JPH07135704A - Levitation type conveyor - Google Patents

Abstract

PURPOSE:To control the levitation of a cart stably even when disturbance on the track side in the detection of gap length is generated by forming constitution having a variable means of a distance between the detecting surface of a detecting means and the levitation support surface of a track. CONSTITUTION:An electromagnet 14, an amplifier 15, a gap length detector 16, an auxiliary wheel 17 and a gap-length computing element 18 are loaded on a cart 13, and levitation is controlled by magnetic attraction force generated from the electromagnet 14 to a rail 10. A gap detecting body 19 is supported and fixed to a height adjusting screw 21 to a track frame 11, and a gap detecting surface 20 is set in parallel with the levitation support surface of the rail 10. When the reflectivity of the gap detecting surface 20 is lowered by fouling 22, the gap length detector 18 moves the position of the gap detecting body 19 by the height adjusting screw 21 by the error section of gap length, and conforms the position of the gap detecting body 19 to physical gap length. Accordingly, the control of the levitation of a conveyor can be stabilized when disturbance is generated in the gap detecting surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a levitation type conveyance device for conveying small items.

[0002]

2. Description of the Related Art Conventionally, a so-called wheel-type carrier, which is a carrier with wheels, is mainly used as a carrier for carrying luggage. However, since this wheel-type carrier causes dust and vibrations, recently, a levitation-type carrier is being used in which the carrier is levitated by air or magnetic force and travels on a track.

By the way, in this type of levitation-type carrier vehicle, various detectors are used for the purpose of controlling the levitation amount of the vehicle body. FIG. 3 is a conceptual diagram of levitation control of a carrier vehicle that is levitation by magnetic force.

In FIG. 3, reference numeral 1 denotes a rail made of a ferromagnetic material, which is fixed to a track frame 2 to form a track 3 and is fixed to a building or the like by a fixing member (not shown). Reference numeral 4 denotes an electromagnet attached to the transport vehicle 5. The coil current of the electromagnet 4 is controlled by the amplifier 6 so that the distance (gap length 1) between the lower surface of the rail 1 and the upper surface of the electromagnet 4 becomes a desired value. It Reference numeral 7 is a gap length detector for detecting the gap length 1 by using the surface of the rail 1 attached to the transport vehicle 5. Reference numeral 8 denotes an auxiliary wheel fixed to the transport vehicle, which is not in contact with the rail 1 in a normal floating state, but is in contact with the rail 1 when the floating is stopped and the vehicle body is fixed to the rail. On the other hand, 9 is a gap length calculator that calculates and outputs a certain gap command value, and the gap length detector 7
The calculated value for the gap length 1 from is output to the amplifier 6.

Now, the gap length control will be described. When the levitation is stopped, the carrier is attracted and supported by the rail 1 by the magnetic force of the electromagnet 4. This time,
The gap length l between the upper surface of the electromagnet 4 and the lower surface of the rail 1 is l
_The auxiliary wheel 8 is in contact with the rail 1 so as to be ₀ .
The carrier is attracted and supported by the magnetic force that acts on itself and exceeds the gravity.

[0006] Here, in order to release the carrier vehicle from the rail 1, if the attractive force of the electromagnetic force 4 is weakened and the attractive force becomes smaller than the gravity acting on the vehicle body itself, the carrier vehicle 5
Naturally falls from the rail 1 and floats. here,
The gap length l ₀ is the levitation limit due to the magnetic force that can be generated by the electromagnetic force 4, and the gap length detector 7 detects the gap length l ₀ and outputs an exciting current from the amplifier 6 to the electromagnet 4 with the calculated value. To do.

Incidentally, the places where the carriage 5 starts or stops the levitation control are, for example, places on the track where loading is carried out, where charging is carried out, where maintenance of the carrying vehicles is carried out, etc. Called a station), many are set.

[0008]

In order to control the vehicle body with respect to the rail 1 to have a desired gap length in such a floating carrier, the gap length detected by the gap length detector 7 is used. Since it is based on the detected value,
The stability of the characteristics of the gap length detector 7 for detecting the gap length is important for controlling the levitation.

By the way, the track on which the levitation transport vehicle travels is composed of various parts, and there is a limit to making physical conditions such as dimensions and surface treatment uniform. For example, in the gap detection method in which the gap length detector 7 is an optical detector and the reflected light from the rail surface that has been specially processed is used, it is very difficult to make the rail surface uniform. However, even if the gap lengths are physically the same, a difference may occur in the detected values. When a large difference occurs in the detected values, for example, when the command value to the amplifier 6 becomes small, the exciting current from the amplifier 6 also becomes small, the magnetic force for levitation cannot be obtained, and levitation cannot start. To do.

Further, a decrease in the amount of reflected light due to stains or scratches on the detection surface also affects the gap length detection. Regarding individual transport vehicles, it is possible to stabilize the gap length detector by using, for example, the reference detection surface, but it is difficult to make the conditions of the detection surface of multiple stations on the track uniform. That's right.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a levitation type conveyance device capable of stably controlling the levitation of a conveyance vehicle even when the above-mentioned disturbance on the track side in the gap length detection occurs.

