JP2009029228A - Conveying device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize stable traveling, while maintaining high conveying efficiency. <P>SOLUTION: A carriage 30 is driven by a linear motor constituted of a primary side iron core 34 mounted on the carriage 30 and a secondary side permanent magnet 3 mounted on a track 10 and is traveled by rotating traveling rollers 49 and 50, while abutting on a lower surface 12 in the track 10. The internal lower surface 12 of a curved part 26 in the track 10 and an opposed plane 3a of the secondary side permanent magnet 3 mounted on the curved part 26 to the primary side iron core 34 are inclined so that angles formed with the horizontal surfaces may be equal to an angle formed by the direction of resultant force of centrifugal force and gravity of the carriage 30 traveling in the curved part 26 with the vertical direction. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a transport device that transports an object to be transported by a transport carriage that is driven by a linear motor and travels on a track.

  2. Description of the Related Art A transport apparatus that is installed in a semiconductor or liquid crystal display panel manufacturing factory and transports an object to be transported (for example, a cassette containing a semiconductor substrate) by a transport carriage supported on a track laid in the factory is known. ing. With such a transport device, the object to be transported can be transported between various devices installed in the factory and sequentially processed. Japanese Patent Application Laid-Open No. 2004-228561 discloses a transport apparatus that employs a linear motor as a drive source for the transport carriage. That is, in the transport device of Patent Document 1, a linear motor is configured by a primary side member attached to the transport carriage and a secondary side member attached to the track so as to face the primary side member. .

In the above-described linear motor type transfer device, the primary member of the transfer carriage and the secondary member of the track that are opposed to each other are usually provided so that the gap between them is constant. Thereby, since the output of the linear motor becomes constant, the transport carriage can travel stably with a constant propulsion force and braking force.
JP 2001-270435 A

  In recent years, it has been desired to increase the speed of a transport apparatus installed in a manufacturing factory or the like in order to increase transport efficiency and improve productivity. However, when the transport cart that travels while being supported on the track as described above travels a curve at a high speed, a centrifugal force is applied to the transport cart. As a result, the wheels of the transport carriage are lifted off the track and the transport carriage is rattled, so that the object to be transported may be damaged. Moreover, since the magnitude | size of the clearance gap between the primary side member of a conveyance trolley and the secondary side member of a track | truck changes when a conveyance trolley inclines with respect to a track | truck, the output of a linear motor changes. This makes it difficult for the transport cart to travel stably.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a transport apparatus that can realize stable travel while maintaining high transport efficiency.

  The transfer device of the present invention is attached to a primary side magnet attached to a transfer carriage, and a track that guides the transfer carriage while supporting it in a suspended state, and has an opposing plane facing the primary side magnet. A transfer device that drives the transfer carriage by a linear motor composed of a secondary magnet to transfer an object to be transferred, while the transfer carriage is in contact with the contact surface facing upward of the track. Has rotating wheels. In addition, the contact surface of the curved curved portion in the track and the opposing plane of the secondary magnet attached to the curved portion are both located on the inner side of the curve. It inclines so that it may become higher than the height position of a part. And when the said conveyance trolley drive | works the linear part of the said track | truck, and when the said conveyance trolley drive | works while inclining the said curved part by contact | abutting to the said contact surface in which the said wheel inclined, The said 1 The amount of change in the gap between the primary magnet and the secondary magnet due to the displacement of the secondary magnet is such that the opposing plane of the secondary magnet attached to the curved portion is not inclined. Less than the amount of change.

  According to this configuration, even when the transport carriage travels on the curved portion at a high speed, it is possible to prevent the wheels of the transport carriage from being lifted from the contact surface of the track by centrifugal force. Accordingly, it is possible to suppress the shakiness of the transport carriage caused by the lifting of the wheels, and to prevent the transported object from being damaged. In addition, when the carriage is traveling while being inclined at the curved portion, it is possible to suppress the output of the linear motor from fluctuating due to a change in the gap between the primary side magnet and the secondary side magnet. Therefore, stable traveling can be realized while maintaining high conveyance efficiency.

  In the transport device according to the aspect of the invention, it is preferable that the degree of inclination of the abutting surface of the curved part is equal to the degree of inclination of the opposing plane of the secondary magnet attached to the curved part. According to this configuration, the primary magnet attached to the transport carriage is tilted so as to be equal to the inclination degree of the opposed plane of the secondary magnet when the transport carriage is tilted at the curved portion. Therefore, the fluctuation | variation of the output of a linear motor resulting from the change of the clearance gap between a primary side magnet and a secondary side magnet can be suppressed reliably.

