CN102826422A - Over-speed detection sensor of vertical lifting elevator - Google Patents

Abstract

The invention relates to the technical field of elevator equipment manufacturing, and relates to an overspeed detection sensor for a vertical lift elevator. The cause of the elevator falling is mainly caused by the shedding or breaking of the steel wire rope, overload operation, speed measurement and speed limiter, and equipment failure, which rarely occurs. In order to overcome the deficiencies of the prior art, the present invention provides a non-contact elevator overspeed photoelectric detection technology as an additional stall sensing device besides the conventional speed governor. The invention is composed of a laser emitting device, a one-dimensional photodiode array, a signal processing system and other components. The laser emitting device includes a laser and a collimating beam expander lens. The laser beam emitted by the laser emitting device has a divergence angle and propagates vertically downward. The shape is conical, and the size of the laser spot that irradiates the one-dimensional photodiode array changes with the movement of the elevator, and there is a corresponding relationship. The photodiodes that receive light signals in turn compare their time intervals with the time threshold t _i of a given safe speed to realize the non-contact overspeed detection of the elevator and provide a signal interface.

Description

A vertical lift elevator overspeed detection sensor

technical field

The invention relates to the technical field of elevator equipment manufacturing, and relates to an overspeed detection sensor for a vertical lift elevator.

technical background

Along with the increase of high-rise buildings, the use of elevators increases thereupon, although the possibility of accidents of losing control or falling of elevators is very small, there are relevant reports of elevators falling both at home and abroad.

At present, the overspeed detection of most vertical elevators is realized by the speed limiter. Centrifugal speed governors commonly used in the market are designed based on the relationship between centrifugal force and rotation speed. The centrifugal hammer will be thrown enough to trigger the position of the speed limiter, so that the speed limiter will act, so as to realize the speed monitoring. The resonance type speed limiter is designed based on the principle that the vibration amplitude is the largest during resonance. When the rotation frequency of the speed limiter sheave reaches the natural frequency of the vibrating block, resonance occurs to make the speed limiter operate, thereby realizing speed monitoring. The above two speed limiters can play a good role in speed detection and protection, but they will lose the elevator speed monitoring ability in the following cases.

1. The elevator wire rope falls off or breaks;

2. The rust, aging and deformation of the speed governor sheave and the wire rope lead to insufficient tension, so that the friction between the speed governor wire rope and the speed governor sheave is insufficient, and the wire rope slips in the sheave groove. The rotational speed does not match the speed of the elevator;

3. During the installation and maintenance of the elevator, it is caused by unreasonable adjustment of the wire rope, sheave, brake, etc.;

4. Overload operation.

Contents of the invention

In order to overcome the above-mentioned shortcomings, the present invention provides a non-contact elevator overspeed photoelectric detection technology independent of the existing safety assurance system, which is suitable for the speed sensor of the vertical lift elevator in high-rise buildings, as an additional stall sensor besides the conventional speed limiter. The device realizes double protection and provides a speed signal interface.

The vertical lift elevator overspeed detection device is realized in this way, including: ① a laser emitting device arranged on the top of the elevator shaft, and the emitted laser beam propagates vertically downward; ② a one-dimensional photodiode array for receiving laser signals is arranged on the upper surface of the elevator car ; ③ signal processing system.

The laser emitting device includes a laser and a collimating beam expander lens, and the laser adopts a semiconductor laser.

The cross-sectional shape of the laser beam is a circle or an ellipse close to a circle, and the energy is uniform. The emitted light has a certain divergence angle, and the laser beam is conical along the propagation direction.

In the one-dimensional photodiode array, unit photodiodes are arranged at specific intervals, and the interval size is determined by the height of each floor (assuming that each floor has a different height). Each unit photodiode corresponds to a corresponding floor, and when the elevator moves to a floor, the size of the laser spot on the one-dimensional photodiode array changes by one unit photodiode interval.

The signal processing system includes a preamplifier circuit, a binarization circuit, a timing circuit and other related circuits, which are compared and judged with the set safe speed parameters, and a safe speed or overspeed signal is given and sent to the interface circuit.

The technical solution adopted in the present invention is: when the elevator starts to run at any position, the laser emitting device 4 emits the laser beam 3 with a divergence angle a to irradiate the one-dimensional photodiode array 2 . Whenever the elevator moves a floor (the size of the laser spot changes by one photodiode interval), the signal processing system 10 collects the number of counting pulses during this period, calculates the time, and compares it with the time threshold t _i (i=1,2,3 ...N) for comparison. Here the time threshold t _i is the time required for the elevator to run at the specified maximum speed v corresponding to the floor height h _i . The change in the size of the laser spot 21 corresponds to the time interval between the photodiodes of the units being less than the time threshold t _i , which means that the elevator runs at an overspeed within this period.

