Push rod limiting control device

Abstract

The invention discloses a push rod limiting control device which comprises a motor and further comprises two Hall sensors, a motor control module and a magnet arranged on a push rod, the motor controls the push rod to move between the two Hall sensors, and when the push rod is close to a certain Hall sensor, the magnet on the push rod triggers the Hall sensors to change signals. The motor control module is triggered to work through change of signals of the Hall sensor, and the motor is controlled to stop running. A traditional switch is replaced with a Hall sensor induction mode, so that the push rod is simpler in overall structure, smaller in size and still applicable to some occasions with limited sizes.

Description

Technical Field

[0001] The invention relates to the technical field of electromechanical control, in particular to a push rod limit control device. Background Art

[0002] There are two main types of existing push rod limit controls, one is to achieve limit by electronic means, and the other is to achieve limit by mechanical structure. The mechanical limit method is to add a limit bracket and a mechanical switch inside the push rod. Once the limit is reached, the mechanical switch is touched to stop the motor. The advantage of this method is that the control can be externalized, and the electronic control will be relatively simple. However, the mechanical limit switch generally requires motor current. Existing push rods are mainly based on DC motors, so especially in low-voltage power supply (such as 12V) occasions, the current is often relatively large, which can easily cause the switch contacts to stick, and ultimately fail to control the motor operation. At the same time, mechanical switches and mechanical limit brackets are often relatively large in size. When some mechanical structures are compact and there is not much internal space, it is difficult to meet the needs through mechanical limit methods.

[0003] The electronic limit method is to install a magnet / magnetic ring at the motor and use Hall to detect the magnet / magnetic ring signal at the motor, so this method generally has a built-in control board; however, the built-in control board will make the overall structure not simple enough, and in some cases, such as where space is limited, it is difficult to implement. Summary of the invention

[0004] The purpose of the present invention is to provide a push rod limit control device to overcome the shortcomings of the push rod limit control device in the prior art that it easily causes switch contacts to stick and is difficult to meet the needs in occasions with small or limited space.

[0005] The purpose of the present invention is achieved through the following technical solutions: A push rod limit control device includes a motor, two Hall sensors, a motor control module and a magnet arranged on the push rod. The motor controls the push rod to move between the two Hall sensors. When the push rod approaches a certain Hall sensor, the magnet on the push rod triggers the Hall sensor signal to change. The change of the Hall sensor signal triggers the motor control module to work, thereby controlling the motor to stop running.

[0006] The two Hall sensors are located at the upper and lower limits of the push rod respectively. When the push rod reaches the upper limit, the magnet will trigger the Hall sensor signal at the upper limit to change, thereby triggering the motor control module to control the motor to stop running, so that the push rod stops moving. Similarly, when the push rod reaches the lower limit, the magnet will trigger the Hall sensor signal at the lower limit to change, thereby triggering the motor control module to control the motor to stop running, so that the push rod stops moving.

[0007] Preferably, the motor control module includes two optocoupler sensors and two MOS tubes. A single Hall sensor, an optocoupler sensor and a MOS tube are matched. The Hall sensor controls the on-off of the optocoupler sensor, and the optocoupler sensor controls the on-off of the MOS tube. The on-off of the MOS tube controls the current passing through the motor and controls the working state of the motor.

[0008] Preferably, the motor control module further includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a diode D1, a diode D2, an external control input power port MO+ and an external control input power port MO-, the MOS tubes are all NMOS tubes, including MOS tube Q1 and MOS tube Q2, the optocoupler sensor includes an optocoupler sensor U3 and an optocoupler sensor U4, the external control input power port MO+ is connected to the anode of the diode D1, one end of the resistor R1, and pin 3 of the optocoupler sensor U3, the other end of the resistor R1 is simultaneously connected to one end of the resistor R2 and pin 4 of the optocoupler sensor U3, the other end of the resistor R2 is connected to the external control input power port MO-; the external control input power port MO- is connected to the anode of the diode D2, one end of the resistor R4, and pin 3 of the optocoupler sensor U4, the resistor R4 The other end is connected to one end of the resistor R3 and the 4th pin of the optocoupler sensor U4 at the same time, and the other end of the resistor R4 is connected to the external control input power port MO+; the source of the MOS tube Q1 is connected to the external control input power port MO+, the drain of the MOS tube Q1 is connected to the motor, the gate of the MOS tube Q1 is connected to the 4th pin of the optocoupler sensor U3, the source of the MOS tube Q2 is connected to the external control input power port MO-, the drain of the MOS tube Q1 is connected to the motor, the gate of the MOS tube Q2 is connected to the 4th pin of the optocoupler sensor U4, the cathode of the diode D1 and the cathode of the diode D2 are connected to the motor at the same time, the 1st pin of the optocoupler sensor U3 and the 1st pin of the optocoupler sensor U4 are both connected to the power supply, the 2nd pin of the optocoupler sensor U3 is connected to the Hall sensor U1, and the 2nd pin of the optocoupler sensor U4 is connected to the Hall sensor U2.

