Quick size switching circuit for electric pruning shears

Abstract

This utility model discloses a rapid opening / closing switching circuit for electric pruning shears, comprising an electric pruning shear body containing a processor and a power supply. The processor includes a main MCU processing unit, a motor drive circuit, an opening / closing position sensor circuit, and a phase inverter circuit. The opening / closing position sensor circuit is electrically connected to the main MCU processing unit, which is electrically connected to both the motor drive circuit and the phase inverter circuit. The motor drive circuit is electrically connected to both the motor in the electric pruning shear body and the power supply. The motor drive circuit includes a power inverter circuit and a BLDC motor back EMF detection circuit, and the phase inverter circuit is electrically connected to the BLDC motor back EMF detection circuit. This utility model makes the operation of switching opening sizes on electric pruning shears more convenient and better meets the needs of operators requiring high work efficiency.

Description

Technical Field

[0001] This utility model relates to the field of electric pruning shears technology, and in particular to a circuit for quickly switching the size of the opening of an electric pruning shear. Background Technology

[0002] Known electric pruning shears (such as...) Figure 1 (As shown) These are devices that allow for easy and efficient pruning of plant branches and stems, widely used in agriculture, forestry, and horticulture. Electric pruning shears are typically equipped with a motor that drives the blades via gear transmission. Motor control is crucial for achieving optimal performance. The ability to switch between large and small openings in electric pruning shears is primarily achieved by adjusting the shear blade opening size. This is commonly used for pruning branches of varying thicknesses. Most electric pruning shears use a mechanical structure for opening adjustment, while some models are equipped with replaceable blades or a sliding adjustment mechanism. For example, SAO mechanical models support switching between 2.5cm and 3cm opening sizes, suitable for pruning hardwood branches from 25mm in diameter to 30mm in diameter softwood branches. The small opening mode (2.5cm) is used for pruning thin branches, buds, or branches requiring fine trimming; the large opening mode (3cm) is used for thicker branches, lignified branches, or hardwood species.

[0003] The current method for switching the size of the electric pruning shear requires holding the trigger down for a certain period of time (usually more than 2 seconds) before switching. The prompts indicate the switch size, and the trigger must be released after the switch takes effect. As you can see, there are many steps involved, which leads to low work efficiency. Therefore, an improvement is urgently needed. Utility Model Content

[0004] (a) Technical problems that need to be solved

[0005] To address the shortcomings of existing technologies, this utility model provides a circuit for quickly switching the size of the opening of electric pruning shears, which makes the operation of switching the size of the opening on electric pruning shears more convenient and better meets the needs of operators for high work efficiency.

[0006] (ii) Technical solutions to be adopted

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0008] A circuit for rapid opening / closing switching of electric pruning shears includes an electric pruning shear body containing a processor and a power supply. The processor includes a main MCU processing unit, a motor drive circuit, an opening / closing position sensor circuit, and a phase inverter circuit. The opening / closing position sensor circuit is electrically connected to the main MCU processing unit. The main MCU processing unit is electrically connected to both the motor drive circuit and the phase inverter circuit. The motor drive circuit is electrically connected to both the motor in the electric pruning shear body and the power supply. The motor drive circuit includes a power inverter circuit and a BLDC motor back EMF detection circuit. The phase inverter circuit is electrically connected to the BLDC motor back EMF detection circuit, and the power inverter circuit and the BLDC motor back EMF detection circuit are also electrically connected.

[0009] The electric pruning shears are equipped with buttons and a DC / DC converter. The power supply is connected to the DC / DC converter and the phase inverter circuit. The DC / DC converter is connected to the main MCU processing unit.

[0010] The electric pruning shears body has an opening sampling sensor H1 and a closing sampling sensor H2 installed at the cutting component. The opening sampling sensor H1 and the closing sampling sensor H2 are respectively connected to the opening / closing position sensor circuit, and the opening / closing position sensor circuit is electrically connected to the main MCU processing unit.

[0011] Preferably, the interface section of the main MCU processing unit contains an integrated circuit U3. In the integrated circuit U3, PINs 6 to PIN8 are the BEMF_U / BEMF_V / BEMF_W back electromotive force signal input terminals, respectively. PIN 11 / IRms in the integrated circuit U3 is the three-phase inverter bus current detection input terminal. PIN 10 / RX1 in the integrated circuit U3 is a serial port receiver used to receive signals from the open / closed position sensor circuit. PIN 22 in the integrated circuit U3 detects the button status.