Description of drawings

Fig. 1 is the schematic diagram of vertical lift elevator overspeed detection device;

FIG. 2 is a schematic diagram of a one-dimensional photodiode array.

Detailed ways

As shown in Figure 1, a vertical lift elevator overspeed detection sensor includes a laser emitting device 4, a fixed frame 5, a one-dimensional photodiode array 2, and a signal processing system 10; wherein the laser emitting device 4 and the fixed frame 5 are connected by connecting screws ; The fixed frame 5 is fixed on the top of the elevator shaft 9; the one-dimensional photodiode array 2 is fixed on the upper surface of the elevator car 1 by fixing screws.

As shown in FIG. 2, in the one-dimensional photodiode array 2, the unit photodiode P1 is arranged at the center position, and the unit photodiodes P2 and P3 are arranged successively at specific intervals in a straight line direction pointing to the edge with the unit photodiode P1 as the reference. To PN, each unit photodiode corresponds to the corresponding floor, and the distance between two adjacent unit photodiodes is D ₁ , D ₂ to D _N-1 respectively; when the elevator moves to a floor, the size change of the laser spot 21 corresponds to it The unit photodiode interval D _i ; the unit photodiode interval D _i is calculated as follows: D _i =tan a×h _i , h _i is the height of each floor.

Take the unit photodiode P1 as the reference, set the unit photodiode 22 at a position symmetrical to the unit photodiode PN, adjust the connecting screw on the fixing frame 5 so that the unit photodiode 22 and the unit photodiode PN are illuminated at the same time when the car is at the bottom , which can ensure that the center of the laser spot accurately falls on the central unit photodiode P1 of the one-dimensional photodiode array 2, thereby improving measurement accuracy.

The laser emitting device 4 includes: a laser 6 and a laser collimator and beam expander lens 7 .

The laser 6 is a visible light semiconductor laser.

The collimating beam expander lens 7 adopts a single convex lens structure or a combination structure of a concave lens and a convex lens.

The divergence angle a of the laser beam 3 is controlled within the range of 0.2mrad˜0.5mrad.

The laser spot 21 irradiated by the laser beam 3 on the surface of the one-dimensional photodiode array 2 is a circular or nearly circular elliptical spot, and the center of the laser spot 21 is on the unit photodiode P1.

When the elevator moves to a floor, the laser spot 21 changes a unit photodiode interval D _i , at this time the signal processing system 10 collects the number of timing pulses during this period for time calculation, compares it with the time threshold t _i , and provides a signal interface ;The time threshold t _i should be calculated in combination with the actual building structure and the specified maximum speed v, the calculation formula is: t _i =h _i /v

And pre-input to the signal processing system as a comparison value; if the time for the laser spot 21 to change by one photodiode interval D _i is less than the time threshold t _i , it means that the elevator runs at an overspeed during this period.

Claims (5)

1. A vertical lift elevator overspeed detection sensor is characterized in that a fixed mount 5 is installed at the top of the hoistway 9, the laser emitting device 4 is connected below the fixed mount 5, and the one-dimensional photodiode array 2 is fixed on the elevator car 1 by fixing screws 23 The signal processing system 10 receives and processes the photoelectric signals of the one-dimensional photodiode array 2. The laser emitting device 4 includes a laser 6 and a collimating beam expander lens 7. The laser beam 3 has a divergence angle a, and is irradiated on the one-dimensional photoelectric The shape of the laser spot 21 on the surface of the diode array 2 is a circle or an ellipse close to a circle. The photodiodes of each unit in the one-dimensional photodiode array 2 are arranged at specific intervals. When the elevator runs on one floor, the one-dimensional photodiode array 2. The laser spot 21 on the surface changes a unit photodiode interval, and the signal processing system 10 measures the time for the laser spot 21 to change a unit photodiode interval, and compares it with the time threshold to detect the overspeed situation of each floor when the elevator is running. 2. The vertical lift elevator overspeed detection sensor according to claim 1, characterized in that the laser 6 is a visible light semiconductor laser. 3. The vertical lift elevator overspeed detection sensor according to claim 1, characterized in that the collimator beam expander lens 7 is made of a single lens or a double lens, and the divergence angle a of the laser beam 3 is 0.2mrad～0.5mrad. 4. vertical elevator overspeed detection sensor according to claim 1 is characterized in that, the interval _D of each unit photodiode in the one-dimensional photodiode array 2 will combine the height _h of each floor of the actual building and the laser beam 3 to calculate the divergence angle a, the calculation formula is: D _i =tan a×h _i . 5. vertical lift elevator overspeed detection sensor according to claim 1, is characterized in that, time threshold value _t will be calculated in conjunction with the height _h of each floor of actual building and the maximum running speed v of elevator regulation, and computing formula is: t _i =h _i /v, and input to the signal processing system 10 as a comparison value in advance.

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