WO2024045022A1

WO2024045022A1 - Electric push-pull mechanism

Info

Publication number: WO2024045022A1
Application number: PCT/CN2022/116120
Authority: WO
Inventors: 马戎
Original assignee: 深圳市戎马易圣科技有限公司
Priority date: 2022-08-31
Filing date: 2022-08-31
Publication date: 2024-03-07

Abstract

An electric push-pull mechanism (10), comprising a mounting bracket (200), a drive unit (300) and a control unit (400), wherein a guide rod (210), which is sleeved in a motion bracket (220) in a slidable manner, is provided on the mounting bracket (200); the drive unit (300) comprises an electric motor (310), a power source (320), a lead screw (330), which is in drive connection with the electric motor (310), and a transmission member (340), on which a positioning member (350) is provided and which is in threaded connection to the lead screw (330) and is connected to the motion bracket (220); the control unit (400) comprises a control circuit board (410), and a plurality of groups of photoelectric through-beam assemblies, which are arranged in a row and are electrically connected to the control circuit board (410), through-beam region are formed between transmitting tubes (420) and receiving tubes (430) of the photoelectric through-beam assemblies, stroke regions are formed between adjacent photoelectric through-beam assemblies, and the through-beam regions and the stroke regions form a sensing channel (440); the tail end of the positioning member (350) is inserted into the sensing channel (440) and moves along the sensing channel (440) to shield or leave the through-beam regions; the transmission member (340) shields a stroke position of one photoelectric through-beam assembly which corresponds to the motion bracket (220); and when the level of a photoelectric through-beam assembly corresponding to a preset stroke position changes, the electric motor (310) is controlled to rotate reversely. The electric push-pull mechanism (10) realizes accurate control of multiple stages of strokes, thereby reducing the production and usage costs of the electric push-pull mechanism (10).

Description

An electric push-pull mechanism

Technical field

The present invention relates to the technical field of electric push-pull devices, and in particular to a low-cost electric push-pull mechanism that can realize multi-stage stroke control.

Background technique

For consumer electronic products with electric push-pull functions, such as power tools (such as electric drills), electric toys, smart homes, or massagers (such as fascia guns), a solution that combines a motor and a reversing transmission device is usually used. To realize the push-pull function of the product, the motor generally uses a DC brush motor, a DC brushless motor, a stepper motor or a servo motor to provide rotational power output, and the reversing transmission device uses crankshaft transmission or screw drive to The rotary motion of the motor is converted into linear push-pull motion.

technical problem

However, DC brush/brushless motors continue to rotate after being powered on, and the angular position of the motor output cannot be accurately controlled. That is, after superimposing a reversing transmission device with linear push-pull motion, the real-time linear position of the output mechanism cannot be accurately controlled. , for example, when using crankshaft transmission, the system can only guarantee reciprocating motion on a fixed linear stroke, but cannot control the specific dwell position of the output end in real time, making it difficult to meet the user's needs for different push-pull movement strokes of the push-pull mechanism. Although stepper motors or servo motors can accurately control the output stroke of the product and achieve multi-level stroke control of the product, their cost is high, and the development of the control system is difficult and large in size. Therefore, the mass production cost, development cost, size and It is difficult to be widely used in consumer electronic products that require high portability and other aspects.

Technical solutions

Based on this, it is necessary to provide a low-cost electric push-pull mechanism that can achieve multi-stage stroke control to address the above shortcomings.

An electric push-pull mechanism, which includes:

Installation bracket, a guide rod is fixedly provided on the installation bracket, and a motion bracket is slidably connected to the guide rod;

The driving unit includes a motor arranged on the mounting bracket, a power supply electrically connected to the motor and supplying power to the motor, a screw rod connected to the output end of the motor and rotating under the driving of the motor, and a screw thread connected to the screw rod. A transmission member that is connected and moves reciprocally along the length direction of the screw rod. The transmission member is fixedly connected to the motion bracket, and the transmission member is provided with a positioning member; and

A control unit, which includes multiple groups of photoelectric through-beam assemblies arranged in a row at intervals along the moving direction of the moving bracket. A through-beam area is formed between the transmitting tube and the receiving tube of each group of photoelectric through-beam assemblies. Two adjacent groups A travel area is formed between the photoelectric through-beam components, and each through-beam area and the travel area together form an induction channel; the free end of the positioning member is inserted into the induction channel, and is driven by the transmission member to move in the induction channel to Block or leave the through-beam area; when the transmission member blocks a group of photoelectric through-beam components, it corresponds to a stroke position of the moving bracket;

The control unit also includes a control circuit board for controlling motor reversal when the level of the photoelectric through-beam component corresponding to the preset stroke position changes. The control circuit board accepts multiple groups of photoelectric through-beam components and is connected to each group respectively. The photoelectric through-beam components are electrically connected.

In one embodiment, the photoelectric through-beam component is disposed on the control circuit board on a side adjacent to the positioning member; or the photoelectric through-beam component is disposed on the control circuit board on a side facing away from the positioning member, and A guide hole connected to the induction channel is provided on the control circuit board at a position corresponding to the induction channel, and the end of the positioning member is penetrated through the guide hole and inserted into the induction channel;

The mounting bracket includes an arc-shaped fixing plate, a motor mounting shell connected to the convex arc surface of the arc-shaped fixing plate, and is arranged on both sides of the motor mounting shell and fixedly connected to the convex arc surface of the arc-shaped fixing plate and the motor mounting shell respectively. Two power supply mounting plates and an intubation tube arranged between the motor mounting shell and the power supply mounting plate;

The arc-shaped fixing plate is provided with a penetration hole extending along the length direction of the arc-shaped fixing plate. The motor is contained in a motor mounting shell. The screw rod passes through the motor mounting shell and is connected to the motor drive. The power supply is fixed on the power supply mounting plate, the intubation tube is fixedly connected to the arc-shaped fixed plate, the motor mounting shell and the power supply mounting plate respectively, the guide rod is inserted into the intubation tube, and the movement bracket is accommodated in the arc-shaped fixing plate. In the area enclosed by the concave arc surface of the plate, the bottom of the movement bracket is provided with legs that pass through holes and are slidably connected to the guide rods.

