JPH0791003B2 - Elevator load detection device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an elevator load detection device for detecting an unbalanced load between a car side and a counterweight by measuring an axial torque of an elevator hoist. Is.

[Prior Art] In an elevator, the load torque acting on the hoisting motor changes depending on the number of passengers in the car. Because of this fluctuation,
Sudden acceleration / deceleration may occur at the time of car start-up and deceleration, impairing riding comfort, and the time to reach the target speed may become long. In order to deal with such a problem, conventionally, for example, as disclosed in Japanese Utility Model Publication No. 60-2138, a method of providing a scale device under the floor of a car has been adopted.

That is, the car floor is supported by an elastic body, the deflection of this elastic body is detected by a microswitch, etc. to detect the load inside the car, and the detection result is used to speed control the hoisting motor for smooth acceleration / deceleration. It is something to do.

FIG. 7 and FIG. 8 show an elevator using a conventional load detecting device, FIG. 7 is a structural view of an elevator using a conventional load detecting device as seen from the side, and FIG. 8 is a conventional load detecting device. It is the block diagram seen from the front of the elevator using the apparatus.

In the figure, 1 is a hoistway, 2 is a machine room provided directly above the hoistway 1, 2a is a floor of the machine room 2, 2b is a hole penetrating the floor 2a, and 3 is upright on the floor 2a. Receiving beams arranged at the positions corresponding to the peripheral wall of the road 1, 4 is a machine base whose both ends are respectively supported by the receiving beams 3, 5 is a base placed on the machine base 4 via a vibration-proof rubber 6, and 7 is A drive sheave in which a rotating shaft is arranged in the width direction of the base 5 and which is arranged substantially at the center of the base 5, and 8 is a deflector attached to a deflector beam 9 hanging from the base 5, the drive sheave being It is arranged corresponding to 7. 10 is the base 5
Fixed to the bearing body supporting one end of the shaft of the drive sheave 7,
Is composed of a balanced shaft gear as a main body and is fixed to the base 5 to drive the drive sheave 7. 12 is an electric motor to drive the speed reducer 11. 13 is cinder concrete laid on the floor 2a. 14 is a main rope wound around the drive sheave 7 and the deflecting sheave 8 and hung from the hole 2b to the hoistway 1, 15 is a car connected to one end of the main rope 14, 15a is a car frame, and 15b is a cab room , 15
c is an elastic body that is placed in the car frame 15a and supports the car floor 15d, and 15e is a microswitch that detects the amount of deflection of the elastic body 15c. The detection result is sent to the machine room via a cable (not shown). 2 is transmitted. 16 is a counterweight.

In the elevator having the above configuration, when the load in the cab 15b is detected by the microswitch 15e, the unbalanced load between the load on the car side and the load on the counterweight side is calculated. Based on this calculation result, it is possible to detect the unbalanced torque applied to the electric motor 12 at the time of starting the sheave 7.

[Problems to be Solved by the Invention] Since the conventional load detection device is composed of the elastic body and the microswitch as described above, the number of installations is limited. Therefore, when the passenger is biased right above the microswitches in the car, the deflection of the elastic body is locally excessive, and the microswitches, which would not operate if they were evenly distributed, operate. On the contrary, when the elastic body is distributed in a deviated place where there is no microswitch, the amount of deflection of the elastic body becomes too small, and the microswitch does not operate. That is, the load in the car is erroneously detected. Also,
Since the micro switch is provided under the basket, a long cable is required up to the control panel, and there is a problem that a wire breakage occurs in the middle or the long cable is used, resulting in high cost.

In order to solve this type of problem, in JP-A-62-88792, a drive sheave around which a main rope having a car on one side and a counterweight on the other side is wound, and the drive sheave are described. Detects the twisting that occurs on the rotating shaft due to the braking device that stops, the rotating shaft that intervenes between the driving sheave and the braking device to transmit the braking force to the driving sheave, and the unbalanced load that acts on the main rope. Disclosed is a technology of an elevator load detection device that includes a twist detector and that detects an unbalanced load between the car side and the counterweight side.