[0012] Preferably, the opening / closing position sensor circuit includes an integrated circuit U2, which is connected to the opening sampling sensor H1 and the closing sampling sensor H2 respectively. The opening sampling sensor H1 is connected to the PIN2 pin of the integrated circuit U2, and the closing sampling sensor H2 is connected to the PIN5 pin of the integrated circuit U2.

[0013] Preferably, the button is connected to the main MCU processing unit via a connecting cable.

[0014] (III) The technical effects to be achieved

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] Firstly, the electric pruning shears of this invention are equipped with buttons and a DC / DC converter. The power supply is connected to the DC / DC converter and the phase inverter circuit. The DC / DC converter is connected to the main MCU processing unit. The cutting component of the electric pruning shears is equipped with an opening sampling sensor H1 and a closing sampling sensor H2. The opening sampling sensor H1 and the closing sampling sensor H2 are respectively connected to the opening / closing position sensor circuit. The opening / closing position sensor circuit is electrically connected to the main MCU processing unit. This allows for switching between large and small openings on the electric pruning shears simply by pressing a button, making operation simpler and greatly improving work efficiency.

[0017] Secondly, the processor of this utility model includes a main MCU processing unit, a motor drive circuit, an opening / closing position sensor circuit, and a phase inverter circuit. The opening / closing position sensor circuit is electrically connected to the main MCU processing unit. The main MCU processing unit is electrically connected to both the motor drive circuit and the phase inverter circuit. The motor drive circuit is used to connect to both the motor and the power supply in the electric pruning shears body. The motor drive circuit includes an inverter power circuit and a BLDC motor back EMF detection circuit. The phase inverter circuit is electrically connected to the BLDC motor back EMF detection circuit, and the inverter power circuit is also electrically connected to the BLDC motor back EMF detection circuit. This processor configuration is more conducive to realizing the acquisition of opening or closing position information at the shearing component by the opening / closing position sensor, which is then processed sequentially by the main MCU processing unit and the motor drive circuit to meet the usage requirements. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of an electric pruning shear in the prior art.

[0019] Figure 2 This is a schematic diagram of the circuit block of this utility model.

[0020] Figure 3 This is a schematic diagram of the motor drive circuit of this utility model.

[0021] Figure 4 This is a schematic diagram of the main MCU unit interface circuit of this utility model.

[0022] Figure 5 This is a schematic diagram of the power supply circuit of this utility model.

[0023] Figure 6 This is a schematic diagram of the opening / closing position sensor circuit of this utility model.

[0024] Figure 7 This is a schematic diagram of the start-up switch button for this utility model.

[0025] In the diagram: 1, button; 2, DC / DC converter; 10, main MCU processing unit; 20, opening / closing position sensor circuit; 30, phase inverter circuit; 40, BLDC motor back EMF detection circuit. Detailed Implementation

[0026] In the description of this utility model, it should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to or indirectly connected to the other element.

[0027] In the description of this utility model, it should be noted that the terms "center," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. Furthermore, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "multiple" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.

[0028] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0029] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. However, it should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit its scope. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the present utility model.

[0030] Example 1: See Figure 2 A rapid opening / closing switching circuit for electric pruning shears includes an electric pruning shear body containing a processor and a power supply. The processor includes a main MCU processing unit 10, a motor drive circuit, an opening / closing position sensor circuit 20, and a phase inverter circuit 30. The opening / closing position sensor circuit 20 is electrically connected to the main MCU processing unit 10. The main MCU processing unit 10 is electrically connected to both the motor drive circuit and the phase inverter circuit 30. The motor drive circuit is used to connect to both the motor and the power supply in the electric pruning shear body. The motor drive circuit includes a converter power circuit and a BLDC motor back EMF detection circuit 40. The phase inverter circuit 30 is electrically connected to the BLDC motor back EMF detection circuit 40. The converter power circuit is also electrically connected to the BLDC motor back EMF detection circuit 40. The motor drive circuit is connected to the three-phase lines of the motor, which are then input to the main MCU processing unit 10 via voltage divider for motor zero-crossing analysis.

[0031] The electric pruning shears are equipped with a button 1 and a DC / DC converter 2. The power supply is connected to the DC / DC converter 2 and the phase inverter circuit 30. The DC / DC converter 2 is connected to the main MCU processing unit 10. The DC / DC converter 2 is used to reduce the voltage of the power supply to the working voltage of 3.3V required by the main MCU processing unit 10. The button 1 is connected to the main MCU processing unit 10. The main MCU processing unit 10 is used to detect the action of the button 1.

