RU44873U1 - SWITCH - Google Patents

Abstract

The utility model is intended for switching electrical circuits in automation systems. A switch comprising a ratchet wheel mounted on a shaft and connected through at least one dog with an electromagnetic drive, a latch, movable and fixed contacts, further comprises at least one output shaft, a return spring, one end of which is fixed to the shaft and the other based on. The ratchet wheel is mounted rotatably relative to the first shaft and is connected via a gear transmission to at least one output shaft. The electromagnetic drive is made in the form of two electromagnets with a common anchor mounted on the first shaft, while the electromagnets are rigidly mounted on the base on different sides relative to the common armature and the first shaft. The latch is made in the form of a rotor, mounted on one of the output shafts and the stator of soft magnetic material, rigidly mounted on the base coaxially to the rotor, made in the form of a permanent magnet of cylindrical shape, on the poles of which are two disks of soft magnetic material, while on one of the rotor disks and on the stator are made toothed protrusions facing each other with an angular pitch equal to or equal on one of them, and on the other a multiple of the angle of rotation of the output shaft by one step. One group of movable and fixed contacts is made with the possibility of supplying control pulses to the electromagnetic drive via two different control circuits, and the other with the ability to disconnect the control circuit in the triggered and initial states of the switch. The movable contact of the first group of contacts is rigidly fixed through the insulator on the output shaft and is made in the form of two electrically connected interconnecting disks, on one

of which the protrusions are made with an angular pitch equal to the angle of rotation of the output shaft by one step, while at each step the protrusions have the ability to interact with only one of the stationary contacts of the control circuit. Technical result: increased shock and vibration resistance, the absence of wear of the locking elements, reduced power consumption and dimensions of the electromagnetic drive, as well as the elimination of the passage of two consecutive pulses along the control circuit, including false ones, and the self-shutdown of the electromagnetic drive in the initial and activated states. 2 ill. 1 zpf

Description

The utility model relates to electrical engineering, in particular to switches with an electromagnetic drive, and can be used for switching electrical circuits in automation systems.

Known electromagnetic remote switch / a.s. USSR No. 416783, IPC N 01 N 63/22, H 01 N 1/10 publ. 11/25/74 bul. No. 7 /, containing an electromagnetic mechanism, a traverse and a contact system. The electromagnetic mechanism is made in the form of a non-reversible stepper motor with a fixed two-coil rotor. To fix the states of the switch, a permanent magnet is used, located in the common part of the rotor cores between the coils.

The switch has vibration resistance. However, to control it, additional equipment is needed.

A multi-position switch / a.s is also known. USSR No. 817768, IPC N 01 N 3/28, H 01 N 3/34, publ. 03/30/81 bul. No. 12 /, comprising a housing on which a disk with lamellae is mounted, a shaft with a ratchet wheel mounted thereon and a traverse with contact elements, an electromagnet and a ratchet gear switching mechanism, consisting of a guide element mounted on the housing, and a working dog with a spring mounted on the axis of the anchor of an electromagnet.

The switch allows for step-by-step switching of the traverse with contacts. However, this design has low shock and vibration resistance due to the unbalance of the armature with the dog, as a result of which a dynamic run-out of the traverse is possible under conditions of vibration and linear acceleration.

As a prototype, the switch closest to the proposed utility model of the type of step finder / a.s is selected. USSR No. 686098, IPC N 01 N 63/00 N 01 N 67/00, publ. 09/15/79, bull. No. 34 /, containing a ratchet wheel mounted on an axis, rigidly

mounted on the board, and connected through a dog with an electromagnetic drive, brake, emphasis, movable and fixed contacts, a fixing wheel with spherical cavities on its outer surface, mounted on a ratchet wheel. The movable contacts are mounted on the ribs of the ratchet wheel, and the fixed contacts are located on the circuit board circumferentially coaxially with the ratchet wheel. A finger brake with a spherical working surface and a locking wheel perform the function of a lock. When a pulse is applied to the electromagnet, the anchor is attracted to the core of the electromagnet, and the dog makes the ratchet wheel turn one step. Together with the ratchet wheel, the locking wheel also rotates, pressing the brake roller with its protrusion. In this case, the roller, rolling through the teeth of the locking wheel, sinks into its cavity, fixing the position of the ratchet wheel.

