JPS62185503A - Levitation type conveying apparatus - Google Patents

Abstract

PURPOSE:To prevent a conveying vehicle from laterally fluctuating by reversing a laterally moving force acting on the vehicle at one side and a lateral movement acting on the vehicle at the other side with the center line of rails as a boundary at a seamed portion. CONSTITUTION:When a conveying apparatus is started in the state that vertical wheels 45a of a conveying vehicle 15 are contacted with either one inner surface of upper and lower walls of emergency guides 13a, 13b, a controller 41 generates magnetic fluxes of the same direction as or reverse direction to a magnetic flux generated from a permanent magnet 52 at magnets 51, 52 and controls a current flowing to an exciting coil 56 to maintain a predetermined air gap between a magnetic supporting unit 31 and guide rails 12a, 12b. Since seamed portions A are formed in a symmetrical shape at two guide rails 12a, 12b when the vehicle 15 passes the seaming portions A of the rails 12a, 12b, lateral moving forces acting on the vehicle 15 act reversely on the rails 12a, 12b to be cancelled to each other out to become zero.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a levitation type conveyance device suitable for conveying small items, and particularly relates to a levitation type conveyance device capable of stabilizing magnetic levitation traveling. .

[Technical background of the invention and its problems]

BACKGROUND ART In recent years, as part of office automation and factory automation, slips, documents, cash, samples, and the like have been moved between multiple locations within buildings using transport devices.

Conveying devices used for such purposes must not harm the office environment, and must not generate dust or the like and have low noise. For this reason, this type of transport device is configured to be able to support the transport vehicle in a non-contact manner with respect to the guide rail. To support a guided vehicle without contact, it is common to use air or magnetism, but methods that use magnetic attraction to support the guided vehicle have improved followability to guide rails and noise reduction. It is highly effective and is considered the most promising support method.

By the way, in a normal office environment, there are many obstacles, so the configuration of the conveyance path is often complicated. Considering this point, it is desirable that the guide rail has a split structure. This is because if the guide rail is made into a divided structure in this way, the installation work can be simplified.

Usually, the magnetic loop generated by the magnetic support unit is often formed along a plane parallel to the traveling direction and the vertical direction of the transport vehicle due to space constraints in the width direction of the transport vehicle. In this case, the joint portion is formed in a stepped shape so that the magnetic loop is not cut at the joint portion of the divided guide rail. However, in the past, as shown in Fig. 5, due to manufacturing problems, the stepped joint A had the same structure on the left and right guide rails 2a and 2b.
The following problems arose.

That is, when the magnetic support unit 3 mounted on the carrier 1 approaches the joint part A of the guide rails 2a and 2b, the magnetic flux Φ generated in the magnetic support unit 3 is directed toward the right side in the direction of movement in the figure. is cut at the joint part A, so the guide rails 2a, 2a, as shown in FIG.
The magnetic coupling force of the magnetic support unit 3 to the guide rails 2b becomes unbalanced between the left and right sides of the guide rails 2a and 2b.
As a result, there was a problem in that the transport vehicle 1 was subjected to a moving force in a sideways direction with respect to the traveling direction, causing sideways vibration. When such a problem occurs, it not only impairs the stability of magnetic levitation travel, but also requires the addition of a new control system to prevent lateral vibration, which also impairs economic efficiency.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and its purpose is to control the lateral movement at the joint of a guided vehicle traveling along a divided guide rail without adding a special control system. It is an object of the present invention to provide a levitation type conveyance device that can prevent vibration and constantly stabilize a magnetic levitation system.

[Summary of the invention]

The present invention provides a transport vehicle that runs on a guide rail formed by connecting a plurality of rail segments made of ferromagnetic material in series through a joint, so that the vehicle faces the lower surface of the guide rail with a gap in between. In a levitation type transport device, a magnetic support unit is mounted on the guide rail, and a magnetic circuit for levitation of the transport vehicle is stabilized by controlling the excitation current of an electromagnet constituting the magnetic support unit. It is characterized by the joint portion being formed as follows.