[0009] The working principle of the motor control module is: when the external control input power port MO+ is positive and the external control input power port MO- is negative, the MOS tube Q2 At this time, the MOS tube Q2 is turned on, and the direction of the current is the external control input power port MO+→diode D1→motor→MOS tube Q2→external control input power port MO-. At this time, when the click runs to the limit, the corresponding Hall sensor U2 output HALL2 is pulled low, so that the optocoupler sensor U4 is turned on, and the 4th pin of the optocoupler sensor U4 is forcibly pulled low by the 3rd pin, the MOS tube Q2 is turned off, and the motor stops running; when the external control input power port MO+ is negative and the external control input power port MO- is positive, the MOS tube Q1 At this time, the MOS tube Q1 is turned on, and the direction of the current is the external control input power port MO-→diode D2→motor→MOS tube Q1→external control input power port MO+. At this time, when the click runs to the limit, the corresponding Hall sensor U1 outputs HALL1 low, so that the optocoupler sensor U3 is turned on, and the 4th pin of the optocoupler sensor U3 is forcibly pulled low by the 3rd pin, the MOS tube Q1 is turned off, and the motor stops running.

[0010] Preferably, the motor control module further includes capacitor C1 and capacitor C2, the external control input power port MO+ is connected to one end of capacitor C1, the other end of capacitor C1 is connected to the gate of MOS tube Q1, the external control input power port MO- is connected to one end of capacitor C2, the other end of capacitor C2 is connected to the gate of MOS tube Q2. In the design of this scheme, capacitor C1 and capacitor C2 are charged and discharged, so that the MOS tube is in an incompletely turned-on state, so that the voltage is slowly too high or slowly drops, achieving the effect of slow start and slow stop, which can better protect the motor.

[0011] Preferably, the motor control module further includes a TVS tube, which includes a TVS tube D13, a TVS tube D14, a TVS tube D15 and a TVS tube D16. The TVS tubes D13 and D16 are connected in parallel between the source and drain of the MOS tube Q1, and the TVS tubes D14 and D15 are connected in parallel between the source and drain of the MOS tube Q2. Since the motor is an inductive load, when the MOS tube is turned off, a momentary high voltage will be generated in the MOS tube, and the MOS tube needs to be protected, otherwise it is easy to cause the MOS tube to break down; in the design of this solution, the TVS tube constitutes a discharge circuit, which effectively protects the MOS tube.

[0012] Preferably, the breakdown voltage of the TVS tube is smaller than the breakdown voltage of the MOS tube, and the power of the TVS tube matches the instantaneous voltage and current of the motor.

[0013] The beneficial effects of the present invention are as follows: the present invention uses a Hall sensor induction method to replace the traditional switch, so that the overall structure of the push rod is simpler and the volume is smaller, and it is still applicable to certain occasions with limited volume; the design of the capacitor plays a role in slow start and slow stop, which can better protect the motor; the large current loop only passes through the MOS tube, and when used in conjunction with the motor load, especially when the load is large, the problem of easy adhesion is effectively avoided; the TVS tube constitutes a discharge circuit, which effectively protects the MOS tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the present invention; Figure 2 It is a circuit schematic diagram of the motor control module of the present invention.

[0015] Among them: 1. Motor, 2. Hall sensor, 3. Motor control module, 4. Magnet. DETAILED DESCRIPTION

[0016] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that this application will be more comprehensive and complete and fully convey the concept of the example embodiments to those skilled in the art.

[0017] In addition, described feature, structure or characteristic can be combined in one or more embodiments in any suitable manner. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application. However, those skilled in the art will appreciate that the technical scheme of the present application can be put into practice without one or more of the specific details, or other methods, components, devices, steps, etc. can be adopted. In other cases, known methods, devices, realizations or operations are not shown or described in detail to avoid blurring the various aspects of the application.

[0018] Example: A push rod limit control device, such as Figure 1 As shown, it includes a motor 1, two Hall sensors 2, a motor control module 3 and a magnet 4 arranged on a push rod. The motor controls the push rod to move between the two Hall sensors. When the push rod approaches a certain Hall sensor, the magnet on the push rod triggers the Hall sensor signal to change. The change in the Hall sensor signal triggers the motor control module to work, and controls the motor to stop running.

