JP2013002549A - Elevator hoisting machine with explosion-proof structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an elevator hoisting machine having an electric motor casing minimized without being upsized for meeting an explosion-proof standard and allowing smooth external maintenance of a brake device.SOLUTION: The elevator hoisting machine includes a pair of brake arms arranged in opposition to both sides of a brake drum which is coaxially fixed to the driving shaft of an electric motor for integral rotation, and rockable between a braking position of pressing a brake shoe against the friction surface formed on the outer peripheral face thereof and a releasing position of releasing it. The casing of an electromagnetically driving device for driving the brake arms to the releasing position is constructed strong and rigid to meet a specified explosion-proof standard. On the casing, a switch depressing device is mounted for depressing a switch in linkage with the drive of the brake arms to sense the operation of the electromagnetically driving device stored inside, while meeting the specified explosion-proof standard.

Description

  The present invention relates to an elevator hoisting machine, and more particularly to an elevator hoisting machine having an explosion-proof structure.

For example, in chemical factories and plant relations, when combustible gases and vapors that are handled are released and leaked into the atmosphere and mixed with air to form an explosive atmosphere, electrical equipment becomes the ignition source, It may lead to an explosion.
Therefore, in particular, an elevator used in a dangerous place where explosive gas is generated as described above needs to conform to various explosion-proof standards.
These elevator hoists have a fully closed structure, and if an explosive atmosphere enters the interior of the container and an explosion occurs, the container can withstand the explosion pressure, and the flame from the explosion is explosive outside the container. It is common to use a flameproof structure that does not ignite the atmosphere.

The elevator hoisting machine is roughly divided into a sheave around which the main rope of the elevator is wound, an electric motor that drives the sheave, a reduction gear that mechanically connects the electric motor and the sheave, and a brake device that stops the elevator on a predetermined floor It consists of.
The reducer and sheave are required to have high structural strength in the first place, and since there is no spark or overheating that can cause ignition of the external explosive atmosphere, it does not become an ignition source of the explosion. Because it does not belong to the category of electrical parts, it is not necessary to consider conforming to explosion-proof standards.
In addition, the electric motor is originally provided with a casing, and the strength and rigidity of the casing may be designed to meet the explosion-proof standard.

  By the way, as seen in Patent Document 1 below, as a brake device, the rotating shaft of the electric motor is extended to the non-output side, and the disc body provided around it is braked by a brake shoe driven by an electromagnetic drive device. As shown in Patent Document 2 and Patent Document 3 below, a brake shoe is disposed on the outer periphery of a brake drum that is coaxially fixed to the output-side rotation shaft of the electric motor, and an electromagnetic drive device is provided via this brake arm. There is a type that brakes with this brake shoe.

JP 2007-195342 A JP 2010-202375 A JP 2011-63434 A

In the case of the former model, it is possible to meet the explosion-proof standard by covering it with the casing of the motor, but for that purpose, it is necessary to enlarge the casing of the motor so as to cover the entire brake device provided on the non-output side of the rotating shaft. There has been an increase in the size and cost of the motor casing.
In particular, in recent years, reflecting the accident of the elevator falling, it has become necessary to install two systems of brake devices in the elevator hoisting machine, so the motor casing must be further enlarged. is there.
Moreover, periodic inspections are required for such brake devices for safety management. Thus, in order to maintain and inspect brake devices in casings that comply with explosion-proof standards, heavy opening and closing lids are removed every time. Since the inspection work must be performed within a limited time, there is a problem that the work load is extremely high.

On the other hand, in the case of the latter type, the brake drum and the brake arm itself do not belong to the category of electrical parts, but are treated as inspection targets as a special case of the explosion-proof certification. However, these are designed to have extremely high strength and rigidity in the first place, so if they can satisfy the condition that the temperature rise during braking does not exceed the specified value, they are considered to meet the explosion-proof standards. As a result of the verification experiment, it has been confirmed that there is no problem in safety at the time of obtaining the explosion-proof standard for the temperature rise.
On the other hand, an electromagnetic drive device including an electromagnet for driving the brake arm is housed in a fully closed steel container having a predetermined strength and rigidity by design, and thus a pressure-proof and explosion-proof structure that meets explosion-proof standards. It can be. Further, in this type of brake device, by arranging two brakes around the brake drum, the brake shoe can be easily inspected and adjusted, and can meet the above-mentioned safety standards.

  However, in order to always check the operation state of the brake device described above, it is necessary to install a micro switch for checking the operation of the brake arm by the electromagnetic drive device around the brake arm. It belongs to the category of electrical components that can be the ignition source of explosions, and it is very difficult to meet explosion-proof standards while maintaining smooth on / off of electrical contacts. It becomes very expensive, such as developing contacts. In addition, since the microswitch and the electromagnetic drive unit are housed in separate fully-closed casings, the mechanism design and installation location selection are performed to ensure cooperation between the two while maintaining the flameproof structure of both casings. Furthermore, adjustment for realizing a smooth operation becomes very difficult.

  In view of the above, an object of the present invention is to solve the above-described problems, and to meet the explosion-proof standard with the minimum casing without enlarging the casing of the motor, and to smoothly perform maintenance and inspection of the brake device from the outside. The aim is to realize an elevator hoist.

  In order to solve the above-mentioned problems, the following technical means were taken in the elevator hoist according to the present invention. That is, a brake drum that is coaxially fixed to the drive shaft of the electric motor and rotates integrally with the brake drum, and a brake shoe that is disposed on both sides of the brake drum and that is formed on the outer peripheral surface of the brake drum. A pair of brake arms swingable between a braking position to be pressed and an open position to be released, a spring that biases one end of the brake arm and presses the brake arm to the braking position, and the brake arm In an elevator hoisting machine having an electromagnetic drive device that contacts the other end of the motor and drives the brake arm to the open position, the motor and the casing that houses the electromagnetic drive device each meet a specific explosion-proof standard The structure has strength and rigidity, and the operation of the electromagnetic drive device is detected inside the casing that houses the electromagnetic drive device. A switch pressing device that has a strength and rigidity that conforms to the specific explosion-proof standard and that presses the switch according to an external operating force. The rod that operates the switch via the switch pressing device in conjunction with the pair of brake arms being driven by the operation of the electromagnetic drive device is connected to the other end of the pair of brake arms. Arranged.

  In the elevator hoisting machine, the switch pressing device is fixed to a pressing shaft that operates the microswitch by pressing the rod, and an inner wall of a casing that houses the electromagnetic driving device, And a main body including a cylindrical body integrally formed with a partition wall through which the pressing shaft is inserted, and the pressing shaft and the main body have strength and rigidity conforming to the explosion-proof standard.

According to the present invention, the two structures of the elevator hoisting machine including the switch for confirming the operation of the electromagnetic brake device are secured while the two brake arms are secured by the two brake arms operated by the electromagnetic brake device. It can be reliably adapted to the desired explosion-proof standard.
Furthermore, since it is not necessary to separately adapt the explosion-proof standard to the switch for detecting the brake operation, the cost of the elevator hoisting machine can be reduced, and the workability of maintenance inspection can be drastically improved.

The figure which shows the whole structure of an elevator. The front view of a winding machine. The top view of a winding machine. The figure which looked at the electromagnetic brake from the drive shaft direction of the electric motor. The internal enlarged view of a microswitch pressing structure. Schematic of an electromagnetic drive device control system.

  Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the entire structure of the elevator, and FIGS. 2 and 3 show a front view and a plan view of the hoisting machine, respectively.
The elevator 1 includes a dedicated machine room 3 at the upper end of the hoistway 2, and a hoisting machine 4 is installed therein. The hoisting machine 4 suspends the car 6 and the counterweight 7 from the hoistway 2 via the wire rope 5.

The hoisting machine 4 moves the car rope 6 and the counterweight 7 up and down along the hoistway 2 by hoisting or rewinding the wire rope 5 by rotating the sheave 8. As shown in FIG. 1, the hoisting machine 4 is installed in a machine base 9 in which a plurality of support columns are combined in the machine room 3.
The hoisting machine 4 includes an electric motor 10, a gear reducer 11, and a drum-type electromagnetic brake 12. A drive shaft of the electric motor 10 is connected to a sheave 8 via a gear reducer 11 including a worm shaft and a worm wheel. Yes.

The electromagnetic brake 12 is for stopping the car 6 at each floor and maintaining the state, and is disposed between the electric motor 10 and the gear reducer 11 and is a view seen from the drive shaft direction of the electric motor 10. As shown in FIG. 4, a brake drum 13, a pair of brake arm levers 14a and 14b, a pair of brake shoes 15a and 15b each having brake pads 15c and 15d, and an electromagnetic drive device 16 are provided.
The brake drum 13 is coaxially fixed to the drive shaft of the electric motor 10 and rotates integrally with the drive shaft. A friction surface for generating a braking force is formed on the outer peripheral surface of the brake drum 13.
Further, the electromagnetic drive device 16 includes an iron core 16a and an electromagnetic coil 16b on the outer periphery thereof, and when energized, the upper ends of the brake arm levers 14a and 14b are drawn through rods 16c and 16d integrally attached to the iron core 16a. Each of the pair of brake shoes 15a and 15b is driven outward to release the brake drum 13.

  That is, the brake arms 14a and 14b are arranged to oppose the outer periphery of the friction surface of the brake drum 13, and along the longitudinal direction thereof, the lower end portion on the machine base 9 side (the lower side in FIG. 4) and the electromagnetic drive device The arm lever pins 17a and 17b having an upper end portion on the 16 side (upper side in FIG. 4) and provided below the end portion on the electromagnetic drive device 16 side are integrally provided below the casing 16e of the electromagnetic drive device 16. The formed arm 16f is pivotally connected.

Openings are provided in the lower ends of the brake arms 14a and 14b, and stud bolts 18a and 18b fixed to a stud bolt fixing block 18 installed in the machine base 9 are inserted into the openings, respectively. The stud bolt fixing block 18 is installed immediately below the drive shaft of the electric motor 10, and includes stud bolts 18a and 18b extending outward.
Coil springs 18g and 18h are inserted into the stud bolts 18a and 18b protruding outward from the respective openings via spring pressing plates 18e and 18f, and a nut screwed into the stud bolts 18a and 18b is rotated, By adjusting the positions of the spring pressing plates 18e and 18f, the elastic force by the coil springs 18g and 18h can be adjusted. The positions of the spring pressing plates 18e and 18f can be confirmed by the scale plates 18c and 18d.

  Since the coil springs 18g and 18h press the lower ends of the brake arms 14a and 14b from the outside to the inside with a predetermined elastic force, the electromagnetic drive device 16 is temporarily activated due to a power failure or an abnormality of the control device. Even if not, the brake arms 14a and 14b pivot about the arm lever pins 17a and 17b, and the brake shoes 15a and 15b are strongly pressed against the outer periphery of the friction surface of the brake drum 13, so that the brake drum 13 is securely attached. It can be maintained in a stopped state.

  On the other hand, the outer ends of the rods 16c and 16d of the electromagnetic drive device 16 are fitted to the upper ends of the brake arms 14a and 14b, respectively. When the electromagnetic drive device 16 is energized, the iron core 16a and the electromagnetic coil 16b. As a result, the rods 16c and 16d are pulled inward, the lower ends of the brake arms 14a and 14b are driven outward against the elastic force of the coil springs 18g and 18h, and the brake shoes 15a and 15b are moved to the brake drum. 13 is released from the friction surface, and the sheave 8 is rotationally driven through the electric motor 10 and the gear reducer 11 to raise and lower the car 6.

  FIG. 6 shows an outline of the control system of the electromagnetic drive device 16. In the normal operation, the electromagnetic drive device 16 is controlled by a control signal from the operation control panel that is input via a connection box provided in the car 6. When the car 6 stopped on a specific floor is controlled to be raised or lowered to the next floor, the brake shoes 15 a and 15 b are released from the friction surface of the brake drum 13. Along with this operation, micro switches 22 (described later) provided on the left and right sides sense the operation of the brake.

In this embodiment, in order to adapt the elevator hoisting machine configured as described above to a predetermined explosion-proof standard, each casing covering the electric motor 10, the gear reducer 11, and the electromagnetic drive device 16 has a predetermined thickness. It is made of steel or the like having a pressure and explosion proof structure so as to obtain predetermined strength and rigidity defined by the explosion proof standard.
As described above, the sheave 8 is originally required to have high structural strength, and is integrally formed below the brake arms 14a and 14b, the rods 16c and 16d of the electromagnetic drive device 16, and the casing 16e. Since the arm 16f and the like also generate a strong braking force, the design strength can sufficiently clear the strength in the explosion-proof standard, and the value that becomes the ignition source even in terms of temperature rise It will not be.

  On the other hand, with regard to the inspection of the electromagnetic brake device 12 that is obligated for maintenance management, it is a matter of course that the electromagnetic drive device 16 is energized to smoothly operate the operating portion, but the friction sticking to the brake shoes 15a and 15b. It is necessary to measure the thicknesses of the materials 15c and 15d, confirm that they are not used below the reference value, and confirm whether or not a sufficient braking force is actually maintained. Since the electromagnetic brake device 12 has the operating part and the drum 13 open, it can be easily visually confirmed and measured even in the explosion-proof area, and the positions of the spring pressing plates 18e and 18f by nuts screwed into the stud bolts 18a and 18b. By adjusting the braking force, the braking force can be adjusted, and the positions of the spring pressing plates 18e and 18f at that time can be confirmed by the scale plates 18c and 18d.

In the present invention, as shown in FIG. 4, the micro switch 22 that turns on and off in accordance with the operation of the brake shoes 15 a and 15 b is accommodated in the casing 16 e that covers the electromagnetic drive device 16, thereby meeting the protection standards. FIG. 5 is an enlarged view of the inside of the microswitch pressing structure.
As shown in FIG. 4, switch brackets 19 are respectively provided at the upper ends of the brake arms 14a and 14b. The switch brackets 19 extend upward along the casing 16e from the brake arms 14a and 14b, and the casing 16e. After being bent toward the center, the casing 16e is disposed so as to face the casing 16e with a predetermined gap therebetween. An adjustable bolt-type rod 20 is screwed to the upper end of the switch bracket 19, and the end portion on the casing 16 e side is connected to the push button 21 b of the switch pressing device 21 as shown in FIG. 5. Opposite. The push button 21b is attached to the outer end of the pressing shaft 21a of the switch pressing device 21, and the end of the rod 20 on the casing 16e side interlocks with the operation of the brake arms 14a and 14b. The position is adjusted to be pressed or released with a predetermined stroke.

  As shown in FIG. 5, a thread groove is formed on the outer periphery of the main body of the switch pressing device 21, and is formed of a cylindrical body 21 c having a partition wall 21 d slightly inside from the outer end (right end as viewed from FIG. 5), A pressing shaft 21 a is inserted into the partition wall 21 d of the cylindrical body 21 c from the center and extends in the direction of the microswitch 22. The cylindrical body 21c is integrally formed of a metal such as steel, has a thickness of about several millimeters including the partition wall 21d, and sufficiently satisfies various conditions stipulated by predetermined protection standards. It is a structure that has strength and rigidity.

  The main body of the switch pressing device 21 is formed by screwing a screw groove provided on the outer periphery of the cylindrical body 21c from an inner side of the casing 16e of the electromagnetic drive device 16 into a screw groove formed in an opening provided in the casing 16e. After the flange portion integrally formed with the body 21c is brought into contact with the inner wall of the casing 16e, the nut 21f is further screwed into the screw groove provided in the cylindrical body 21c from the outside of the casing 16e and tightened. The bolts are firmly attached to the inner wall of the casing 16e with bolts using the screw holes provided in the flange portion formed integrally with the casing 16e.

  The push shaft 21a inserted through the cylindrical body 21c has a push button 21b integrally attached to an end portion protruding outward from the partition wall 21d, and the press portion formed on the inner end portion of the casing 16e has a casing 16e. Inside, it is positioned so as to come into contact with the switch end 22a of the microswitch 22 attached to the mounting bracket 21e formed integrally with the cylindrical body 21c. On the other hand, a spring 21g is inserted between the partition wall 21d and the spring receiver of the push button 21b attached to the outer end of the pressing shaft 21a.

  When the push button 21b is pressed, the spring 21g is compressed, and the inner side end of the press shaft 21a operates the micro switch 22, and when the press is released, the push button 21b is caused by the elastic force of the spring 21g. Can be returned to contact with a stopper formed at the outer end of the cylindrical body 21c.

When the brake arms 14a and 14b are driven outward by energizing the electromagnetic drive device 16 and the brake shoes 15a and 15b are released from the friction surface, the brake arms 14a and 14b The upper end of 14b is driven inward via the arm lever pin 17a, and the rod 20 provided on the switch bracket 19 presses the push button 21b against the spring 21j. As a result, whether or not the brake arms 14a and 14b are properly adjusted can be easily confirmed based on whether or not the microswitch 22 is activated by the inner stroke of the pressing shaft 21a.
It should be noted that the abnormality of the micro switch 22 itself can be easily checked by manually pressing the push button 21b from the outside.

  In the above embodiment, the microswitch 22 is used as a switch for detecting the operation of the brake arm by the switch pressing device 21 inside the casing 16e of the electromagnetic drive device 16, but is protected by the casing 16e of the electromagnetic drive device 16. Therefore, various switches such as a cheaper contact type switch can be employed.

  As described above, according to the present invention, the two brake arms 14 a and 14 b operated by the electromagnetic drive device 16 ensure two systems of brakes and the switch for confirming the operation of the electromagnetic drive device 16. The entire structure of the elevator hoisting machine can be reliably adapted to the explosion-proof standard. Furthermore, since it is not necessary to provide a switch for detecting brake operation in the casing of the electric motor, the cost of the elevator hoisting machine can be reduced, and the workability of maintenance inspection can be drastically improved. It can be expected to be widely adopted not only for elevators installed in hazardous areas where explosive gases are generated, but also for elevator hoists with high safety and maintainability.

DESCRIPTION OF SYMBOLS 1 Elevator 2 Hoistway 3 Machine room 4 Hoisting machine 5 Wire rope 6 Car cage 7 Balance weight 8 Sheave 9 Machine base 10 Electric motor 11 Gear reducer 12 Drum type electromagnetic brake 13 Brake drums 14a and 14b Brake arm levers 15a and 15b Brake Shoe 16 Electromagnetic driving device 17a, 17b Arm lever pin 18 Stud bolt 19 Switch bracket 20 Bolt type rod 21 Switch pressing device 21a Pressing shaft 21b Push button 21c Cylindrical body 21d Bulkhead 22 Micro switch

Claims (2)

A brake drum that is coaxially fixed to the drive shaft of the electric motor and rotates integrally;
A pair of brakes disposed opposite to both sides of the brake drum and swingable between a braking position where the brake shoe is pressed against a friction surface formed on the outer peripheral surface of the brake drum and an open position where the brake shoe is released Arm,
A spring that biases one end of the brake arm and presses the brake arm against the braking position;
In an elevator hoisting machine provided with an electromagnetic drive device that contacts the other end of the brake arm and drives the brake arm to the open position,
The casing for housing the electric motor and the electromagnetic drive device has a structure having strength and rigidity conforming to specific explosion-proof standards,
A switch that senses the operation of the electromagnetic drive device is disposed inside the casing that houses the electromagnetic drive device, and
A casing that houses the electromagnetic drive device is provided with a switch pressing device that has strength and rigidity conforming to the specific explosion-proof standard, and that presses the switch in accordance with an external operating force.
A rod for operating the switch via the switch pressing device is provided at the other end of the pair of brake arms in conjunction with the pair of brake arms being driven by the operation of the electromagnetic drive device. An elevator hoisting machine characterized by   The switch pressing device is integrally formed with a pressing shaft that operates the micro switch by pressing the rod, and a partition wall through which the pressing shaft is inserted while being fixed to an inner wall of a casing that houses the electromagnetic brake device. The elevator hoisting machine according to claim 1, wherein the pressing shaft and the main body have strength and rigidity that conform to the explosion-proof standard. .

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