However, in the technique disclosed in this publication, a slight change in magnetism of the magnetostrictive material attached on the rotary shaft caused by a twist applied to the rotary shaft changes the inductance of the detection coil for detecting the twist, and the change is extracted. However, even if a slight twist generated on the rotating shaft is detected, a voltage is applied to extract the resistance component of the detection coil and the output signal connected in series with the detection coil. There is a problem that the twist cannot be detected with high accuracy because the resistance value of the resistor to be generated fluctuates due to the temperature change.

Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to provide a high-accuracy load detection device for an elevator that can detect the load of a car even if passengers are offset in the car. .

[Means for Solving Problems] An elevator load detection device according to the present invention is a drive sheave in which a main rope having a car on one side and a balance weight on the other side is wound around the drive sheave, and the drive sheave. And a rotating shaft for interposing a braking force between the driving sheave and the braking device to transmit a braking force to the driving sheave, and an unbalanced load acting on the main rope to cause the rotating shaft. A load detector for an elevator, comprising a twist detector for detecting a twist, and detecting an unbalanced load between the car side and the counterweight side, wherein the twist detector has an inclination angle around the rotary shaft. Of 45 degrees and a plurality of spirals of which the inclination angle is 135 degrees are formed in two rows separated from each other in the axial direction of the rotation shaft, and a first surrounding the two rows of magnetostrictive materials, respectively.
A superconducting coil, an exciting coil located between each of the first superconducting coils for exciting the rotating shaft, each of the magnetoelectric converting elements for magnetoelectrically converting a magnetic field induced in each of the first superconducting coils, A second superconducting coil that surrounds each of the magnetoelectric conversion elements in a magnetically shielded state.

[Operation] In the present invention, the torsion detector includes a first superconducting coil that surrounds each of the two rows of magnetostrictive materials, and a magnetoelectric conversion element that magnetoelectrically converts a magnetic field induced in each first superconducting coil. And a second superconducting coil that surrounds the magnetoelectric conversion element in the state of being magnetically shielded, a load difference occurs in the cage and the counterweight, and this load difference causes a slight twist in the rotating shaft of the drive sheave. However, this slight twist can be detected with high accuracy by a circuit in which the magnetic flux entering the loop of the first superconducting coil and the second superconducting coil becomes zero due to complete diamagnetism due to superconductivity, and the imbalance that occurs in the drive sheave. The torque can be detected, and the unbalanced torque can be accurately detected even when the passenger gets on the car in one side of the car.

[Embodiment] An elevator load detector according to an embodiment of the present invention will be described below with reference to Figs. 1 to 6. In the figure,
The same reference numerals and symbols as those of the conventional example indicate the same or corresponding components as those of the conventional example, and therefore, duplicated description will be omitted here.

FIG. 1 is an explanatory diagram showing a method of mounting a load detector of an elevator according to an embodiment of the present invention.

In FIG. 1, 11a is an input shaft which is an extension of the electric motor shaft of the electric motor 12, 11b is a first gear fixed to the input shaft 11a, 11c is a second shaft, and 11d is axially supported by the second shaft 11c. A second gear that meshes with the first gear 11b, a third gear 11e that is also axially supported by the second shaft 11c, and an output shaft 11f, to which the drive sheave 7 is fixed. 11g is fixed to the output shaft 11f,
The fourth gear 11h meshes with the gear 11e, and 11h is a gear box. Reference numeral 12a is a brake for stopping the input shaft 11a, and 17 is a detector for detecting the twist generated in the output shaft 11f due to the unbalanced torque applied to the drive sheave 7, the details of which are shown in FIG.

FIG. 2 is an explanatory view showing a method of detecting the twist of the rotary shaft of the load detector of the elevator according to the embodiment of the present invention.

In FIG. 2, 17a is a first magnetic layer, which is composed of a plurality of magnetostrictive materials (for example, permalloy) spirally formed along the surface so that the inclination angle is 45 degrees with respect to the center line of the output shaft 11f. The magnetostrictive material is arranged at a predetermined interval in the circumferential direction of the shaft 11f. Reference numeral 17b is a second magnetic layer, which is inclined in a direction opposite to that of the first magnetic layer 17a and has an inclination angle of 45 degrees, and is arranged so as to be symmetrical to the first magnetic layer 17a. 17c is an exciting coil. 17
d and 17e are the first superconducting coils, 17f is a cylindrical non-magnetic body through which the output shaft 11f penetrates, 17g is a support member that houses the non-magnetic body 17f and is fixed to the gear box 11h, and 17h is a non-magnetic body 17f. Is an end member attached to the open end of the.

