JP2006027421A - Transporting device using linear motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a transporting device using a linear motor including a permanent magnet installed on a track to serve as the primary side, capable of improving the conventional problem such that the motor efficiency is dropped to a significant degree owing to a deviation generated in the magnetic pole phase sensed by a magnetic pole sensor from the magnetic pole phase required to control the primary side of the linear motor while it is running on a curved track or a track part with convergence and/or divergence. <P>SOLUTION: The transporting device using the linear motor is equipped with a bogie mechanism 7 installed proprietarily for installation of the magnetic pole sensor 8, which is furnished with a guide roller 7f so as to make movement perpendicularly to the longitudinal direction of the permanent magnet 5bx in case it intrudes to a curved track or a track with convergence or divergence and is confronting the permanent magnet 5bx where the magnetic pole sensor 8 is confronting. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a linear motor type transfer device for transferring an article such as a cassette in which a substrate is stored in a manufacturing process of a semiconductor or a liquid crystal display device, for example. Arrangement mechanism of magnetic pole detection sensor that accurately detects the position of the magnetic pole when using a linear motor having a permanent magnet as a secondary side that is alternately arranged with different polarities along the conveyance path of the object to be conveyed It is about.

  Conventionally, in hospitals, warehouses, factories, etc., a transport system that travels a transport cart along a predetermined track and transports an object to be transported (a cassette or other cargo containing a semiconductor substrate) by this transport cart has been widely adopted. Yes. For example, such a transport system is used as a transport cart for transporting tableware, medical instruments, etc. in hospitals, etc., used as a transport cart for moving materials in warehouses, etc., or in a factory, etc. Used as a substrate or semiconductor wafer transfer device.

By the way, the transport cart is self-propelled by receiving electric power from a driving means other than a linear motor by contactless power feeding, power feeding from an external power source such as a trolley, or a battery loaded by itself. And it drive | works along the track | orbit which regulates the traveling direction of a conveyance trolley | bogie. At this time, the type of track of the transport carriage basically includes a straight portion 31, a curved portion 32, and a junction branching portion 33 as shown in FIGS. 3 (a), (b), and (c).

On the other hand, the conveyance cart has a configuration shown in FIG. In FIG. 4, two power supply transformers 42 a and 42 b are provided on the front and rear sides in the traveling direction indicated by the arrow of the transport carriage 41. This is because one power supply transformer lacks electric power necessary for traveling the transport carriage 41. Further, in the case of the transport carriage 41 having a branching mechanism, it is not known whether the primary power supply line 43 is present on either the left or right side, and thus power feeding transformers are disposed on the left and right sides of the transport carriage 41.
Therefore, in the case of the non-contact power supply method, a total of four power supply transformers, that is, power supply transformers 42a and 42b on the right side in the traveling direction and power supply transformers 42c and 42d on the left side in the traveling direction are provided for one transport carriage 41. Yes. Of course, when using the power supply transformers 42c and 42d on the left side in the traveling direction, the primary power supply line 43 is arranged on the left side. When using the power supply transformers 42a and 42b on the right side in the traveling direction, the primary power supply line 43 is arranged on the right side. Has been.

Since communication between the ground controller (not shown) and the carriage 41 is performed by power line superimposition communication, each of the power supply transformers 42a, 42b, 42c, and 42d also serves as a communication transformer. Alternatively, instead of serving as a communication transformer, a communication transformer (not shown) can be arranged separately.
44 is a linear motor primary side, which is installed at a predetermined position facing the track of the transport carriage 41, and a linear motor secondary side (not shown) in which permanent magnets having different polarities are alternately arranged along the track. This constitutes a so-called linear motor.

A magnetic pole detection sensor 45 is installed at a position facing the central portion of the track of the transport carriage 41 and sequentially detects the linear motor secondary side permanent magnets. Based on the detection signal, the linear motor primary side winding is detected. The excitation direction of the line (not shown) is switched, and a propulsive force along the track is applied to the transport carriage 41 by the interaction of the primary and secondary magnetic fluxes constituting the linear motor.
Reference numeral 46 denotes an encoder, which is installed on the opposite side to the magnetic pole detection sensor 45 in the traveling direction of the transport carriage 41, and increases or decreases the count value according to the traveling direction of the transport carriage for each magnetic pole detection. Check the current position.