That is, the first invention of the present application cuts an arbitrary position of the joint part of the guide rail in a direction perpendicular to the traveling direction of the vehicle, and cuts a cross section located on one side of the joint part, particularly on one side. When looking only at the cross section of the rail division body (the cross section of the rail division body on the other side is abstracted), the length in the rail width direction of the said cross section on both sides of the track center line of the carrier The total sum is equal, and the center of gravity of the cross sections on both sides of the orbit center line are located at symmetrical positions with respect to the orbit center line. By having the same total length in the rail width direction, the total magnetic flux passing through this part can be made equal on both sides of the track center, and by arranging the center of gravity of the cross section at a symmetrical position, the lateral direction generated by the above magnetic flux can be made equal. It becomes possible to cancel out the moving force on both sides of the orbit center.

Further, in the second invention of the present application, when looking at the cross section similarly to the above, the sum of the lengths in the rail width direction of the cross sections on both sides with the center line of the guide rail as a border is equal, and the length of the guide rail is equal. The center of gravity of the cross sections on both sides of the center line are located at symmetrical positions with respect to the center line of the guide rail.

In this case, no lateral movement force is generated on the transport vehicle at the guide rail portion.

In addition, in each of the above cases, even if there is only one guide rail,
It goes without saying that a plurality of wires may be laid in parallel.

〔Effect of the invention〕

According to the present invention, the lateral moving force acting on the guided vehicle on one side of the track center line at the joint and the lateral moving force acting on the guided vehicle on the other side are in opposite directions. It is possible to prevent the transport vehicle from being suspended, or from being subjected to a lateral movement force on the transport vehicle. As a result, it is possible to prevent lateral vibration from occurring. Therefore, according to the present invention, it is possible to stabilize the floating traveling system at the joint portion without requiring a special control system.

[Embodiments of the invention]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A floating conveyance device according to an embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 11 has an inverted U-shaped cross section, and is designed to avoid obstacles in an office space, for example.
It is a crossed track frame. Two guide rails 12a are provided on the lower surface of the upper wall of the track frame 11.

12b are laid in parallel, and on the inner surface of the side wall of the track frame 11 are emergency guides 13a, each having a trowel-shaped cross section.
13b are laid with their open sides facing each other.

A transport vehicle stop is arranged below the guide rails 12a, 12b so as to be movable along the guide rails 12a, 12b. In addition, on the lower surface of the upper wall of the track frame 11 between the guide rails 12a and 12b,
A stator 16 of the linear induction motor is arranged along the guide rail at a predetermined distance.

The guide rails 12a and 12b have a split structure to facilitate installation work in an office, and are constructed by connecting in series a plurality of rail split bodies 21 made of ferromagnetic material and painted white on the lower surface. has been done.

The joint part A of each rail divided body 21 is the same as the rail divided body 2.
A portion a1 extending in the width direction of the divided body 21 from the inner end of the divided body 21 to the center thereof, and a portion a1 extending in the width direction of the divided body 21 from the inner side end of the divided body 2
a portion a2 extending in the length direction of 1; and a portion a extending in the width direction from this portion a2 to the outer end of the divided body 21.
It has a staircase shape consisting of 3.

A portion a2 extending in the length direction of the divided body 21 is set longer than the length of the magnetic flux generated by the magnetic support unit uj, which will be described later, in the traveling direction of the transport vehicle. The joint portion A between the two guide rails 12a and 12b has a shape that is symmetrical to each other with respect to the track center line of the transport vehicle length. This joint portion A has been subjected to a predetermined joining process.

Next, the composition of the Transport Minister will be explained. That is, a flat base 25 is arranged so as to face the lower surfaces of the guide rails 12a and 12b. The bases are two divided plates 26a arranged in the direction of travel.

