阅读说明：本技术 中药煎药机的自动挤压装置及其控制电路和压力控制方法 (Automatic extrusion device of traditional Chinese medicine decocting machine and control circuit and pressure control method thereof ) 是由 陈政 陈建平 于 2020-05-27 设计创作，主要内容包括：本发明公开了一种中药煎药机的自动挤压装置及其控制电路和压力控制方法。所述控制电路主要包括电流采集模块、与该电流采集模块连接的运算/控制模块,与所述运算/控制模块连接的脉冲发生模块以及与该脉冲发生模块连接的步进电机驱动器。通过采集步进电机的电流及转速来计算其输出力矩,以对所述挤压装置的压力进行控制。且进一步设有选通电路,能够实现对多个挤压装置进行控制。所述控制电路中设有通信接口,可与上位机或其他外部设备进行通信连接。本发明的挤压装置及其控制电路和压力控制方法仅靠测量电机的电流和转速即可实现压力控制,同时规避了现有的自动挤压装置中所需的各种传感器的使用,提高了设备的可靠性,降低了设备的运维成本。(The invention discloses an automatic extrusion device of a traditional Chinese medicine decocting machine, a control circuit and a pressure control method thereof. The control circuit mainly comprises a current acquisition module, an operation/control module connected with the current acquisition module, a pulse generation module connected with the operation/control module and a stepping motor driver connected with the pulse generation module. The output torque of the stepping motor is calculated by collecting the current and the rotating speed of the stepping motor so as to control the pressure of the extrusion device. And a gating circuit is further arranged, so that the control over a plurality of extrusion devices can be realized. The control circuit is provided with a communication interface and can be in communication connection with an upper computer or other external equipment. The extrusion device, the control circuit and the pressure control method thereof can realize pressure control only by measuring the current and the rotating speed of the motor, and simultaneously avoid the use of various sensors required in the existing automatic extrusion device, thereby improving the reliability of the equipment and reducing the operation and maintenance cost of the equipment.)

1. The utility model provides a control circuit of traditional chinese medicine machine of decocting medicinal herbs's automatic extrusion device which characterized in that includes: current acquisition module, the operation/control module who is connected with this current acquisition module, with the pulse generation module that operation/control module is connected and the step motor driver who is connected with this pulse generation module, wherein:

the current acquisition module comprises a sampling element, an amplifying circuit connected with the sampling element, and an analog-to-digital converter connected with the amplifying circuit; the sampling element is used for collecting the current of the stepping motor, and the current is amplified by the amplifying circuit and then is input into the analog-to-digital converter so as to convert the analog quantity of the current of the stepping motor into digital quantity data;

the analog-to-digital converter is connected with the operation/control module through a parallel I/O interface and is used for inputting the digital quantity data into the operation/control module;

the operation/control module is connected with the pulse generation module through an I/O interface, so that parameters for controlling the stepping motor are sent to the pulse generation module, and the parameters comprise pulse number and acceleration/deceleration signals;

an I/O interface of the pulse generation module is connected with a pulse signal input end CP of the stepping motor driver and used for sending a pulse signal to the stepping motor driver;

and an I/O interface of the operation/control module is connected with a direction signal input end DIR of the stepping motor driver and used for sending a direction signal to the stepping motor driver.

2. The control circuit of claim 1, wherein the sampling element is a sampling resistor connected in series to a power supply terminal of the stepping motor driver, one end of the sampling resistor is further connected to a first input terminal of the amplifying circuit, and the other end of the sampling resistor is further connected to a second input terminal of the amplifying circuit.

3. The control circuit of claim 2, wherein the amplification circuit is a two-stage amplification circuit.

4. The control circuit of claim 1, wherein an I/O interface of the computing/control module is connected to a wire of an emergency stop device and receives an emergency stop signal generated by the emergency stop device to control the stop of the stepping motor in abnormal situations.

5. The control circuit according to claim 1, wherein a gating circuit is further arranged in the control circuit, the gating circuit comprises a plurality of photoelectric coupling circuits and a plurality of relays, and one path of photoelectric coupling circuit is correspondingly connected with and controls one relay; and the other four contact ends of the relay are used for being connected with the stepping motor.

6. The control circuit of claim 1, wherein the operation/control module further comprises an I/O expansion circuit, and is connected to the photocoupling circuit via the I/O expansion circuit.