  In the transport device according to the aspect of the invention, the curved portion of the track has the contact surface of the curved portion and the opposed plane of the secondary magnet attached to the curved portion both having the height of the outer portion of the curve. It is preferable to incline as a whole so that the position becomes higher than the height position of the inner part of the curve. According to this configuration, when the carriage is traveling while being inclined at the curved portion, the carriage can be prevented from coming into contact with a portion other than the contact surface of the track and being damaged.

  In the transport device according to the aspect of the invention, an angle formed by the contact surface of the curved portion and a horizontal plane of at least a part of the opposed plane of the secondary magnet attached to the curved portion may travel the curved portion. It is preferable to be equal to the angle formed by the vertical direction of the resultant force of the centrifugal force applied to the carriage and gravity. According to this configuration, stable running can be realized with certainty.

  A preferred embodiment of the present invention will be described below with reference to the drawings.

  The transfer apparatus according to the present embodiment is a transfer apparatus that transfers a FOUP (Front Opening Unified Pod) in which a substrate is stored in a semiconductor manufacturing facility, and is supported by a track laid on the ceiling while holding the FOUP. This is a suspended transport device (OHT: Over head Hoist Transport) that transports the cart. FIG. 1 is a top view showing a schematic configuration of an OHT transport system to which the OHT according to the present embodiment is applied.

  As shown in FIG. 1, the track 10 of the OHT 1 of the present embodiment is connected to the in-process track 21 via a plurality of in-process tracks 21 and branch tracks 22, and all the in-process tracks 21 are connected. And an inter-process track 23. Each of the intra-process track 21 and the inter-process track 23 is annular and includes a straight portion 25 and a curved portion 26. A plurality of semiconductor manufacturing apparatuses 91 are arranged in the vicinity immediately below the in-process track 21. The transport carriage 30 is supported on the track 10 in a suspended state, and travels while being guided by the track 10. The transport carriage 30 holds the FOUP 60 and travels between the semiconductor manufacturing apparatuses 91, and places the FOUP 60 on them, and collects the FOUP 60 therefrom.

  Next, the configuration of the OHT 1 will be described in more detail with reference to FIGS. FIG. 2 is a longitudinal sectional view of the linear portion 25 of the track 10 and a schematic configuration diagram of the transport carriage 30 that travels on the linear portion 25. FIG. 3 is a longitudinal sectional view of the curved portion 26 of the track 10 and the curved portion 26. It is a schematic block diagram of the conveyance trolley 30 which drive | works. In FIG. 3, the right side in the drawing is the outside of the curve of the track 10, and the left side in the drawing is the inside of the curve.

  As shown in FIGS. 2 and 3, the track 10 is a duct-shaped member having a substantially rectangular cross section, and is laid so as to be suspended from the ceiling 97. As shown in FIG. 2, the track 10 is attached to the ceiling 97 at the straight portion 25 so that the inner upper surface 11 and the inner lower surface 12 of the track 10 are horizontal. Further, as shown in FIG. 3, the track 10 is attached to the ceiling 97 by being inclined as a whole at the curved portion 26 so that the inner upper surface 11 and the inner lower surface 12 of the track 10 are inclined. More specifically, the inner upper surface 11 and the inner lower surface 12 of the track 10 in the curved portion 26 have a height position of the outer side (right side in FIG. 3) of the curve, and the height position of the inner side (left side in FIG. 3) of the curve. It is inclined to be higher than the position.

  Note that the degree of inclination of the track 10 in the curved portion 26 is determined by the curvature radius r of the curved portion 26 and the traveling speed v of the conveyance carriage 30 in the curved portion 26. That is, assuming that the total mass of the transport cart 30 and the FOUP 60 transported by the transport cart 30 is m and the gravitational acceleration is g, centrifugal force F1 and gravity F2 applied to the transport cart 30 traveling on the curved portion 26 are as follows. (Expression 1) and (Expression 2).

From (Expression 1) and (Expression 2) described above, the angle θ1 formed with the vertical direction of the direction of the resultant force F3 of the centrifugal force F1 and the gravity F2 can be expressed by the following (Expression 3).

