force can be adjusted by the bolt 20. Thereby, the tension of the belt 22 described later can be adjusted.

A belt 22 made of a non-magnetic material is wound around the drive pulley 15 and the tension pulley 18 with tension, and is driven to rotate in the horizontal direction. The belt 22 may be a resin belt or a metal belt such as stainless steel. Belt 22
Is formed thin, and the transport surface (feed side) 22 of the belt 22
a is movable in the horizontal direction in the gap between the upper yoke 6 and the rail 1. The back surface of the belt 22 is supported by the side surface of the yoke 6, and the transport surface 22 a of the belt 22 is substantially perpendicular to the guide surface 2 of the rail 1. Transport surface 2
2a has an end surface (second surface) of the tie bar b of the lead frame W
Stick to each other.

Here, the operation of the carrying device will be described. Since the yokes 6 and 7 are arranged at the upper and lower poles of the permanent magnet 5, magnetic lines of force are gathered between the boundaries between the yokes 6 and 7 and the permanent magnet 5 as shown in FIG. Since the guide surface 2 of the rail 1 is located in the vicinity of the boundary between the upper yoke 6 and the permanent magnet 5, the tie bar b of the lead frame W sliding on the guide surface 2 is also arranged at the position where the magnetic force lines are gathered. It will be effectively affected by the magnetic force.

At this time, the attraction force by the magnetic force to the lead frame W can be divided into two component forces X and Y. That is, the component force X is the tie bar b of the lead frame W.
Component Y is a component force for bringing the end surface of the tie bar b into close contact with the belt 22, and component force Y is a component force for bringing the side surface of the tie bar b of the lead frame W into close contact with the rail 1. The component force X is larger than the component force Y.

Due to the magnetic force of the permanent magnet 5 as described above, the end surface of the lead frame W is the conveying surface 22a of the belt 22.
While maintaining close contact with the guide surface 2 of the rail 1, the side surface is kept in contact with the guide surface 2. Here, when the belt 22 is driven, the lead frame W is conveyed integrally with the belt 22 while being in sliding contact with the rail 1. Therefore, even if the belt 22 is moved at high speed, the lead frame W can be prevented from rising, bending, or deforming. Moreover, since the belt 22, which is the carrier, is driven to rotate, it is possible to suppress the generation of vibration and noise like the conventional reciprocating feed claws.

Since the belt 22 and the lead frame W are in close contact with each other over the entire length, the contact state can be secured at a long distance, and there is no fear that a large load locally acts on the lead frame W. Therefore, even if the lead frame W is formed of a thin material, deformation of the lead frame W,
It is possible to effectively prevent warping and bending.

When the belt 22 is stopped, the lead frame W holds the stopped position by the magnetic force of the permanent magnet 5, so that the position of the lead frame W does not change even if the lead frame W is subjected to vibration or shock in this state. High positioning accuracy can be obtained. Therefore, when the carrying device is used in an electronic component assembling process or a characteristic measuring process, the position of the electronic component is not significantly misaligned. Further, since a device for preventing the lead frame W from moving backward and for applying a tension is not required, the device can be downsized and simplified.

In the prior art, it was difficult to cut the hoop material into a constant length to carry it, and the hoop material was carried in a continuous state. However, in the present invention, the hoop material is carried in close contact with the belt 22,
The hoop material can be cut into a certain length and transported. Therefore, the carrier device can be applied to products with many specifications.

The belt 22 can change the feed speed of the lead frame W by controlling the drive of the motor 9, and can perform tact feed and forward / reverse switching in addition to continuous feed. .

Although a single unit has been described in the above embodiment, a plurality of units can be connected in series as shown in FIG. In this case, the transport path becomes long, and the work can be transported between many steps. In this case, by controlling the motor of each unit, the belt of each unit can be operated in synchronization. In this way, adding units according to equipment specifications,
It has the characteristics that it can be deleted easily and the degree of freedom in design is increased.

FIG. 9 shows another example of the work which can be carried by the carrying device of the above embodiment. The work W is, for example, a pallet made of a magnetic material, and has a plurality of recesses d formed on its upper surface, and small parts e such as chip parts can be stored in these recesses d. Also in this case, the pallet W
The lower surface of the pallet W may be slidably supported by the guide surface 2 of the rail 1, and the side surface of the pallet W may be brought into close contact with the belt 22. The inner wall of the recess d may be formed of an elastic body such as silicon rubber so that the chip component e is not damaged by the inner wall of the recess d.

FIG. 10 shows a second embodiment of the carrying device according to the present invention. This carrier uses a non-magnetic turntable 30 having a cylindrical peripheral wall 31 as a carrier. The rotary shaft 32 of the turntable 30 is a motor 33.
Driven by The permanent magnet 3 is provided on the inner peripheral side of the peripheral wall 31.
4 and the upper and lower poles thereof are provided with yokes 35 and 36,
An annular or arcuate rail 37 is arranged on the outer peripheral side. The work W is slidably arranged on a rail 37, and its side surface is in close contact with the peripheral wall 31 of the turntable 30 by the magnetic force of the permanent magnet 34. Therefore, when the turntable 30 is rotated, the work W is conveyed in the circumferential direction together with the peripheral wall 31 of the turntable 30. In the case of this embodiment as well, as in the first embodiment, the turntable 3
Even if 0 is rotated at high speed, vibration and noise are small, and high stop position accuracy can be obtained in the traveling direction of the work W.