7. The control circuit of claim 6, wherein the I/O expansion circuit is a decoder.

8. The control circuit of claim 1, wherein the calculation/control module is further connected to a communication interface device via an I/O interface.

9. The utility model provides an automatic extrusion device of traditional chinese medicine machine of decocting medicinal herbs, includes a step motor, receives this step motor driven drive mechanism, actuating mechanism and step motor's control circuit, its characterized in that:

the control circuit of the stepping motor is the control circuit of any one of claims 1 to 8;

the transmission mechanism comprises a driving gear, a driven gear meshed with the driving gear and a screw rod, and the top of the screw rod is fixedly connected with the driven gear;

an output shaft of the stepping motor is fixedly connected with the driving gear;

the stepping motor drives the main gear and the driven gear to rotate, and drives the driven gear and the screw rod to rotate at the same time, so that the actuating mechanism is driven to extrude medicinal materials downwards or reset upwards;

the stepping motor is connected with the control circuit through a lead.

10. The automatic extrusion device as claimed in claim 9, wherein a buffering torsion spring is disposed between the output shaft of the stepping motor and the driving gear, one end of the buffering torsion spring is fixedly connected to the output shaft of the stepping motor, and the other end is fixedly connected to the driving gear; the stepping motor drives the driving gear to rotate by means of the buffering torsion spring.

11. A pressure control method of an automatic extrusion device of a traditional Chinese medicine decocting machine is characterized by comprising the following steps:

s1, when the motor is unloaded, measuring the current i of the stepping motor₀And simultaneously obtaining the rotating speed n of the stepping motor so as to obtain a current-rotating speed characteristic curve i of the stepping motor₀(n)；

S2, according to the curve i₀(n), obtaining the range of the rotating speed n in the process of self-starting operation to stopping operation of the stepping motor, and selecting a rotating speed interval [ n ] corresponding to the linear working area of the rotating speed of the stepping motor₁,n₂]；

S3, when the motor is in idle load, the motor is in fixed speed n₁Measuring the output torque curve T of the stepping motor₀[n₁,i](ii) a At a constant rotational speed n₂Measuring the output torque curve T of the stepping motor₀[n₂,i]；

S4, according to the two output torque curves T₀[n₁,i]And T₀[n₂,i]Obtaining the interval [ n ] of the rotating speed by adopting an interpolation fitting algorithm₁,n₂]Output torque curve T in the range₀[n,i]；

S5, when the extruding device extrudes the medicinal materials, collecting the current i and the rotating speed n of the stepping motor and outputting the torque curve T according to the output torque curve₀[n,i]Calculating the real-time output torque T of the motor, and when the value of the real-time output torque T of the motor reaches a set threshold value T_sAnd controlling the stepping motor to stop rotating so as to realize pressure control.

12. The pressure control method according to claim 11, wherein the threshold T is set according to a decocting process requirement_sAnd the required extrusion times are used for carrying out extrusion operation; and when the extrusion device is reset, judging and controlling whether the reset action is stopped or not according to the output torque of the stepping motor.

Technical Field

The invention belongs to the field of traditional Chinese medicine decocting machines, and particularly relates to an automatic extrusion device of a traditional Chinese medicine decocting machine, a control circuit of the automatic extrusion device and a pressure control method of the automatic extrusion device.

Background

The decoction of Chinese herbs is one of the most common processing methods for Chinese herbs. During the process of decocting the traditional Chinese medicine, the effective components of the medicinal materials are favorably released into the liquid medicine by proper extrusion. The difference of the dosage and the type of the medicinal materials requires that the extrusion pressure degree should be adapted, and insufficient extrusion or excessive extrusion is not beneficial to the decoction of the Chinese medicinal materials and even causes the abnormal work of equipment.

The traditional Chinese medicine decocting machine mainly adopts two control modes of manual extrusion and automatic extrusion. The manual extrusion mode is a traditional mode, the manual extrusion mainly depends on the experience of operators to control the extrusion pressure, the labor intensity is high, and the necessary stability is difficult to ensure in the modern traditional Chinese medicine decoction production process; the main development direction at present is the automatic extrusion mode. Some traditional Chinese medicine decocting machines are provided with automatic squeezing devices to complete the squeezing operation. The automatic extrusion device of the traditional Chinese medicine decocting machine can complete extrusion operation at present, but does not provide control over extrusion pressure, and has a plurality of defects:

1. a plurality of sensors and matching mechanisms are required to acquire and control information such as displacement and position of the extrusion device. The working environment of the medicine decocting machine has various adverse factors such as high temperature, high humidity and the like. The existence of the sensors and the matching mechanism leads to the increase of the complexity of the decocting machine, the reduction of the reliability and the increase of the operation and maintenance cost.