FIG. 5 schematically shows the situation of the linear motor-related elements in a straight track. In FIG. 5, elements corresponding to those in FIG. 4 are denoted by the same reference numerals, and description thereof is omitted to avoid duplication. Reference numeral 47 denotes a permanent magnet that constitutes the secondary side of the linear motor. The polarities of the permanent magnets are alternately opposite to each other and are arranged as shown.
Thus, when the linear motor primary side 44 travels on the linear track shown in FIG. 5, the magnetic pole detection sensor 45 can detect the magnetic pole while facing the central portion of each magnetic pole 47, and the accurate Along with the detection of the magnetic pole position, the current switching timing can be accurately performed on the winding (not shown) of the linear motor primary side 44, and the efficiency of the linear motor can be increased.

By the way, as shown in FIG. 6 (the same reference numerals are given to the same parts as in FIG. 5 and the detailed description is omitted), in the curved track L1, a series of permanent different polarities along this is provided. The center line L2 of the magnet 47 also forms a curve. As a result, the magnetic pole detection position of the magnetic pole detection sensor 45 deviates from the center of the magnetic pole detection sensor 45 due to the relationship between the center line L 3 on the primary side of the linear motor and the center line L 2 of the permanent magnet 47.
Such a phenomenon also occurs at the junction branching portion shown in FIG. 7, and the junction branching portion further increases the influence on the configuration of the junction and branching of the linear motor secondary side permanent magnet array.

When the viewpoint is shifted to the patent document as the prior art related to the present invention separately from the prior art described above, first, there are Patent Document 1 and Patent Document 2 disclosed for the linear motor traveling conveyance carriage having a bogie mechanism. These do not describe the magnetic pole detection sensor. In addition, although there is a description of the speed detection sensor and the position sensor, both sensors are installed on the track. Therefore, the present application is intended to provide a magnetic pole detection sensor described later on a bogie mechanism dedicated to the installation. Each invention differs from the invention in two respects: the installation configuration of the magnetic pole detection sensor and the type of sensor.
Further, Patent Document 3 describes a linear motor type conveying unit having a magnetic sensor. However, a bogie mechanism dedicated to sensor installation is not disclosed, and is different from the inventions of the present application whose main point is to install a magnetic pole detection sensor on a bogie mechanism dedicated to installation.
6-29303 6-29304 JP 6-30522

In the prior art described in the section of the background art, each technique disclosed in Patent Literatures 1 to 3 alternately includes magnets arranged on the secondary side of the linear motor and along the primary side track. There is no disclosure of a magnetic pole detection sensor for detecting differently arranged permanent magnets.
Incidentally, in the linear carriage on the primary side of the conveyance carriage and the linear motor mounted thereon shown in FIG. 5, the linear motor secondary side is formed and arranged along the track of the conveyance carriage so as to have NS polarity alternately. The permanent magnet can be properly detected by the magnetic pole detection sensor, and the carriage can normally run without any trouble.

On the other hand, when the transport carriage travels on the curved portion shown in FIG. 6, the position of the magnetic pole detection sensor 45 greatly deviates from the center line of the series of permanent magnets 47, and the linear motor primary side 44 mounted on the actual transport carriage. The arrangement of the permanent magnets 47 facing directly below and the arrangement of the permanent magnets 47 detected by the magnetic pole detection sensor were shifted. As a result, the exciting current of the winding on the primary side of the linear motor is controlled by the detection signal of the magnetic pole detection sensor 45. As a result, the inefficient linear motor is driven and overload abnormalities frequently occur.
In particular, the arrangement of the permanent magnets 47 on the secondary side of the linear motor in the junction branching portion shown in FIG. 7 is more complicated than in the case of a simple curved portion. Further, the permanent magnets 47 directly below the actual primary side of the linear motor 47 are arranged. There is a tendency that the arrangement of the detected permanent magnets is shifted, for example, the permanent magnet 47 detected by the magnetic pole sensor 45 detects the permanent magnet 47 that moves from another path to the branch point.