The advantage of the prototype is that continuous stepwise movement can be carried out without the use of additional equipment. However, this design has a number of significant drawbacks: increased mechanical wear of the locking wheel and the brake caused by mutual friction of the contacting surfaces;

low shock and vibration resistance due to the imbalance of the moving elements of the electromagnetic drive and brake; the irrational use of the traction moment of the electromagnetic drive, which consists in the fact that when the locking wheel is rotated in the first half of its angular step, when maximum torque is required, the electromagnetic drive has minimal traction moment, and in the second half of the angular step, when the roller passes the tooth of the fixing wheel, less torque is sufficient, and the traction moment of the electromagnetic drive increases to the maximum.

The problem to which the proposed utility model is directed is to increase operational reliability and create optimal electromechanical conditions for switching contacts.

A new technical result obtained in the implementation of the utility model is to increase the shock resistance, the absence of wear of the locking elements, reducing the power consumption and dimensions of the electromagnetic drive, as well as eliminating the passage of two consecutive pulses along the control circuit, including false ones, and ensuring the self-shutdown of the electromagnetic drive in the original and triggered states.

This is achieved by the fact that the proposed switch, comprising a ratchet wheel mounted on the shaft and connected through at least one dog with an electromagnetic drive, a latch, movable and fixed contacts, in contrast to the prototype, additionally contains at least one output a shaft, a return spring, one end of which is mounted on the shaft, and the other on the base. The ratchet wheel is mounted rotatably relative to the first shaft and is connected via a gear transmission to at least one output shaft. The electromagnetic drive is made in the form of two electromagnets with a common anchor mounted on the first shaft, while the electromagnets are rigidly mounted on the base on different sides relative to the common armature and the first shaft. The latch is made in the form of a rotor, mounted on one of the output shafts and the stator of soft magnetic material, rigidly mounted on the base coaxially to the rotor, made in the form of a permanent magnet of cylindrical shape, on the poles of which are two disks of soft magnetic material, while on one of the rotor disks and on the stator are made toothed protrusions facing each other with an angular pitch equal to or equal on one of them, and on the other a multiple of the angle of rotation of the output shaft by one step.

One group of movable and fixed contacts is made with the possibility of supplying control pulses to the electromagnetic drive through different control circuits, and the other with the ability to disconnect the control circuit in the triggered and initial states

switch. The movable contact of the first group of contacts is rigidly fixed through the insulator on the output shaft and is made in the form of two electrically connected interconnecting disks, on one of which there are protrusions with an angular pitch equal to the angle of rotation of the output shaft by one step, while at each step the protrusions have the opportunity interact with only one of the fixed contacts of the control circuit.

In the specified version of the switch, the latch performs the function of a brake with a locking wheel and is designed to prevent dynamic run-out of the output shaft when making a stepwise movement and then holding it in a stable position. The absence of unbalanced elements in the latch increases shock and vibration resistance of the switch. Unlike the prototype, in which braking occurs due to friction when the finger is lowered into the cavity of the fixing wheel, in the proposed switch, the output shaft is braked and held due to the forces of the magnetic interaction of the rotor and stator, which completely eliminates the mechanical wear of the locking elements. In addition, when the output shaft makes a step movement, the magnetic forces of the clamp create an additional torque in the second half of the angular step that coincides in sign with the moment of the return spring. This makes it possible to use a spring with low torque, resulting in reduced energy consumption of the electromagnetic drive and its dimensions.

The group of movable and fixed contacts, which provides the supply of control pulses to the electromagnetic drive through different electric control circuits, eliminates the passage of two consecutive pulses along the same control circuit, including false ones, the group of movable and fixed contacts, which disconnects the control circuit, allows you to complete switch duty cycle strictly

preset positions of the output shaft, excluding the passage of the total number of pulses during the cycle more than the set.

Figure 1 shows the kinematic diagram of an example of a specific implementation of the proposed switch.

In FIG. 2 shows graphs of changes in moments M, reduced to the output shaft when it is rotated by one angular step φ.

Here a is the traction characteristic of the electromagnetic drive;

b - mechanical characteristic of the return spring;

c is a graph of the change in the moment of friction forces in the interaction of contacts;

g is a graph of the change in the moment of the magnetic clamp;

d is a graph of the change in torque acting on the output shaft.

