JP2500546B2 - Elevator device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an elevator driven by a linear motor.

[0002]

2. Description of the Related Art A conventional elevator is a so-called rope in which a rope having a car at one end and a counterweight suspended at the other end is wound around a sheave of a hoisting machine and the friction between the rope is used to raise and lower the car. The traction system is generally used, but recently, various elevators using a linear motor as a drive source have been proposed.

As an example of this, for example, Japanese Patent Laid-Open No. 2-261789
There is one as shown in Japanese Patent Publication. This is provided with secondary conductors of the linear motor on both sides of the car and primary coils of the linear motor on the hoistway side.The car is driven by the linear motor and is guided by guide rollers attached to the upper and lower parts of the car. It is designed to go up and down while being guided on the rails.

[0004]

However, in the structure in which the linear motors are provided only on the left and right side surfaces of the car as described above, even if the car shifts in the front-rear direction while the car is running, the restoring force for the car can be obtained from the linear motor. Since there is no guide device, traveling will be very unstable if there is no guide device. Therefore, in this configuration, it is necessary to always keep the guide device and the guide rail traveling while keeping contact with each other, and as a result, the contact noise and sliding noise between the guide device and the guide rail should be avoided during traveling. However, there is a problem that the generated sound becomes loud especially when traveling at high speed. Further, when this guide device is applied, it is necessary to keep the accuracy of the guide rail high, but there is a problem that it is extremely difficult to ensure the installation accuracy due to the lateral swing of the building, especially in a skyscraper building.

The present invention has been made in view of the above problems, and it is possible to drive stably without providing a guide device in the car, or even if the guide device is provided for safety, It is an object of the present invention to provide an elevator device that can make a gap between the guide rails large, and therefore the car does not come into contact with the guide rails or the like during traveling, and can travel extremely quietly.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a horizontal cross-sectional shape of a car is, for example, an octagon, having a polygonal shape including two sets of four sides in which the center lines connecting two opposite sides are orthogonal to each other. The structure is such that secondary conductors of the linear motor are arranged on each of the four sides, and primary coils of the linear motor are arranged inside the tower at positions facing the secondary conductors. The primary coil is connected to the null flux so that the induction current generated in each primary coil is canceled when the car is located at the center. Further, it is provided with a phase control device for controlling the current phase of the primary coil so as to advance by more than 90 ° with respect to the field phase of the secondary conductor when the elevator is traveling at a low speed.

[0007]

In the region where the car speed is high, even if the car shifts in the front-rear direction or the left-right direction, a repulsive force is generated in the part where the secondary conductor and the primary coil are close to each other, and the repulsive force is generated between the other primary coil and the secondary conductor. Then, because a suction force is generated, the restoring force always works regardless of the direction in which the car position shifts, and the car runs stably. Also, in the low car speed region, the phase difference between the primary current and the field magnetic flux of the secondary conductor is made larger than 90 °, so that the repulsive force is always generated between the primary coil and the secondary conductor, and The smaller the gap between the coil and the secondary conductor, the greater this repulsive force, so the gaps at the four locations are kept almost constant, and the car runs stably.

[0008]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an overall configuration of the present invention, showing a horizontal section of a car and a hoistway and a state where a primary coil arranged on the hoistway side is developed. In FIG. 1, reference numeral 1 denotes a car, in which the horizontal cross-sectional shape is sides 11-18.
The case of an octagon having is shown as an example. 2A-2
D is a secondary conductor of the linear motor, which is arranged on each of the four sides of the car (sides 12 and 16 and sides 14 and 18, that is, two sets of four sides in which the center lines connecting the opposite two sides are orthogonal to each other). Is a superconducting coil (superconducting magnet).

Reference numeral 3 is a hoistway wall, 4A to 4D are positions facing the secondary conductor, primary coils of a linear motor laid on the hoistway wall 3 throughout the hoisting stroke, and 5U to 5W are primary coils, respectively. It is an electric power converter which supplies electric power of a variable voltage variable frequency to each of three phases of 4A-4D.

