SU43593A1 - Group Electropneumatic Contactor - Google Patents

Description

The invention relates to a group electrocneumatic contactor, used mainly in the field of control of electric trains and consisting of a cam roller or rollers that actuate the contacts.

Good quenching of volt arcs in contactors requires a quick movement of the camshaft, and the latter is invariably associated with the large kinetic energy that the shaft must receive during this movement.

Bringing this energy will require a powerful drive if it is created while the cam shaft is moving; Therefore, in the proposed contactor, this energy is stored in a combined way — in the form of the kinetic energy of rotating parts and the potential energy of springs or weights.

The design of the proposed contact is shown in the drawing, where FIG. 1 shows a mechanical transmission from a pneumatic motor to a cam shaft; FIG. 2 — adaptability for mechanical connection between the roller and the springs or weights; FIG. 3-pneumatic engine; FIG. 4 is one of the valves for controlling this engine; FIG. 5 diagram of the main electric circuit (i.e. the traction motor circuit); FIG. 6 is a control circuit diagram.

The cam shaft O (fig. 1) of the contactor receives movement from shaft A by means of the Maltese mechanism through the shaft B and gearing.

On shaft A there is a lever with a load G, the purpose of which is twofold: first, to store work, in the form of its kinetic energy, at the beginning of the movement of shaft A when turning it to

angle a and give this energy to the cam shaft; second, after turning the cam shaft, bring the leading pin of shaft A to the lower position; for the latter purpose it can be replaced by a spring.

In the Maltese cross, cuts b are inserted, and in the disk near the finger and the cut is reduced accordingly. This achieves an exact fixation of the position of the cross, eliminating the possibility of a disk jamming on the cross and eliminating the blows of the finger on the cross at the beginning of its movement.

The use of the Maltese mechanism ensures reliable fixation of the position of the camshaft and the absolute impossibility of overshoot by the contactor at once in two positions.

The work of the contactor is as follows. At the beginning of the movement of the shaft A, it is accelerated during rotation by angle a, the reserve of kinetic energy in the load G and other parts located aa it. With a further turn, he carries away a Maltese cross, driven into motion by a camshaft. In doing so, much of its kinetic energy is given to the cam shaft. Due to the exceptionally favorable acceleration law given by the Maltese mechanism, the transfer proceeds smoothly and without impacts. Upon further movement, the Maltese cross (and with it the camshaft) gradually slows down and stops, returning its kinetic energy of the shaft A,

Upon further rotation of the shaft A at an angle a, it is braked with compressed air and smoothly stops.

In order to achieve an even higher speed of the camshaft, the work required to communicate this speed to it is stored by springs. To do this, a cam is mounted on shaft B, depicted in FIG. 2 in the position corresponding to the cam shaft stop. According to this cam there are rollers pressed by strong springs. In the first period of the camshaft, these springs, with the help of the rollers and the cam, accelerate the shaft, giving it their energy. In the second period of motion, the turn, they absorb energy from the camshaft and slow it, i.e., the movement of the shaft, by its law, approaches its free oscillation under the influence of a spring.

The cam protrusions are provided with small depressions defined by a radius, somewhat larger than the radius of the roller, not intended to stop the mechanism, since the latter is very reliably reached by the Maltese cross, but only to reduce the friction of the disk on the shaft A of the Maltese cross. Therefore, these recesses may be absent. The profile of the cup must be chosen so that the work of the rollers on it is ensured without impact. To do this, it should be outlined on the line of an equidistant logarithmic spiral, rounded the inner corners with a radius greater than the radius of the roller.

External corners can be rounded arbitrarily; iai iycoM (for these curvatures, see the article by the author and the “Journal of Engineers for 1932 .N2 I).

To rotate VA.A, a pneumatic rotary motor (Fig. 3) serves. Such engines are used in vacuum pumps and hydraulic gear boxes.

The compressed air supply is controlled by conventional electromagnets. N; The electromagnet L is provided with an auxiliary winding designed to hold the core during the switching of the main winding from one electrical circuit to another. The auxiliary winding can be made short-circuited and powered by a current, inductively, with the extra-current of opening the main winding.

If there is no current in both electromagnets W and N, then M reports the left cavity with the compressed air pipeline, and the N-right cavity with the atmosphere. By the pressure of this air, the contactor turns to the off position and in it and holds. When an LG electromagnet is used, the cavity is connected to the compressed air pipeline, but this is not enough to move the contactor, since the left cavity is also connected to this pipeline. When the electromagnet M, which is controlled by the accelerator relay, is excited, the air from the left cavity is released. The drive moves and turns the cam shaft one notch.