26b, and a connecting mechanism 27 that rotatably connects both side plates 26a and 26b in a plane orthogonal to the direction of travel. A total of four magnetic support units are mounted on each of the four corners of the upper surface of this base. These magnetic support units are attached to the base wall using bolts and pedestals 33 (not shown) on the base-formed upper surface. An optical gap sensor 34 is attached to these magnetic support units to detect the gap length between the magnetic support units and the lower surfaces of the guide rails 12a and 12b. Further, on the lower surface of each dividing plate 26a, 26b, 2
Container 3 for accommodating goods to be transported via a pair of connecting members 35
7.38 are installed respectively. In these containers 37 and 38, there are a control device 41 for controlling each of the four magnetic support units, a constant voltage generator 42, and a small-capacity power source 43 for supplying power to these devices. A total of four are installed. In addition, at the four corner positions of the lower surface of the base, the emergency guides 13a,
Four vertical wheels 45a contact the inner surfaces of the upper and lower walls of the guide 13b to support the transport vehicle ratio in the vertical direction, and the emergency guide 1
Four lateral wheels 45b are attached to the inner surfaces of the side walls of 3a and 13b to support the transport vehicle in the left-right direction. The base support also serves as a conductor plate, which is a movable element of the linear induction motor mentioned above, and is placed at a height facing the stator 16 with a slight gap when the device is in operation. There is.

The upper end of the magnetic support unit is the guide rail 12a.
, two electromagnets 51.5 arranged in a direction parallel to the direction of movement of the transport minister in the figure, so as to face the lower end of the transport member 51.5.
2, and a permanent magnet 53 interposed between these electromagnetic needles and each lower side surface of the mouse, and has a U-shape as a whole. Each electromagnet υ-1 path includes a yoke 55 made of ferromagnetic material and a coil 56 wound around this yoke 55.
Each coil 56 includes an electromagnet 51.5.
They are connected in series in such an orientation that the magnetic fluxes formed by 2 are added to each other.

Further, the control device 41 is configured as shown in FIG. 2, for example. In this figure, arrows indicate signal paths and bar lines indicate power paths. This control device 4
1 is a sensor unit 61 that is attached to the carrier stop and detects changes in the magnetomotive force or magnetic resistance in the magnetic circuit formed by the magnetic support unit or the movement of the carrier j-.
Based on the signal from the sensor section 61, the coil 56
It consists of an arithmetic circuit 62 that calculates the power to be supplied to the coil 56, and a power amplifier 63 that supplies power to the coil 56 based on the signal from the arithmetic circuit 62. The support units 41 are controlled respectively. The sensor section 61 includes a modulation circuit 64 that modulates the signal of the optical gap sensor 34 described above in order to suppress the influence of external noise, and a current detector 65 that detects the current value of the coil 56. The arithmetic circuit 62, on the one hand, introduces the signal from the optical gap sensor 34 via the modulation circuit 64, subtracts the gap length setting value Z) with a subtracter 66, and directly outputs the output of this subtracter 66. Alternatively, the signal from the current detector 65 is guided to the feedback gain compensator 68 and 69 via the differentiator 67, and the signal from the current detector 65 is guided to the feedback gain compensator 70. After being compared with the O signal at step 71, the signal compensated by the integral compensator 72 and the addition output from the adder 73 of the three feedback gain compensators 68 to 70 are compared at a subtracter 74, and the deviation thereof is calculated. is output to the power amplifier 63.

Further, the constant voltage generator 42 includes a power source 43 and a control device 41.
are interposed between the modulation circuit 64 and the arithmetic circuit 62.
A current is always supplied to the optical gap sensor 34 at a constant voltage. This constant voltage generator 42
This is to eliminate the influence of voltage drops caused by load fluctuations in the reference voltage generator 7 on the control device 41.
5, and a current amplifier 76 that always supplies the required current at a constant voltage to the control device 41 based on the output signal of the reference voltage generator 75.

Next, the operation of the floating conveyance device according to this embodiment configured as described above will be explained.

When the device is in a stopped state, the emergency guide 13a
, 13b, the vertical wheels 45a of the transport vehicle stop are in contact with the inner surfaces of either one of the upper and lower walls. When the device is started in this state, the control device 41 causes the electromagnets to generate magnetic flux in the same direction or in the opposite direction to the magnetic flux generated by the permanent magnet 53, and causes the magnetic support unit and the guide rail 12 to
The current flowing through the excitation coil 56 is controlled to maintain a predetermined gap length between the excitation coil 56 and the excitation coil 56. by this,
As shown in FIG. 3(b), permanent magnet 53 ~ yoke 55 ~
A magnetic circuit consisting of a path from the gap P to the guide rail 12a (12h) to the gap P to the yoke 55 to the permanent magnet 53 is formed. The magnetic flux Φ formed in this magnetic circuit is shown in FIG.
As shown in (C), it occurs along a plane parallel to the traveling direction of the transport vehicle stop and to the vertical. The gap length is determined by the weight of the supported object such as a carrier stop and the magnetomotive force of the permanent magnet 53 between the magnetic support unit 31 and the guide rail 12a (
12b) is set to a length that exactly balances the magnetic attraction between them. The control device 41 controls the excitation current of the electromagnet 5-9 in order to maintain this gap length. This results in so-called zero power control.