2. The general control scheme mainly aims at controlling forward and reverse rotation and starting and stopping. In fact, the squeezing process of the medicine decocting machine is an important link in the medicine decocting process. Repeated extrusion and matching with proper extrusion force according to the difference requirements of the types and the dosages of the medicinal materials are the main tasks of the automatic extrusion device. The forward and reverse rotation and the start and stop should be only the basic requirements of the automatic extrusion device which must be met.

Disclosure of Invention

The invention aims to provide a control circuit of an automatic squeezing device of a traditional Chinese medicine decocting machine. The invention relates to a control circuit of an automatic extrusion device of a traditional Chinese medicine decocting machine, which comprises a current acquisition module, an operation/control module connected with the current acquisition module, a pulse generation module connected with the operation/control module and a stepping motor driver connected with the pulse generation module, wherein:

the current acquisition module comprises a sampling element, an amplifying circuit connected with the sampling element, and an analog-to-digital converter connected with the amplifying circuit; the sampling element is used for collecting the current of the stepping motor, and the current is amplified by the amplifying circuit and then is input into the analog-to-digital converter so as to convert the analog quantity of the current of the stepping motor into digital quantity data;

the analog-to-digital converter is connected with the operation/control module through a parallel I/O (input/output) interface and is used for inputting the digital quantity data into the operation/control module;

the operation/control module is connected with the pulse generation module through an I/O interface, so that parameters for controlling the stepping motor are sent to the pulse generation module, and the parameters comprise pulse number, acceleration/deceleration signals and the like;

an I/O interface of the pulse generation module is connected with a pulse signal input end CP of the stepping motor driver and used for sending a pulse signal to the stepping motor driver;

and an I/O interface of the operation/control module is connected with a direction signal input end DIR of the stepping motor driver and used for sending a direction signal to the stepping motor driver.

According to a preferred embodiment, the sampling element is a sampling resistor, the sampling resistor is connected in series with a power supply end of the stepping motor driver, one end of the sampling resistor is further connected with a first input end of the amplifying circuit through a wire, and the other end of the sampling resistor is further connected with a second input end of the amplifying circuit through a wire.

According to a preferred embodiment, the amplifying circuit is a two-stage amplifying circuit.

Furthermore, an I/O interface of the operation/control module is connected with a wire of an emergency stop device and receives an emergency stop signal generated by the emergency stop device so as to control the stepping motor to stop running under abnormal conditions.

Furthermore, a gating circuit is also arranged in the control circuit, the gating circuit comprises a plurality of photoelectric coupling circuits and a plurality of relays, and one path of photoelectric coupling circuit is correspondingly connected with and controls one relay; and the other four contact ends of the relay are used for being connected with the stepping motor. The plurality of stepping motors are controlled in a gate control manner.

Furthermore, the operation/control module is also provided with an I/O expansion circuit, and is connected with the photoelectric coupling circuit by means of the I/O expansion circuit, so as to expand the I/O interface of the operation/control module and support more gating control objects.

According to a preferred embodiment, the I/O expansion circuit is a decoder.

Furthermore, the operation/control module is also connected with a communication interface device through an I/O interface, and can communicate with external equipment through the communication interface.

The second purpose of the invention is to provide an automatic extruding device of a traditional Chinese medicine decocting machine. The invention relates to an automatic extrusion device of a traditional Chinese medicine decocting machine, which comprises a stepping motor, a transmission mechanism driven by the stepping motor, an actuating mechanism and a control circuit of the stepping motor, wherein:

the control circuit of the stepping motor is the control circuit of the automatic extrusion device of the traditional Chinese medicine decocting machine;

the transmission mechanism comprises a driving gear, a driven gear meshed with the driving gear and a screw rod, and the top of the screw rod is fixedly connected with the driven gear;

an output shaft of the stepping motor is fixedly connected with the driving gear;

