Direct-current push rod extreme position control circuit
By using a push rod position detection circuit and a position comparison circuit, and by using multi-turn resistors and comparators to determine the limit position, the problems of inflexible control of existing DC push rod motors and easy failure of limit switches are solved. This enables the motor to stop automatically at the limit position, improving the accuracy and reliability of control.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SUZHOU UNIV OF SCI & TECH
- Filing Date
- 2025-05-12
- Publication Date
- 2026-04-10
AI Technical Summary
Existing limit position control methods for DC linear actuator motors lack flexibility, limit switches are prone to failure, and they cannot accurately distinguish between true limit positions and ordinary stall positions. Existing methods are limited in terms of complexity and applicable scenarios.
The system employs a push rod position detection circuit, a position comparison circuit, and a position control circuit. It uses a multi-turn resistor and a comparator to determine the push rod position and a relay to control the motor's forward and reverse switches, thus avoiding the use of limit switches.
It enables automatic motor stop when the push rod position exceeds the limit position, eliminating the need for limit switches, thus improving control flexibility and accuracy, and reducing system complexity and failure rate.
Smart Images
Figure CN224111073U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to a push rod position control circuit of direct current push rod motor, especially a direct current push rod limit position control circuit. BACKGROUND
[0002] The limit position control principle of the direct current push rod motor under the prior art is as follows: when the motor reaches the limit position, the travel switch is used to control the rotation or stop of the motor. When the motor reaches the front limit position, the front travel switch acts to cut off the forward rotation current of the motor. When the motor reaches the rear limit position, the rear travel switch acts to cut off the reverse rotation current of the motor. If the travel switch is used to control the direct current push rod, the travel is fixed, and the control is not flexible enough. If a Hall sensor is added on the basis of the travel switch to perform positioning, the system complexity will be increased. The long-term operation failure rate of the travel switch is high, and the switch is prone to failure, thereby causing the machine to be locked.
[0003] Other schemes in the prior art, for example, use a Hall element to detect the motor speed, and if the detected speed is 0, it is considered that the motor has reached the limit position. Although this method does not use a travel switch, it cannot distinguish between the true limit position and the ordinary stall.
[0004] Other schemes in the prior art, for example, judge whether the motor is stalled by detecting the size of the current, and then judge whether the motor position reaches the limit. Although this method does not use a travel switch, its application scenario is limited, and it is only suitable for fixed load occasions, and it cannot distinguish between the true limit position and the ordinary stall. INVENTION CONTENTS
[0005] The technical problem to be solved by the utility model is to provide a direct current push rod limit position control circuit, which can stop the driving motor of the direct current push rod motor when the push rod position is greater than the front limit position or smaller than the rear limit position.
[0006] The technical scheme adopted by the utility model to solve the above technical problem is as follows: a direct current push rod limit position control circuit, comprising:
[0007] A push rod position detection circuit detects the position of the push rod in the direct current push rod motor and outputs a push rod position signal. The direct current push rod motor comprises a driving motor and a push rod.
[0008] A position comparison circuit comprises a comparator one and a comparator two. The push rod position signal and the front limit position given signal are input to the comparator one, and the comparator one outputs a front limit signal. The push rod position signal and the rear limit position given signal are input to the comparator two, and the comparator two outputs a rear limit signal.
[0009] Position control circuit, including amplifier circuit 1, relay 1, amplifier circuit 2, relay 2; the front limit signal is amplified by amplifier circuit 1 and connected to the coil of relay 1, the switch of relay 1 is connected in series to the forward switch circuit of the DC push rod motor; the rear limit signal is amplified by amplifier circuit 2 and connected to the coil of relay 2, the switch of relay 2 is connected in series to the backward switch circuit of the DC push rod motor.
[0010] Preferably, the push rod position detection circuit includes a multi-turn resistor R1 with an input rotating shaft;
[0011] The driving motor of the DC push rod motor drives the push rod to advance or retreat through the first output shaft of the reduction gearbox, the rotary linear conversion mechanism, and the second output shaft of the reduction gearbox connected to the first output shaft, and the input rotating shaft of the multi-turn resistor R1 connected to the second output shaft of the reduction gearbox through the gear transmission mechanism; when the driving motor drives the second output shaft of the reduction gearbox to rotate, the input rotating shaft of the multi-turn resistor R1 rotates in linkage, and the voltage across the multi-turn resistor R1 is obtained as the push rod position signal.
[0012] Preferably, the voltage across the multi-turn resistor R1 is obtained by a voltage conversion circuit, and the voltage conversion circuit includes a resistor R0 and a power supply VCC, and the resistor R0 is connected in series with the resistance wire of the multi-turn resistor R1; the connection point of the resistor R0 and the resistance wire of the multi-turn resistor R1 is led out as the push rod position signal.