FIG. 2 is a view showing the appearance of the car as seen from the X direction indicated by the arrow in FIG. 1. Here, a double-deck car is shown as an example, and is the same as FIG. Are denoted by the same reference numerals. In FIG. 2, reference numeral 6 denotes an entrance / exit of the car, which is provided on the side 13 where the superconducting coil is not arranged. Reference numeral 7 is a car door, and 8 is a storage space for storing the car door when the door is opened. The storage space 8 is provided on the side 12 on which the superconducting coils are arranged as shown in the drawing, and a plurality of superconducting coils 2A are arranged in a vertical direction at positions that do not interfere with the superconducting coils 2A. With such a configuration, it is possible to arrange the linear motors at four locations around the car, and to secure a sufficiently wide car entrance / exit.

In a linear synchronous motor composed of a superconducting coil as a secondary conductor and a primary coil as described above, when the superconducting coil moves and the magnetic flux from the superconducting coil crosses the primary coil one after another, it is induced in the primary coil. A current flows and a magnetic flux in the opposite direction to the magnetic flux of the superconducting coil is generated, so that a repulsive force (induced repulsion) is generated between the superconducting coil and the primary coil.

FIG. 3 shows how this induced repulsion occurs. FIG. 3 (a) shows the case where the moving speed of the superconducting coil or car is slow, and FIG. 3 (b) shows the moving speed of the superconducting coil or car. Each case is fast. In FIG. 3, the polarity of the magnetic flux on the primary coil side is shown only for the magnetic flux generated by the induced current, and the magnetic flux based on the power supplied from the power converter is not shown.

When the moving speed of the superconducting coil is slow, the phase of the voltage induced in the primary coil and the induced current due to this are almost the same, and the voltage induced in the primary coil is 90 ° with respect to the magnetic flux of the superconducting coil. Because of the deviation, the magnetic flux due to the induced current in the primary coil is 90 ° out of phase with the magnetic flux in the superconducting coil as shown in Fig. 3 (a), and the voltage itself induced in the primary coil is small. It hardly happens.

On the other hand, when the moving speed of the superconducting coil is high, the frequency of the voltage induced in the primary coil increases, so that the reactance of the primary coil increases and the phase difference between the induced voltage and the induced current caused thereby. Grows larger. Therefore, as shown in FIG. 3B, the phases of the magnetic flux of the superconducting coil and the magnetic flux induced in the primary coil are close to each other, and a repulsive force in the direction perpendicular to the moving direction is generated.

In the present invention, as shown in FIG. 1, since the linear synchronous motors are formed at four places around the car, when electric power is supplied to each of the linear motors independently, the linear motor induces repulsion. As a result, a stable guide force can be obtained especially when traveling at high speed.

However, in the case of a linear synchronous motor, the repulsive force due to the induced current in the primary coil has a component in the direction perpendicular to the moving direction acting as an induced repulsive force (guide force), and at the same time, has a component in the same direction as the moving direction. It works as a repulsive force (magnetic resistance) against the propulsive force, and the thrust is blocked accordingly. The relationship between the magnetic drag force and the induced repulsive force with respect to the elevator speed is shown in FIG.

In the case of an elevator, since acceleration and deceleration are repeated frequently, it is necessary to minimize the influence of thrust loss due to magnetic drag. Therefore, if the primary coil is connected to the null flux, the influence of the magnetic drag can be minimized and a stable guiding force can be obtained.
Null-flux connection is a system in which two sets of primary coils facing the electromotive coil are connected in parallel so that the induced currents generated in the opposing primary coils cancel each other.
The principle will be described with reference to FIG.

FIG. 5 is a diagram showing a state in which a null flux connection of the primary coil and a generation of an induced current (indicated by a dashed arrow) are generated when a pair of the superconducting coil and the primary coil are arranged on both left and right sides of the car. Fig. 5 (a) shows the gap L ₁ between the superconducting coil and the primary coil on the left side and the gap on the right side.
FIG. 5 (b) shows the case where L ₂ is equal, and the case where the car is shifted to the right and the gap becomes L ₁ > L ₂ respectively.

