SU1672230A1 - Discrete weigh hopper - Google Patents

Abstract

The invention relates to weighing technology and allows for improved accuracy. Depending on the weight of the material supplied to the receiver 9 from the hopper 2, the pressure in the pneumatic line connects the weight converter in the form of a measuring spring 5, bar 6 and ball 7 located in the cone 8, to the load forming unit 12 and loading control unit 13 . The unloading control unit 14 is connected by pneumatic line to the unloading mechanism 11. Comparison element 29 of unit 13, which acts as a regulator, receives a reference pressure, which varies exponentially, and a variable pressure from the weight converter. The law of regulation is established by means of drossel 31. The pneumatic signal from the output of the comparison element 29 through the repeater 30, the relay 28, 33 and 34 is fed to the material feed mechanism 1. The signal about the dose set is produced at the output of the element 25 of the comparison unit 12 and is fed to the pneumatic tube 44. 1 sludge.

Description

This invention relates to a weight measuring technique.

The purpose of the invention is to improve the accuracy

The drawing shows a diagram of a discrete weighting dispenser.

The dispenser contains a material loading mechanism 1, a hopper 2 in which the rippers 3 are located, a pneumatic generator 4, a weight converter into a pneumatic signal in the form of a measuring spring 5, a bar 6 and a ball 7 located in a cone 8, a receiver 9 of a weighed dose, a cone 10, a mechanism 11 discharges, a unit for the formation of the law of surcharge, a unit 13 for loading control and an unloading control unit 14, gauges 15-17.

The unit 12 of the formation of the law of supplying includes the first setting device 18, the first comparison element 19, the first relay 20, the third inductor 21, the second relay 22, the second pneumatic container 23, the second setting 24, the second comparison element 25, the repeater 26 with a shift, the second inductor 27.

The load control unit 13 comprises a third relay 28, a third comparison element 29, a repeater 30, a first throttle 31. a first pneumatic capacity 32, a fourth relay 33, a fifth relay 34.

The unloading control unit 14 comprises a sixth relay 35, a button 36, a seventh relay

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37, toggle switch 38, eighth relay 39, ninth turnip 40 third pneumatic volume 41, fourth choke 42, tenth relay 43, pneumatic lamp 44.

In the device there are also chokes 45 - 54, which limit the flow of air.

The dispenser works as follows.

When a control command is sent from node 13 to mechanism 1, material from hopper 2 enters receiver 9.

With the help of the rippers 3, the material in the hopper 2 is maintained in a movable state.

The dose is set in two modes: in the first mode, approximately 90% of the dose is set at the maximum speed possible, and in the second mode, supplementation is carried out, which is controlled by the controller according to the proportional-integral-differential law, but the task is supplied to it exponentially, starting from the moment of transition to this mode.

The unit 18 of the unit 12 sets the pressure Pi, the value of which is close to zero, but greater than the pressure P2, when there is no pressure on the ball 7 from the bar 6, i.e. when the variable pressure P2 is equal to the force that compensates for the weight of the ball 7.

This condition ensures the transition to automatic filling with Ra Pi, i.e. when you start pressing the bar 6 on the ball 7, when the material begins to flow into the receiver 9.

When this happens, the comparison element 19 is triggered, the output pressure of which, in this case, is 1 (Pz 1) and goes to relay 28, which translates mechanism 1 to automatic operation, and to relay 20, which closes the release of pressure after throttles 27. With a time delay, determined by the choke 21, the relay 22 is triggered, and the air capacity 23 is powered through the choke 27.

At the same time, at the moment of switching, due to the high feed rate of the material from the hopper 2 to the receiver 9, the pressure value P2 can take an indefinite value, i.e. Р2 Рт, where Р is the pressure in the line after drossel 27 (rel input & 22).

In order for the pressure P to be greater than or equal to the pressure Pa (P 5: Pa), the time is required during which the filling of material is stopped and P grows exponentially.

Whatever value the pressure Pa takes

on the growth of its exponential law, starting with the equality of these pressures (Ra P).

The unit 24 sets the pressure value Pe.

The pressure Re flows to the reference element 25, where it is compared with the pressure Pa.