3 (a) and 3 (b) are explanatory views showing a magnetic flux detection method using a superconducting coil.

In FIG. 3, 17d is a first superconducting coil, 20d is a superconducting coil, a second superconducting coil having an inductance smaller than that of the first superconducting coil 17d connected to the first superconducting coil 17d, 21d is a hall element, and a second superconducting coil. It is surrounded by the coil 20d. Reference numeral 22d is a magnetic shield that covers the second superconducting coil 20d and the Hall element 21d and shields the magnetic flux entering from the outside.

The exact same configuration is provided for the other superconducting coils 17e. The inductance of the first superconducting coils 17d and 17e is set to L
1. Let L2 be the inductance of the second superconducting coils 20d and 20e. First superconducting coils 17d, 17e, second superconducting coils 20d, 2
0e is operated at such a low temperature that it becomes superconducting.

Next, the first superconducting coils 17d and 17e will be described.

The first superconducting coil 17d is placed in the magnetic flux detection position, that is, in the external magnetic field to be measured. Let the magnetic flux density be B1. The magnetic flux entering the loop made of the first and second superconducting coils becomes "0" as a whole due to perfect diamagnetism due to superconductivity. When the first superconducting coil 17d is placed at the detection position and the detected magnetic flux Φ1 is linked, the first superconducting coil is shielded because of the magnetic shielding.
The opposite magnetic flux Φ2 that is linked to L1 of 17d is linked to L2 of the second superconducting coil 20d. That is, L1 · Φ1 = L2 · Φ2. Also, the magnetic flux density in the second superconducting coil 20d is
Assuming 2, the magnetic flux density B2 is approximately expressed by the following equation.

B2 = L1 · B1 / L2 In this embodiment, since L1> L2, the magnetic flux density B2 becomes larger than the magnetic flux density B1 in the second superconducting coil 20d. That is, the magnetic flux is amplified and added to the Hall element 21d,
Highly sensitive measurement is possible.

As the superconducting material according to this embodiment, for example, Nb
Various superconductors such as Ti-based superconducting alloys, Nb3Sn-based intermetallic compounds, and high-temperature oxide superconductors such as Ba-Y-Cu-O-based and Sc-Sr-CuO-based having a high critical temperature are used.

Further, although the Hall element is used as the magnetic sensor in the above-mentioned embodiment, the measurement magnetic flux density can be amplified even when applied to other magnetic sensors, and the measurement sensitivity can be greatly improved.

Next, the measurement principle of the magnetic sensor using the Hall effect is shown in FIG.

FIG. 4 is an explanatory diagram showing the measurement principle of the magnetic sensor using the Hall effect.

In FIG. 4, 23d and 24d are terminals for passing a current I through the hall element 21d, and terminals for measuring the voltage V of the hall element 21d for 25d and 26d. Place the Hall element 21d in the magnetic field and connect both terminals 23d, 2
When a current I is passed between 4d and a magnetic field is applied to the Hall element 21d, a voltage is generated in a direction perpendicular to both the current and the magnetic field. This is called the Hall effect, and when a magnetic field is applied, the electrons in the Hall element 21d move while bending. In this way, a potential difference V is generated in the direction perpendicular to the electric field and the magnetic field. This potential difference is expressed by the following equation.

V = Rh · B · I / d where d is the thickness of the Hall element, B is the strength of the magnetic field, I is the current flowing through the element, and Rh is the Hall coefficient. Therefore, the magnetic field B can be measured by measuring the voltage V. Here, the superconducting coil 17d has been described, but the same applies to the superconducting coil 17e.

FIG. 5 is a configuration diagram of a torque control signal output circuit of an electric motor in an elevator load detector according to an embodiment of the present invention.

In FIG. 5, 30 is an AC power supply, Vd and Ve are voltages generated in the hall elements 21d and 21e, 31 is an amplifier circuit for amplifying the voltage Vd, 41 is an amplifier circuit for amplifying the voltage Ve, and 32 is a peak hold circuit. , A diode 33, a capacitor 34 that stores the output of this diode 33, a contact 35 that is opened immediately before the car 15 is opened and closed when it starts moving, a field effect transistor (hereinafter simply referred to as "FET") 36, and Power 37
And a resistor 38 connected to the negative power source (-V). 42 is a peak hold circuit having the same configuration as the peak hold circuit 32. Reference numeral 43 is a subtraction circuit for subtracting the outputs of the two sets of peak hold circuits 32 and 42. When the car 15 side is heavier, it becomes positive, when the counterweight 16 is heavier, it becomes negative, and the torque value acting on the output shaft 11f becomes It outputs an unbalanced torque signal having a proportional value.

