JPH04256626A - Carrier device - Google Patents

Abstract

PURPOSE:To carry out complete stopping at a prescribed position and shorten the time required for stopping in a carrier device utilizing a linear motor by rolling braking wheels against a seat to apply frictional force. CONSTITUTION:When a carrier 10 is stopped at a parts unloading station 14, a controller 30 reads out the speed of the carrier 10 which enters a station 14 from the detected value of an optical detecting device 28, and temporarily controls to decelerate a linear motor 16 to keep the carrier 10 at a prescribed low speed. Then, it is judged that the carrier 10 approaches the edge of the seat 42 and energizes to an electromagnet 40. Braking wheels 34 approach a position where the operating part 32b of a magnetic block 32 faces an edge of the electromagnet 40 while they are rolling along the seat 42 and their interval becomes shorter, and magnetic force which is applied to the magnetic block 32 of the electromagnet 40 becomes bigger. It is thus finally possible to stop the carrier 10 accurately at a position where the operating part 32b of the magnetic block 32 faces the edge of the electromagnet.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transport device suitable for transporting semiconductor products, and more particularly to an improvement in the stopping mechanism of the transport device. Recently, there has been a growing demand for differentiation and diversification of semiconductor products, and semiconductor factories are now having to respond to high-mix, low-volume production. Therefore, it is required not only to improve the reliability and speed of manufacturing equipment for each process, but also to speed up the transfer of parts. In particular, for the transportation of components such as wafers and masks, there is a need for a transportation device that is fast, highly reliable, and does not become a source of dust. 2. Description of the Related Art As a transport device for such semiconductor components, a transport device using a linear motor has been developed. That is, by installing a linear motor on a travel path and attaching the secondary conductor of this linear motor to a transport vehicle for components such as wafers and masks, the transport vehicle can be caused to travel. With this configuration, it is possible to achieve lightweight and agile running performance without attaching a conventional rotary motor to the transport vehicle, and it also maintains cleanliness because it does not spread dust like a conventional rotary motor. can. In a device for transporting semiconductor components, it is not necessary to install linear motors along the entire travel path of the transport vehicle, but it is often sufficient to provide linear motors at intervals along the travel path. For example, a short linear motor may be installed at a specific location to be a parts unloading station, and the linear motor will start and accelerate the transport vehicle, allowing it to coast when the linear motor cuts out and arrive at the next parts unloading station. be able to. When the transport vehicle reaches the next parts loading/unloading station in this manner, the transport vehicle must be stopped at a predetermined position. For this reason, in the above-mentioned conveyance device, an electromagnet installed at a predetermined position on the traveling path,
It was equipped with a braking mechanism consisting of a magnetic material attached to the carriage. When the transport vehicle approaches the parts loading/unloading station, the speed of the transport vehicle is detected by a sensor installed in front of the electromagnet, and the linear motor is temporarily controlled to decelerate, keeping the speed of the transport vehicle at a constant low speed. Then, the electromagnet was energized. The electromagnet attracts the magnetic material on the carrier, and the carrier is stopped at the position where the magnetic material is closest to the electromagnet. [0004]Problem to be Solved by the Invention In this way, if the transport vehicle is set at a constant low speed and the electromagnet is energized, the transport vehicle should surely stop at the position of the electromagnet. . However, even if the transport vehicle is set to a constant low speed, the speed of the transport vehicle will inevitably vary, so in reality the transport vehicle may stop at a position in front of the electromagnet, or may stop at a position after passing the electromagnet. There were times when it stopped. This is due to the relationship between the speed of the transport vehicle and the range of action of the magnetic force of the electromagnet. For example, if the transport vehicle stops before the range of action of the electromagnet's magnetic force, the electromagnet will no longer be able to attract the magnetic material of the transport vehicle, and if the transport vehicle passes the electromagnet's position at a relatively high speed. The magnetic force of the electromagnet cannot stop the carrier, and the carrier passes through the range of action of the electromagnet's magnetic force. Therefore, in order to stop the transport vehicle at a predetermined position,
It is desirable to increase the magnetic force of the electromagnet. However, if the magnetic force of the electromagnet is increased, the magnetic force of the electromagnet will act from a location far away from the transport vehicle, and the transport vehicle will be strongly attracted to it. For this reason, when the transport vehicle is moving toward the electromagnet, its inertia increases, and even when it reaches the position of the electromagnet, it does not stop and travels too far. The carriage is then pulled back again by the electromagnet from the position it has gone too far. In this way, when the transport vehicle stops, it vibrates around the electromagnet, and stops at the electromagnet position after a considerable period of time while damping the vibrations. When the magnetic force of the electromagnet is increased, there is a problem in that the vibration movement becomes larger and the time required for stopping the transport vehicle becomes longer. SUMMARY OF THE INVENTION An object of the present invention is to provide a conveying device that can reliably stop at a predetermined position and reduce the time required for stopping. Means for Solving the Problems [0007] A conveyance