In both cases shown in FIGS. 6 and 7, if the magnetic pole detection sensor can be arranged at the central portion in the width direction and the longitudinal direction on the linear motor primary side, the above problem can be alleviated, but the linear motor 1. If a magnetic pole detection sensor is embedded on the secondary side, there is a possibility of detecting a magnetic field due to the current flowing into the primary winding of the linear motor, and it is theoretically difficult to prevent this. In addition, the gap between the primary electromagnet and the secondary permanent magnet constituting the linear motor is actually set to the smallest practical size from the viewpoint of improving efficiency. It is difficult to place the sensor.

Accordingly, an object of the present invention is not affected by the magnetic field generated by the excitation of the primary winding of the linear motor, and even if the track of the transport carriage driven by the linear motor is a curve or a junction branch point. The magnetic pole detection sensor that obtains the excitation switching signal of the winding on the primary side of the linear motor is the secondary side of the linear motor, and the permanent magnet arranged along the trajectory of the transport carriage is accurately conformed to the linear trajectory. It is to provide a mechanism that can be detected.

Means and effects for solving the problems

In order to solve the above-described problem, a linear motor-type conveyance device according to claim 1 includes a winding, a movable part that constitutes a primary side that generates an alternating magnetic flux in accordance with excitation switching of the winding, A transport carriage that is driven along a track of a movable part, and that is driven by a linear motor that includes a fixed part that constitutes a secondary side in which permanent magnets of different polarities are alternately laid. It has a positive and negative magnetic pole detection sensor for magnets and one or more bogie mechanisms, and has a dedicated bogie mechanism for arranging magnetic pole detection sensors among the one or more bogie mechanisms. .

According to the first aspect of the present invention, the position of the magnetic pole detection sensor of the secondary permanent magnet in the linear motor arranged by alternately changing the polarity along the track of the transport carriage is at the center of each permanent magnet. It is automatically adjusted to face each other.
Therefore, the efficiency of the linear motor can be made substantially the same as that of the linear track even when the transfer cart passes through the curve and branching points in the track of the transport cart.
Incidentally, as shown in FIG. 8, the relationship between the permanent magnet 47 on the secondary motor side and the magnetic pole detection sensor 45 on the curved track is as shown by the solid line when the magnetic pole detection sensor is installed in the bogie mechanism. When the sensor is fixed to a place other than the bogie mechanism (the transport carriage body), it is as shown by the dotted line.
The above-mentioned effect is supported by the mutual relationship between the permanent magnet 47 and the magnetic pole detection sensor 45.

The linear motor type transfer device according to claim 2 is laid along a winding, a movable part that constitutes a primary side that generates an alternating magnetic flux in accordance with excitation switching of the winding, and a track of the movable part. And a conveyance carriage that is driven and controlled by a linear motor that is configured by a linear motor composed of secondary magnets alternately arranged with permanent magnets of different polarities, and for detecting positive and negative magnetic poles of the permanent magnets. And a single bogie mechanism, and a magnetic pole detection sensor is disposed in the bogie mechanism.
According to the second aspect of the invention, in addition to the effect of the first aspect, the bogie mechanism is only for the magnetic pole detection sensor on the secondary motor secondary side, so the mechanism of the entire transport carriage can be simplified. it can.

The linear motor type conveying apparatus according to claim 3 is the linear motor type conveying apparatus according to claim 1 or 2, wherein the bogie mechanism is provided with a direction regulating means that is always positioned in a direction perpendicular to the traveling direction of the predetermined track. It is characterized by having.
According to the invention of claim 3, the effects of claims 1 and 2 are based on the fact that the movement trajectory of the magnetic pole detection sensor installed in the bogie mechanism is the case where the trajectory of the transport carriage is curved. Since it can set so that it can pass through the center part of a series of permanent magnets on the secondary side of the linear motor, the magnetic pole detection accuracy of the magnetic pole detection sensor can be improved.

According to a fourth aspect of the present invention, there is provided the linear motor type conveyance device according to the third aspect, wherein each of the direction regulating means is located on both sides of the bogie mechanism with respect to the guide surfaces located on both sides of the track. It is characterized by comprising a pair of guide rollers in contact with each other.
According to the fourth aspect of the present invention, the effect of the third aspect of the invention is that the bogie mechanism can always be maintained in a direction perpendicular to the track of the transport carriage.