The current in the electromagnet M is interrupted by the acceleration relay or by the interlock drum of the contactor. Due to this, compressed air through the check valve P will fill the left cavity and, consequently, the pressures in both cavities are equalized.

The drive will continue to move by inertia, pushing the compressed air out of the left cavity into the pipeline. Valve P will then close and air will flow only through a narrow orifice regulated by valve p (the latter can be replaced with a hole in valve P).

Due to the fact that braking occurs with compressed air, it will be much stronger than in conventional pneumatic cataracts, approaching its properties to hydraulic braking. However, the smoothness of deceleration is much higher.

When the acceleration relay closes the electromagnet M. circuit again, the contactor turns to the next position in exactly the same way, etc. The contactor is turned off (moving in the opposite direction) in exactly the same way, with the only difference being that both the M and N electromagnets are current free. The contactor is stopped and braking occurs when the electromagnet L is excited.

Since the control current is also switched off when the traction motors are completely turned off, to stop the contactor in the extreme off position, it is necessary to mechanically move the solenoid valve N to the position corresponding to the compressed air inlet. This is achieved by a cam sitting on a cam shaft and a lever. This adaptation in FIG. 3 is shown in letter L.

In those cases when the contactor is turned on for a full parallel connection of motors with a weakening of the floor after a short current is turned off, when the train speed has not managed to decrease, and also when it is turned off, it has to pass through eighteen positions cpi3v. Since the drive speed will increase with each turn, it will be difficult to brake it in the last position. Therefore, after the first rotation of shaft A (Fig. 1), it is necessary to throttle the incoming B03iyx so that the speed of this shaft does not descend further.

A device for this is shown in FIG. 4. The air from the pipeline enters the valve Q through the R-pipe, equipped with a spring, which attempts to open it. The valve is closed by pressing the cam, which is seated on vac.ch A (Fig. 1), onto the roller. This closure occurs after the end of the rotation of the shaft A at the corner;. With this closure, the pressure downstream of valve K drops and this valve remains impacted by air pressure to this seat.

Air to valve Q is supplied only through valve g, with which it is throttled, so that a further increase in speed is stopped. If the YEAR happens only in one position, then closing the valve R helps braking. To the next movement of the contactor, valve K will already be opened by its spring, since pressures are compared through valve G. To throttle the air when the contactor is turned on, it is necessary to install the same device in front of valve P with the only difference that the corresponding valve will be closed at a different time than valve B.

Holding the valve R pressed to the saddle can be produced by a dog released by an electromagnet activated by the acceleration relay when it is operated.

The scheme of the main switchboard of the proposed contactor is given in FIG. 5. It represents the o6HqHY o serial-parallel DC motor control circuit with bridging transition.

All 18 contactors are driven by a spindle shaft; linear contactors and shunt-field switches are completely absent, which, however, simplifies and reduces the cost of control equipment.

The proposed contactor allows the current to be switched off from parallel connection to the club with a secret aole, not only by turning it backward, but immediately by turning it forward. At this, jBce rheostats are first switched on, whereby the current is greatly weakened, and then the current is broken in ten places (four contactors in series), which, together with a very fast movement of the camshaft, gives good damping of volt arcs.

When going from parallel to serial connection, the current is broken "; four places (contactors B-, BZ, GI. Go); and when switched off from the serial connection, in five places (see the contactors closure table). When the current is turned off, the field-contactors / j are also involved. Fa, Fg, F, due to the fact that, with a small total number of contactors, there is a large number of current interruption sites. In order to increase safety in case of failure of a group contactor, if the pipeline is clogged or there is no compressed BOUD or an foreign body enters the system, an emergency switch AB is inserted to ensure reliable current shutdown.

It is an electro-pneumatic individual contactor without a scriber. Parallel to it, through a resistor, a fuse is inserted, designed to melt the load current. With the emergency switch closed, almost all the load current goes through it and therefore the fuse does not melt. In case of accidents, the safety switch opens, all current passes through the fuse, melts it and breaks. Blutdog such an emergency switch device does not allow it to open under voltage and is therefore very simple and cheap. Further shutdown of the emergency switch is possible only when the fuse is replaced, since otherwise the HP nullary relay will be turned on without current.