the actuating mechanism is driven by the screw rod to move upwards/downwards when the screw rod rotates;

the stepping motor drives the main gear and the driven gear to rotate, and drives the driven gear and the screw rod to rotate at the same time, so that the actuating mechanism is driven to extrude medicinal materials downwards or reset upwards;

the stepping motor is connected with the control circuit through a lead. The stepping motor is controlled by a driving signal transmitted to the stepping motor by the control circuit, and the control circuit controls the output torque of the stepping motor by collecting the current of the stepping motor. The control circuit judges whether to stop the stepping motor by judging whether the output torque of the stepping motor reaches a control threshold value, so that the lower limit and the upper limit of the extrusion mechanism can be realized.

Furthermore, a buffer torsion spring is arranged between the output shaft of the stepping motor and the driving gear, one end of the buffer torsion spring is fixedly connected with the output shaft of the stepping motor, and the other end of the buffer torsion spring is fixedly connected with the driving gear; the stepping motor drives the driving gear to rotate by means of the buffering torsion spring. The buffering torsion spring can relieve the rigid collision of the extrusion mechanism.

The third purpose of the invention is to provide a pressure control method of the automatic extrusion device of the traditional Chinese medicine decocting machine. The invention relates to a pressure control method of an automatic extrusion device of a traditional Chinese medicine decocting machine, which comprises the following steps:

s1, when the motor is unloaded, measuring the current i of the stepping motor₀And simultaneously obtaining the rotating speed n of the stepping motor so as to obtain a current-rotating speed characteristic curve i of the stepping motor₀(n); under the condition of no step loss, the rotating speed n of the stepping motor can be obtained by calculation according to a formula n-Kf, wherein f is the working frequency of the stepping motor output by the motor driver, K is a constant and is determined by the pulse number and subdivision parameters required by one rotation of the output shaft of the stepping motor;

s2, according to the curve i₀(n), obtaining the range of the rotating speed n in the process of self-starting operation to stopping operation of the stepping motor, and selecting a rotating speed interval [ n ] corresponding to the linear working area of the rotating speed of the stepping motor₁,n₂]；

S3, when the motor is in idle load, the motor is in fixed speed n₁Measuring the output torque curve T of the stepping motor₀[n₁,i](ii) a At a constant rotational speed n₂Measuring the output torque curve T of the stepping motor₀[n₂,i]；

S4, according to the two output torque curves T₀[n₁,i]And T₀[n₂,i]Obtaining the interval [ n ] of the rotating speed by adopting an interpolation fitting algorithm₁,n₂]Output torque curve T in the range₀[n,i]；

S5, when the extruding device extrudes the medicinal materials, collecting the current i and the rotating speed n of the stepping motor and outputting the torque curve T according to the output torque curve₀[n,i]Calculating the real-time output torque T of the motor, and when the value of the real-time output torque T of the motor reaches a set threshold value T_sAnd controlling the stepping motor to stop rotating so as to realize pressure control.

Further, the threshold value T is set according to the requirements of the decoction process_sAnd the required extrusion times are used for carrying out extrusion operation; and when the extrusion device is reset, judging and controlling whether the reset action is stopped or not according to the output torque of the stepping motor.

Compared with the prior art, the invention has the beneficial effects that:

1) the control circuit can control the output torque of the stepping motor, so that the extrusion pressure can be controlled according to the process requirements of the decoction prescription, and different extrusion requirements of different prescriptions are met.

2) The extrusion device is not provided with any displacement and position sensor and matching mechanism, thereby greatly improving the reliability of the equipment and reducing the operation and maintenance cost of the equipment.

3) A communication interface is arranged in a control circuit of the extrusion device and can be in communication connection with external equipment; and the control circuit can control the extrusion devices of a plurality of decoction machines.

4) The extrusion device is internally provided with a buffer torsion spring, so that the rigid collision of the equipment in operation can be buffered, the equipment failure or damage can be avoided, meanwhile, the up/down limit of an actuating mechanism of the extrusion device can be realized by monitoring the output torque of the stepping motor, the complexity of a mechanical structure of the equipment is reduced, and the reliability and the stability of the equipment are improved.

Drawings

Fig. 1 is a block diagram of a control circuit of an automatic squeezing device of a traditional Chinese medicine decocting machine according to an embodiment.

Fig. 2 is a partial block diagram of the current collection module of fig. 1.