Next, the operation of the load detector of the elevator according to this embodiment will be described.

While the car 15 is stopped, the brake 12a is operating to stop the input shaft 11a.

First, it is assumed that the car 15 is stopped and the car 15 side is heavier than the counterweight.

The output shaft 11f is twisted in the direction shown by the arrow c in FIG. Therefore, tension is applied to the first magnetic layer 17a, and
Compressive force acts on each of the magnetic layers 17b. By the way, first
The second magnetic layers 17a and 17b have the characteristics shown in FIG.

FIG. 6 is a BH curve diagram of the magnetic layer on the rotation axis.

As shown in FIG. 6, B-H when no force is applied
The curve is as shown by the code do, and when tension acts, the code du
As indicated by, the inclination becomes large in accordance with the magnitude of the tension, and when the compressive force acts, the inclination becomes small in accordance with the magnitude of the compressive force as indicated by the symbol dα. Since B / H has a magnetic permeability μ, the magnetic permeability changes depending on whether the tension or the compression force is applied. When tension acts, μ → large, and when compressive force acts, μ → small.

The leakage flux induced in the output shaft 11f by the exciting coil 17c changes depending on the permeability μ, and the larger μ, the greater the leakage flux. Therefore, the voltage Ve generated in the hall element 21e> the voltage Vd generated in the hall element 21d. The voltage Vd is amplified by the amplifying circuit 31, is inversely rectified by the diode 33 of the peak hold circuit 32, and charges the capacitor 34. Immediately before the start of the car 15, the contact 35 is open, so that the peak voltage is generated in the capacitor 34. This peak voltage equivalent is generated in the resistor 38 via the FET 36. The generated voltage α is input to the terminal (−) of the subtraction circuit 43.

On the other hand, the voltage Ve generated in the hall element 21e is processed in the same manner and becomes the generated voltage β from the peak hold circuit 42 and is input to the terminal (+) of the subtraction circuit 43. The subtraction circuit 43 outputs the subtraction result (β-α). This output (β-α) displays the unbalanced torque of the output shaft 11f, and is input to the control circuit 44 as a torque signal for generating a torque corresponding to the unbalanced torque in advance before starting the electric motor 12. It

Next, it is assumed that the car 15 is stopped and the counterweight 16 side is heavier than the car 15.

The output shaft 11f is twisted in the direction shown by the arrow W in FIG. 2, a compressive force is applied to the first magnetic layer 17a, and a second magnetic layer 17b is applied.
Tension acts on each. Therefore, the voltage Vd generated in the Hall element 21d> the voltage Ve generated in the Hall element 21e, and the output (β−α) of the subtraction circuit 43 has a negative value. That is, a torque in the opposite direction to that in the case of the first term is generated in the electric motor 12, and it becomes commensurate with the unbalanced torque due to the fact that the counterweight 16 is heavier.

Next, it is assumed that the car 15 side and the counterweight 16 side have the same weight.

If the basket 15 side and the counterweight 16 side have the same weight, the output shaft
There is no twist in 11f. Therefore, the voltage Vd generated in the Hall element 21d = the voltage Ve generated in the Hall element 21e, and the outputs α and β of the peak hold circuits 32 and 42 have the same value. Therefore, the output of the subtraction circuit 43 becomes zero. That is, the torque for canceling the unbalanced torque is not generated from the electric motor 12.

According to the above-described embodiment, the torque based on the unbalanced load is directly detected from the twist of the output shaft 11f of the hoisting machine, so that the unbalanced torque can be accurately detected even if the passenger is biased in the car 15.

In addition, the unbalanced torque can be detected continuously as compared with the case of using a micro switch, and finer grain control is possible. Furthermore, in the above embodiment, the magnetic layers 17a and 17b are the output shaft 1
Since it is inclined by 45 degrees with respect to the axial direction of 1f, it responds best to twisting, and since the magnetic layers 17a and 17b are inclined symmetrically in opposite directions and are symmetrically arranged with respect to each other, The other will be compressed, further improving the sensitivity.