device according to the present invention includes a traveling body capable of traveling along a traveling path, a driving means for driving the traveling body to travel, and a magnetic body provided on the traveling body. a braking wheel supported by the running body together with the magnetic body; an electromagnet provided at a predetermined position on the running path; and a braking wheel provided at approximately the same position as the electromagnet and with the braking wheel. a seat having a flat surface that is engageable and extends along the traveling direction of the traveling body; and a brake wheel and the magnetic body so that the brake wheel and the sheet approach or separate from each other. The present invention is characterized by comprising a support means for supporting the traveling body, and a control means for energizing the electromagnet when the traveling main body reaches a predetermined position. [0008] In the above structure, semiconductor components and the like are loaded on the traveling body (carrying vehicle) and transported. The support means for variably supporting the position of at least one of the braking wheel and the seat is, for example, one that supports the position of the braking wheel variably, and the seat is fixedly disposed. In this case, the position of the magnetic body also changes together with the braking wheel. During normal running of the traveling body, the braking wheel is supported at a position away from the seat, and does not come into contact with electromagnets or seats, even if they are present in the middle of the traveling path. When the traveling body approaches a stop position, for example a parts loading/unloading station, the drive means is controlled so that the speed of the traveling body is at a constant low speed, and the electromagnet is energized. The electromagnet attracts the magnetic body of the traveling body, and moves the braking wheel together with the magnetic body toward the seat. Therefore, the braking wheel contacts the seat and rolls along the seat. At this time, the distance between the magnetic body and the electromagnet becomes smaller, and the electromagnet applies a large magnetic force to the magnetic body, stopping the traveling body at the position where the magnetic body is closest to the electromagnet. As described above, when the magnetic force of the electromagnet increases, the damping motion when the traveling body comes to a stop increases, and the time for convergence thereof increases, but in the present invention, the braking wheel rotates relative to the seat. By moving, frictional force is applied, reducing the amplitude of the damping motion in the stop area of the traveling body and shortening the convergence time. Therefore, the traveling body can be reliably stopped at a predetermined position, and the time required for stopping can be reduced. [Embodiment] FIG. 1 shows an embodiment of the present invention.
2 is a diagram showing a vehicle about to arrive at a parts unloading station 14 along a travel path 12. FIG. A linear motor 16 of a certain length is installed on the running path 12. As shown in FIG. 2, the linear motors 16 are provided at intervals along the travel path 12. A linear motor 16 is provided for each component unloading station 14, but may also be provided at any position between adjacent component unloading stations 14, as shown in FIG. As shown in FIG. 4, a rail 18 is provided on the traveling path 12, and the linear motor 16 is driven along the rail 18.
8. A secondary conductor 2 is installed at the bottom of the transport vehicle 10.
0 is set. The linear motor 16 and the secondary conductor 20 have a relationship similar to that of the stator and rotor of a rotary motor, and the magnetic force generated by the linear motor 16 causes the secondary conductor 20 to move. 10 is driven to travel. In addition, in the embodiment, the transport vehicle 10
runs along the running path 12 with running wheels 22,
Instead of providing the traveling wheels 22, a magnetic levitation type can also be used. Furthermore, as shown in FIG.
A baggage placement section 24 is provided on the top surface. As shown in FIG. 1, a slit plate 26 is attached to the transport vehicle 10, and a slit plate 26 is installed in front of the linear motor 16 of the parts loading/unloading station 14 (on both sides when the transport vehicle 10 reciprocates), for example. Optical detection means 28 are provided. The detection value of the optical detection means 28 is input to the control device 30, and the control device 30 reads the speed of the transport vehicle 10 entering the parts loading/unloading station 14, and temporarily controls the linear motor 16 to decelerate. 10 is set to a predetermined low speed. Further, the control device 30 also controls the linear motor 16 when the transport vehicle 10 is started. As shown in FIGS. 1, 3, and 4,
For example, a magnetic block 3 made of iron is provided on the side surface of the transport vehicle 10.
2 can be installed. A braking wheel 34 is attached to the magnetic block 32. The magnetic block 32 has a main body portion 32a that extends long toward the side closer to the side surface of the transport vehicle 10.
and two actuating parts 32b extending outward from the main body part 32a at right angles, and each braking wheel 34 is mounted by a shaft 34a perpendicular to the actuating parts 32b. A portion of the braking wheel 34 protrudes slightly outward from the outer end surface of the operating portion 32b of the magnetic block 32. This braking wheel 34 is made of a material such as soft urethane rubber that has a high coefficient of friction and is less likely to generate dust. The magnetic block 32 is supported on the side surface of the carriage 10 by a horizontal shaft-shaped support member 36. This support member 36 is fixed to the transport vehicle 10 and is slidably fitted into an axial hole provided in the magnetic block 32. The support member 36 has a stopper portion 36a, and a tension spring 38 is disposed between the magnetic block 32 and the carrier 10. Therefore, the magnetic block 32 is