When the gaps L ₁ and L ₂ are equal as shown in FIG. 5 (a), the induced voltages V ₁ and V ₂ generated in the left and right primary coils by the movement of the superconducting coil are equal in magnitude, Since the directions are opposite, the induced currents generated by them cancel each other out, and the primary coil generates a propulsive current supplied from the power converter (primary current).
Only the flowing current does not generate the above-mentioned induced repulsive force or magnetic drag force. Normally, the elevator runs in this state, and therefore thrust loss does not occur at all.

On the other hand, when the car shifts to the right as shown in FIG. 5 (b) and the gap becomes L ₁ > L ₂ , the induced voltage generated in the primary coil becomes V ₁ <V ₂ and Due to the difference, a loop current (induction current) as indicated by a dashed arrow flows. The magnetic flux generated by this induced current acts as an induced repulsive force in the right side primary coil as in the case of FIG. 3, but in the left side primary coil an induced current in the direction opposite to the induced voltage flows, so the generated magnetic flux The polarity is opposite to that of FIG. 3 and thus acts as an attractive force on the left primary coil, which results in the car returning to the center position.

When the primary coil is connected to the null flux in this way, when the car is displaced from the center position, the repulsive force acts in the small gap and the attractive force in the large gap, so that only the induced repulsive force is exerted. The restoring force is even greater than when using the car, and since the induced currents do not cancel each other out while the car is traveling in the center position, the thrust loss due to magnetic drag can be minimized and unnecessary coil loss can be reduced. Can also be suppressed.

FIG. 5 shows an example in which one set of coils is arranged on both sides of the car, but even when the primary coils are arranged at four places as shown in FIG. 1, the primary coils 4A to 4A are arranged.
D can be connected to null flux. This is shown in FIG.

FIG. 6 is a diagram showing how the guide force is generated when four primary coils are connected to the null flux. When the car is in the center position, each primary coil 4
Since the magnitudes of the voltages induced in A to 4D are equal, the induced currents of the primary coils cancel each other and do not flow when connected to the null flux, but as shown in Fig. 6 (a), for example, the position of the car is displaced. When the primary coil 4A and the superconducting coil 2A approach each other, the induced voltage V _A of the primary coil 4A increases and the induced voltage V _C of the primary coil 4C decreases, as shown in FIG. 6 (b).

As a result, a loop current (induction current) as indicated by a dashed arrow flows in each of the primary coils 4A to 4D due to the difference in induced voltage. The length of the dashed arrow represents the magnitude of the current, and here only the induced current is shown. Due to this loop current, a large repulsive force is generated between the primary coil 4A and the superconducting coil 2A, while an attractive force is generated between the primary coil 4C and the superconducting coil 2C.
A small attractive force is also generated between the primary coil 4B and the superconducting coil 2B and between the primary coil 4D and the superconducting coil 2D, and the car is immediately returned to the center position.

As described above, when the primary coils are arranged at four positions around the car and further connected to the null flux, a repulsive force is generated in a small gap without any control, and a suction force is generated on the opposite side. Since it occurs, the car can be restored to its original position immediately in either direction, and very stable running performance can be obtained. Further, since the induced voltage of the primary coil as described above can be obtained regardless of the presence or absence of the power source on the primary side, a stable guiding force can be obtained even during a power failure or an abnormality of the control device.

On the other hand, as described with reference to FIG. 3A, when the car speed, that is, the moving speed of the superconducting coil is low, the induced repulsive force becomes small. However, since the car speed itself is low, running noise and other problems will not be a problem. However, even when traveling at low speed, a stable guiding force can be obtained as follows.

That is, in the linear synchronous motor, if the primary current supplied from the power converter to the primary coil is I, the field magnetic flux of the secondary conductor (superconducting coil) is Φ, and the phase difference between I and Φ is γ, the thrust is Thrust ∝Φ ・ I sinγ Further, the force acting in the horizontal direction, that is, the repulsive force acting between the primary coil and the superconducting coil is the repulsive force ∝Φ ・ I cosγ, so by controlling the phase difference γ and the primary current, Thrust and repulsion can be controlled independently. In the present invention, the primary coil and the secondary conductor are respectively arranged at four places around the car, and by utilizing this repulsive force, the gaps at the four places can be kept substantially constant, and even when the car is traveling at a low speed. A stable guiding force can be obtained.