The unbalanced torque of the output shaft 11f and the subtraction circuit 4 of this embodiment are
The output from 3 is not necessarily proportional. If necessary, the output of the subtraction circuit 43 may be once input to a correction circuit (not shown) to be corrected so as to have a proportional relationship, and this correction value may be input to the control circuit 44 of FIG.

[Effects of the Invention] As described above, the load detector of the elevator according to the present invention performs the magnetoelectric conversion on the first superconducting coils surrounding the two rows of magnetostrictive materials and the magnetic fields induced in the respective first superconducting coils. It is composed of a magnetoelectric conversion element and a detector composed of a second superconducting coil surrounding each of the magnetoelectric conversion elements in a magnetically shielded state. Therefore, since the superconducting coil is used, it is necessary to consider the resistance of the detection coil. In addition, since it can be directly input from the detection coil to the magnetoelectric conversion element and taken out as a voltage signal, the current generated in the detection coil is voltage-converted, amplified, and taken out as a voltage signal by the peak hold circuit. Since it is not necessary to use a complicated circuit that uses a large number of elements, the magnetoelectric conversion element can be Since it is surrounded by two superconducting coils, the influence of the external magnetic field can be cut off from the Meissner effect, and a highly accurate load detector can be realized. The elevator load required here is the load imbalance between the cage and the counterweight applied to the rotating shaft.Unlike the load detector installed in the cab, the twist due to the load imbalance directly applied to the rotating shaft is used. Since the measurement is performed, it is possible to detect the load of the car with high accuracy without the need to consider the influence of the main ropes and control cables that change depending on the car position, or the case where the passenger in the car leans toward the vehicle.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a method of mounting an elevator load detector according to an embodiment of the present invention, and FIG. 2 is an explanatory view showing a method of detecting twist of a rotary shaft of an elevator load detector according to an embodiment of the present invention. FIGS. 3 (a) and 3 (b) are explanatory views showing a magnetic flux detection method using a superconducting coil, and FIG. 4 is an explanatory view showing a measurement principle of a magnetic sensor utilizing the Hall effect,
FIG. 5 is a configuration diagram of a torque control signal output circuit of an electric motor in an elevator load detector according to an embodiment of the present invention, FIG. 6 is a BH curve diagram of a magnetic layer on a rotating shaft, and FIG. FIG. 8 is a configuration diagram seen from a side surface of an elevator using a load detection device, and FIG. 8 is a configuration diagram seen from a front surface of an elevator using a conventional load detection device. In the figure, 7 ... drive sheave, 11f ... output shaft, 12 ... electric motor, 14 ...
… Main rope, 15 …… Cage, 16 …… Balance weight, 17 …… Detector,
17c ... Excitation coil, 17d, 17e, 20d, 20e ... Superconducting coil, 21d, 21e ... Hall element. In the drawings, the same reference numerals and symbols indicate the same or corresponding constituent parts.

Claims (1)

[Claims] 1. A drive sheave around which main ropes, each of which has a car on one side and a counterweight on the other side, are wound, a brake for stopping the drive sheave, the drive sheave and the brake. A rotating shaft for transmitting a braking force to the drive sheave interposed between the rotating sheave and a twist detector for detecting a twist generated in the rotating shaft due to an unbalanced load acting on the main rope; In a load detecting device for an elevator that detects an unbalanced load with the counterweight side, the twist detector has a plurality of spirals having an inclination angle of 45 degrees and a plurality of spirals having an inclination angle of 135 degrees around the rotation axis. And a magnetostrictive material formed in two rows spaced apart in the axial direction of the rotating shaft, a first superconducting coil surrounding each of the magnetostrictive materials formed in the two rows, and located between each of the first superconducting coils,
An exciting coil that excites the rotating shaft, a second superconducting coil that is connected to each of the first superconducting coils to form a closed circuit, and is arranged at a position surrounded by the second superconducting coil. A load detecting device for an elevator, comprising a magnetoelectric conversion element for detecting a magnetic field generated, a magnetic shield surrounding each of the second superconducting coils and a corresponding magnetoelectric conversion element.