Although it is movable with respect to 0, it is usually fixedly located at a predetermined position. Furthermore, an electromagnet 40 and a seat 42 are provided at predetermined positions of the parts loading/unloading station 14. The electromagnet 40 consists of a magnetic body 40a and a coil 40b. In the embodiment, the magnetic body 40a has a U-shaped shape, the coil 40b is wound around the middle part of the U-shape, and the coil 40b is wound at both ends of the U-shape. The portion faces the conveyance vehicle 10 side through a hole in the sheet 42. Both ends of the magnetic body 40a have the same cross-sectional shape as the operating portion 32b of the magnetic block 32, and can face each other. The seat 42 is made of a material with a high friction coefficient and low dust generation, such as soft urethane rubber, similar to the braking wheel 34. The seat 42 is the transport vehicle 1
0 and has a flat surface 42a that can be engaged with the braking wheel 34. That is, when the transport vehicle 10 is at the parts loading/unloading station 14, the magnetic block 32 and the braking wheel 34 face the flat surface 42a of the seat 42, and by energizing the electromagnet 40, the magnetic block 32 is activated by the spring 38. The braking wheel 34 is brought into contact with the flat surface 42a of the seat 42. As shown in FIG. 1, optical detection means 44 are provided within the component unloading station 14. In addition, the transport vehicle 10 includes a detected portion 46 (
3) is provided, and the optical detection means 44 is the detected part 46.
The control device 3 determines whether the transport vehicle 10 approaches the end of the sheet 42 by detecting the detection value, and receives the detected value.
0 energizes the electromagnet 40. In addition, in FIG. 3, a switch 50 is provided between the electromagnet 40 and the power source 48, and the control device 30 controls opening and closing of this switch 50. FIGS. 5 and 6 are diagrams showing the relationship between the magnetic block 32 and the braking wheel 34, the electromagnet 40, and the seat 42 when the electromagnet 40 is not energized and when it is energized, respectively. When the transport vehicle 10 is normally running, the electromagnet 40 is not energized, and as shown in FIG. The vehicle can run passing through the magnetic block 32 and the braking wheel 34. When stopping the transport vehicle 10 at the parts unloading station 14, the control device 30 determines the speed of the transport vehicle 10 entering the parts unloading station 14 from the detected value of the optical detection means 28, as described above. Then, the linear motor 16 is temporarily decelerated to bring the speed of the transport vehicle 10 to a predetermined low speed. Then, the control device 30 detects the transport vehicle 10 based on the detection value of the optical detection means 44.
is approaching the edge of the sheet 42, and the electromagnet 40 is energized. Then, as shown in FIG. 6, the magnetic block 32 and the brake wheel 34 approach the electromagnet 40 and the seat 42, and the brake wheel 34 comes into contact with the seat 42.
It comes to roll along the flat surface 42a of the sheet 42. When the electromagnet 40 is initially energized, the actuating portion 32b of the magnetic block 32 is located away from the end of the magnetic body 40a, which serves as the attraction portion of the electromagnet 40, in the traveling direction of the carrier 10; Due to the suction action of
While the braking wheel 34 is rolling along the seat 42, the actuating portion 32b of the magnetic block 32 is moving the magnetic body 4 of the electromagnet 40.
0a, and finally the actuating portion 32b of the magnetic block 32 touches the magnetic body 40 of the electromagnet 40.
The carriage 10 stops at a position facing the end of a. When the electromagnet 40 is energized and the braking wheel 34 comes into contact with the seat 42, the distance between the operating portion 32b of the magnetic body block 32 and the end of the magnetic body 40a of the electromagnet 40 becomes small, and the electromagnet The magnetic force acting on the magnetic block 32 of 40 increases. Therefore, even if the speed of the transport vehicle 10 varies, the transport vehicle 10 can be reliably stopped at a predetermined position. Since the braking wheel 34 and the seat 42 are each made of a material such as soft urethane rubber that has a high coefficient of friction and a viscous property that prevents slipping, there is a gap between the braking wheel 34 and the seat 42. Frictional resistance increases, helping the conveyance vehicle 10 to stop. Although the braking wheel 34 and the seat 42 are in contact with each other in this way, since they are made of a material that does not generate much dust, there is no problem in cleaning the factory. FIG. 7 is a diagram showing vibration attenuation when the transport vehicle 10 stops. As mentioned above, the transport vehicle 10
When stopped by the electromagnet 40, the carriage 10 passes the position of the electromagnet 40, and stops while performing a vibration damping motion so as to be pulled back from the position beyond which it has passed. In FIG. 7, the solid line shows the damping of vibrations without the brake wheels 34 and the seat 42, and the broken line shows the damping of vibrations with the brake wheels 34 and the seat 42. According to the present invention, when the braking wheel 34 and the seat 42 are provided, the vibration damping convergence time T2 is determined by the braking wheel 34 and the seat 42.
and the convergence time T of vibration damping when the seat 42 is not provided.
It is much shorter than 1. [0021] As explained above, according to the present invention,
A traveling body capable of traveling along a traveling path, a driving means for driving the traveling body, a magnetic body provided on the traveling body, and a braking wheel supported on the traveling body together with the magnetic body. and an electromagnet provided at a predetermined position on the travel path;
a seat provided at approximately the same position as the electromagnet and having a flat surface extending along the running direction of the traveling body so as to be engageable with the braking wheel, and the braking wheel and the seat facing each other; The braking wheel and the magnetic body are configured to include a support means for supporting the braking wheel and the magnetic body so as to approach or separate from each other, and a control means for energizing the electromagnet when the traveling body reaches a predetermined position. To surely stop a traveling body at a predetermined position and to reduce the time required for stopping.