[0019] The two Hall sensors are located at the upper and lower limits of the push rod respectively. When the push rod reaches the upper limit, the magnet will trigger the Hall sensor signal at the upper limit to change, thereby triggering the motor control module to control the motor to stop running, so that the push rod stops moving. Similarly, when the push rod reaches the lower limit, the magnet will trigger the Hall sensor signal at the lower limit to change, thereby triggering the motor control module to control the motor to stop running, so that the push rod stops moving.

[0020] like Figure 2 As shown, the motor control module includes two optocoupler sensors and two MOS tubes. A single Hall sensor, an optocoupler sensor and a MOS tube are matched. The Hall sensor controls the on-off of the optocoupler sensor, and the optocoupler sensor controls the on-off of the MOS tube. The on-off of the MOS tube controls the current passing through the motor and controls the working state of the motor.

[0021] The motor control module also includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a diode D1, a diode D2, an external control input power port MO+ and an external control input power port MO-, the MOS tubes are all NMOS tubes, including MOS tubes Q1 and MOS tubes Q2, the optocoupler sensor includes an optocoupler sensor U3 and an optocoupler sensor U4, the external control input power port MO+ is connected to the anode of the diode D1, one end of the resistor R1, and the 3rd pin of the optocoupler sensor U3, the other end of the resistor R1 is simultaneously connected to one end of the resistor R2 and the 4th pin of the optocoupler sensor U3, the other end of the resistor R2 is connected to the external control input power port MO-; the external control input power port MO- is connected to the anode of the diode D2, one end of the resistor R4, and the 3rd pin of the optocoupler sensor U4, the other end of the resistor R4 At the same time, it is connected to one end of the resistor R3 and the 4th pin of the optocoupler sensor U4, and the other end of the resistor R4 is connected to the external control input power port MO+; the source of the MOS tube Q1 is connected to the external control input power port MO+, the drain of the MOS tube Q1 is connected to the motor, the gate of the MOS tube Q1 is connected to the 4th pin of the optocoupler sensor U3, the source of the MOS tube Q2 is connected to the external control input power port MO-, the drain of the MOS tube Q1 is connected to the motor, the gate of the MOS tube Q2 is connected to the 4th pin of the optocoupler sensor U4, the cathode of the diode D1 and the cathode of the diode D2 are connected to the motor at the same time, the 1st pin of the optocoupler sensor U3 and the 1st pin of the optocoupler sensor U4 are both connected to the power supply, the 2nd pin of the optocoupler sensor U3 is connected to the Hall sensor U1, and the 2nd pin of the optocoupler sensor U4 is connected to the Hall sensor U2.

[0022] The working principle of the motor control module is: when the external control input power port MO+ is positive and the external control input power port MO- is negative, the MOS tube Q2 At this time, the MOS tube Q2 is turned on, and the direction of the current is the external control input power port MO+→diode D1→motor→MOS tube Q2→external control input power port MO-. At this time, when the click runs to the limit, the corresponding Hall sensor U2 output HALL2 is pulled low, so that the optocoupler sensor U4 is turned on, and the 4th pin of the optocoupler sensor U4 is forcibly pulled low by the 3rd pin, the MOS tube Q2 is turned off, and the motor stops running; when the external control input power port MO+ is negative and the external control input power port MO- is positive, the MOS tube Q1 At this time, the MOS tube Q1 is turned on, and the direction of the current is the external control input power port MO-→diode D2→motor→MOS tube Q1→external control input power port MO+. At this time, when the click runs to the limit, the corresponding Hall sensor U1 outputs HALL1 low, so that the optocoupler sensor U3 is turned on, and the 4th pin of the optocoupler sensor U3 is forcibly pulled low by the 3rd pin, the MOS tube Q1 is turned off, and the motor stops running.

[0023] The motor control module also includes capacitor C1 and capacitor C2, the external control input power port MO+ is connected to one end of capacitor C1, the other end of capacitor C1 is connected to the gate of MOS tube Q1, the external control input power port MO- is connected to one end of capacitor C2, and the other end of capacitor C2 is connected to the gate of MOS tube Q2. In the design of this scheme, capacitor C1 and capacitor C2 are charged and discharged, so that the MOS tube is in an incompletely turned-on state, so that the voltage is slowly too high or slowly drops, achieving the effect of slow start and slow stop, which can better protect the motor.

[0024] The motor control module also includes TVS tubes, including TVS tubes D13, TVS tubes D14, TVS tubes D15 and TVS tubes D16. TVS tubes D13 and TVS tubes D16 are connected in parallel between the source and drain of MOS tube Q1, and TVS tubes D14 and TVS tubes D15 are connected in parallel between the source and drain of MOS tube Q2. Since the motor is an inductive load, when the MOS tube is turned off, a momentary high voltage will be generated in the MOS tube, and the MOS tube needs to be protected, otherwise it is easy to cause the MOS tube to break down; in the design of this solution, the TVS tube constitutes a discharge circuit, which effectively protects the MOS tube.