When Pa S Pe at the output of the element 25

0 comparison pressure is equal to one (Ps 1). This pressure, as a control signal, goes to relay 34, tripping mechanism 1, to relay 35, allowing a reset of the weighed portion from button 36, to relay 39, automatically equalizing a reset, and to pneumatic light 44, indicating a portion is ready for unloading.

In addition, the pressure of Pe through the choke

0 27 in the form of pressure P is fed to the repeater 26 with a shift.

The pressure from the output of the repeater 26 with a shift comes as a task to the comparison element 29, which performs the role of

5 regulators A repeater 26 with a shift due to a shift of Pc Pa at P 0 provides Pn 0 (signal for switching off mechanism 1) at the beginning of the transition to automatic filling and PA (P + P shift) Pe, but Re,

This ensures reliable operation of the reference element 25.

The throttle 27 and the pneumatic capacitance 23 provide an increase in pressure P exponentially, starting from the achieved

5 values of pressure (P Pa), and the shape of the exponent is determined experimentally.

The element 29 of the comparison of the node 13 receives the pressure of the job PA (variable

0 exponentially) and the variable pressure Pa, proportional to the weight of the dosed material.

The law of regulation (proportional or proportional-integral-differential) is established during adjustment with the help of throttle 31.

The ru signal from the output of the reference element 29, acting as a regulator, through the repeater 30, relay 28,

33 and 34 enters the material feed mechanism 1.

Relay 28 switches the power supply of the mechanism 1 from the network to the comparison element 29, relay 34 prohibits the supply of material if the pressure Pa has reached the specified value, and relay 33 if unloading from receiver 9 is in progress.

The discharge control unit 14 operates as follows. The PS dose signal comes from node 25

12. If the toggle switch 38 is set to manual mode, the ready-for-unloading signal is supplied by the pneumatic tube 44. At the same time, the relay 35 is activated and when the button 36 is pressed, the pneumatic signal is fed through the relay 35 and 37 to the relay 40, the output of which causes the relay 43 to operate.

The output signal of the relay 43 affects the mechanism 11 unloading. The unloading continues until the control mechanism (not shown) works. It is possible to adjust the time of unloading by setting the Drossel 42 depending on the properties of the material.

Claims (1)

Invention Formula A discrete weigher dispenser containing a bunker with a material loading mechanism into the receiver, an unloading mechanism, a weight converter into a pneumatic signal connected kinematically to a receiver, and a loading control unit with a repeater, the first pneumatic capacity and the first choke connected to the loading and unloading mechanisms, characterized in that, in order to improve accuracy, a node for forming the filing law, made in the form of a first and second relay, is introduced into it, a repeater with a shift, the first and second elements vneny, second and third inductors and a second gnevmoemkosti. the third, fourth and fifth relays and the third comparison element were introduced into the load control unit, and the discharge control unit was introduced, made in the form of the sixth, seventh, eighth, ninth and tenth relays, pneumolamps, toggle switches and buttons, the first sensor connected to one input of the first comparison element, to the other input of which a weight converter to a pneumatic signal is connected, the output of the first comparison element is connected to the first inputs of the first, second and third relays, the second unit is connected to the first input of the second ele The comparator and through the second choke are connected to the second inputs of the first and second relays (and the repeater input is shifted, the second pneumatic capacitance is connected to the third input of the second relay, the second input of the second comparison element, the first input of the third comparison element and the third input of the second relay are connected to the weight converter to the pneumatic signal, the second input of the third comparison element is connected to the output of the repeater with a shift, and the output through the repeater to the input of the third relay, the output of which and the outputs of the fourth and fifth relays are connected to the fur load signal, input of the fourth relay is connected to the unloading mechanism, input of the fifth relay is connected to the output of the second comparison element, fourth and fifth relays are interconnected, the first inputs of the sixth and eighth relays and pneumolamp are connected to the output of the second comparison element, the button is connected to the second the input of the sixth relay, the output of which is connected to the first input of the seventh relay, to the second input of which the output of the eighth relay is connected, and to the third input - a toggle switch, the output of the seventh relay is connected to the input of the ninth relay, whose output is through ec Toe relay is connected to the discharge mechanism, and the third and fourth inputs of the third comparing element and interconnected via a first throttle and a first pneumosizes associated with its fifth input. 24 C V 17 5320 15 I 51 26} in 50