[Brief explanation of the drawing]

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

FIG. 2 is a diagram showing a running path on which a linear motor is installed.

FIG. 3 is a plan view of the carrier.

FIG. 4 is a front view of the carrier.

FIG. 5 is a diagram showing the magnetic block and the braking wheel in a position away from the electromagnet and the seat.

FIG. 6 is a diagram showing a magnetic block and a braking wheel in a position close to an electromagnet and a seat.

FIG. 7 is a diagram showing attenuation of vibration when the transport vehicle stops.

[Explanation of symbols] 10...Transportation truck 12...Running route 14...Parts loading and unloading station 16...Linear motor 20...Secondary conductor 22...Traveling wheel 32...Magnetic block 34...Brake wheel 36...Support member 38...Spring 40...Electromagnet 42... Sheet

Claims (3)

[Claims] [Claim 1] A traveling body (
10), and a drive means (16) for driving the traveling body to travel.
), a magnetic body (32) provided on the traveling body, and a braking wheel (34) supported on the traveling body together with the magnetic body.
) and an electromagnet (40
), a seat (42) having a flat surface that is provided at approximately the same position as the electromagnet and extends along the traveling direction of the traveling body so as to be engageable with the braking wheel; a support means (36) for supporting the braking wheel and the magnetic body so that the seat approaches or separates from the seat; and control for energizing the electromagnet when the traveling body reaches a predetermined position. A conveyance device comprising means (30). 2. The support means (36) is such that the magnetic body (32) is slightly spaced apart from the electromagnet (40) when the braking wheel (34) abuts the seat (42). 2. The conveying device according to claim 1, wherein the magnetic body and the braking wheel are simultaneously supported so as to be movable toward the sheet. 3. The conveying device according to claim 1, wherein the braking wheel (34) and the seat (42) are each made of a material with a high coefficient of friction and low dust generation.