[0013] Preferably, the front or rear limit position given signal is formed by a front or rear limit position given circuit, and the front or rear limit position given circuit includes a voltage dividing circuit and an operational amplifier conditioning circuit; the power supply VCC outputs the front or rear limit position corresponding reference voltage signal through the respective voltage dividing circuit, and the front or rear limit position corresponding reference voltage signal outputs the front or rear limit position given signal through the respective operational amplifier conditioning circuit.
[0014] Preferably, in the position comparison circuit, the front limit position given signal is connected to the first input end of comparator 1 through resistor R4, the front limit position given signal is connected to the power supply VCC through resistor R4, resistor R5, and resistor R6, the push rod position signal is connected to the second input end of comparator 1 through resistor R7, and the output end of comparator 1 outputs the front limit signal.
[0015] The push rod position signal is connected to the power supply VCC through resistor R8, resistor R9, and resistor R10, the push rod position signal is connected to the first input end of comparator 2 through resistor R8, the rear limit position given signal is connected to the second input end of comparator 2 through resistor R11, and the output end of comparator 2 outputs the rear limit signal.
[0016] Preferably, the comparator 1 or the comparator 2 is a hysteresis comparator.
[0017] Preferably, in the position comparison circuit, when the push rod position signal is greater than the front limit position given signal, the front limit electric signal output is 0, otherwise 1; when the push rod position signal is less than the rear limit position given signal, the rear limit electric signal output is 0, otherwise 1.
[0018] In the position control circuit, when the push rod advances, the relay one is connected when the front limit signal is 1, and the relay one is disconnected when the front limit signal is 0; when the push rod retreats, the relay two is connected when the rear limit signal is 1, and the relay two is disconnected when the rear limit signal is 0.
[0019] The beneficial effects of the utility model are: through the direct current push rod limit position control circuit of the utility model, the driving motor can be stopped running when the push rod position is greater than the front limit position or less than the rear limit position, without using front and rear stroke switches. BRIEF DESCRIPTION OF DRAWINGS
[0020] Figure 1 It is the structure schematic diagram of driving motor, push rod, reduction box and multi-turn resistance R1 in the utility model;
[0021] Figure 2 It is the circuit connection principle diagram of one embodiment of the push rod position detection circuit in the utility model;
[0022] Figure 3 It is the principle diagram of front or rear limit position given circuit in the utility model;
[0023] Figure 4 It is the circuit example diagram of operational amplifier conditioning circuit in the utility model;
[0024] Figure 5 It is the principle block diagram of position comparison circuit in the utility model;
[0025] Figure 6 It is the circuit example diagram of position comparison circuit in the utility model;
[0026] Figure 7 It is the principle block diagram of position control circuit in the utility model;
[0027] Figure 8 It is the circuit example diagram of position control circuit in the utility model. DETAILED DESCRIPTION
[0028] The utility model will be explained further in detail in combination with the drawings and preferred embodiments. These drawings are all simplified schematic diagrams, only illustrate the basic structure of the utility model in a schematic way, therefore only show the relevant constitution of the utility model.
[0029] As shown in Figures 1-8 , a direct current push rod limit position control circuit, comprising:
[0030] a push rod position detection circuit for detecting the position of the push rod in the DC push rod motor and outputting a push rod position signal;
[0031] a position comparison circuit including a comparator one and a comparator two; the push rod position signal and the front limit position given signal are inputted into the comparator one, and the comparator one outputs a front limit signal; the push rod position signal and the rear limit position given signal are inputted into the comparator two, and the comparator two outputs a rear limit signal;
[0032] a position control circuit, as shown in Figure 7 , including an amplification circuit one, a relay one, an amplification circuit two, and a relay two; the front limit signal is amplified by the amplification circuit one and then connected to the coil of the relay one, and the switch of the relay one is connected in series to the forward switch circuit of the DC push rod motor; the rear limit signal is amplified by the amplification circuit two and then connected to the coil of the relay two, and the switch of the relay two is connected in series to the backward switch circuit of the DC push rod motor.
[0033] Specifically, in an alternative embodiment, the push rod position detection circuit includes a multi-turn resistor R1 with an input rotating shaft; as shown in Figure 1 , the multi-turn resistor R1 includes an input rotating shaft and a resistor wire output contact point, and the output resistance value of the multi-turn resistor R1 changes accordingly when the input rotating shaft rotates.