In one embodiment, the electric push-pull mechanism includes a main control circuit provided on the control circuit board, and a transmitting circuit, a receiving circuit, a switching circuit and a driving circuit that are electrically connected to the main control circuit respectively; the main control circuit It includes an MCU controller, the transmitting circuit includes an NMOS tube and a current limiting resistor for driving the transmitting tube to work, the receiving circuit includes a signal amplifier and an emitter resistor, the switching circuit includes a plurality of independently connected switches, The drive circuit includes a motor drive IC used for starting, stopping and steering control of the motor.

In one embodiment, the MCU controller detects the time when the positioning member continuously passes through two adjacent groups of photoelectric through-beam assemblies, and calculates the average speed of the moving bracket passing between the adjacent two groups of photoelectric through-beam assemblies.

In one embodiment, the MCU controller detects the time it takes for the positioning member to pass through a preset travel range on both sides of a set of photoelectric through-beam components, and calculates the average of the moving bracket passing through the preset travel range on both sides of the photoelectric through-beam component. speed.

In one embodiment, the drive circuit further includes a current sampling resistor connected in series with the motor drive IC. The current sampling resistor is connected to a first analog-to-digital converter electrically connected to the MCU controller. The first analog-to-digital converter is electrically connected to the MCU controller. The converter is used to convert the voltage signal collected by the current sampling resistor into a real-time motor supply current. The MCU controller calculates the load power of the motor and the moving speed of the moving bracket based on the real-time motor supply current.

In one embodiment, the electric push-pull mechanism further includes a voltage sampling circuit connected to the drive circuit to detect the drive voltage in real time.

In one embodiment, the MCU controller calculates the real-time speed of the moving bracket at each moment and performs differential processing on the motion of the moving bracket, and calculates the position of the moving bracket at a preset time point through integration.

In one embodiment, the MCU controller adjusts the resistance of the current-limiting resistor or adds a constant current drive circuit to adjust the drive circuit and emitted light intensity of the photoelectric through-beam component. The MCU controller adjusts the emitter resistor. resistance or increase the post-stage operational amplifier circuit to adjust the receiving sensitivity of the receiving circuit; the receiving circuit is also connected to a second analog-to-digital converter electrically connected to the MCU controller, and the second analog-to-digital converter is used to convert the voltage signal of the receiving circuit Convert to light intensity information.

In one embodiment, when the positioning member is located between the two preset groups of photoelectric through-beam components, the MCU controller receives the light intensity information sent by the receiving tube with the two groups of photoelectric through-beam components and weights the evaluation. To calculate the percentage position of the positioning member between the two sets of photoelectric through-beam components.

beneficial effects

To implement the electric push-pull mechanism of the present invention, multiple sets of photoelectric through-beam assemblies are provided on the control circuit board to form an induction channel composed of an through-beam area and a stroke area, and positioning parts are provided on the transmission parts that cooperate with the screw threads. The motor drives the screw rod to rotate, and the transmission part will drive the positioning part to move in the induction channel to block or leave the beam area. When the electric push-pull mechanism is set to work at different stroke positions, the control circuit board receives the photoelectric signals corresponding to the corresponding stroke positions. After changing the electrical signal sent by the beam assembly, the motor is controlled to rotate in the reverse direction. In this way, only low-cost motors such as DC brush/brushless motors can be used to achieve precise control of the multi-stage formation of the electric push-pull mechanism, reducing the cost Production and use costs of electric push-pull mechanisms.

Description of drawings

Figure 1 is a schematic structural diagram of an electric push-pull mechanism in one embodiment of the present invention;

Figure 2 is a schematic structural diagram of the electric push-pull mechanism after removing the outer casing in one embodiment of the present invention;

Figure 3 is a schematic diagram of the exploded structure of the electric push-pull mechanism in one embodiment of the present invention;

Figure 4 is a partially enlarged structural schematic diagram of part A in the embodiment shown in Figure 3;

Figure 5 is a schematic structural diagram of the mounting bracket from one perspective according to an embodiment of the present invention;

Figure 6 is a schematic structural diagram of the mounting bracket from another perspective according to an embodiment of the present invention;

Figure 7 is a schematic structural diagram of the motion bracket in one embodiment of the present invention;

Figure 8 is a circuit schematic diagram of the main control circuit in one embodiment of the present invention;

Figure 9 is a circuit schematic diagram of a transmitting circuit in an embodiment of the present invention;

Figure 10 is a circuit schematic diagram of a receiving circuit in an embodiment of the present invention;

Figure 11 is a circuit schematic diagram of a switching circuit in one embodiment of the present invention;

Figure 12 is a schematic circuit diagram of a driving circuit in an embodiment of the present invention.