  Here, as shown in FIG. 3, the angle θ <b> 1 formed with the vertical direction of the resultant force F <b> 3 applied to the transport carriage 30 traveling on the curved portion 26 is inclined by the curved portion 26 due to the influence of centrifugal force. It is equal to an angle θ2 formed by 30 horizontal planes. In the present embodiment, the trajectory 10 in the curved portion 26 is entirely so that the angle θ3 formed by the horizontal surface of the inner upper surface 11 and the inner lower surface 12 of the trajectory 10 is equal to θ1 obtained by the above (Equation 3). As inclined. That is, the inclination degree of the transport carriage 30 and the inclination degree of the track 10 are equal. In the vicinity of the boundary between the straight line portion 25 and the curved portion 26, the inclination of the track 10 gradually increases from a horizontal state to a state where θ3 is equal to θ1.

  In the lower wall of the duct-shaped track 10, a slit 2 for suspending a carriage unit 31 (to be described later) of the transport carriage 30 is formed along the extending direction (the front and back directions in FIG. 2 and 3).

  Guide members 15 and 16 with which guide rollers 41 and 42 (to be described later) of the carriage 30 are engaged are provided at the branch locations on the track 10. The guide members 15 and 16 extend along the extending direction of the track 10 and are substantially parallel to the inner upper surface 11 of the track 10, and are provided on the inner side surfaces 13 and 14 of the track 10, respectively. . One end portion of the guide members 15 and 16 in the width direction is formed integrally with the inner side surfaces 13 and 14, and the other end portion is formed to be bent downward.

  A secondary permanent magnet 3 is provided on the inner upper surface 11 of the track 10. The secondary-side permanent magnet 3 is a secondary-side member of a linear motor that is a drive source for running the transport carriage 30, and a large number of permanent magnets processed into a predetermined shape are used to reverse the polarity of the track 10. They are arranged in order along the extending direction (the front and back direction in FIGS. 2 and 3). The surface of the secondary permanent magnet 3 is an opposing flat surface 3a that faces a primary iron core 34 to be described later. As shown in FIG. 2, the opposing flat surface 3 a of the secondary permanent magnet 3 provided in the linear portion 25 of the track 10 is horizontal. As shown in FIG. 3, the opposing flat surface 3 a of the secondary permanent magnet 3 provided in the curved portion 26 of the track 10 is inclined in the same manner as the inner upper surface 11 and the inner lower surface 12 in the curved portion 26. That is, the opposing flat surface 3 a of the secondary permanent magnet 3 provided in the curved portion 26 is inclined to the same degree as the inclination of the transport carriage 30 that travels through the curved portion 26.

  Further, the inner side surfaces 13 and 14 of the track 10 are paired with a reciprocating reciprocating path, and the primary power supply line 4 extending along the extending direction of the track 10 (the front and back sides in FIG. 2 and 3). Is provided. High frequency power is applied to the primary power supply line 4, and non-contact power supply to the transport carriage 30 is realized together with a secondary iron core 35 provided on the transport carriage 30 as will be described later. It is. The primary power supply line 4 is also used as a communication line between a controller (not shown) that controls the movement of the transport carriage 30 and the transport carriage 30.

  A coil is wound around the transport carriage 30 and a primary iron core 34 that constitutes a linear motor together with the secondary permanent magnet 3 is provided. As shown in FIGS. 2 and 3, the primary iron core 34 is provided to face the secondary permanent magnet 3 provided on the inner upper surface 11 of the track 10 with a predetermined interval. Here, as described above, the opposing flat surface 3 a of the secondary permanent magnet 3 provided on the track 10 is horizontal in the straight portion 25, and the curved portion 26 travels through the curved portion 26. It is inclined to the same degree as the degree of inclination of the transport carriage 30. Therefore, the gap between the secondary permanent magnet 3 and the primary iron core 34 is constant in both the straight portion 25 and the curved portion 26.

  Further, the transport carriage 30 has a substantially E-shaped cross section, and a secondary side iron core into which a pair of primary power supply lines 4 provided on the inner side surfaces 13 and 14 of the track 10 are inserted into the two recesses. 35. When high frequency power is applied to the primary power supply line 4, primary high frequency power is induced in a coil (not shown) wound around the secondary side iron core 35, and power is transmitted in a non-contact manner. To be done. Note that all the electric power necessary for the transport carriage 30 is covered by this non-contact power feeding.