[0032] The electric pruning shears are equipped with an opening sampling sensor H1 and a closing (small opening) sampling sensor H2 at the shearing assembly. The opening sampling sensor H1 and the closing (small opening) sampling sensor H2 are respectively connected to the opening / closing position sensor circuit 20. The opening / closing position sensor circuit 20 is electrically connected to the main MCU processing unit 10. The opening / closing position sensor circuit 20 provides the blade opening limit signal or closing limit signal in the shearing assembly to the main MCU processing unit 10. The main MCU processing unit 10 outputs a three-phase inverter synchronous drive signal for back electromotive force signal input, for button 1 signal detection, and for opening / closing position signal detection in the shearing assembly, thus completing the working logic control. The main MCU processing unit 10 is used to calculate the blade position in the shearing assembly.

[0033] This invention allows for immediate switching between large and small openings by simply operating button 1, thereby increasing work efficiency.

[0034] Example 2: This can be explained based on Example 1, such as... Figure 3 As shown, in the motor drive circuit, Q1 / Q4, Q2 / Q5, and Q3 / Q6 form three half-bridges and three half-bridges form a three-phase bridge. For example, Q3 / Q6 form the U phase, Q1 / Q4 form the V phase, and Q2 / Q5 form the W phase. One half-bridge is called a single phase, two half-bridges are called two phases, and three half-bridges are called three phases. The main MCU processing unit 10 detects the back electromotive force voltage and calculates whether there is a zero-crossing point based on the BLDC three-phase energizing law. The main MCU processing unit 10 performs BLDC synchronous commutation by integrating the time from the zero-crossing point to the commutation point. The bus branch resistor R7 is used as the shunt resistor for sampling the bus current. The voltage drop across the sampling resistor is filtered and input to PIN11 / IRms of the BLDC synchronous commutation. The bus current value I = Vr7 / R7. The sampled current is used for real-time detection of the power branch current in the BLDC synchronous commutation. If the current exceeds a certain threshold, it can be used for current limiting, motor input power calculation, etc. Figure 3 Connect the same U terminals (same network connection), connect the same V terminals (same network connection), connect the same W terminals (same network connection), HOU is the drive signal connection for the upper U-phase transistor, LOU is the drive signal connection for the lower U-phase transistor, and VSU is the midpoint connection for the U-phase drive circuit. For example... Figure 3 In the circuit, Q1 to Q6 form a power inverter circuit to convert DC power into AC power; R8 / R11 / C8 form a back EMF detection circuit for phase U; R9 / R12 / C9 form a back EMF detection circuit for phase V; and R10 / R13 / C10 form a back EMF detection circuit for phase W.

[0035] Further explanation as follows Figure 4As shown, the interface section of the main MCU processing unit 10 is managed by the MCU. The interface section contains an integrated circuit U3, which is a PT32M625 (a system-in-package chip integrating a microcontroller (PT32U301) and a motor gate driver (PT5619), mainly used for brushless motor control in power tools, industrial equipment, etc.). U3 is responsible for logic processing / operation, including inverter synchronous drive signal outputs PIN30-PIN44. HOU / LOU are the upper and lower transistor drive signals for the U-phase half-bridge, HOV / LOV are the upper and lower transistor drive signals for the V-phase half-bridge, HOW / LOW are the upper and lower transistor drive signals for the W-phase half-bridge, and the motor back EMF detection input signal. PIN6-PIN8 are the back EMF signal input terminals for BEMF_U / BEMF_V / BEMF_W respectively. PIN11 / IRms is the three-phase inverter bus current detection input terminal. PIN10 / RX1 is a serial port receiver used to receive signals from the opening / closing position sensor circuit 20. PIN22... Detect the status of button 1.

[0036] Example 3: This can be described based on Example 1 or Example 2, such as... Figure 5 As shown, in DC / DC converter 2, the power input is stepped down to 12V via integrated circuit U2. The 12V is used to power the inverter pre-drive module and is also connected to the LDO step-down network composed of power circuit integrated circuits U4 / U1 to output a 3.3V voltage for power supply to the main MCU processing unit 10.

[0037] Example 4: This can be described based on Example 1, Example 2, or Example 3, such as... Figure 6 As shown, the open / closed position sensor circuit 20 includes an integrated circuit U2. The integrated circuit U2 is connected to an open sampling sensor H1 and a closed (small opening) sampling sensor H2. The open sampling sensor H1 is connected to PIN2 of the integrated circuit U2, and the closed (small opening) sampling sensor H2 is connected to PIN5 of the integrated circuit U2. After power-on, the integrated circuit U2 continuously scans the status of the open sampling sensor H1 and the closed (small opening) sampling sensor H2, and continuously sends the scanned status of the open sampling sensor H1 and the closed (small opening) sampling sensor H2 to PIN10 of the main MCU processing unit 10 through PIN8 of the integrated circuit U2, thus completing the signal uploading of the open sampling sensor H1 and the closed (small opening) sampling sensor H2.