FIG. 11 shows a third embodiment of the carrying device according to the present invention. This transfer device is for transferring a wide work W such as an IC lead frame having liners f on both left and right sides. Two non-magnetic rails 41 and 42 are fixed in parallel on a base 40, and The belt 22 similar to that shown in FIG. 1 is arranged on the outer side of the rail 41. Belt 2
A magnet (not shown) and a yoke 6 are arranged on the inner side of the belt 2 on the belt 22 in parallel with the moving direction. A driving pulley 15 is arranged on one end side of the belt 22.
The motor 5 is driven by a motor 12 arranged below the base 40. A tension pulley 18, which also functions as a driven pulley, is rotatably supported on a base 40 at the other end of the belt 22. In this embodiment, a pair of rails 4
Since the lower surfaces of both sides of the work W are supported by 1, 42, even if the work W is a wide member, it can be stably transported.

It is needless to say that each of the above-mentioned embodiments shows only a few examples of the present invention, and various modifications can be made. In the above embodiment, the guide surface that slidably guides the first surface of the work is the horizontal surface, and the transfer surface that contacts the second surface of the work is the vertical surface. However, the transfer surface is the horizontal surface.
The guide surface may be a vertical surface. Further, the guide surface and the transport surface do not have to be perpendicular to each other and may be obliquely angled. In the above embodiment, the yokes are attached to both poles of the permanent magnet, but the work can be attracted to the guide surface and the transport surface without using the yokes. However, when the yoke is used, the magnetic force density is increased and the work can be more effectively adsorbed. The magnet in the present invention is not limited to a permanent magnet, but an electromagnet can be used.
In particular, if the electromagnet is demagnetized when the work is taken out from the transport device, the work can be taken out easily.

[0028]

As is apparent from the above description, according to the present invention, the first surface of the work is slidably guided by the non-magnetic rail and the second surface of the work is non-magnetic by the attraction of the magnet. Since the carrier is brought into close contact with the carrier to carry it, high-accuracy positioning can be performed even at high speed. Moreover, since the first surface and the second surface of the work are respectively attracted to the rail and the carrier, the posture of the work is stable, and even if the work is suddenly stopped, the work can be stopped without displacement. It is possible. Further, since the carrier is orbitally driven, there is no need for a returning operation such as a feed claw, and the work can be carried at high speed with low vibration and noise. Further, the work back-travel prevention device and the tension applying device are not required, and the conveying device can be made small and simple.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an example of a carrying device according to the present invention.

FIG. 2 is a front view of a specific example of the transfer device shown in FIG.

FIG. 3 is a plan view of the transport device of FIG.

FIG. 4 is a left side view of the transfer device shown in FIG.

5 is a right side view of the transport device of FIG.

FIG. 6 is an enlarged perspective view of a portion of the conveyance device of FIG. 2 taken along the line AA.

FIG. 7 is a cross-sectional view showing the direction of magnetic force of the transport device of FIG.

FIG. 8 is a schematic perspective view of a state in which a plurality of the transfer devices of FIG. 1 are connected.

FIG. 9 is a perspective view of another example of the work.

FIG. 10 is a sectional view of a second embodiment of the transport device according to the present invention.

FIG. 11 is a perspective view of a third embodiment of the carrying device according to the present invention.

[Explanation of symbols]

 W Work 1 Rail 2 Guide surface 5 Permanent magnet 6,7 Yoke 12 Motor 15 Drive side pulley 18 Tension pulley (driven side pulley) 22 Belt (conveyor) 22a Transfer surface

Claims (4)

[Claims] 1. A device for conveying a magnetic work having two adjacent surfaces, comprising a non-magnetic rail having a guide surface for slidably guiding the first surface of the work, and a second surface of the work. A non-magnetic carrier that has a contacting transfer surface and is movable along a rail, a driving unit that drives the carrier to rotate, and a position that opposes the rail with the carrier in between. A carrier device, comprising: a magnet that generates a magnetic force having a component force for bringing the second surface into close contact with the carrier and a component force for bringing the first surface of the workpiece into contact with the rail. 2. The transport apparatus according to claim 1, wherein yokes are attached to both poles of the magnet, and the guide surface of the rail is located near a boundary between one pole of the magnet and the yoke. Characteristic transport device. 3. The conveyor according to claim 1 or 2, wherein the conveyor is a non-magnetic belt, and the driving means is composed of a pulley around the belt and a motor for driving the pulley. A transport device characterized by the following. 4. The transfer device according to claim 1, wherein the work is a magnetic hoop material.