Detailed ways

In order to make the above objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the invention. However, the present invention can be implemented in many other ways different from those described here. Those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

Referring to Figures 1 to 3, the present invention discloses a low-cost electric push-pull mechanism 10 that can achieve multi-stage stroke control. The electric push-pull mechanism 10 is based on a combination of screw drive and photoelectric tube positioning, achieving a Ordinary low-cost DC brush/brushless motors are used as driving force to achieve linear push-pull motion with precise and controllable real-time movement position. Specifically, multiple sets of photoelectric components corresponding to different stroke gears are set up, and according to the photoelectricity at a specific position The level change generated when the photoelectric signal of the through-beam component is blocked is used to determine the position of the moving bracket, and then the control circuit board 410 controls the motor to reverse, so that the electric push-pull mechanism 10 controls the circuit at the preset stroke gear. The board 410 always controls the motor 310 to reciprocate in the area between the stroke position corresponding to the stroke gear and the initial position. In this way, by adjusting the stroke gear input to the control circuit board 410, the electric push-pull mechanism can be realized with more than 10 levels. For stroke control, in this mechanism, there is no need to program the motor, and an ordinary low-cost DC motor can be used, which is beneficial to reducing the production and use costs of the electric push-pull mechanism 10, thereby reducing the cost of related products.

The electric push-pull mechanism 10 of the present invention can be used for electric tools such as electric drills and electric bits, and can also be used for smart home products such as alarm clocks. It can also be used for fascial guns or other massagers, and electronic products such as electric toys. It has multiple different stroke gears. position, in each different stroke gear, the push-pull component (i.e., the moving bracket) of the electric push-pull mechanism 10 reciprocates within the preset stroke range to output vibration driving force to the outside. Specifically, please refer to Figures 1-4. The electric push-pull mechanism 10 includes a shell 100, a mounting bracket 200, a drive unit 300 and a control unit 400. The shell 100 is formed by an upper half shell 110 and a lower half shell 120. The upper half shell 110 It is buckled or screwed to the lower half shell 120. There is an installation space between the upper half shell 110 and the lower half shell 120. The installation bracket 200, the drive unit 300 and the control unit 400 are all accommodated in the installation space. The mounting bracket 200 is fixed with a guide rod 210, and a motion bracket 220 is slidably connected to the guide rod 210. The mounting bracket 200 is used to provide the skeleton of the electric push-pull mechanism 10 and to support the drive unit 300 and the control unit 400. The motion bracket 220 serves as the output member of the electric push-pull mechanism 10 and is used to install the component to be vibrated or directly used as a vibrating component.

The driving unit 300 includes a motor 310 disposed on the mounting bracket 200, a power supply 320 electrically connected to the motor 310 and supplying power to the motor 310, a screw rod 330 connected to the output end of the motor 310 and rotated by the motor 310, and a screw rod 330 connected to the output end of the motor 310. The rod 330 is threadedly connected to the transmission member 340 that moves reciprocally along the length direction of the screw rod 330. The transmission member 340 is fixedly connected to the motion bracket 220, and the transmission member 340 is provided with a positioning member 350. In this embodiment, the motor 310 is a DC brush motor or a DC brushless motor. The motor 310 can be used to directly drive the screw rod 330 to rotate, or the power can be transmitted to the screw rod 330 after being changed by a gear set or other transmission device. Preferably, a motor gearbox (reduction gear set) meshed with multi-stage gears is provided between the output end of the motor 310 and the screw rod 330 to adjust the rotational speed of the screw rod 330 and thereby adjust the vibration frequency of the moving bracket 220 .

The control unit 400 includes multiple groups of photoelectric through-beam components arranged in a row at intervals along the moving direction of the moving bracket 220. A through-beam area is formed between the emitting tube 420 and the receiving tube 430 of each group of photoelectric through-beam components. In this embodiment, The transmitting tube 420 and the receiving tube 430 are respectively an infrared transmitting tube and an infrared receiving tube. A travel area is formed between two adjacent groups of photoelectric beam assemblies. Each of the beam beam areas and the travel area together form the sensing channel 440; the free end of the positioning member 350 Insert into the induction channel 440, and move in the induction channel 440 driven by the transmission member 340 to block or leave the through-beam area; when the transmission member 340 blocks a group of photoelectric through-beam components, it corresponds to a stroke position of the moving bracket 220; The control unit 400 also includes a control circuit board 410 for controlling motor reversal when the level of the photoelectric through-beam component corresponding to the preset stroke position changes. The control circuit board 410 accepts multiple groups of photoelectric through-beam components and communicates with each group respectively. The photoelectric through-beam component 410 is electrically connected. When the positioning member 350 moves linearly with the moving bracket 220, it can cut off the light path (i.e., the through-beam area) of each group of photoelectric through-beam components. In this way, the control circuit board 410 detects the working status of the receiving tube 430 of each photoelectric through-beam component (receiving area) in real time. The level signal transmitted by the tube 430) can be used to determine the real-time position of the moving bracket 220. In this embodiment, the control circuit board 410 can be a whole piece, or it can be a plurality of sub-circuit boards arranged separately to adapt to the structure of the electric push-pull mechanism 10 . It only needs to ensure that at least one sub-circuit board is adjacent to the moving bracket 220 . Transmission member 340, and multiple sets of photoelectric through-beam components are arranged on the sub-circuit board.

In addition, the housing 100 of the electric push-pull mechanism 10 is provided with a plurality of control buttons 130. By pressing the control buttons 130, the level of the preset pin on the control circuit board 410 can be triggered to change, that is, a start or stop signal is sent to the control circuit board 410. signal or stroke level adjustment signal. In this way, when the level of the pin representing the status of the photoelectric through-beam component associated with the pin corresponding to the stroke level changes, the control circuit board 410 determines that the motion bracket 220 has reached the preset Location.