The electromagnetic drive contains two identical electromagnets 1, rigidly mounted on the base, an anchor 2, rigidly connected to the shaft 3, and a return spring 4, one end of which is mounted on the shaft 3, and the other on the base. The kinematic connection of the armature 2 with the ratchet wheel 5 mounted on the shaft 3 with the possibility of rotation around it is carried out by means of dogs 6. In this case, the dogs 6 are constantly pressed against the ratchet wheel 5 by springs 7. The ratchet wheel 5 is rigidly connected to the gear wheel 8 and has gears through the gears 9 and 10 kinematic connection with the output shafts 11 and 12.

The output shaft 11 of non-magnetic material is connected to the latch, which is a magnetic system consisting of a stator 13 fixed to the base and a rotor made in the form of a permanent magnet 14 rigidly mounted on the said shaft with soft magnetic disks 15 and 16 at the poles. On the stator 13 and on the disk 15, gear protrusions are made opposite each other, the angular pitch of which is equal to the angle of rotation of the shaft 11 by one step. It is possible to perform the angular pitch of the protrusions either on the stator 13 or on the disk 15 by a multiple of the angle corresponding to one step of the shaft 11.

The closure of the field of the permanent magnet 14 is carried out through the air gap between the tooth protrusions of the stator 13 and the disk 15.

On the output shafts 11 and 12, movable contacts 17, 18 and 19, 20, isolated from them, are rigidly fixed, with the possibility of interaction with the corresponding fixed contacts installed on the basis of them.

The electromagnets 1, electrically connected to each other, have a constant electrical connection with the movable contacts 17 and 19 through the fixed contacts 21 and 22, respectively. The fixed electrical contacts 23 and 24, connected to the power buses I and II, have the possibility of periodic interaction with the movable contact 17, and the fixed contacts 25 and 26 associated with the power buses III and IV - with the movable contact 19.

The principle of operation of the switch is as follows.

In the initial state, the armature 2 is pressed by the return spring 4 to the stop 27, the working stationary contacts 28, 29 and 30, 31 are closed by the movable contacts 18 and 20, respectively.

The serrated protrusions of the stator 13 and the disk 15 are oriented against each other, i.e. are in the position of maximum magnetic conductivity. The field of the permanent magnet 14, which closes along the tops of the tooth protrusions of the stator 13 and the disk 15, creates a fixing moment that holds the output shafts 11 and 12, kinematically connected by gears 8, 9 and 10, in a stable position.

When a control pulse is applied via the fixed contacts 24 and 26 of the bus II-IV, the armature 2 is attracted to the electromagnets 1 and twists the spring 4, accumulating potential energy in it, and the dogs 6 connected to the armature 2 emerge from the interdental depressions of the ratchet wheel 5 and, slipping along the tops of the teeth, sink into adjacent interdental cavities. At the same time, the ratchet 5 connected to the output shaft 11 through the gears 8 and 9 remains stationary due to

magnetic forces of a clamp. After removing the control impulse from the electromagnets 1, the armature 2, under the action of the spring 4, returns to its initial state and stops 27, and the dogs 6, pushing the ratchet wheel 5, turn the output shafts 11 and 12 through the gears 8, 9, 10 with movable contacts on one step. After that, the latch will take a new stable position, in which the serrated protrusions of the disk 15 will again be against the protrusions of the stator 13, keeping the output shafts 11 and 12 from turning until the next control pulse passes. The movable contact 17, opening with the fixed contact 24, breaks the power circuit along the buses II-IV and, closing with the fixed contact 23, forms a power circuit along the buses I-IV. Then, with the supply of the control pulse, the cycle will be repeated and the previous power circuit via the II-IV buses will be restored.

Thus, the oscillatory movement of the armature 2 is converted using the dogs 6 and the ratchet wheel 5 into the intermittent (step) rotational movement of the output shafts with movable contacts.

The dynamic process of switching contacts in the range of one angular step is illustrated in FIG. 2.

When the armature 2 is attracted to the electromagnets 1 (from φ ° to 0 °), the spring 4, twisting, receives an increment of the moment from Mп1 to Мп2 (graph "a"). In this case, the traction characteristic of the electromagnetic drive (schedule "b"), overcoming the spring 4, is located above its mechanical characteristics ("a").