According to a fifth aspect of the present invention, there is provided the linear motor type conveyance device according to any one of the first to fourth aspects, wherein power is supplied to the conveyance carriage by a non-contact power supply method.
According to the fifth aspect of the present invention, the effects of the first to fourth aspects can be communicated between the transport carriage and the ground in addition to the non-contact power supply to the transport carriage.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The linear motor type transfer apparatus according to the present embodiment is a linear motor arranged along a predetermined track of a transfer carriage in a transfer system for a cassette storing substrates in a semiconductor manufacturing apparatus or a transfer system for various instruments in a hospital. This is a mechanism for sequentially detecting a series of permanent magnets constituting the secondary side of the magnetic pole using a magnetic pole detection sensor. In particular, the main configuration of each invention of the present application is an installation mechanism of a magnetic pole detection sensor for detecting a permanent magnet at a curved portion or a junction branch portion included in a track.

An embodiment of such a technique will be described with reference to FIG. In FIG. 1, reference numeral 1 denotes a track that regulates the travel path of the transport carriage. A guide surface 2 is formed along the track 1. Reference numeral 3 denotes a transport carriage, which travels along the track 1 with the semiconductor substrate storage cassette and other instruments used in a hospital transport system. Reference numeral 4 denotes a traveling carriage traveling wheel, which has a function of moving the transportation carriage 3 along the track 1 and a function of keeping a gap between a primary side and a secondary side of a linear motor to be described later constant.

Reference numeral 5a denotes a primary side of the linear motor, which is composed of a winding and an iron core (not shown), and has a well-known configuration that changes the direction of magnetic flux generation in accordance with the switching of the current direction of the winding. 5b is a secondary side of the linear motor, which is composed of permanent magnets 5bx having different polarities along the track 1, and the linear motor 5 is composed of the linear motor primary side 5a and the secondary side 5b. Reference numeral 6 denotes an encoder which is mounted on the transport carriage 3 and divides the magnetic poles of the permanent magnet constituting the linear motor secondary side detected by a magnetic pole sensor, which will be described later, into the number of pulses necessary for control, and counts one by one. It will increase. As a result, the excitation phase of the linear motor primary coil can be controlled, and at the same time, the moving distance of the transport carriage 3 and the current position of the transport carriage can be detected.

The above configuration is a premise of each invention of the present application. Hereinafter, the configuration forming the gist of each invention of the present application will be described as follows.
That is, referring to FIGS. 1 and 2, reference numeral 7 denotes a bogie mechanism, and the base material 7 a is pivotally attached to a shaft 7 c in a horizontal direction with respect to a support member 7 b fixed to the transport carriage 3. Has been. Reference numerals 7d denote guide rollers, which are paired at both ends of the base material 7a and are rotatably attached to the arm member 7e. The four guide rollers 7d are in contact with the guide wall 2 and roll as the transport carriage 3 travels. 7f is a bogie mechanism traveling wheel, which is rotatably supported by a supporting member 7g extending downward from an appropriate position on both sides of the base material 7a, and rolls on the surface of the track 1 as the transport carriage 3 travels along the track 1. To do. Reference numeral 8 denotes a magnetic pole detection sensor, which has a known configuration that outputs a magnetic pole detection signal by interlinking a magnetic flux with a Hall element (not shown) as a constituent element. The magnetic pole detection sensor 8 is supported by a support member 7h extending downward from the base material 7a, and is adjusted so as to maintain an appropriate gap with respect to the linear motor secondary side 5b.

Next, the operation of the configuration disclosed in FIGS. 1 and 2 will be described.
First, the transport carriage 3 generates thrust in the linear motor 5 by current switching control to the winding of the linear motor primary side 5a by a control device (not shown), and the transport carriage 3 starts running.
At this time, the magnetic pole detection sensor 8 sequentially detects the permanent magnet 5bx constituting the linear motor secondary side 5b, and at that timing, the excitation current direction of the linear motor primary side winding is switched each time, and the transport carriage 3 runs. And the count value of the encoder 6 increases, whereby the current position of the transport carriage 3 can be confirmed.
Further, the traveling wheel 4 rolls on the track 1 to cause the transport carriage 3 to travel, and keeps the gap between the opposing surfaces of the magnetic surfaces of the primary side 5a and the secondary side 5b of the linear motor 5 constant.