The above-mentioned electric push-pull mechanism 10 is provided with multiple sets of photoelectric through-beam components on the control circuit board 410 to form an induction channel 440 composed of an through-beam area and a stroke area, and a positioning member is provided on the transmission member 340 that is threaded with the screw rod 330 350. The motor 310 drives the screw rod 330 to rotate, and the transmission member 340 will drive the positioning member 350 to move in the induction channel 440 to block or leave the facing area. When the electric push-pull mechanism 10 is set to work at different stroke positions, the control circuit board 410 After receiving the changing electrical signal sent by the photoelectric beam component corresponding to the corresponding stroke position, the motor 310 is controlled to rotate reversely, so that the electric push-pull mechanism 10, after being set to the preset stroke position, aligns with the preset position at the initial position. Assume movement within the area between stroke positions. In this embodiment, the stroke position corresponding to when the through-beam area of a group of photoelectric through-beam components at the head end or the end of the multiple groups of photoelectric through-beam components is blocked by the positioning member 350 is set as the initial position.

Please refer to Figure 3-6. The mounting bracket 200 includes an arc-shaped fixing plate 230, a motor mounting shell 240 connected to the convex arc surface of the arc-shaped fixing plate 230, and is disposed on both sides of the motor mounting shell 240 and connected to the arc-shaped fixing plate respectively. The convex arc surface of 230 is fixedly connected to the two power supply mounting plates 250 of the motor mounting shell 240, and the insert tube 260 is provided between the motor mounting shell 240 and the power supply mounting plate 250. In this embodiment, the arc-shaped fixing plate 230 is a plate with an upward opening and an arc-shaped cross-section. The convex arc surface of the arc-shaped fixing plate 230 is the outside of the opening of the arc-shaped fixing plate 230 . The concave arc surface is the inside of the opening of the arc-shaped fixing plate 230 . The part on the side of the movable bracket 220 adjacent to the arc-shaped fixed plate 230 has an arc surface structure. For example, the movable bracket 220 has a tubular structure. When the movable bracket 220 has a tubular structure, the interface of the movable bracket 220 can also be of different shapes. For example, an assembly bayonet 221 is provided at the interface of the motion bracket 220 to adapt to various application structural components. For example, a power tool bit with a corresponding interface shape is inserted into the assembly bayonet 221 , or a power tool bit with a corresponding interface shape is inserted into the assembly bayonet 221 . An electric pneumatic cupping can be formed by inserting a cup-shaped cavity with a suitable shape and a cushioned head. The motor mounting shell 240 is located at one end of the arc-shaped fixing plate 230 and is fixedly connected to the arc-shaped fixing plate 230. The motor mounting shell 240 is located in the middle outside the opening of the arc-shaped fixing plate 230, that is, outside the lowest point on the arc-shaped fixing plate 230. The motor mounting shell 240 is a cylindrical structure adapted to the shape of the motor 310.

The arc-shaped fixing plate 230 is provided with a through hole 231 extending along the length direction of the arc-shaped fixing plate 230. The through hole 231 can penetrate the end face of the arc-shaped fixing plate 230. Of course, if the stroke of the movement bracket 220 allows, the through hole 231 can pass through the arc-shaped fixing plate 230. The connecting hole 231 may not penetrate the end surface of the arc-shaped fixing plate 230 . It should be noted that the motor 310 and the guide rod 210 are both assembled on the mounting bracket 200 to ensure that the motion bracket 220 moves linearly on the track defined by the screw rod 330 and the guide rod 210 . The motor 310 is contained in the motor mounting shell 240. In this embodiment, the motor 310 is stably engaged in the motor mounting shell 240. The front end cover of the gearbox of the motor 310 or the motor 310 is provided with a screw positioning hole, and the wire is further screwed through the screw. The connecting body of the rod 330 and the motor 310 is fastened to the motor mounting shell 240 to prevent the motor 310 from loosening during operation. The screw rod 330 passes through the motor mounting shell 240 and is drivingly connected to the motor 310. The power supply 320 is fixed on the power supply mounting plate 250. In this embodiment, one power supply 320 is provided on each of the two power supply mounting plates 250 to ensure that the electric push-pull mechanism has Enough power.

The intubation tube 260 is fixedly connected to the arc-shaped fixed plate 230, the motor mounting shell 240 and the power supply mounting plate 250 respectively. The guide rod 210 is inserted into the intubation tube 260, and the movement bracket 220 is accommodated in the concave arc surface of the arc-shaped fixed plate 230. in the area, and the bottom of the movement bracket 220 is provided with legs 222 that pass through the through holes 231 and are slidably sleeved with the guide rod 210 . In this embodiment, the bottom of the motion bracket 220 is symmetrically provided with two legs 222, each leg 222 is provided with a circular hole, and the arc-shaped fixed plate 230 is provided with two penetration holes 231 at intervals. The motor mounting shell 240 is There is an intubation tube 260 on each side, and a guide rod 210 is inserted in each of the two intubations 260. Each leg 222 on the movement bracket 220 is respectively provided with a penetration hole 231 and is sleeved on a guide rod 210. , to realize the sliding connection between the motion bracket 220 and the guide rod 210. It should be noted that the legs 222 at the bottom of the motion bracket 220 can be directly drilled, or a fixed bushing assembly can be assembled at the bottom of the motion bracket 220. In this embodiment, the motion bracket 220 is formed of POM wear-resistant material, so the legs can be directly connected to the legs 222. 222, in practice, additional wear-resistant components with holes can also be assembled to achieve the same function, that is, to support the movement bracket 220, prevent it from rotating and be wear-resistant relative to the guide rod 210. In addition, it needs to be emphasized that when the screw rod 330 and the transmission member 340 rotate relative to each other to drive the moving bracket 220 to reciprocate, the screw rod 330 will generate a torsional force on the moving bracket 220 along the rotation direction of the screw rod 330. By setting the guide The rod 210, on the one hand, realizes the positioning, guidance and support of the motion bracket 220, preventing the screw rod 330 from being broken or damaged due to overload. On the other hand, it can also prevent the motion bracket 220 from rotating to ensure reliable motion control of the motion bracket 220. sex.