[0034] As shown in Figure 1 , the driving motor of the DC push rod motor drives the push rod to move forward or backward through the first output shaft of the reduction gearbox, the rotating linear conversion mechanism (for example, a screw pair), and the input rotating shaft of the multi-turn resistor R1 connected to the second output shaft of the reduction gearbox through the gear transmission mechanism, and the input rotating shaft of the multi-turn resistor R1 rotates in linkage when the second output shaft of the reduction gearbox rotates driven by the driving motor, and the voltage across the multi-turn resistor R1 is obtained as the push rod position signal. The rotating linear conversion mechanism can adopt a conventional screw nut, etc. The output shaft of the driving motor rotates the input shaft of the reduction gearbox through gear transmission, and the first output shaft and the second output shaft of the reduction gearbox rotate in linkage through multiple sets of gear transmission, and the push rod moves forward or backward through the rotating linear conversion mechanism when the first output shaft of the reduction gearbox rotates. The input rotating shaft of the multi-turn resistor R1 rotates in linkage when the second output shaft of the reduction gearbox rotates, and the output resistance value of the multi-turn resistor R1 changes accordingly, and the voltage of the multi-turn resistor R1 changes accordingly, so the number of rotations of the output shaft of the driving motor can be obtained by obtaining the voltage of the multi-turn resistor R1, and the position of the push rod moving forward or backward is reflected, and thus the voltage across the multi-turn resistor R1 is obtained as the push rod position signal.
[0035] Specifically, in an alternative embodiment, as shown in Figure 2As shown, the voltage across the multi-turn resistor R1 is obtained by a voltage conversion circuit, which includes a resistor R0 and a power supply VCC, the resistor R0 is connected in series with the resistance wire of the multi-turn resistor R1; the connection point of the resistor R0 and the resistance wire of the multi-turn resistor R1 is led out as the push rod position signal.
[0036] Specifically, in an optional embodiment, as shown in Figure 3 As shown, the front or rear limit position given signal is formed by a front or rear limit position given circuit, which includes a voltage dividing circuit and an operational amplifier conditioning circuit; the power supply VCC outputs a front or rear limit position corresponding reference voltage signal through the respective voltage dividing circuit, and the front or rear limit position corresponding reference voltage signal is output as the front or rear limit position given signal through the respective operational amplifier conditioning circuit. The voltage dividing circuit can be a single resistor or a plurality of resistors connected in series, for example, resistors R2 and R3 connected in series. The operational amplifier conditioning circuit can be a follower voltage circuit, a proportional circuit or other operational amplifier circuit with a linear relationship between input and output. The sizes of the resistors R2 and R3 are selected according to the stroke of the push rod and the range of the push rod position signal. Figure 4 As shown, the front or rear limit position corresponding reference voltage signal is output as the front or rear limit position given signal through the respective operational amplifier conditioning circuit.
[0037] Specifically, in an optional embodiment, as shown in Figure 5 , Figure 6 In the position comparison circuit, the front limit position given signal is connected to the first input terminal of a comparator one through a resistor R4, the front limit position given signal is connected to the power supply VCC through the resistor R4, a resistor R5 and a resistor R6, the push rod position signal is connected to the second input terminal of the comparator one through a resistor R7, and the output terminal of the comparator one outputs a front limit signal.
[0038] The push rod position signal is connected to the power supply VCC through a resistor R8, a resistor R9 and a resistor R10, the push rod position signal is connected to the first input terminal of a comparator two through the resistor R8, the rear limit position given signal is connected to the second input terminal of the comparator two through a resistor R11, and the output terminal of the comparator two outputs a rear limit signal.
[0039] Specifically, in an optional embodiment, in the optional device, the comparator one or the comparator two is a hysteresis comparator.
[0040] Specifically, in an optional embodiment, in the position comparison circuit, when the push rod position signal is greater than the front limit position given signal, the front limit signal is output as 0, otherwise as 1; when the push rod position signal is less than the rear limit position given signal, the rear limit signal is output as 0, otherwise as 1.
[0041] As shown in Figure 8As shown, the connection example of the front limit signal and the relay one in the position control circuit, the front limit signal is connected with the coil of the relay one through the amplification circuit.
[0042] In the position control circuit, when the push rod advances, the relay one is connected when the front limit signal is 1, and the relay one is disconnected when the front limit signal is 0. When the push rod retreats, the relay two is connected when the rear limit signal is 1, and the relay two is disconnected when the rear limit signal is 0.
[0043] In the advance switch circuit, the advance switch is connected, the advance switch connection indicates that the driving motor rotates to make the push rod advance, the resistance value of the multi-turn resistance R1 changes with the rotation number of the driving motor, when the push rod position signal is greater than the front limit position given signal, the relay one of the position control circuit is disconnected, the switch of the relay one is connected in series in the advance switch circuit to make the advance switch circuit disconnected, and the driving motor stops running.
[0044] When the retreat switch circuit is connected, the retreat switch is connected, indicating that the driving motor rotates to make the push rod retract, the resistance value of the multi-turn resistance R1 changes with the rotation number of the driving motor, when the push rod position signal is less than the rear limit position given signal, the relay two of the position control circuit is disconnected, the switch of the relay two is connected in series in the retreat switch circuit to make the retreat switch circuit disconnected, and the driving motor stops running.