Fig. 3 is a partial block diagram of the structure between the stepping motor driver, the operation/control module and the pulse generation module shown in fig. 1.

Fig. 4 is a block diagram of the operation/control module, the pulse generation module and the emergency stop device/external emergency stop signal structure of fig. 1.

Fig. 5 is a block diagram of a gating circuit which is additionally arranged between the stepping motor and the stepping motor driver in fig. 1 and is controlled by an operation/control module.

Fig. 6 is a detailed block diagram of the gating circuit of fig. 5.

Fig. 7 is a block diagram of the communication interface device and an I/O expansion circuit added to fig. 5.

Fig. 8 is a detailed circuit diagram of a control circuit of the automatic squeezing device of the traditional Chinese medicine decocting machine according to the embodiment.

Fig. 9 is a schematic diagram of the circuit connection between the stepping motor driver, the relay and the stepping motor in the embodiment.

FIG. 10 is a schematic sectional view of an automatic pressing device of the machine for decocting herbal medicine according to the embodiment.

Fig. 11 is a flow chart illustrating a pressure control method of an automatic pressing device of a traditional Chinese medicine decocting machine according to an embodiment.

FIG. 12 is a current-rotation speed characteristic curve i of a stepping motor₀(n) schematic representation.

FIG. 13 is an output torque curve T of the stepping motor₀[n₁,i]And T₀[n₂,i]Schematic representation of (a).

Description of the figure numbers:

110. the current acquisition module comprises a current acquisition module, a sampling element, a 112 amplifying circuit, a 113 analog-to-digital converter, a 114 first operational amplifier, a 115 second operational amplifier, a 116 first input end of the amplifying circuit, a 117 second input end of the amplifying circuit and an 118 output end of the amplifying circuit.

120. Operation/control module 121, I/O expansion circuit 122, communication interface device.

130. And a pulse generation module.

140. The stepping motor driver 141, the stepping motor 142, the transmission mechanism 143, the driving gear 144, the driven gear 145, the lead screw 146, the actuator 147, the buffer torsion spring 148 and the pressing plate.

150. And a gating circuit 151. a relay.

161. The first strobe signal 162, the second strobe signal 163, the third strobe signal 164, the fourth strobe signal 165, the fifth strobe signal 166, the sixth strobe signal 167, the seventh strobe signal 168, and the eighth strobe signal.

170. And (4) an upper computer. 180. Photocoupler circuit, 181 photocoupler. 190. An emergency stop device.

200. The decocting machine comprises a decocting machine body 201, a decocting machine cover 202, an inner sleeve 202, a screw nut 203, an outer sleeve 204 and a motor fixing seat 205.

Detailed Description

The invention is further described below with reference to the accompanying drawings.

In the following embodiments, the term power source refers to a power source VCC of an input circuit, and a component connected to the power source refers to a component connected to the VCC wire.

As shown in fig. 1, the control circuit of the automatic squeezing device of the traditional Chinese medicine decocting machine of the present embodiment includes a current collecting module 110, an operation/control module 120 connected to the current collecting module 110, a pulse generating module 130 connected to the operation/control module 120, and a stepping motor driver 140 connected to the pulse generating module 130, wherein the stepping motor driver 140 is used for being connected to a stepping motor 141 to further control the stepping motor 141.

As shown in fig. 2, the current collection module 110 includes a sampling element 111, an amplifying circuit 112 connected to the sampling element 111, and an analog-to-digital converter 113 connected to the amplifying circuit 112. As shown in fig. 8, preferably, the sampling element 111 is a sampling resistor R1, the sampling resistor R1 is connected in series to a power supply terminal of the stepping motor driver 140, one end of the sampling resistor R1 is further connected to the first input terminal 116 of the amplifying circuit by a wire, the other end of the sampling resistor R1 is connected to the second input terminal 117 of the amplifying circuit by a wire, the output terminal 118 of the amplifying circuit is connected to an analog input terminal of the analog-to-digital converter 113 by a wire, and a digital output terminal of the analog-to-digital converter 113 is connected to the operation/control module 120. The sampling resistor R1 is connected in series with the power supply terminal of the stepping motor driver 140, collects the voltage signal of the sampling resistor R1, and inputs the voltage signal to the analog-to-digital converter 113 after being amplified by the amplifying circuit 112. The voltage signal is converted into a digital signal and then input to the operation/control module 120, and the current of the sampling resistor R1, that is, the current of the stepping motor 141, is obtained through calculation. The analog-to-digital converter 113 may be, for example, an analog-to-digital converter of type ADC 0809.