  Here, a driving method of a linear motor that is a driving source of the transport carriage 30 will be described. First, as described above, the high-frequency power induced in the secondary iron core 35 by the non-contact power feeding method is converted into direct current by full-wave rectification in a rectification unit (not shown), and further, a power supply control unit (not shown). Is converted to PWM-type three-phase AC power and then supplied to a coil wound around a primary iron core 34 constituting a linear motor. At this time, a traveling magnetic field that moves linearly is generated in the primary iron core 34, and a propulsive force is generated in the primary iron core 34 by the magnetic action between the secondary permanent magnets 3 that are arranged opposite to each other. To do. In the present embodiment, as described above, the gap between the secondary permanent magnet 3 and the primary iron core 34 is constant in both the linear portion 25 and the curved portion 26, so that the output of the linear motor Is also constant.

  Further, the transport carriage 30 is connected to the traveling unit 40 to which the above-described primary iron core 34 is connected and the traveling unit 40, and includes a carriage unit 31 that holds the FOUP 60. As shown in FIGS. 2 and 3, the traveling unit 40 is located in the duct-shaped track 10, and is driven in the extending direction of the track 10 by the linear motor described above and travels in the track 10. It is like that. The carriage unit 31 is connected to the traveling unit 40 by a suspension member 33 extending from the inside of the track 10 to the outside via the slit 2 of the track 10, and is held in a suspended state below the track 10.

  The traveling unit 40 includes guide rollers 41 and 42 for selecting the traveling direction of the transport carriage 30 and two traveling rollers 49 and 50 for traveling the transport carriage 30. The guide rollers 41 and 42 are horizontally rotatable rollers respectively provided at both ends in the width direction of the traveling unit 40, and are engaged with any of the above-described guide members 15 and 16 at a branch point of the track 10. Thus, it is possible to select whether the transport carriage 30 goes straight, branches, or merges.

  The traveling rollers 49 and 50 are rotatably provided in pairs at both ends in the width direction of the traveling unit 40 and are in contact with the inner lower surface 12 of the track 10 as shown in FIGS. That is, as shown in FIG. 2, when the transport carriage 30 travels on the straight portion 25 of the track 10, the travel rollers 49 and 50 of the travel unit 40 rotate while contacting the horizontal inner lower surface 12 of the track 10. To do. Further, as shown in FIG. 3, when the transport carriage 30 travels on the curved portion 26 of the track 10, the travel rollers 49 and 50 of the travel unit 40 rotate while contacting the inclined inner lower surface 12 of the track 10. To do.

  As described above, in the OHT 1 according to the present embodiment, the transport carriage 30 includes the linear iron core 34 attached to the transport carriage 30 and the secondary permanent magnet 3 attached to the track 10. It is driven by a motor. And the opposing lower surface 3a with respect to the internal lower surface 12 of the curved part 26 in the track | orbit 10 and the primary side iron core 34 of the secondary side permanent magnet 3 attached to this curved part 26 has the height position of the outer part of a curve. It inclines so that it may become higher than the height position of the inner part of a curve. Therefore, even when the transport carriage 30 travels on the curved portion 26 at a high speed, the traveling rollers 49 and 50 can be prevented from being lifted from the inner lower surface 12 of the track 10 by centrifugal force. Therefore, rattling of the transport carriage 30 due to the lifting of the traveling rollers 49 and 50 can be suppressed, and damage to the substrate stored in the FOUP 60 can be prevented. Further, when the conveyance carriage 30 travels while being inclined at the curved portion 26, the output of the linear motor is prevented from fluctuating due to a change in the gap between the primary iron core 34 and the secondary permanent magnet 3. can do. As a result, stable traveling can be realized while maintaining high conveyance efficiency.

  Further, in the OHT 1 of the present embodiment, the degree of inclination of the inner lower surface 12 of the curved part 26 is equal to the degree of inclination of the opposing flat surface 3 a of the secondary permanent magnet 3 attached to the curved part 26. Therefore, the primary side iron core 34 attached to the conveyance carriage 30 is inclined so as to be equal to the degree of inclination of the opposed plane 3 a of the secondary permanent magnet 3 when the conveyance carriage 30 is inclined at the curved portion 26. Therefore, fluctuations in the output of the linear motor due to changes in the gap between the primary iron core 34 and the secondary permanent magnet 3 can be reliably suppressed.