[0045] The direct current push rod limit position control circuit of the utility model can make the driving motor stop running when the push rod position is greater than the front limit position or less than the rear limit position, and does not need to use the front and rear stroke switches. The front / rear limit signal can distinguish the real limit position and the ordinary stall, and the front / rear limit signal is 1, indicating that the limit has not been reached, and if the push rod does not move, it is ordinary stall.
[0046] The above description in the specification is only the specific implementation manner of the utility model, various examples do not constitute the limitation to the essential content of the utility model, and the ordinary skilled in the art can modify or deform the above described specific implementation manner after reading the specification, without departing from the essence and scope of the utility model.
Claims
1. A direct current push rod limit position control circuit, characterized by: The direct current push rod limit position control circuit comprises: a push rod position detection circuit for detecting the position of a push rod in a direct current push rod motor and outputting a push rod position signal; the direct current push rod motor comprises a driving motor and a push rod; a position comparison circuit comprising a comparator one and a comparator two; the push rod position signal and a front limit position given signal are inputted into the comparator one, and the comparator one outputs a front limit signal; the push rod position signal and a rear limit position given signal are inputted into the comparator two, and the comparator two outputs a rear limit signal; a position control circuit comprising an amplification circuit one, a relay one, an amplification circuit two and a relay two; the front limit signal is amplified by the amplification circuit one and then connected to the coil of the relay one, and the switch of the relay one is connected in series to the forward switch circuit of the direct current push rod motor; the rear limit signal is amplified by the amplification circuit two and then connected to the coil of the relay two, and the switch of the relay two is connected in series to the backward switch circuit of the direct current push rod motor.
2. The DC push rod limit position control circuit of claim 1, wherein: The push rod position detection circuit comprises a multi-turn resistor R1 with an input rotating shaft; the driving motor of the direct current push rod motor drives the push rod to move forward or backward through a first output shaft of a speed reducer, a rotating linear conversion mechanism and a second output shaft of the speed reducer connected with the first output shaft, and the input rotating shaft of the multi-turn resistor R1 is connected with the second output shaft of the speed reducer through a gear transmission mechanism, so that the input rotating shaft of the multi-turn resistor R1 rotates when the second output shaft of the speed reducer rotates, and the voltage between the two ends of the multi-turn resistor R1 is obtained as the push rod position signal.
3. The DC push rod limit position control circuit of claim 2, wherein: The voltage between the two ends of the multi-turn resistor R1 is obtained by a voltage conversion circuit, and the voltage conversion circuit comprises a resistor R0 and a power supply VCC, and the resistor R0 is connected in series with the resistance wire of the multi-turn resistor R1; the connection point of the resistance wire of the multi-turn resistor R1 and the resistor R0 is led out as the push rod position signal.
4. The DC push rod limit position control circuit of claim 1, wherein: The front or rear limit position given signal is formed by a front or rear limit position given circuit, and the front or rear limit position given circuit comprises a voltage division circuit and an operational amplifier conditioning circuit respectively; the power supply VCC outputs a front or rear limit position corresponding reference voltage signal through the respective voltage division circuit, and the front or rear limit position corresponding reference voltage signal is outputted as the front or rear limit position given signal through the respective operational amplifier conditioning circuit.
5. The DC push rod limit position control circuit of claim 1, wherein: In the position comparison circuit, the front limit position given signal is connected to the first input end of the comparator one through a resistor R4, the front limit position given signal is connected to the power supply VCC through the resistor R4, a resistor R5 and a resistor R6, the push rod position signal is connected to the second input end of the comparator one through a resistor R7, and the output end of the comparator one outputs the front limit signal; the push rod position signal is connected to the power supply VCC through a resistor R8, a resistor R9 and a resistor R10, the push rod position signal is connected to the first input end of the comparator two through the resistor R8, the rear limit position given signal is connected to the second input end of the comparator two through a resistor R11, and the output end of the comparator two outputs the rear limit signal.
6. The DC push rod limit position control circuit of claim 1, wherein: The comparator one or the comparator two is a hysteresis comparator.
7. The direct current push rod limit position control circuit according to claim 1, wherein: in the position comparison circuit, when the push rod position signal is greater than the front limit position given signal, the front limit signal is outputted as 0, otherwise as 1; when the push rod position signal is less than the rear limit position given signal, the rear limit signal is outputted as 0, otherwise as 1. In the position control circuit, when the push rod advances, the relay one is turned on when the front limit signal is 1, and the relay one is turned off when the front limit signal is 0; when the push rod retreats, the relay two is turned on when the rear limit signal is 1, and the relay two is turned off when the rear limit signal is 0.