[0012]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a carrier vehicle that travels on a track, a levitation unit that floats the carrier vehicle by magnetic force, and the like. Track, a flying height detector for detecting the flying height between the track and the carrier, a detecting means having a flying height detecting surface parallel to the track and parallel to the floating support surface of the track, and detecting the detecting means. It is characterized by having a surface and a variable means for varying the distance between the surface and the floating support surface of the track.

[0013]

In the present invention thus constructed, the flying height of the carrier vehicle is detected by the detector having the gap length detecting surface parallel to the track and parallel to the track surface. If there is a difference in the output value of the flying height detector of the carrier even though the physical gap length between the track and the carrier is the same, determine the distance between the detection surface and the track surface as the output value of the detector. By changing only the difference, the physical gap length and the output value of the flying height detector can be matched.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a levitation type transport device according to the present invention. In FIG. 1, a rail 10 made of a ferromagnetic material is fixed to a track frame 11 to form a track 12. The transport vehicle 13 is equipped with an electromagnet 14, an amplifier 15, a gap length detector 16, auxiliary wheels 17 and a gap length calculator 18,
Levitation control is performed by the magnetic attraction force generated by the electromagnet 14 on the rail 10. The electromagnet 14 is formed by a combination of a permanent magnet and a coil (not shown), and in a state where the levitation control is not performed, the carrier 13 is attracted and fixed to the rail 10 by a magnetic attraction force of only the permanent magnet. The gap length detector 16 is an optical detector, and detects the gap length between the surface of the gap detector 19 supported in parallel with the rail 10, that is, the gap detection surface 20, and the gap length calculator 18
Output the gap length to. The gap length calculator 18 calculates based on the gap length signal from the gap length detector 16 and a preset gap length value, outputs a command value to the amplifier 15, and from the amplifier 15 to the electromagnet 14. An exciting current flows, and by controlling the attractive force to the seal 10, it is possible to float.

The gap detecting surface 20 which is the surface of the gap detecting body 19 is a surface for reflecting the light projected from the gap length detector 16 and is subjected to a uniform surface treatment. The gap detection body 19 is a uniform continuous body with a small gap due to a seam like the rail 10, but can be deformed to some extent when adjusting the height described later (for example, A thin belt).

The gap detector 19 is fixed to the track frame 11 by being supported by height adjusting screws 21. Normally, the gap detection surface 20 is parallel to the levitation support surface of the rail 10, here the lower surface. Is set to be

Now, the operation when the gap detection surface 20 is contaminated or has uneven surface treatment will be described with reference to FIG. Note that, here, the operation when the transport vehicle starts to float will be described.

When the reflectance of the gap detecting surface 20 is lowered by the dirt 22, the optical gap length detector 18 normally sets the gap length on the detecting surface to l ₀ (FIG. 2 (a)). On the plane, it is recognized as l ₁ (l ₁ > l ₀ ) (Fig. 2
(B)). However, it is assumed that the gap length between the lower surface of the rail 10 and the electromagnet 14 is maintained at the gap length L by the auxiliary wheel 17. Here, when the gap length detector 18 erroneously recognizes the physically same gap length as described above, the position of the gap detector 19 is raised by the gap length error (l ₁ −l ₀ ). It is possible to match the output of the gap length detector 18 with the physical gap length by moving the height adjusting screw 21 (FIG. 2C). In this case, the height adjusting screw 21 is provided on the track 12 at the place where the levitation control of the guided vehicle is started, that is, at the station.

[0019]

As described above, according to the present invention, when a disturbance occurs on the gap detection surface, the gap detection surface is moved by the erroneous detection amount of the gap length, so that the physical gap length and the gap The output from the long detector can be matched.

Therefore, the conditions on the track side as seen from the gap length detector of the carrier can be made uniform. Further, it is not necessary to consider the gap length detection error in the calculation of the floating control of the carrier vehicle.

[Brief description of drawings]

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

FIG. 2 is a configuration diagram illustrating an operation according to an embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing a conventional floating type transport device.

[Explanation of symbols]

10 ... Rail, 11 ... Track frame, 12 ... Track, 13 ... Transport vehicle, 16 ...
Gap length detector, 17 ... Gap length calculator, 19 ... Gap detector, 20 ... Gap detection surface, 21 ... Height adjustment screw.

Claims (1)

[Claims] 1. A transportation vehicle that travels on a track, a levitation unit that floats the transportation vehicle by magnetic force, a track on which the transportation vehicle floats, and a levitation system that detects a floating amount between the track and the transportation vehicle. An amount detector, and a detection means having a flying height detection surface parallel to the track and parallel to a floating support surface of the track;
A levitation type conveyance device comprising: a varying means for varying a distance between a detecting surface of the detecting means and a floating supporting surface of a track.