Next, the operation of the bogie mechanism 7 as a configuration constituting the gist of each invention of the present application will be described.
As shown in FIG. 1, when the traveling direction of the transport carriage 3 on the track 1 changes from a straight line to a curved line, a process in which the four guide rollers 7 d roll in contact with the guide surface 2 before changing the direction of the transport carriage 3. The base material 7a is regulated parallel to the longitudinal center line of the permanent magnet 5bx constituting the linear motor secondary side 5b from the geometrical principle. Accordingly, the magnetic pole detection sensor 8 moves while facing the central portion in the longitudinal direction of the permanent magnet 5bx.
With this action, when the track 1 is a straight line, the magnetic pole detection sensor 8 accurately detects a series of permanent magnets 5bx constituting the linear motor secondary side 5b even if it is originally a curved portion, and the linear motor primary. Appropriate excitation switching control to the winding of the side 5a is enabled. As a result, the transport carriage 3 can be driven while the linear motor 5 is driven efficiently.

In FIG. 1, the traveling wheel 4 of the transport carriage 3 is configured not to have a bogie mechanism. However, in addition to the bogie mechanism 7 of the magnetic pole detection sensor, the transport carriage travel wheel 4 may also include a bogie mechanism. .

In FIG. 1, a guide roller is not used in the transport carriage, but a guide roller may be provided if necessary.

It is a planar view schematic block diagram which shows suitable embodiment of this invention. It is a principal part notch side view of FIG. It is a planar view conceptual diagram which shows the form of the traveling path of a conveyance trolley, (a) shows a linear traveling path (b) as a curved traveling path, (c) shows the example of a merge branch road. It is a perspective view which shows the structure of a conveyance trolley | bogie. It is a schematic conceptual diagram of a linear motor system conveying apparatus carrying. It is a plane view schematic diagram for demonstrating the condition in case a conveyance trolley drive | works a curved part. It is a plane view schematic diagram for demonstrating the condition in case a conveyance trolley drive | works a merge branch part. It is a plane view schematic diagram for demonstrating the effect of each invention of this application.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Track | truck 2 Guide surface 3 Carriage cart 5 Linear motor 5a Linear motor primary side 5b Linear motor secondary side 5bx Permanent magnet 7 Bogie mechanism 7d Guide roller 8 Magnetic pole detection sensors 42a-42d Feeding transformer 43 Primary feeding line

Claims (5)

Winding, a movable part that constitutes a primary side that generates an alternating magnetic flux in accordance with excitation switching of the winding, and permanent magnets of different polarities are alternately laid along the track of the moving part. A transport carriage that is driven and controlled by a linear motor that comprises a fixed part that constitutes the secondary side, and includes a positive and negative magnetic pole detection sensor for the permanent magnet, and one or more bogie mechanisms. ,
A linear motor type conveying apparatus having a dedicated bogie mechanism for arranging a magnetic pole detection sensor among the one or more bogie mechanisms. Winding, a movable part that constitutes a primary side that generates an alternating magnetic flux in accordance with excitation switching of the winding, and permanent magnets of different polarities are alternately laid along the track of the moving part. A carriage that is driven and controlled by a linear motor that comprises a fixed portion that constitutes the secondary side, and has a positive and negative magnetic pole detection sensor for the permanent magnet, and a single bogie mechanism,
The bogie mechanism is provided with a magnetic pole detection sensor second process, and the linear motor type conveying apparatus.   The linear motor-type conveyance device according to claim 1 or 2, wherein the bogie mechanism is provided with direction restricting means that is always positioned in a direction perpendicular to the traveling direction of the predetermined trajectory.   4. The linear motor system according to claim 3, wherein each of the pair of guide rollers located on both sides of the bogie mechanism is in contact with the guide surfaces located on both sides of the track. Conveying device. 5. The linear motor type transfer device according to claim 1, wherein power is supplied to the transfer carriage by a non-contact power supply method.

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