The control circuit diagram is given in FIG. 6. It works as follows. When the main controller (master controller) is set to the first (shunting) position, the current from the positive pole is through the switch: 1 and the safety button enters the controller, where it branches: first, the current goes to the controller's reverse bfaban and position, in the wire And or 12, in the corresponding coil of the reverser and to the negative pole.

The reverser jumps over, closes its notepad: 5th contact and current goes to contact d of the locking drum of the contactor, then through the contact / to the main coil N of the contactor and through the contacts of the zero relay and the overload relay to minus. From contact d current, moreover,

the contact li goes C, the emergency switch coil, the contacts of the zero relay and the overload relay and into minus. The emergency switch will shut down and close its AB interlock contact, which will keep it closed all the time. Another current path: from control loop. Wire 1 (winding), contact a, contact G and from there part-cut auxiliary coil of the acceleration relay RU, solenoid M of the contactor, blocking contacts of the zero relay ne,. Loads to minus. Both electromagnet M to N controllers will be excited and it will come into motion. When the contactor moves from zero to first, the contactor pulls the circuit of the electromagnet M in contact G and the further movement will be canceled. In addition, the coil is an electromagnet, ita N switches from wire pjwe, serum to shunting. In order to avoid measles when switching, the auxiliary cap turns on by contact e (only for the duration of the switch).

If the controller is sequentially or one of the further positions, the current through wire 2, contact /, contact L will approach the contact of the accelerator relay, and if the latter has disappeared, then the electromagnet coil Ai, t, d. The contactor will go from the first to the second position , closure of one section of the starting resistors. In this case, the coil of the electromagnet JV is switched from the Maierovog proyida 1 to the serial 2.

During DBA ke1: and the contactor closes the current through pin 6 to the electromagnet A {, which ensures the movement of the contactor by one division, despite the fact that the accelerator relay contacts are broken. Further movement of the tee contactor successive positions will occur in the same order when the acceleration relay cortex falls off. In the last (eighth) position of the accelerator relay from the after-one wire, it switches to parallel 3 with the help of contacts L. i and / g, and a further contacting of the contactor occurs only when a current is blown to pin A.

“This is possible only when the controller is in the proper position and when all the thrusters are working, since the current to contact k is supplied through the interlocking contacts of the MOi switches of the OM motors.

;; When changing from a serial line: 1 connection, the electric coil N switches from wire 2 to wire 3.

In the same way, the transition to the shunting field and switching off is carried out.

In order to overload the motors with a premature transition by weakening the field, a demagnetization coil is arranged in the acceleration relay, co-current is fed through a resistor to regulate the acceleration, the short circuit of the running wire through contact b. This coil off: luts in the transition positions of the contactor, providing a reliable attraction of the accelerator relay.

The acceleration relay is designed so that when controlling the starting rheostat its measles fall off at the desired main current strength with the demagnetizing coil turned on.

in the last parallel connection, the demagnetizing coil is turned off and therefore the acceleration relay disappears and switches the contactor to weakening the field only when the current in the drive circuits is very low. This eliminates the possibility of using the weakened field of the pickup, on the climbs, etc., from the driver's side.

The forward switching off of the contactor occurs when current is supplied to the contact t on the wire 8.

This is achieved either by turning the controller to the fifth position (for which the controller is arranged with rotating the knob circle) or by the contacts of a zero relay or an overload relay connecting wire 8 with the shunting wire J; since these relays are simultaneously repaired by other contacts, turn off the coils of electromagnets M and N and, therefore, can cause the contactor to move backwards, a special CP relay is provided in the circuit. This relay is powered by the current flowing through the weakening wire 4 and through the wire 8 and connects with its contacts the end of the coils of electromagnets M l N with minus in addition to the contacts of the zero relay and the overload relay. This connection is made only in the position of a parallel connection with a weakened field.

The applied circuit for switching the winding of the electromagnet L to the wire of this connection allows the transition to the reverse direction — from parallel connection to serial and rotating. In order to make you understand how this happens, you can follow the transition from parallel connection by weakening the floor to the next closet. For this, the main controller is translated and .; the first position to the second. This turns off the current in the leads 3 and 4.

The electromagnets M and N will remain without current and the contactor will move in the direction of shutdown. This movement will occur to the eighth position of the series connection, in which the current from the wire 2 through the contacts / and / gets into the coil of the electromagnet L, will initiate it and the movement will stop.

In this way, any movement of the contactor in the circulating direction is carried out.

The operation of the contactor during manual start using the bypass coil is the same as usual.