FIG. 7 shows how a repulsive force is generated by the control of the phase difference γ. The polarity of the magnetic flux on the primary coil side shows only the magnetic flux based on the power supplied from the power converter, and the induced current. Illustration of the magnetic flux generated by is omitted. When the current phase of the primary coil is advanced 90 ° with respect to the field phase of the superconducting coil as shown in Fig. 7 (a), the thrust becomes maximum, but the repulsive force between the primary coil and the superconducting coil becomes zero, and Only the guiding force by On the other hand, as shown in Fig. 7 (b), when the current phase of the primary coil is further advanced, the thrust decreases slightly, but the repulsive force between the primary coil and the superconducting coil increases, and the guiding force due to the above-mentioned induced current is also added to this. . That is, when the car is traveling at a low speed, a stable guide force can be obtained by performing a simple control such that the current phase of the primary coil is advanced further than 90 ° with respect to the field phase of the superconducting coil.

FIG. 8 shows an example of the overall configuration of the control circuit. In FIG. 8, 20 is a position command generator, 21 is a position controller, 22 is a speed command generator, 23 is a speed controller,
24-26 are multipliers, 27-29 are power converters, 30
~ 32 are coils of each phase of the primary coil arranged in the tower, 3
3 and 34 are superconducting coils attached to the car 1, 35 is a load detector, 36 is a position detector for detecting the car position, 37
Is a speed electromotive force phase arithmetic circuit, 38 is a speed arithmetic circuit, 39
Is a function generator whose output becomes 0 at a predetermined speed or more and increases in inverse proportion to the speed at a predetermined speed or less, and 40 is a phase advance circuit which advances the phase in accordance with the output of the function generator 39.

Since the basic structure of the control circuit is well known in the above structure, a detailed description thereof will be omitted. However, in the linear synchronous motor, as described above, with respect to the field phase of the secondary conductor (superconducting coil), It can be operated at the point where the maximum thrust is obtained by advancing the current phase of the primary coil by 90 °. Therefore, using the fact that the speed electromotive force (the induced voltage of the primary coil) is always 90 ° in phase with respect to the field of the superconducting coil,
If the primary coil current phase is controlled so that it is always in phase with this velocity electromotive force, the phase of the primary coil current will always advance 90 ° with respect to the field phase of the superconducting coil, and the amplitude of the primary coil current The required thrust can be obtained by controlling.

Therefore, as shown in FIG. 8, the speed electromotive force phase signal of each phase obtained by the speed electromotive force phase calculation circuit 37,
The current command is obtained by the product of the thrust command and is input to the power converter (inverter or cycloconverter) to advance the primary coils 30 to 32 of each phase by 90 ° with respect to the field phase of the superconducting coil. In addition, the primary current of the amplitude corresponding to the thrust command is supplied.

In the calculation of the phase in the speed electromotive force phase calculation circuit, as described above, the phase of the speed electromotive force always advances 90 ° with respect to the field of the superconducting coil. Superconducting coil position) signal can be easily used. For detecting the car position, for example, a position signal can be obtained as a pulse train corresponding to the car movement by projecting light from a car side to a reflecting plate provided at a constant interval in the tower and receiving the reflected light.

Further, since the required thrust is composed of the weight of the car itself, the thrust for holding the load inside the car, and the thrust for obtaining the acceleration, the thrust command as shown in FIG. 8 is the thrust for obtaining the acceleration. Output of the speed adjuster 23, the car's own weight which is pre-written data, and the load detector 3
The thrust force command is obtained by adding the in-car load signal from 5 to the above. Further, the speed signal is fed back from the position detector 36 because the speed calculation circuit 38 obtains a speed signal from the position signal of the position detector 36 to perform speed feedback control and the elevator requires precise position control. However, the position feedback control is also performed.