In one embodiment, the mounting bracket 200 also includes a sealing plate 270 located at the other end of the arc-shaped fixing plate 230 and fixedly connected to the motor mounting shell 240 and the power supply mounting plate 250 respectively. The sealing plate 270 is connected to the motor mounting shell 240 and the power supply mounting plate 250 . They are collectively enclosed to form a sliding area, and the screw rod 330, the transmission member 340 and the positioning member 350 are contained in the sliding area; when the photoelectric facing component is installed on the control circuit board 410 on the side facing away from the positioning member 350, the sealing plate 270 There is a socket 271 connected with the guide hole. The socket 271 serves as a channel through which the end of the positioning member 350 passes, so that when the movement bracket 220 and the transmission member 340 drive the positioning member 350 to move, the end of the positioning member 350 can be in the sensing channel. 440, thereby blocking the through-beam area between the emitting tube 420 and the receiving tube 430 of a set of photoelectric through-beam assemblies when moving to a predetermined stroke position.

It should be noted that the transmission member 340 can be provided separately from the movement bracket 220 , or they can be an integrated structure. Of course, the transmission member 340 can also be a part of the movement support 220 , for example, provided at the bottom of the movement support 220 bulge, and a threaded hole threaded with the screw rod 330 is opened on the bulge, and the positioning member 350 is installed at the bottom of the bulge. Please combine Figure 3 and Figure 7. When the transmission member 340 and the motion bracket 220 are arranged separately, the transmission member 340 includes a nut threaded with the screw rod 330, a limit plate fixedly connected to the nut, and a limit plate fixed on the limit plate. Positioning member 350; the outer surface of the end of the movement bracket 220 away from the intubation tube 260 is provided with a lug 223. The lug 223 is provided with a slot 224. The limiting plate is inserted into the slot 224 and is limitedly matched with the movement bracket 220. Therefore, when the transmission member 340 moves on the screw rod 330, it can drive the movement bracket 220 to move through the cooperation between the limiting plate and the inner wall of the slot 224, thereby driving the movement bracket 220. Furthermore, the limiting plate is also connected with screws or pins to the lugs 223 to further improve the stability of the connection between the transmission member 340 and the moving bracket 220 and prevent the moving bracket 220 from shaking during vibration.

In this embodiment, the positioning member 350 includes a light-blocking portion that faces away from the limiting plate and blocks or leaves the opposite area. For example, the positioning member 350 is designed as an L-shaped structure, and the transverse portion of the L-shaped structure of the positioning member 350 is in contact with the transmission member 340 Fixed connection, the vertical part of the L-shaped structure of the positioning member 350 serves as a light blocking part and is used to block the through-beam area of the photoelectric through-beam component at the preset position. The positioning component 350 may be a hardware component or a plastic component that is separated from the transmission component 340 , or may be integrally formed with the motion bracket 220 or form a part of the motion bracket 220 .

Further, the electric push-pull mechanism also includes a positioning end cover 500. The positioning end cover 500 is located on the end of the mounting bracket 200 facing away from the intubation tube 260 and is fixedly connected to the sealing plate 270 and the power supply installation plate 250 respectively. The positioning end cover 500 is provided with a A first limiting slot at the end of the insertion guide rod 210, and a second limiting slot at the end of the rotating insertion screw rod 330. By providing the positioning end cover 500, the end of the guide rod 210 can be limited to prevent the guide rod 210 from moving. In this embodiment, the end of the screw rod 330 is provided with a positioning pin, and the positioning pin is connected with the second limiting plug. Grooved pin connection. Further, a bearing sleeve is provided in the second limit slot, and a bearing is installed on the bearing sleeve to cooperate with the end of the screw rod 330 to improve the wear resistance of the end of the screw rod 330 .

In this embodiment, multiple groups of photoelectric through-beam components are integrated on the control circuit board 410. Each group of photoelectric through-beam components includes a transmitting tube 420 and a receiving tube 430. Preferably, when the electric push-pull mechanism is working, through the control circuit The board detects whether the receiving tube 430 is illuminated by infrared rays to determine whether the light path (ie, the through-beam area) of each group of photoelectric through-beam components is cut off.

In this embodiment, the photoelectric through-beam component is arranged on the control circuit board 410 in two ways. One is that the photoelectric through-beam component is disposed on the control circuit board 410 on a side adjacent to the positioning member 350 (as shown in Figure 3 ); the second is that the photoelectric through-beam component is arranged on the control circuit board 410 on one side of the positioning member 350, and the control circuit board 410 is provided with a guide hole connected to the sensing channel 440 at the position corresponding to the sensing channel 440. The end of the positioning member 350 is passed through a guide hole and inserted into the sensing channel 440 .