[0025] The breakdown voltage of the TVS tube is lower than the breakdown voltage of the MOS tube, and the power of the TVS tube matches the instantaneous voltage and current of the motor.

[0026] In practical applications, TVS tubes can also be replaced by capacitors, which can absorb voltage changes and provide AC paths. Capacitors are not as effective as TVS tubes, but are less expensive.

[0027] In this embodiment, the model of the MOS tube is NCEP068N10G, the model of the TVS tube is SMBJ64CA-AT / TR13, the model of the optocoupler sensor is EL357, the resistors R1 and R4 are 10KΩ, the resistors R2 and R3 are 15KΩ, J3 is the motor lead port, and J4 is the power supply port for external control input.

[0028] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the embodiments disclosed herein. The present application is intended to cover any variations, uses or adaptations of the present application, which follow the general principles of the present application and include common knowledge or customary technical means in the art that are not disclosed in the present application.

[0029] It should be understood that the present application is not limited to the precise structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A push rod limit control device, comprising a motor, characterized in that: It also includes two Hall sensors, a motor control module and a magnet set on the push rod. The motor controls the push rod to move between the two Hall sensors. When the push rod approaches a Hall sensor, the magnet on the push rod triggers the Hall sensor signal to change. The change in the Hall sensor signal triggers the motor control module to work and control the motor to stop running.

2. A push rod limit control device according to claim 1, characterized in that: The motor control module includes two optocoupler sensors and two MOS tubes. A single Hall sensor, an optocoupler sensor and a MOS tube are matched. The Hall sensor controls the on-off of the optocoupler sensor, and the optocoupler sensor controls the on-off of the MOS tube. The on-off of the MOS tube controls the current passing through the motor and controls the working state of the motor.

3. A push rod limit control device according to claim 2, characterized in that: The motor control module also includes a resistor R1, a resistor R2, a resistor R3, a resistor R4, a diode D1, a diode D2, an external control input power port MO+ and an external control input power port MO-, the MOS tubes are all NMOS tubes, including MOS tubes Q1 and MOS tubes Q2, the optocoupler sensor includes an optocoupler sensor U3 and an optocoupler sensor U4, the external control input power port MO+ is connected to the anode of the diode D1, one end of the resistor R1, and the 3rd pin of the optocoupler sensor U3, the other end of the resistor R1 is simultaneously connected to one end of the resistor R2 and the 4th pin of the optocoupler sensor U3, the other end of the resistor R2 is connected to the external control input power port MO-; the external control input power port MO- is connected to the anode of the diode D2, one end of the resistor R4, and the 3rd pin of the optocoupler sensor U4, the other end of the resistor R4 At the same time, it is connected to one end of the resistor R3 and the 4th pin of the optocoupler sensor U4, and the other end of the resistor R4 is connected to the external control input power port MO+; the source of the MOS tube Q1 is connected to the external control input power port MO+, the drain of the MOS tube Q1 is connected to the motor, the gate of the MOS tube Q1 is connected to the 4th pin of the optocoupler sensor U3, the source of the MOS tube Q2 is connected to the external control input power port MO-, the drain of the MOS tube Q1 is connected to the motor, the gate of the MOS tube Q2 is connected to the 4th pin of the optocoupler sensor U4, the cathode of the diode D1 and the cathode of the diode D2 are connected to the motor at the same time, the 1st pin of the optocoupler sensor U3 and the 1st pin of the optocoupler sensor U4 are both connected to the power supply, the 2nd pin of the optocoupler sensor U3 is connected to the Hall sensor U1, and the 2nd pin of the optocoupler sensor U4 is connected to the Hall sensor U2.

4. A push rod limit control device according to claim 3, characterized in that: The motor control module also includes a capacitor C1 and a capacitor C2, the external control input power port MO+ is connected to one end of the capacitor C1, the other end of the capacitor C1 is connected to the gate of the MOS tube Q1, the external control input power port MO- is connected to one end of the capacitor C2, and the other end of the capacitor C2 is connected to the gate of the MOS tube Q2.

5. A push rod limit control device according to claim 3, characterized in that: The motor control module also includes TVS tubes, which include TVS tubes D13, TVS tubes D14, TVS tubes D15 and TVS tubes D16. TVS tubes D13 and D16 are connected in parallel between the source and drain of MOS tube Q1, and TVS tubes D14 and TVS tubes D15 are connected in parallel between the source and drain of MOS tube Q2.

6. A push rod limit control device according to claim 5, characterized in that: The breakdown voltage of the TVS tube is lower than the breakdown voltage of the MOS tube, and the power of the TVS tube matches the instantaneous voltage and current of the motor.

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