Assuming that the carrier stop is located directly below the stator 16 of the linear induction motor, when this stator 16 is energized, the base pressure receives electromagnetic force from the stator 16, so the carrier U- is magnetically levitated. The guide rail 12a remains as it is.

Start driving C along 12b. If the stator 16 is placed again before the transport vehicle stop comes to a complete standstill due to the influence of air resistance, the transport vehicle U is energized again and the guide rail 1
Continue moving along lines 2a and 12b. This movement continues until the destination point.

In this way, the carrier stop can be moved to the destination point in a non-contact manner.

According to this embodiment, even when the carrier stop passes through the joint A of the guide rails 12a and 12b during the movement process, as is clear from FIG. Since the portion parallel to the traveling direction of the stop coincides with the direction in which the magnetic flux Φ is generated, the magnetic flux does not completely cross the joint portion A. Therefore, changes in magnetic resistance can be suppressed, and control performance when passing through the joint can be stabilized.

In this way, the joint part A is the two guide rails 1.
2a and 12b have a symmetrical shape, as is clear from FIGS. 3 and 4, especially (C), the transport vehicle 15
Even if the magnetic flux Φ is cut in half when the guide rails 12a and 12b approach the joint, the breakage occurs between the outer sides of the guide rails 12a and 12b or between the inner sides of the guide rails 12a and 12b. For this reason, the lateral movement force that moves the transport vehicle 15 is applied to the two guide rails 12a, 12.
b act in opposite directions, and eventually the lateral moving forces cancel each other out and become zero. For this reason, it is possible to prevent lateral vibration and stabilize floating travel.

Furthermore, in the device of this embodiment, the guide rail 12a,
If the flatness of the magnetic support unit 12b is out of alignment or the center of gravity of the conveyor stop changes, etc., create a gap in each magnetic support unit so that the permanent magnet 53 generates an attractive force that is in proportion to the weight that each magnetic support unit arm is to support. magnetic support unit ■ and guide rail 12a,
12b. In this case,
The dividing plate 26a is connected to the dividing plate 26b around the connecting mechanism 27.
The magnetic support units rotate relative to each other and act to maintain appropriate gap lengths between the respective magnetic support units.

Note that the present invention is not limited to the embodiments described above.

For example, in the above embodiment, the joint portion A has a one-step staircase shape, but this is because the guide rails 12a, 1
There is no limitation on the shape of the joint part of the band member 21 forming the part 2b, and even if the joint part A has a multi-step shape as shown in FIG. 5, or as shown in FIG. Even if the shape is sloped, the object of the present invention can be achieved as long as the shape is symmetrical with respect to the center of the track of the vehicle stop.

Furthermore, in the mortise and tenon method shown in FIG. 7, when looking at the cross section of one rail segment (for example, the left side in the figure) 21, the length of the cross section in the rail width direction is Sum (
If a+b) are equal and the distances from the center line of the track to the center of gravity of the above-mentioned cross sections on both sides are equal, the lateral moving forces acting on the vehicle stop are exactly balanced, so the present invention It can be effective.

Further, each guide rail 12a has the above relationship.

When it comes to the cross sections on both sides of the center line of 12b, no lateral moving force is generated on the conveyor stop, so that the above-mentioned objective can be achieved. FIG. 8 shows one example, in which the guide rail 12a
, 12b is provided with a wedge-shaped joint portion A that is symmetrical with respect to the center line.

In this way, the joint part A is connected to the guide rails 12a, 12
If the shape is symmetrical with respect to the center line of b, regardless of whether it is symmetrical with respect to the track center line, no lateral movement force is originally generated on the conveying vehicle piece.

Furthermore, it goes without saying that the present invention is not limited to the case where there are two guide rails, but can also be applied to the case where there is one guide rail, or even to the case where there are three or more guide rails. do not have.