Please refer to Figures 8-12. The electric push-pull mechanism of this embodiment includes a main control circuit provided on the control circuit board, as well as a transmitting circuit, a receiving circuit, a switching circuit and a driving circuit that are electrically connected to the main control circuit respectively; the main control circuit Including MCU controller U5, the transmitting circuit includes an NMOS tube Q5 and a current-limiting resistor used to drive the transmitting tube. The NMOS tube Q5 is controlled by the MCU controller U5 through the signal IR_LED. The receiving circuit includes a signal amplifier and an emitter resistor. , the emitter signal is connected to the independent IO of the MCU controller U5, and the absorbed light intensity of each receiving tube can be judged through the level change. In this embodiment, four groups of photoelectric components are set up, and the four switches in the switch circuit are respectively Correspondingly connected to the pins SL+, SL-, SR+ and SR- of the MCU controller U5, each switch corresponds to different actions of the control button or is connected to different control buttons respectively. The switch circuit includes multiple independently connected switches. Preferably, Each switch is connected in parallel, and the drive circuit includes a motor drive IC for starting, stopping, and steering control of the motor. MCU controller U5 is connected to the drive circuit through the MOT_FI signal and MOT_BI signal. The drive circuit is further electrically connected to the motor to adjust the motor's power supply polarity and supply voltage, thereby realizing the start, stop, steering, and speed regulation of the motor.

When the operation control button 130 sends a signal to the MCU controller U5 on the control circuit board 410 so that the electric push-pull mechanism enters the M position, the MCU controller U5 needs to receive the changing level signal sent by the photoelectric through-beam component corresponding to the M position. When the positioning member 350 does not move to the group of photoelectric through-beam components, the receiving tube 430 of the group of photoelectric through-beaming components can normally receive the infrared signal emitted by the transmitting tube 420, and the receiving tube 430 sends a high-level signal to the control circuit board 410 , when the positioning member 350 moves to the group of photoelectric components, due to the obstruction of the positioning member 350, the receiving tube 430 cannot receive the infrared signal emitted by the transmitting tube 420, and the receiving tube 430 will send a low-level signal to the control circuit board 410 , in this way, the control circuit board 410 determines whether the moving bracket 220 moves to the preset stroke according to whether the level signal sent by the receiving tube 430 of the photoelectric through-beam component corresponding to the preset stroke position changes. When the group of photoelectric through-beam components When the level signal sent by the receiving tube 430 changes, the control circuit board 410 controls the motor 310 to reverse, thereby causing the moving bracket 220 to reciprocate within a preset stroke range.

It should be noted that the electric push-pull mechanism of this embodiment uses the MCU processor to determine which group of photoelectric through-beam components has the light path cut off to determine the moving position of the moving bracket 220. In this structure, the positioning accuracy of the moving bracket 220 depends on the distribution. The number of photoelectric through-beam components on the control circuit board, that is, the greater the number and the greater the density of the photoelectric through-beam components, the higher the positioning resolution of the electric push-pull mechanism. When the number of photoelectric through-beam components remains unchanged, the circuit of the electric push-pull mechanism can also be optimized from two aspects: precise motion positioning and obtaining the real-time speed of the electric push-pull mechanism. By adjusting its circuit, the motion control can be realized. The positioning resolution of the bracket 220 is improved.

Real-time speed collection solution

In one embodiment, the MCU controller detects the time when the positioning member continuously passes through two adjacent groups of photoelectric through-beam assemblies, and calculates the average speed of the moving bracket passing between the adjacent two groups of photoelectric through-beam assemblies. In this embodiment, What is measured is the speed at which the positioning part passes between two nodes. The time for the positioning part to pass through the photoelectric beam assembly can be collected and recorded by a timer. In another embodiment, the MCU controller detects the time it takes for the positioning member to pass through a preset travel range on both sides of a set of photoelectric through-beam components, and calculates the average speed of the moving bracket passing through the preset travel range on both sides of the photoelectric through-beam component. It should be noted that when the positioning member is near the central optical path of the two sets of photoelectric counter-beam components (the axis of symmetry connecting the two), the receiving circuit is in the most sensitive section, that is, the detected signal intensity is the highest and the signal reliability is the highest. Okay, therefore, in this embodiment, the distance between the two sets of photoelectric through-beam components is set to D, and by detecting the average speed of the positioning member within the range of 1/2 D on both sides of the set of photoelectric through-beam components, that is The speed of the moving bracket passing through the corresponding photoelectric through-beam component can be calculated.

Since the greater the load of the motor system during operation, the greater the power consumption. Therefore, if the circuit system detects the power consumption of the motor system in real time, it can determine the real-time load condition of the motion system. In addition, since the real-time load reflects the position of the motion bracket, For the actual resistance during work, the mathematical relationship between load and real movement speed (speed-load curve) can be known through actual data collection. Therefore, by monitoring the real-time power consumption of the electric push-pull mechanism, the real-time speed of the moving bracket can also be judged. Specifically, in this embodiment, the motor uses a lithium battery for constant voltage power supply, and the drive circuit also includes a current sampling resistor R11 connected in series with the motor driving IC. The current sampling resistor R11 is connected to a first analog digital circuit electrically connected to the MCU controller. converter, the sampling voltage signal Imot_DET of the current sampling resistor R11 is directly connected or connected to the first analog-to-digital converter or the MCU with the built-in first analog-to-digital converter after being amplified by the operational amplifier circuit signal. The first analog-to-digital converter is used for acquisition. The voltage signal is converted into a digital signal and sent to the MCU controller. It is converted into a current through the built-in program algorithm of the MCU controller, and then the load power of the motor and the moving speed of the motion bracket are calculated based on the real-time motor supply current.