[0038] Example 5: This can be described based on Example 1, Example 2, Example 3, or Example 4, such as... Figure 7As shown, button 1 is connected to the main MCU processing unit 10 via a connecting cable. After button 1 is pressed, the main MCU processing unit 10 detects that button 1 has been pressed, and this utility model initiates a request for switching between large and small ports. This method of quickly switching between large and small ports by pressing button 1 is used, as shown in the figure. Figure 7 As shown, KEY represents the connection network of the button, where button 1 is the connection to the microcontroller (a circuit has many connections, and when describing the circuit connections, each connection between the components is often given a name, which is professionally called a network), and K1 is the button, the light touch button.

[0039] All standard parts used in this application can be purchased from the market. The specific connection methods of each part adopt conventional methods such as bolts and rivets that are mature in the existing technology. The internal components of the switches and processors adopt conventional models in the existing technology, and their internal structures are existing technical structures. Workers can complete normal operation by referring to existing technical manuals. In addition, the circuit connection adopts conventional connection methods in the existing technology, and will not be described in detail here.

[0040] It should be noted that although the above embodiments have been described herein, this does not limit the scope of patent protection for this utility model. Therefore, any changes and modifications made to the embodiments described herein based on the innovative concept of this utility model, or equivalent structural or procedural transformations made using the content of this utility model's specification and drawings, directly or indirectly applying the above technical solutions to other related technical fields, are all included within the scope of protection of this utility model patent.

Claims

1. A circuit for rapidly switching the opening size of electric pruning shears, comprising an electric pruning shear body, wherein the electric pruning shear body contains a processor and a power supply, characterized in that: The processor includes a main MCU processing unit (10), a motor drive circuit, an opening / closing position sensor circuit (20), and a phase inverter circuit (30). The opening / closing position sensor circuit (20) is electrically connected to the main MCU processing unit (10). The main MCU processing unit (10) is electrically connected to the motor drive circuit and the phase inverter circuit (30) respectively. The motor drive circuit is used to be electrically connected to the motor and the power supply in the electric pruning shears body respectively. The motor drive circuit includes a converter power circuit and a BLDC motor back EMF detection circuit (40). The phase inverter circuit (30) is electrically connected to the BLDC motor back EMF detection circuit (40). The converter power circuit and the BLDC motor back EMF detection circuit (40) are electrically connected. The electric pruning shears are equipped with a button (1) and a DC / DC converter (2). The power supply is connected to the DC / DC converter (2) and the phase inverter circuit (30). The DC / DC converter (2) is connected to the main MCU processing unit (10). The electric pruning shears body has an opening sampling sensor H1 and a closing sampling sensor H2 installed at the cutting component. The opening sampling sensor H1 and the closing sampling sensor H2 are respectively connected to the opening / closing position sensor circuit (20). The opening / closing position sensor circuit (20) is electrically connected to the main MCU processing unit (10).

2. The electric pruning shears' rapid opening size switching circuit as described in claim 1, characterized in that: The interface section of the main MCU processing unit (10) contains an integrated circuit U3. In the integrated circuit U3, PIN6 to PIN8 are the BEMF_U / BEMF_V / BEMF_W back electromotive force signal input terminals respectively. In the integrated circuit U3, PIN11 / IRms is the three-phase inverter bus current detection input terminal. In the integrated circuit U3, PIN10 / RX1 is a serial port receiving port used to receive the signal of the opening / closing position sensor circuit (20). In the integrated circuit U3, PIN22 detects the state of the button (1).

3. The electric pruning shears rapid opening size switching circuit as described in claim 1 or 2, characterized in that: The opening / closing position sensor circuit (20) includes an integrated block U2, which is connected to the opening sampling sensor H1 and the closing sampling sensor H2 respectively. The opening sampling sensor H1 is connected to the PIN2 pin of the integrated block U2, and the closing sampling sensor H2 is connected to the PIN5 pin of the integrated block U2.

4. The electric pruning shears rapid opening size switching circuit as described in claim 1 or 2, characterized in that: The button (1) is connected to the main MCU processing unit (10) via a connecting line.

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