As shown in fig. 8, the amplifying circuit 112 is preferably a two-stage amplifying circuit, and includes a first operational amplifier 114 and a second operational amplifier 115.

A resistor R2 is connected in series between the inverting input terminal of the first operational amplifier 114 and the first input terminal 116 of the amplifying circuit; a resistor R3 is connected in series between the non-inverting input terminal of the first operational amplifier 114 and the second input terminal 117 of the amplifying circuit; the non-inverting input terminal of the first operational amplifier 114 is further connected to one terminal of a resistor R4, and the other terminal of the resistor R4 is grounded; a feedback resistor R5 is connected in parallel between the inverting input terminal and the output terminal of the first operational amplifier 114. The output end of the first operational amplifier 114 is connected to one end of a resistor R6 through a wire, the other end of the resistor R6 is simultaneously connected to one ends of capacitors C1 and C2 and a resistor R7 through wires, the other ends of the capacitors C1 and C2 are grounded, and the other end of the resistor R7 is connected to the inverted input end of the second operational amplifier 115 through a wire.

The non-inverting input end of the second operational amplifier 115 is connected with one end of a resistor R8 through a lead, and the other end of the resistor R8 is grounded; the inverting input terminal of the second operational amplifier 115 is further connected to one end of a resistor R9 through a wire, and the other end of the resistor R9 is connected to the power supply; the output terminal of the second operational amplifier 115 is connected to an analog input terminal of the analog-to-digital converter 113, and a feedback resistor R10 is connected in parallel between the output terminal and the inverting input terminal of the second operational amplifier 115. The first and second operational amplifiers 114 and 115 may be, for example, a TL072 operational amplifier.

The eight-bit digital output of the adc 113 is connected to an eight-bit parallel I/O interface of the calculation/control module 120. The end-of-conversion signal terminal EOC of the analog-to-digital converter 113 is connected to an I/O interface conductor of the operation/control module 120, the address latch ENABLE signal terminal ALE and the START-of-conversion pulse input terminal START of the analog-to-digital converter 113 are simultaneously connected to another I/O interface conductor of the operation/control module 120, and the ENABLE terminal ENABLE of the analog-to-digital converter 113 is connected to an I/O interface conductor of the operation/control module 120. Other arrangements of the reference voltage circuit, the clock signal circuit, and the like of the analog-to-digital converter 113 are common knowledge and will not be described herein.

The operation/control module 120 is connected to the pulse generation module 130 through an I/O interface wire, and the I/O connection mode of the operation/control module 120 and the pulse generation module 130 adopts parallel I/O connection or serial I/O connection, which is not limited in the present invention. The operation/control module 120 sends parameters for controlling the stepping motor 141 to the pulse generation module 130, where the parameters include a pulse number, i.e., a frequency, and an acceleration/deceleration signal, and the pulse generation module 130 may obtain the frequency according to the pulse number. It is easily understood that the operation/control module 120 may use an operation/control chip such as a 51-series single chip microcomputer, PLC, etc., and the pulse generation module 130 may use a programmable logic device such as a model ispLSI-1032E of leddise semiconductor ltd. Similarly, the arrangement of the conventional circuits such as the crystal oscillator circuit/clock signal is not described herein.

As shown in fig. 3 and in conjunction with fig. 8, an I/O interface of the pulse generating module 130 is connected to the pulse signal input end CP of the stepping motor driver 140, and sends a pulse control signal to the stepping motor driver 140. An I/O interface of the calculation/control module 120 is connected to the direction signal input DIR of the stepping motor driver 140, and the calculation/control module 120 sends a direction control signal to the stepping motor driver 140.

As shown in fig. 4, an I/O interface of the calculation/control module 120 is connected to an emergency stop device 190 via a wire, and receives an emergency stop signal generated by the emergency stop device 190 to control the stepping motor 140 to stop operation in an abnormal situation. The emergency stop device 190 may be an emergency stop button, and the emergency stop signal is generated by pressing the emergency stop button.