Furthermore, the electric push-pull mechanism also includes a voltage sampling circuit connected to the driving circuit to detect the driving voltage in real time. In this embodiment, the motor driving IC (i.e. U2) controls the motor. By adjusting the PWM duty cycle of the control signals MOT_FI and MOT_BI, the driving voltage of the motor can be controlled. When setting the voltage sampling circuit, the voltage sampling circuit can be used. To detect the driving voltage of the motor in real time, the MCU controller compares the detected real-time driving voltage with the theoretical driving voltage sent to the motor, and dynamically adjusts the motor driving voltage (ie, feedback adjustment) to ensure control accuracy. In addition, the power adjustment of the motor voltage through the voltage sampling circuit can also be combined with the load detection (current detection) of the electric push-pull mechanism. Under different driving voltages, that is, different system powers, the current load conditions can be compared to obtain dynamic Two-dimensional power change data is used to optimize the speed calculation method to obtain a more accurate speed algorithm.

It should be noted that the above-mentioned real-time speed acquisition scheme can be used independently, or multiple schemes can be combined to detect the real-time speed of the moving bracket. In addition, in practice, data samples can be obtained through repeated experiments to calculate the weight of each solution, or the calculation formula can be obtained directly through convolutional network training.

Precise motion positioning solution

When the electric push-pull mechanism is actually used, the circuit system of the electric push-pull mechanism is not only used to determine whether there is light on the receiving tube of the photoelectric through-beam assembly, but also needs to further improve the accuracy of position detection by detecting the intensity of light received by the receiving tube. In one embodiment, the MCU controller calculates the real-time speed of the moving bracket at each moment and performs differential processing on the motion of the moving bracket, and calculates the position of the moving bracket at a preset time point through integration. Specifically, after using the above real-time speed acquisition scheme to obtain the real-time speed of the moving bracket, the differential formula of the real-time speed and time of the moving bracket can be established based on its real-time speed information. When the position at a certain moment is accurately known (for example, the receiving tube identifies that the optical path is blocked) When it is completely cut off, that is, the real-time position of the positioning member is at the position of the corresponding photoelectric through-beam component, the position at a certain time after a period of time is the position at the previous moment plus the integral of the real-time speed relative to time within that period of time.

Furthermore, the transmitting circuit and the receiving circuit can be adjusted to determine the intensity of light collected by the receiving tube, and the position of the moving bracket can be determined based on the intensity of the light.

Specifically, the MCU controller adjusts the resistance of the current-limiting resistor or adds a constant current drive circuit to adjust the drive circuit and emitted light intensity of the photoelectric component. The MCU controller adjusts the resistance of the emitter resistor or adds a subsequent stage. An operational amplifier circuit is used to adjust the receiving sensitivity of the receiving circuit; the receiving circuit is also connected to a second analog-to-digital converter electrically connected to the MCU controller. The second analog-to-digital converter is directly connected to the receiving circuit, or is powered by a built-in second analog-to-digital converter. The MCU of the digital converter is connected to the receiving circuit. The second analog-to-digital converter is used to convert the voltage signal into a digital signal and send it to the MCU controller. The built-in program of the MCU controller calculates the light intensity. It should be noted that when the positioning member gradually approaches the emitting tube and the receiving tube of a set of photoelectric counter-beam components, the amount of light emitted by the emitting tube and transmitted to the receiving tube is gradually increased. That is to say, when the positioning member During the movement, the light intensity received by the receiving tube does not suddenly reach 0, but gradually decreases and then gradually increases. Therefore, by detecting the voltage of the receiving tube, the light intensity collected by the receiving tube can be judged. The specific location of the positioning piece can be determined. Specifically, when the positioning member is located between the two preset groups of photoelectric through-beam assemblies, the MCU controller receives the light intensity information sent by the receiving tube with the two groups of photoelectric through-beam assemblies and weights the evaluation to calculate the position of the positioning member between the two groups. The percentage position between the group of photoelectric through-beam components.

The electric push-pull mechanism of the present invention has at least the following beneficial effects:

1. Cost: In the electric push-pull mechanism, the motor 310 part can use a low-cost DC brush motor or a DC brushless motor. Both the single product cost and the R&D cost are significantly reduced; the drive unit 300 and the control unit 400 are related. All core components can be compactly assembled on the same mounting bracket 200, which can effectively save the amount of plastic parts and assembly costs.

2. Controllable motion position: The electric push-pull mechanism has high motion positioning accuracy, and can be used with the motor 310 control system to achieve real-time control of the motion position. In low-cost, small-size applications, it can effectively replace high-cost, large-size stepper motor systems. and servo motor systems.

3. Development difficulty: Compared with stepper motor and servo motor systems, the development of control circuits is less difficult, which can greatly shorten the product development cycle.

4. In terms of size: The mechanism adopts a DC brush motor or DC brushless motor with a simpler size, and the requirements for the power supply 320 system and motor 310 control system are also reduced accordingly, so the overall machine size can be smaller under the same functional conditions.

5. Performance: Compared with open-loop control brushed DC motor or brushless DC motor control systems, this mechanism is a feedback control system with its own real-time positioning function, and its motion control capabilities are significantly improved.

The technical features of the above-described embodiments can be combined in any way. To simplify the description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, All should be considered to be within the scope of this manual.

The above-mentioned embodiments only express several implementation modes of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention. It should be noted that, for those of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the scope of protection of the patent of the present invention should be determined by the appended claims.