  Furthermore, in the OHT 1 of the present embodiment, the curved portion 26 of the track 10 is inclined as a whole. Therefore, when the transport carriage 30 travels while being inclined at the curved portion 26, the transport carriage 30 can be prevented from coming into contact with the inner side surfaces 13 and 14 of the track 10 and being damaged.

  In addition, in the OHT 1 of the present embodiment, the degree of inclination of the curved portion 26 of the track 10 is equal to the degree of inclination of the resultant force of the centrifugal force and the gravity applied to the transport carriage 30 traveling on the curved portion 26 with respect to the vertical direction. Therefore, stable traveling of the transport carriage 30 can be realized with certainty.

  The preferred embodiment of the present invention has been described above. However, the present invention is not limited to the above-described embodiment, and various design changes can be made as long as they are described in the claims. Is something. For example, in the above-described embodiment, the case where the degree of inclination of the inner lower surface 12 in the curved part 26 of the track 10 is equal to the degree of inclination of the opposing flat surface 3a of the secondary permanent magnet 3 attached to the curved part 26 has been described. However, they may be different.

  Moreover, although the above-mentioned embodiment demonstrated the case where the track | orbit 10 inclined as a whole in the curved part 26, it is not limited to this. Only the inner lower surface 12 of the curved portion 26 of the track 10 and the opposing flat surface 3a of the secondary permanent magnet 3 attached to the curved portion 26 may be inclined.

  Further, in the above-described embodiment, the case where the inclination degree of the curved portion 26 of the track 10 is equal to the inclination degree with respect to the vertical direction of the resultant force of the centrifugal force and the gravity applied to the transport carriage 30 traveling on the curved portion 26 will be described. However, it is not limited to this. The track 10 only needs to be inclined to such an extent that the traveling rollers 49 and 50 of the transport carriage 30 to which the centrifugal force is applied do not float from the inner lower surface 12.

It is a figure which shows schematic structure of the OHT conveyance system to which OHT concerning this Embodiment was applied. It is a longitudinal cross-sectional view of the linear part of the track | orbit shown in FIG. 1, and the schematic block diagram of the conveyance trolley which drive | works this linear part. It is a longitudinal cross-sectional view of the curved part of the track | orbit shown in FIG. 1, and the schematic block diagram of the conveyance trolley which drive | works this curved part.

Explanation of symbols

1 OHT (Conveyor)
3 Secondary permanent magnet (secondary magnet)
3a Opposing plane 10 Track 12 Internal lower surface (contact surface)
25 Linear portion 26 Curved portion 30 Carriage truck 34 Primary iron core (primary magnet)
49, 50 Traveling roller

Claims (4)

Linear composed of a primary side magnet attached to the transport carriage and a secondary side magnet attached to a track that supports and guides the transport carriage and has an opposing flat surface facing the primary side magnet. A transport device that drives the transport carriage by a motor and transports an object to be transported,
The transport carriage includes a wheel that rotates while abutting on a contact surface facing upward of the track;
The contact surface of the curved curved portion in the trajectory and the opposing plane of the secondary magnet attached to the curved portion both have the height position of the outer portion of the curve of the inner portion of the curve. When the conveyance cart is inclined so as to be higher than the height position, and the carriage is in contact with the inclined contact surface, the conveyance cart is moved along the curved portion. The amount of change in the gap between the primary side magnet and the secondary side magnet due to the displacement of the primary side magnet when traveling while tilting the vehicle is the secondary side attached to the curved portion. The conveying apparatus characterized by being small compared with the said variation | change_quantity when the said opposing plane of a magnet is not inclined.   The conveying apparatus according to claim 1, wherein a degree of inclination of the abutting surface of the curved part is equal to a degree of inclination of the opposing plane of the secondary magnet attached to the curved part.   The curved portion of the track is such that the height position of the outer portion of the curve is the height of the inner portion of the curve of the contact surface of the curved portion and the opposed plane of the secondary magnet attached to the curved portion. The conveying device according to claim 2, wherein the conveying device is inclined as a whole so as to be higher than a height position.   Centrifugal force and gravitational force applied to the transport carriage that travels on the curved portion, the angle between the contact surface of the curved portion and the horizontal plane of at least a portion of the opposed plane of the secondary magnet attached to the curved portion. The conveying device according to claim 2, wherein the conveying device is equal to an angle formed with a vertical direction of a direction of the resultant force.

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