In the opinion of the author, the proposed contactor has the following advantages: 1) simplicity and low cost due to the absence of a line contactor and a floor switch; 2) the absolute impossibility of overshoot by the contactor of two positions at once, which is very dangerous for engines; 3) performance and reliability due to the smooth movement and the absence of shocks and high switching speed; 4) good quenching of volt arcs due to high speeds and a large number of current interruption sites; 5) the ability to switch from fast running (parallel connection, weakening the floor) to quiet (serial and shunting connection) without turning off the current, thereby making the load more uniform and improving the use of substations and wires; 6) unconditionally reliable current shutdown even when the contactor is damaged due to the use of an emergency switch that transfers the current to a fuse; 7) the ability of the driver to be misused by the weakened field, thanks to what is possible; widespread use of weakening the floor, thereby reducing losses in rheostats, increasing the speed of movement and improving the use of the composition; 8) decrease, more than twice the number of individual switchings of the contactors due to the switching off of the current contactor forwards and the ability to switch from high speed to slow without switching off the current; therefore, the durability of the contactor increases greatly; 9) large accelerations when starting and chorlon use of traction engines due to the transition by the bridge method; 10) great economy of air for the following reasons: a) during 1 hour of stopping or riding the train, air can seep through only one gland of a small meter, and not through two large pistons of a conventional contactor; 6) to switch to one division 1: only a small amount of compressed air is released, and not all air from a cylinder designed to rotate at all positions.

The subject of the patent.

Claims (13)

1. A grouped electropneumatic contactor in which the contacts are driven by a rotary cam roller or rollers characterized in that. that, for rotation of the roller or rollers, a rotary, for example, pneumatic motor was used to, firstly, automatically stop the drive: mechanism south of the contactor after switching from one position to another, and secondly, applying transmission with energy-accumulating parts. J. The form of the contactor according to claim 1, characterized in that the pipes supplying compressed air to the elactromagnetic valve 1: am, controlling BnjCKOM and exhausting air from the engine, are equipped with Yi check valves (5 and bypass valves for the latter. " by pans qn q, for the purpose of pneumatic braking of cam 1; alik. 3. The form of the execution of the contactor on PP. 1 and 2 ,. characterized in that the cam roller is provided with a cam L interacting with a closing valve and serving to open it in the zero (off) position of the roller, in order to stop the latter. 4. The form of the execution of the contactor on PP; 1-3; characterized in that the valve P. is located in the pipe supplying Air to the closing valve. It is controlled by means of a cylinder or the like attached to the engine axis and bypass valve r for the purpose of braking the engine each time it is turned by throttling these clinics entering the engine compressed air. 5. In the case of a contactor according to claim 4, the use of a pawl for valve R, holding it in a closed state and a controlled acceleration relay black: via an electromagnet. 6. When contactor on PP. 1-5 use of the Maltese cross, which serves as an intermediate element of the transfer from the driver to a cam roller and provided with notches located in the middle parts of the edges of the cross, fixing the position of the latter, which notches are intended to reduce the size of the cut in the disk carrying the driving pin. 7. With a contactor on the PC. 1-6 use as springs, acting through a transmission mechanism on a cam roller, springs so proportioned that they serve to transfer the energy accumulated by them to the roller in a period. accelerating the latter and for absorbing the energy of the movement during the slow roller period. 8. When contactor on PP. 1-7 the use of a distance-controlled (for example, electropneumatic) contactor AB, which serves to open the circuit, which draws a fuse in the circuit of the traction motors, designed to be melted by the operating current of the latter. 9. With contactor on PP. 1-8 Use an auxiliary coil of an electromagnet, L, controlling a closing valve, for the purpose of holding and the core when the main coil is switched to a particular circuit. 10. When contactor on PP. 1-9 application of the demagnetizing winding in the acceleration relay U controlled by the locking drum of the contactor and turned off before switching the latter to the position of the weakened excitation of the traction motors and the transition positions. 11. With contactor on PP. 1-10 use an auxiliary CP relay that serves to turn the contactor from the last position to the shutdown position of the traction motors in the same direction that the contactor turned when the motors were turned on, in order to turn off the latter via an overload relay or zero. 12. When contactor on PP. 1-11, therein is a cam E in it which serves to turn on the coil of the electromagnet N of the closing valve in a chain corresponding to the occupied position (maneuvering, sequential, etc.). 13. When contactor on PP. 1-12 use as a main controller of such a controller, which can make a full turn. Phin..y fig t Fig5