Claims

An electric push-pull mechanism, characterized by including:

An installation bracket, a guide rod is fixedly provided on the installation bracket, and a motion bracket is slidably connected to the guide rod;

The driving unit includes a motor arranged on the mounting bracket, a power supply electrically connected to the motor and supplying power to the motor, a screw rod connected to the output end of the motor and rotating under the driving of the motor, and a screw thread connected to the screw rod. A transmission member that is connected and moves reciprocally along the length direction of the screw rod, the transmission member is fixedly connected to the motion bracket, and the transmission member is provided with a positioning member; and

A control unit, which includes multiple groups of photoelectric through-beam assemblies arranged in a row at intervals along the moving direction of the moving bracket. A through-beam area is formed between the transmitting tube and the receiving tube of each group of photoelectric through-beam assemblies. Two adjacent groups A travel area is formed between the photoelectric through-beam components, and each through-beam area and the travel area together form an induction channel; the free end of the positioning member is inserted into the induction channel, and is driven by the transmission member to move in the induction channel to Block or leave the through-beam area; when the transmission member blocks a group of photoelectric through-beam components, it corresponds to a stroke position of the moving bracket;

The control unit also includes a control circuit board for controlling motor reversal when the level of the photoelectric through-beam component corresponding to the preset stroke position changes. The control circuit board accepts multiple groups of photoelectric through-beam components and is connected to each group respectively. The photoelectric through-beam components are electrically connected.
The electric push-pull mechanism according to claim 1, wherein the photoelectric facing component is arranged on a side of the control circuit board adjacent to the positioning member; or the photoelectric facing component is arranged on the back of the control circuit board. A guide hole connected to the induction channel is provided on one side of the positioning member and at the position corresponding to the induction channel on the control circuit board, and the end of the positioning member is penetrated through the guide hole and inserted into the induction channel;

The mounting bracket includes an arc-shaped fixing plate, a motor mounting shell connected to the convex arc surface of the arc-shaped fixing plate, and is arranged on both sides of the motor mounting shell and fixedly connected to the convex arc surface of the arc-shaped fixing plate and the motor mounting shell respectively. Two power supply mounting plates and an intubation tube arranged between the motor mounting shell and the power supply mounting plate;

The arc-shaped fixing plate is provided with a penetration hole extending along the length direction of the arc-shaped fixing plate. The motor is contained in a motor mounting shell. The screw rod passes through the motor mounting shell and is connected to the motor drive. The power supply is fixed on the power supply mounting plate, the intubation tube is fixedly connected to the arc-shaped fixed plate, the motor mounting shell and the power supply mounting plate respectively. The guide rod is inserted into the intubation tube, and the movement bracket is accommodated in the arc-shaped fixing plate. In the area enclosed by the concave arc surface of the plate, the bottom of the motion bracket is provided with legs that pass through holes and are slidably connected to the guide rods.
The electric push-pull mechanism according to claim 2, characterized in that the electric push-pull mechanism includes a main control circuit provided on the control circuit board, and a transmitting circuit, a receiving circuit, a switching circuit and a transmitting circuit electrically connected to the main control circuit respectively. Driving circuit; the main control circuit includes an MCU controller, the transmitting circuit includes an NMOS tube and a current-limiting resistor for driving the transmitter tube, the receiving circuit includes a signal amplifier and an emitter resistor, and the switching circuit includes an independent A plurality of switches are connected, and the driving circuit includes a motor driving IC for starting, stopping, and steering control of the motor.
The electric push-pull mechanism according to claim 3, characterized in that the MCU controller detects the time when the positioning member continuously passes through two adjacent groups of photoelectric facing assemblies, and calculates the time when the moving bracket passes through the adjacent two groups of photoelectric facing assemblies. Average speed between components.
The electric push-pull mechanism according to claim 4, characterized in that the MCU controller detects the time when the positioning member passes through the preset travel range on both sides of a set of photoelectric through-beam components, and calculates the time when the moving bracket passes through the photoelectric through-beam component. The average speed of the preset travel range on both sides.
The electric push-pull mechanism according to claim 5, characterized in that the drive circuit further includes a current sampling resistor connected in series with the motor driving IC, and the current sampling resistor is connected to a first analog circuit electrically connected to the MCU controller. Digital converter, the first analog-to-digital converter is used to convert the voltage signal collected by the current sampling resistor into a real-time motor supply current. The MCU controller calculates the load power of the motor and the moving speed of the motion bracket based on the real-time motor supply current.
The electric push-pull mechanism according to claim 6, characterized in that the electric push-pull mechanism further includes a voltage sampling circuit connected with the drive circuit to detect the drive voltage in real time.
The electric push-pull mechanism according to claim 7, characterized in that the MCU controller calculates the real-time speed of the moving bracket at each moment and performs differential processing on the movement of the moving bracket, and calculates the moving bracket at the preset time point through integration. s position.
The electric push-pull mechanism according to claim 8, characterized in that the MCU controller adjusts the resistance of the current-limiting resistor or adds a constant current drive circuit to adjust the drive circuit and emitted light intensity of the photoelectric through-beam component, and the The MCU controller adjusts the resistance of the emitter resistor or adds a post-stage operational amplifier circuit to adjust the receiving sensitivity of the receiving circuit; the receiving circuit is also connected to a second analog-to-digital converter that is electrically connected to the MCU controller. The converter is used to convert the voltage signal of the receiving circuit into light intensity information.
The electric push-pull mechanism according to claim 9, characterized in that when the positioning member is located between the two preset groups of photoelectric through-beam assemblies, the MCU controller receives the signal sent by the receiving tube with two groups of photoelectric through-beam assemblies. Light intensity information and weighted evaluation to calculate the percentage position of the positioning member between the two sets of photoelectric through-beam components.