The return stroke of the armature 2 to its initial state is associated with overcoming the moment of friction forces of the interacting contacts and the holding moment of the clamp.

The graph “c” shows the change in the moment of friction forces during the interaction of moving and fixed contacts in the area from 0 ° to φ °. At the initial stage of the angular step, the moment of friction forces during sliding of the contacts is constant Мтр2 and after opening part of the contacts drops to

Mtr1, remaining constant until the meeting of moving contacts with motionless. When “moving” movable contacts into a pair of fixed contacts, the moment of friction forces sharply increases to Mtr4 and, upon further rotation, also sharply decreases to Mtr3.

The change in the moment of the magnetic latch is shown in the graph "g". At the beginning of the movement, the magnetic forces of the retainer counteract the rotation of the shaft, reaching a maximum in the region from 0 ° to 1 / 4φ °. After that, the serrated protrusions of the disk 15 begin to interact with adjacent along the serrated protrusions of the stator 13 and after passing half the angular pitch (1 / 2φ °), the locking moment becomes positive with respect to the moment of the spring 4, reaching a maximum at an angle of 3 / 4φ °.

The torque acting on the output shaft, taking into account the influence of the clamp moment, will change along the curve "d", which is the sum of the graphs "a" and "g". As you can see, the curve "e" almost smoothly goes around the curve "c" - changes in the moment of friction forces, i.e. the torque acting on the shaft in the first half of the angular step, when the moment of friction forces is small, drops to the optimum value, and in the second half increases to the value necessary to overcome the moment of friction forces when the contacts are “cut in”, exceeding the moment of the return spring 4.

In fact, the potential energy of the spring spent on completing the work to overcome the clamp moment in the first half of the angular step returns to the second - more loaded half (shaded areas). The specified redistribution of spring energy creates optimal electromechanical conditions for switching contacts. This allows the use of a spring with a low torque, resulting in reduced power consumption and the dimensions of the electromagnetic drive.

After applying to the electromagnets 1 alternately in two circuits (buses I-IV and II-IV) the specified number of control pulses

the switch goes into the triggered state. This means that the movable contacts 18 and 20 break the electrical circuits between the contacts 28-29 and 30-31, respectively, and connect the contacts 32-33, 34-35. In this case, the movable contact 19 breaks the connection with the fixed contact 26, excluding the possibility of supplying control pulses via the I-IV and II-IV buses, and closes with the fixed contact 25, forming a circuit for bringing the switch to its initial state.

Bringing the switch to its initial state is carried out by alternately supplying a series of control pulses along buses I-III and II-III

The indicated principle of operation of the switch excludes the possibility of supplying two consecutive control pulses along the same electrical circuits and the passage of the total number of pulses is greater than the established one.

Claims (2)

1. A switch comprising a ratchet wheel mounted on a shaft and connected through at least one dog with an electromagnetic drive, a latch, movable and fixed contacts, characterized in that it further comprises at least one output shaft, a return spring, one end of which is mounted on the shaft, and the other on the base, the ratchet wheel is mounted for rotation relative to the first shaft and connected through a gear transmission to at least one output shaft, the electromagnetic drive is made in e two electromagnets with a common anchor mounted on the first shaft, while the electromagnets are rigidly mounted on the base on opposite sides relative to the common armature and the first shaft, the latch is made in the form of a rotor mounted on one of the output shafts and the stator of soft magnetic material, rigidly mounted on the base coaxially with the rotor, made in the form of a permanent magnet of cylindrical shape, on the poles of which are two disks made of soft magnetic material, while on one of the rotor disks and on the stator Toothed protrusions attached to each other with an angular pitch equal to or equal on one of them, and on the other a multiple of the angle of rotation of the output shaft by one step. 2. The switch according to claim 1, characterized in that one group of movable and fixed contacts is configured to supply control pulses to the electromagnetic drive through different control circuits, and the other with the ability to turn off the control circuit in the triggered and initial states of the switch, the movable contact is the first groups of contacts are rigidly fixed through an insulator on the output shaft and is made in the form of two electrically connected interconnected conductive disks, on one of which protrusions with an angular pitch equal to the angle of rotation of the output shaft by one step, while at each step, the protrusions have the ability to interact with only one of the stationary contacts of the control circuit.