As shown in fig. 5 and 6, a gating circuit 150 is further disposed in the control circuit, the gating circuit 150 includes a plurality of photocoupling circuits 180 and a plurality of relays 151, one of the photocoupling circuits 180 is correspondingly connected to one of the relays 151, and gating control is implemented through the photocoupling circuit 180 and the relay 151.

As shown in fig. 8 and 9, the photocoupler circuit 180 includes a photocoupler 181 and a resistor R13 connected in series to the positive input terminal of the photocoupler 181, the other terminal of the resistor R13 is connected to the power supply, and the negative input terminal of the photocoupler 181 is connected to an I/O interface lead of the operation/control module 120; the output end of the emitter of the photoelectric coupler 181 is grounded, the output end of the collector of the photoelectric coupler 181 is connected with one end of the coil of the relay 151, and the other end of the coil of the relay 151 is connected with a power supply; four contact terminals 5, 6, 7, 8 of the relay 151 are connected to four output terminals of the stepper motor driver 140, respectively, by one-to-one lines, and the other four contact terminals 9, 10, 11, 12 of the relay 151 are used to connect to the stepper motor 141, respectively. When the photocoupling circuit 180 is switched on, the power supply to the coil of the relay 151 is also switched on, and the four contact terminals 9, 10, 11, 12 of the relay are switched on in accordance with the four contact terminals 5, 6, 7, 8. The plurality of stepping motors 141 are controlled in a gate control manner by the gate circuit 150.

As shown in fig. 7, the operation/control module 120 is further provided with an I/O expansion circuit 121, and the I/O expansion circuit 121 is connected to the photocoupling circuit 180 for expanding the I/O interface of the operation/control module 120 to support more gating control objects, i.e., the stepping motor 141. As shown in fig. 8, preferably, the I/O expansion circuit 121 is a decoder, for example, a three-to-eight-line decoder with model number SN74LS138, an address input end of the I/O expansion circuit is connected to an I/O interface wire of the operation/control module 120, and each of eight pins of an output end of the I/O expansion circuit is correspondingly connected to one of the photocoupling circuits 180. For this version of the decoder, eight strobe signals-first through eighth strobe signals 161, 162, 163, …, 168-can be extended.

As shown in fig. 8, the computing/controlling module 120 is further connected to a communication interface device 122 through an I/O interface, for example, a communication interface with a model MAX485, and the communication interface device 122 can communicate with an external device, for example, establish a communication connection with the upper computer 170.

As shown in fig. 10, the automatic pressing device of the machine for decocting herbal medicine of this embodiment includes a stepping motor 141, a transmission mechanism 142 driven by the stepping motor, an actuator 146, and a control circuit (not shown) of the stepping motor 141. The control circuit of the stepping motor 141 is the control circuit of the automatic squeezing device of the traditional Chinese medicine decocting machine. The transmission mechanism 142 comprises a driving gear 143, a driven gear 144 engaged with the driving gear 143, and a screw 145, and the top of the screw 145 is fixedly connected with the driven gear 144;

an output shaft of the stepping motor 141 is fixedly connected with the driving gear 143;

the actuator 146 is driven by the lead screw 145 to move up/down when the lead screw 145 rotates.

The stepping motor 141 drives the master-slave gear 143 to rotate, and drives the slave gear 144 and the lead screw 145 to rotate, so as to drive the actuating mechanism 146 to extrude the medicinal materials downwards or reset upwards.

The stepping motor 141 is connected to the control circuit by a wire, and the stepping motor 141 is controlled by a driving signal supplied to the stepping motor 141 by the control circuit. The control circuit may control the output torque of the stepping motor 141. The control circuit judges whether the stepping motor stops rotating or not by judging whether the output torque of the stepping motor reaches a control threshold value or not, so that the lower limit and the upper limit of the extrusion mechanism can be realized, and the downward extrusion is stopped; or judging that the executing mechanism is reset and further stopping moving upwards. The pressing mechanism may be implemented using any suitable prior art. The actuator 146 mainly includes a platen 148 disposed inside the drug-decocting machine 200, an inner sleeve 202 passing through the lid 201 of the drug-decocting machine, and a lead screw nut 203 on top of the inner sleeve 202. The screw 145 is sleeved in the middle of the screw nut 203 and is matched with the screw nut through threads, the circumferential movement of the actuating mechanism 146 and the outer sleeve 204 on the outer side of the actuating mechanism is limited in a sliding strip-sliding groove (not shown in the figure) matching mode, the sliding groove is formed in the inner side wall of the outer sleeve 204, and the sliding strip is fixedly connected to the screw nut 203. Therefore, when the lead screw 145 rotates, the lead screw nut moves up and down along the lead screw 145, thereby moving the entire actuator 146 up/down.