Furthermore, the present invention is also applicable to a floating conveyance device that uses only electromagnets as magnetic support units.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a floating conveyance device according to an embodiment of the present invention, FIG. 2 is a block diagram showing an electrical configuration of a control device of the device, and FIG. 3 is a conveyance device in the same device. These are diagrams for explaining the state of the magnetic circuit when the car approaches a joint, where (a) is a plan view, (b) is a partially cutaway side view, and (C) is a partially cutaway side view. is a partially cutaway front view,
Figure 4 is a diagram for explaining the state of the magnetic circuit when the conveyance vehicle crosses the joint in the same device, and Figure 4 (a)
is a plan view, (b) is a partially cutaway side view, and (C) is a partially cutaway side view.
) is a partially cutaway front view, FIGS. 5 to 8 are plan views showing the structure of guide rails according to other embodiments of the present invention, and FIG. 9 is a diagram of the magnetic circuit of a conventional floating conveyance device. FIG. 3 is a diagram for explaining the situation. 1, 31... magnetic support unit, 2, 12a,
12b... Guide rail, 11... Track frame, 13
a, 13b...Emergency guide, ■-...Transportation vehicle, 1G...Stator of linear induction motor, 25...Base, 26a, 26b...Dividing plate, 27...Connection Mechanism, 34... Gap sensor, 37.38... Container, 41... Control device, 42... Constant voltage generator,
43...Power supply, 51°52...Electromagnet, 53...
Permanent magnet, 55... Yoke, 56... Coil, A...
・Joint part, P... air gap. Applicant's agent Patent attorney Takehiko Suzue No. 5 Figure 6 Figure 91

Claims (4)

[Claims] (1) A guide rail formed by connecting a plurality of rail segments made of ferromagnetic material in series at joints, a carrier disposed so as to be able to travel freely along the guide rail, and a carrier mounted on the carrier. one or more magnetic support units each having an electromagnet facing the lower surface of the guide rail with an air gap therebetween; and controlling the excitation current of the electromagnet to stabilize a magnetic circuit through which the magnetic flux generated by the magnetic support unit passes. In the floating conveyance device, in a section where the magnetic support unit generates magnetic flux along a plane parallel to the traveling direction and the vertical direction of the conveyance vehicle, the magnetic flux on one side of the joint portion is When looking at an arbitrary cross section of the rail division body, the sum of the lengths in the rail width direction of the cross sections on both sides bordering the track center line of the transport vehicle is equal;
The floating conveyance device is characterized in that the positions of the centers of gravity of the cross sections on both sides of the orbit center line are located at symmetrical positions with respect to the orbit center line. (2) The magnetic support unit includes the electromagnet, and a permanent magnet that is interposed in a magnetic circuit composed of the electromagnet, the guide rail, and the air gap and supplies a magnetomotive force necessary to levitate the carrier. A floating conveyance device according to claim 1, characterized in that it is comprised of: (3) A guide rail formed by connecting a plurality of rail segments made of ferromagnetic material in series at joints, a carrier disposed so as to be able to travel freely along the guide rail, and a carrier mounted on the carrier. one or more magnetic support units each having an electromagnet facing the lower surface of the guide rail with an air gap therebetween; and controlling the excitation current of the electromagnet to stabilize a magnetic circuit through which the magnetic flux generated by the magnetic support unit passes. In the floating conveyance device, in a section where the magnetic support unit generates magnetic flux along a plane parallel to the traveling direction and the vertical direction of the conveyance vehicle, the magnetic flux on one side of the joint portion is When looking at an arbitrary cross section of the rail division body, the sum of the lengths in the rail width direction of the cross sections on both sides with the center line of the guide rail as the border is equal, and with the center line of the guide rail as the border. A floating conveyance device characterized in that the positions of the centers of gravity of the cross sections on both sides thereof are located symmetrically with respect to the center line of the guide rail. (4) The magnetic support unit includes the electromagnet, and a permanent magnet that is interposed in a magnetic circuit composed of the electromagnet, the guide rail, and the air gap and supplies the magnetomotive force necessary to levitate the carrier. A floating conveyance device according to claim 3, characterized in that it is comprised of: