RU2774460C1 - Device and method for monitoring the parameters of the speed limiter - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: invention relates to lifting and transport machines. The two-way centrifugal type speed limiter contains rocker arms with two symmetrical divergent weights and a movable locking roller on the carrier and a locking disc. The rollers are mounted on a rotating pulley on the axis. The pulley is made with pressure surfaces of the shaped profile for interaction with the locking roller. The locking disc interacts with the locking roller. The limiter has an additional polyhedron connected to the pulley in order to attach a torque wrench to it. A method for checking the sufficiency of the friction force between the rope and the working pulley and a method for determining the force in the rope are described.

EFFECT: ensured possibility of operational control of parameters is achieved.

3 cl, 9 dwg

Description

Technical field

The invention relates to hoisting-and-transport machines, namely to devices for controlling the speed of an elevator car or a lifting platform of a passenger-and-freight vertical transport.

In accordance with the requirements of the legislation on technical regulation, the main requirement for machines and mechanisms is safety. This is of particular importance for elevators and other lifting machines, where any failure in operation can lead to tragic consequences for a person.

In order to ensure control over the safe operation of this equipment, it is necessary to have special safety devices that ensure this quality. One such device is the speed limiter, which is designed to prevent an elevator car or lifting platform from exceeding a set speed limit when moving. Modern requirements of state standards regulate the need to operate the speed limiter when the cabin moves in any direction: either down or when moving up.

Prior Art

The most widespread are centrifugal limiters, which include a traction sheave with two loads symmetrically placed on it, interconnected by a lever kinematic connection with the possibility of adjusting the linear size between them and changing the forces of inertia (Arrangement, maintenance and repair of elevators: A textbook for the beginning. Prof. education / S. B. Manukhin, I. K. Nelidov. - M .: Publishing Center "Academy", 2004. - 336 p. Fig. 2.64, p. 109). With an increase in the speed of rotation of the traction sheave, the loads, under the action of centrifugal force, diverge from the axis of rotation and interact with fixed stops, triggering the pulley stop mechanism. In this case, the stops can be located either on the outer radius of the limiter (AS 680968, B66V5 / 04), or on the inner radius of the pulley installation on the fixed axle or on the limiter hub (US Pat. RU 2034766 C1).

Modern speed limiters are also equipped with additional pulley blocking systems when the cab and shaft doors are open, consisting of an electromagnet, a safety switch, articulated levers and stops in different versions and combinations. Also in analogues, electronic systems for controlling the speed of rotation of the pulley are used, which include, in different versions and configurations, a perforated disk, an inductive or optical sensor (US Pat. RU 199074 U1).

The disadvantage of such devices is large dynamic loads at the moment of impact contact of goods against stops and sudden braking, which negatively affects the elements of the metal structure of the entire lifting device, as well as intensive wear of the ropes.

The main disadvantage of these analogues of speed limiters is their impossibility of practical application in Russia due to unilateral action, i.e. implementation of its operation when rotating only in one direction (as a rule, when the cabin moves down).

Known speed limiter centrifugal type double-acting (ES 2306623 A), presented by JSC "Gerval-Rus" (https://www.gervall.ru), containing rocker arms with two symmetrical divergent loads and a movable locking roller on the carrier, mounted on a rotating on axis of the pulley, which is made with the clamping surfaces of the shaped profile to interact with the locking roller, and the locking disk that interacts with the locking roller.

At the moment the set speed is exceeded, the loads begin to diverge under the action of centrifugal force. At this moment, the lock roller on the carrier, connected to the centrifugal mechanism, moves to the center of the pulley rotation axis and, touching the surface of the lock disk with its surface, is carried away by it to one of the sides until it jams with the inner surface of the pulley stop, after which the limiter pulley stops.

In addition, the limiter is equipped with a device for actuating by means of a mechanical or electrical remote means, which is a wedge connected to a hinged centrifugal system of levers and weights, which penetrates at the moment of dilution of the weights between the teeth of an asterisk, additionally installed on the axis, which initiates the movement of the unbalance disk with a groove, leading the roller of the limit switch of the electronic elevator control system out of this groove.

Unlike previous analogues, this speed limiter operates in both directions during rotation, which allows you to meet the requirements of regulatory and technical documents on the safety of elevators and expand the scope of the speed limiter in hoisting and transport engineering.

This device was chosen as a prototype, since it has the closest set of common features with the claimed device.

The technical problems of the prototype are:

- the inability to check the sufficiency of the friction force between the rope and the working pulley, necessary to actuate the safety gear when the car is moving (the requirement is fixed in 5.4.7.5.5 GOST 53780-2010);

- the inability to determine the force in the rope that activates the safety gear when the speed limiter is triggered (the requirement is fixed in 5.6.2.2.1 GOST 33984.1);

Disclosure of the essence of the invention

The aim of the invention is to create a speed limiter device and provide the possibility of operational control of the parameters regulated by the current regulatory and technical documents.

This is achieved by the fact that the speed limiter of the double-acting centrifugal type is declared, containing the rocker arms 11 with two symmetrical divergent loads 12 and a movable locking roller 17 on the carrier 16, mounted on a pulley 4 rotating on the axis 2, which is made with clamping surfaces of a shaped profile for interacting with locking roller 17, and locking disc 3, which interacts with locking roller 17, also has an additional polyhedron 6 connected to pulley 4 in order to attach a torque wrench to it, which makes it possible to determine the value of the static torque on the pulley when the ropes of the elevator car lift mechanism are fixed , as well as by creating two ways to control the parameters: a method for checking the sufficiency of the friction force between the rope and the working pulley to actuate the safety gear when the speed limiter is triggered and the method for determining the force in the rope that activates the safety gear when the limiter is triggered. speed meter.

Figure 1 shows the speed limiter, isometric view.

Figure 2 shows the speed limiter, front view.

Figure 3 shows the speed limiter, side view.

Figure 4 shows the speed limiter, top view.

Figure 5 shows the speed limiter, a sectional view along

arrow "A-A".

Figure 6 shows the speed limiter, view along the arrow "A".

Figure 7 shows the speed limiter, a sectional view along

arrow "B-B".

Figure 8 shows the speed limiter, a sectional view along

arrow "D-D".

Figure 9 shows the speed limiter, a sectional view along

arrow "Y-Y"

Description of the device of the invention

The essence of the invention: the speed limiter contains a frame 1, on which a fixed locking corrugated disk 3 is fixed by means of a central fixed axis 2 and a pulley 4 is mounted on bearings, to which are rigidly attached: a disk 5 with sectoral stops, a polyhedron 6 and a universal perforated disk 7. Pulley 4 has on one of its lateral side symmetrical internal grooves of a certain shaped profile 8, and on its other side an additional hub protrusion with a control stream of small diameter 9. freely deviating two rocker arms 11 with rigidly fixed and symmetrically mounted relative to axis 2 weights 12. Rocker arms 11 are interconnected by a rod 13 and an adjusting spring 14, designed to adjust the sensitivity of the limiter operation depending on the speed of rotation of the pulley. At the end of one of the rocker arms 11 there is a lever 15 for interacting with the electronic security system, and at the end of the other rocker there is a carrier 16 with a locking roller 17.

Additionally, on the fixed axis 2, the unbalance 18 is installed with free rotation, having a shaped groove on the side surface for interacting with the limit switch of the electronic security system and an asterisk 19 attached to it.

Additionally, an electromagnet 21 is installed on the frame 1 by means of an adjustable bracket 20 and additionally there is a locking pin 22 of the solenoid 23, necessary to check the operation of the electronic and mechanical safety system of the elevator.

Description of the principle of operation of the device

In the mode of normal operation, during the rotation of the pulley 4, the rocker arms 11 are in a stationary state relative to each other under the action of the spring 14. When the critical speed of rotation of the pulley 4 is reached and the setting value of the stiffness of the spring 14 is exceeded by a certain amount, the rocker arm 11 is under the action of centrifugal force, which two symmetrically located loads 12 contribute, they begin to deviate on the axes 10, moving away from the center of rotation of the pulley 4. Due to the middle point of attachment of the rocker arms 11 on the pulley 4, a swinging movement pattern is formed - at the beginning of the deviation of the loads 12 from the center, the other ends of the rocker arms 11 begin to move vice versa towards the center . This leads to the fact that the carrier 16, together with the locking roller 17, moves towards the center of rotation of the pulley 4 to the point of contact with the locking corrugated disk 3. At the moment of contact of the roller 17 with the disk 3, friction forces arise and as the rotation of the pulley 4 continues, the roller 17 is carried away by the outer radial the surface of the corrugated locking disk 3, moving along the shaped groove 8, until the moment of final jamming by its opposite side with the inner surface of the shaped groove, which completely stops the pulley 4 and initiates another safety device through the ropes - catchers. When the pulley rotates in the opposite direction, the limiter is actuated in a similar way, but in the other direction.

The operation of the system for blocking the movement of the elevator car with the doors closed is as follows: the solenoid 23 is in the retracted state together with the locking pin 22, guaranteeing the free rotation of the pulley 4. When the doors of the shaft or the elevator car are opened, an electrical signal ensures that the armature of the solenoid 23 and the locking pin 22 are pushed out , which enters between the stops of the disk 5, thereby blocking the rotation of the pulley.

Checking the operation of the speed limiter when the cab is moving at a speed less than the values regulated by the state standard is carried out as follows. When the electromagnet 21 is turned on, an electromagnetic field is created that acts on the loads 12, attracting them to the magnet. At the moment when the force of attraction to the magnet is exceeded relative to the set holding force of the adjusting spring 14, the loads 12 will begin to diverge from the center of rotation of the pulley and forced separation of the arms of the rocker arms 11 begins. which, turning, will turn on the contact of the limit switch.

Description of parameter control methods

To check the sufficiency of the friction force between the rope and the working pulley, necessary to actuate the safety catchers (clause 5.4.7.5.5 of GOST 53780-2010), a polyhedron 6 is used, connected to the pulley 4, with a torque wrench installed on it. The method consists in using a torque wrench to load the polyhedron 6 with an external static moment before the start of the joint rotation of the pulley and the rope and visually fix the absence of slippage between the surface of the rope and the pulley groove.

Initially, the value of the static moment is set on the torque wrench, determined by the formula (Elevators and lifts / Pavlov N.G. -M.-L.: Mashinostroenie, 1965. -204 p. Fig. 10, p. 28):

M = S ⋅ Rsh ⋅ Kzap , N⋅m

where: S - force in the rope, N;

Rsh - pulley radius, m;

Kzap - safety factor, taking into account the relative error of the torque wrench and measurement uncertainty, Kzap=1.1.

Then the torque wrench is installed on the polyhedron 6 and gradually increase the value of the static moment until the joint rotation of the pulley and the rope begins and visually fix the absence of slippage between the surface of the rope and the pulley groove, which indicates the sufficiency of friction forces. The obtained value of the static moment is fixed.

To determine the force in the rope that activates the safety gear when the speed limiter is triggered (p.p d p.5.6.2.2.1 GOST 33984.1), a polyhedron 6 is used with a torque wrench installed on it. The method consists in the fact that with a fixed state of the ropes of the lifting mechanism, a torque wrench is installed on the polyhedron 6 connected to the pulley 4, and a gradual loading with an external moment is created until the joint rotation of the pulley and the rope begins, followed by registration of the measured static moment and further determination of the force value by calculation in the rope that drives the catchers, as a private static moment per pulley radius.

The calculation of the force in the rope Scalc is carried out from the formula for determining the static moment:

Scalc \u003d Mism / (Rsh ⋅ Kzap ) , N

where: Мizm - values of the measured torque, N⋅m;

Rsh - pulley radius, m;

Kzap - safety factor, taking into account the relative error of the torque wrench and measurement uncertainty, Kzap=1.1.

The obtained value of the design force in the rope Scalc is compared with the criterion of clause 5.6.2.2.1 of GOST 33984.1 and a conclusion is made about the fulfillment of the requirements of the regulatory document.

The proposed device will improve the safety of vertical transport equipment and ensure compliance with the requirements of regulatory and technical documents.

Thus, the technical result of the invention is to provide the possibility of operational control of the parameters regulated by the current regulatory and technical documents, thanks to the installed polyhedron, designed to be connected to a torque wrench.

Examples of the implementation of methods for controlling the parameters of the speed limiter.

An example of the implementation of a method for checking the sufficiency of the friction force between the rope and the working pulley , necessary to actuate the safety gear.

In accordance with clause 5.4.7.5.5 of GOST 53780-2010, it should be possible to check the sufficiency of the friction force between the rope and the working pulley to actuate the safety gear.

The logic of the implementation of the method. It follows from the wording of GOST that a quantitative assessment of specific values of the friction force is not required. The condition for the sufficiency of friction forces is the absence of slippage between the surface of the rope and the pulley stream when a static torque is applied to the latter (to the pulley), which is fixed visually.

Operating procedure:

The work is carried out with the lift drive mechanism stopped.

1. Set the minimum force in the rope S. The recommended value of the force S=300N. This value is required for pre-setting the torque wrench.

2. Determine the radius of the pulley, Rsh = 0.1 m.

3. Calculate the static torque Mcalc on the pulley, created by the rope, according to the formula:

Mcalc = S ⋅ Rsh ⋅ Kzap = 300 ⋅ 0.1 ⋅ 1.1 = 33 N⋅ m

where S is the minimum force in the rope, N;

Rsh - pulley radius, m;

Kzap - safety factor, taking into account the relative error of the torque wrench and measurement uncertainty, Kzap.=1.1.

4. On the scale of the torque wrench of the limiting moment, the calculated value of the static torque Mcalc = 33 N⋅m is set.

5. The torque wrench is installed on the polyhedron 6, connected to the speed limiter pulley, and force is applied to the handle. In the process of creating force on the handle, a visual control of the movement of the pulley relative to the rope is carried out.

6. Gradually increase the value of the static moment until the start of the joint rotation of the pulley and the rope and visually fix the absence of slippage between the surface of the rope and the pulley groove, which indicates the sufficiency of friction forces.

An example of the implementation of the method for determining the force in the rope that activates the safety catchers when the speed limiter is triggered.

In accordance with paragraph d) of paragraph 5.6.2.2.1 of GOST 33984.1 “The force in the element (rope, belt, lever) that actuates the safety gear when the speed limiter is triggered must be at least greater than the following two values: - twice the value required to activate the catchers; or 300 N".

The logic of the implementation of the method: The reason for the operation of the safety catchers is the instantaneous change in the force in the rope as a result of an abrupt stop of the speed limiter. This is only possible if there is sufficient frictional force between the rope and the limiter pulley. Otherwise, the rope will slip along the pulley stream and it will be impossible to activate the catchers. Therefore, it is necessary to initially determine the sufficiency of the friction force to ensure the absence of slippage in the limiter and, then, by calculation, determine the value of the force in the rope that drives the safety gear.

Operating procedure:

The work is carried out with the lift drive mechanism stopped.

Stage 1. Determination of the sufficiency of the friction force to ensure that there is no slippage between the rope and the sheave.

1.1 Set the standard value of the minimum force in the rope, for example Smin = 300 N.

1.2 Determine the radius of the pulley, Rsh \u003d 0.1 m.

1.3 Calculate the static torque Mcalc on the pulley, created by the rope according to the formula:

Mcalc = Smin ⋅ Rsh ⋅ Kzap = 300 ⋅ 0.1 ⋅ 1.1 = 33 N⋅m

where: Smin is the minimum force in the rope, N;

Rsh - pulley radius, m;

Kzap - safety factor, taking into account the relative error of the torque wrench and measurement uncertainty, Kzap=1.1.

1.4 On the scale of the torque wrench of the limiting moment, the calculated value of the static torque is set, Mcalc = 33N⋅m.

1.5 A torque wrench is installed on a polyhedron connected to the speed limiter pulley, and a force is applied to the handle.

1.6 In the process of creating force on the handle, visual control of the movement of the pulley relative to the rope is carried out.

1.7 Gradually increase the value of the static moment until the start of the joint rotation of the pulley and the rope and visually fix the absence of slippage between the surface of the rope and the pulley groove, which indicates the sufficiency of friction forces. In this case, the value of the static moment is fixed.

Stage 2. Determining by calculation the value of the force in the rope that actuates the safety gear.

2.1 The force in the rope Scalc is determined as the quotient of the static moment per pulley radius.

Scalc \u003d Mism / (Rsh ⋅ Kzap ) \u003d 55 / (0.1 ⋅ 1.1) \u003d 500 N

where:

Msm - values of the measured torque, Msm=55 N⋅m;

Rsh - pulley radius, Rsh=0.1 m;

Kzap - safety factor, taking into account the relative error of the torque wrench and measurement uncertainty, Kzap=1.1.

2.2 Compare the obtained value of the design force in the rope Scalc with the criterion according to p.p.p d) p.5.6.2.2.1 of GOST 33984.1 and make a conclusion about the fulfillment of the requirements of the regulatory document.

Claims (3)

1. Speed limiter centrifugal type double-acting, containing rocker arms with two symmetrical diverging loads and a movable locking roller on the carrier, mounted on a pulley rotating on the axis, which is made with clamping surfaces of a shaped profile to interact with the locking roller, and a locking disc that interacts with the locking roller. roller, characterized in that the limiter has an additional polyhedron connected to the pulley in order to attach a torque wrench to it. 2. A method for checking the sufficiency of the friction force between the rope and the working pulley, necessary to actuate the safety catchers, which consists in the fact that, with the ropes of the lifting mechanism fixed, a torque wrench is installed with a pre-configured value of the static moment on the polyhedron connected to the pulley, and gradually increase the value of the static moment before the start of the joint rotation of the pulley and the rope and visually fix the absence of slippage between the surface of the rope and the pulley creek, which indicates the sufficiency of friction forces. 3. A method for determining the force in the rope that activates the safety catchers when the speed limiter is triggered, consisting in the fact that, with the ropes of the lifting mechanism in a fixed state, a torque wrench is installed on a polyhedron connected to the pulley and a gradual loading with an external moment is created until the joint rotation of the pulley and rope with subsequent registration of the measured static moment and further determination by calculation of the value of the force in the rope, which actuates the safety gear, as a private static moment per pulley radius.

Images