Further, a buffer torsion spring 147 is arranged between the output shaft of the stepping motor 141 and the driving gear 143, one end of the buffer torsion spring 147 is fixedly connected with the output shaft of the stepping motor 141, and the other end is fixedly connected with the driving gear 143; the stepping motor 141 drives the driving gear 143 to rotate by means of the buffer torsion spring 147.

Further, the stepping motor 141 is fixedly installed by a motor fixing base 205 fixedly connected to the top outer side of the outer sleeve 204.

As shown in fig. 11, the method for controlling the pressure of the automatic squeezing device of the traditional Chinese medicine decocting machine of the present embodiment includes the following steps:

referring to fig. 12, S1, when the motor is unloaded, the current i of the stepping motor is measured₀And simultaneously obtaining the rotating speed n of the stepping motor so as to obtain a current-rotating speed characteristic curve i of the stepping motor₀(n); in the case of no step loss, the rotation speed n of the stepping motor can be calculated according to the formula n-Kf.

S2, according to the curve i₀(n), obtaining the range of the rotating speed n in the process of self-starting operation to stopping operation of the stepping motor, and selecting a rotating speed interval [ n ] corresponding to the linear working area of the rotating speed of the stepping motor₁,n₂]. Accordingly, when the pressing device performs the pressing operation, the stepping motorWorking in the speed interval [ n₁,n₂]And (4) the following steps.

The output torque of the stepping motor is influenced by a plurality of parameters, and a nonlinear relation exists. Therefore, the following steps are taken to find the relationship between the current of the stepping motor and its output torque.

Referring to fig. 13, at S3, when the motor is idling, the constant rotation speed n is equal to n₁Under n, measuring the output torque curve T of the stepping motor₀[n₁,i](ii) a At a constant speed n ═ n₂Measuring the output torque curve T of the stepping motor₀[n₂,i]；

S4, according to the two output torque curves T₀[n₁,i]And T₀[n₂,i]Obtaining the interval [ n ] of the rotating speed by adopting an interpolation fitting algorithm₁,n₂]Output torque curve T in the range₀[n,i]。

The rotation speed of the stepping motor can be obtained by the working frequency output by the controller of the stepping motor, and the current parameters of the stepping motor are collected and output by the output torque curve T₀[n,i]The output torque of the stepping motor can be calculated. When the pressure of the extrusion device is controlled, parameters needing to be obtained in real time comprise current i and rotating speed n, wherein the current i is collected through the sampling element, and the rotating speed n can be obtained by calculating the pulse number/frequency parameter sent to the pulse generation module by the operation/control module.

Setting the output torque threshold T of the stepping motor according to the requirement of the extrusion pressure degree_sAs a control parameter for the stepper motor.

S5, when the extruding device extrudes the medicinal materials, collecting the current i and the rotating speed n of the stepping motor and outputting the torque curve T according to the output torque curve₀[n,i]Calculating the real-time output torque T of the motor, and when the value of the real-time output torque T of the motor reaches the threshold value T_sAnd controlling the stepping motor to stop rotating so as to realize pressure control.

And after the stepping motor finishes one-time extrusion, resetting, and setting the extrusion times according to the extrusion task. In the process, pressure parameters do not need to be directly acquired, so that a pressure sensor does not need to be arranged, the structure of the executing device is simplified, and particularly the structure of the inner space of the medicine decocting machine is simplified.

Further, the threshold value T is set according to the requirements of the decoction process_sAnd the required extrusion times are used for carrying out extrusion operation; and when the extrusion device is reset, judging and controlling whether the reset action is stopped or not according to the output torque of the stepping motor.

The above embodiments describe in detail the structure, the operation principle and the pressure control method of the automatic squeezing device of the traditional Chinese medicine decocting machine, the control circuit thereof, but should not be construed as limiting the invention. It will be readily understood that modifications, substitutions and further improvements may be made by those skilled in the art based on the teachings of the present invention, but any modifications or equivalents will fall within the scope of the present invention as claimed in the claims.