With such a structure, the current phase of the primary coil is controlled so as to always advance 90 ° with respect to the field phase of the superconducting coil, and its amplitude depends on the thrust command, that is, the required thrust. Since it is controlled based on the above, it is possible to always obtain stable and efficient thrust. But Figure 7
As explained in (a), if the current phase of the primary coil is advanced by 90 ° with respect to the field phase of the superconducting coil, the guide force will be small when the car is running at low speed, and running will be unstable. As shown in FIG. 8, a phase control device including a function generator 39 and a phase advance circuit 40 is provided so that the current phase of the primary coil advances more than 90 ° when the car runs at low speed.

That is, when the speed of the car is equal to or higher than the predetermined value, the output of the function generator 39 is zero, and the phase advance circuit 40 is used.
Output becomes zero, but when the speed of the car is below a predetermined value, the output of the function generator 29 increases in inverse proportion to the speed,
The phase advance circuit 40 outputs a phase advance signal according to the output signal of the function generator 39. Therefore, the phase of the speed electromotive force output from the speed electromotive force phase calculation circuit 37 is advanced as the car speed becomes lower when the speed of the car is equal to or lower than a predetermined value. As shown in b), the repulsive force in the horizontal direction increases as the car speed decreases.

On the other hand, the repulsive force due to the induced current becomes smaller as the car speed becomes lower as described above. As a result, the guide force, which is a combination of the repulsive force due to the induced current and the repulsive force due to the primary current, is the car at a predetermined speed. Below, the value is almost constant, and stable guide force can be obtained even when the car is traveling at low speed.

[0037]

According to the present invention, the linear synchronous motor is formed at four places around the car, and the primary coil is connected to the null flux. Especially, no special control is performed during high speed running. However, extremely stable traveling performance can be obtained, and also extremely stable traveling performance can be obtained by adding a simple control circuit for advancing the phase of the primary current even at low speed traveling. Therefore, since the vehicle can travel in a non-contact manner with a large gap between the guide device and the guide rail during traveling, extremely quiet traveling performance can be obtained, and the effect increases as the building rises.

[Brief description of drawings]

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

FIG. 2 is a diagram showing an external structure of a car according to the present invention.

FIG. 3 is a diagram showing how induction repulsion of a linear synchronous motor occurs.

FIG. 4 is a diagram showing a relationship between a magnetic drag force and an induced repulsive force with respect to an elevator speed.

FIG. 5 is a diagram showing how the primary coil is connected to a null flux and an induced current is generated.

FIG. 6 is a diagram showing how the primary coil null flux connection and guide force are generated according to the present invention.

FIG. 7 is a diagram showing a state of repulsive force due to a phase difference between a primary current and a field magnetic flux of a secondary conductor.

FIG. 8 is a diagram showing a control circuit of a linear synchronous motor according to the present invention.

[Explanation of symbols]

 1 car 2A to 2D superconducting coil 3 hoistway wall 4A to 4D primary coil 5U to 5W power converter 6 car doorway 7 car door 8 storage space 11 to 18 car sides

Claims (4)

(57) [Claims] 1. An elevator apparatus for driving a car by a linear motor, wherein the horizontal cross-sectional shape of the car is a polygonal structure including two sets of four sides whose center lines connecting two opposing sides are orthogonal to each other. The secondary conductor of the linear motor is arranged on each of the four sides, and the primary coil of the linear motor is arranged at a position facing the secondary conductor inside the tower, and the current phase of the primary coil during low speed traveling of the elevator. Is provided with a phase control device for controlling so that the magnetic field phase of the secondary conductor is advanced by more than 90 °. 2. In an elevator apparatus for driving a car by a linear motor, a horizontal cross-sectional shape of the car is a polygonal structure including two sets of four sides in which a center line connecting two opposing sides is orthogonal to each other. The secondary conductor of the linear motor is arranged on each of the four sides, the primary coil of the linear motor is arranged at a position facing the secondary conductor inside the tower, and the entrance and exit of the car are not arranged on the side where the secondary conductor is arranged. In the elevator apparatus, a storage space for the car door when the door is opened is provided on each side where the secondary conductor is arranged, and the secondary conductor is arranged at a position where it does not interfere with the storage space. 3. The elevator apparatus according to claim 1 or 2, wherein the horizontal cross section of the car is octagonal. 4. The elevator apparatus according to claim 1 or 2, wherein the primary coil is connected to a null flux.