Flushing head handle with locked-rotor detection module

Abstract

The utility model relates to the field of treatment equipment, in particular to a flushing head handle with a locked-rotor detection module. A detection circuit is connected to a coil of a driving motor to detect coil current, when it is detected that the coil current is zero, a driver is adopted to judge the current zero-crossing direction of the coil when the current is zero, terminal voltage sampling is conducted at the rear end of the current zero-crossing direction, and the sampled voltage serves as counter electromotive force. The counter electromotive force of the driving motor is induced electromotive force generated by rotation of the driving motor in the running process of the driving motor, and the size of the induced electromotive force is in direct proportion to the rotating speed of the driving motor, so that when the rotating speed of the driving motor is increased, the counter electromotive force is also increased; conversely, when the rotating speed of the driving motor is reduced, the back electromotive force is correspondingly reduced. And when the back electromotive force is detected to be unchanged or is lower than a preset threshold value, the rotating speed of the motor is abnormal, so that the locked-rotor of the driving motor can be accurately judged.

Description

Technical Field

[0001] The utility model relates to the field of treatment equipment, and particularly relates to a flushing head handle with a stall detection module. Background Art

[0002] As a component of a beauty treatment instrument, the flushing head handle is mainly used to provide a flushing function during treatment and nursing. The flushing head handle is usually connected to the main body of the treatment instrument. By operating the buttons on the main body or the handle, the rotation speed of the stepping motor in the flushing head handle is controlled to adjust the size and intensity of the flushing water flow. The stepping motor has the advantages of simple structure and convenient control, and is widely used in open-loop control systems with low load and low speed requirements. Stepping motor stall refers to the situation where the motor still outputs torque when the rotation speed is 0 r / min, usually caused by mechanical or human factors, such as excessive load, mechanical failure, bearing damage, etc. During stall, the power factor of the motor is extremely low, and the stall current can reach up to 7 times the rated current. Prolonged stall will cause the motor winding to burn out. The traditional methods for detecting stepping motor stall mainly include the following two.

[0003] 1. Encoder feedback: Adding an encoder to the lead screw is the most reliable method, and the feedback information of the encoder can be used to accurately judge whether stall occurs. However, this method has a high cost and a large volume.

[0004] 2. Detecting motor current change: By detecting the change of the motor winding current in real time, during the normal operation of the motor, the current of the motor winding is smaller than the rated current. If the operation of the motor remains unchanged and the current suddenly increases to the output current of the driver, it can be basically judged that the motor has stalled. However, some models of stepping motors or drive circuits have an overcurrent protection function, and the MCU cannot accurately detect the current change.

[0005] Therefore, how to implement the stall detection function has become one of the research focuses of the flushing head handle device. Content of the Utility Model

[0006] The inventor found that when the stepping motor rotates, a back electromotive force will be generated in the motor coil. The magnitude of the motor back electromotive force only depends on the speed of the motor. By detecting the back electromotive force, the operating state of the motor can be known. Specifically as follows: During the normal operation of the stepping motor: when the two power switch tubes of the upper and lower bridge arms are conducting, the back electromotive force is related to the voltage U and the current I; when the current passes through zero, that is, when the two power switch tubes of the upper or lower bridge arm are completely turned off, the motor coil continues to flow through its own inductance until the current is zero. At this time, the back electromotive force can be obtained by detecting the phase voltage when the current passes through zero. And how to accurately detect the phase voltage when the current passes through zero has become a technical difficulty.

[0007] The technical problem to be solved by the present utility model is to provide a flushing head handle, and the stall detection module of the handle can accurately detect the back electromotive force when the current passes through zero.

[0008] To solve the above problems, the present utility model provides a flushing head handle with a stall detection module, which includes a housing, a fixing seat arranged above the housing for fixing a syringe, and a driving motor arranged inside the housing; a guide groove is opened behind the fixing seat above the housing, and the guide groove penetrates downward through the housing and communicates with the inside of the housing. The driving motor is connected with a driving rod and a controller. The driving rod is used to connect the piston push rod of the syringe. The driving motor rotates forward and backward under the control of the controller, so as to drive the driving rod to drive the connected piston push rod to move back and forth along the guide groove.

[0009] The driving motor includes a coil. The handle further includes a stall detection module electrically connected to the controller and the coil. The stall detection module includes a detection circuit and a driver. The detection circuit is used to detect the current of the coil in the driving motor, and the driver is used to judge the current zero-crossing direction of the coil when the current is zero. After a short time period when the detection circuit detects that the current of the coil is zero, the detection circuit samples the terminal voltage of the coil and outputs the sampled terminal voltage as the back electromotive force generated by the coil when the current is zero to the controller. The controller is used to output a stall signal according to the state that the back electromotive force is lower than a preset threshold.

[0010] Further, the driving motor is specifically a bipolar stepper motor.

[0011] Further, the driver is specifically a microstep stepper motor driver of model NCV70522, and the driver is electrically connected to the controller through an SPI interface.

[0012] Further, the preset threshold is 1.5V.

[0013] Further, the driving motor includes two power switch tubes respectively connected before and after the coil. The short time period refers to the time period required for the power switch tube located downstream of the coil with zero current to switch from the off state to the on state along the current zero-crossing direction judged by the driver.

[0014] Further, a slider is installed in the guide groove. The slider is respectively connected to the piston push rod and the driving rod up and down. Specifically, the upper part of the slider is exposed, and the lower part extends into the housing through the guide groove and is installed on the driving rod of the driving motor. The piston push rod is located above the guide groove. When the slider is driven by the driving rod, it moves back and forth along the guide groove and pushes the piston push rod to realize the back and forth movement.

[0015] Further, it includes the syringe which has a hollow injection cavity for containing the treatment liquid. There is a liquid outlet communicating with the injection cavity at the front end of the syringe and a liquid filling port communicating with the injection cavity at the rear end. A piston push rod extending backward is installed at the liquid filling port. When the piston push rod moves forward relative to the injection cavity, the treatment liquid in the injection cavity is pushed towards the liquid outlet of the syringe for liquid discharge.

[0016] Further, an installation seat is provided above the housing, and the installation seat is located in front of the fixed seat; an injection head is detachably installed in the installation seat, and the front end and the rear end of the injection head are connected. The front end is used for treating the human body and the rear end is aligned with and connected to the liquid outlet of the syringe.

[0017] Further, an installation cavity with an upward-facing cavity opening is formed at the top of the housing, and the installation seat is detachably installed and accommodated in this installation cavity.

[0018] Further, the main body of the fixed seat is U-shaped and made of an elastic material, and can detachably clamp the side wall of the syringe for fixation.

[0019] Beneficial effects: In the present utility model, a detection circuit is connected to the coil of the drive motor to detect the coil current. When the detected coil current is zero, the driver judges the current zero-crossing direction of the coil at this time and samples the terminal voltage at the rear end in this direction, and uses the sampled voltage as the back electromotive force. Since the back electromotive force of the drive motor refers to the induced electromotive force generated during the operation of the drive motor due to the rotation of the drive motor, the magnitude of this induced electromotive force is proportional to the rotational speed of the drive motor. When the rotational speed of the drive motor increases, the back electromotive force also increases; conversely, when the rotational speed of the drive motor decreases, the back electromotive force also decreases accordingly. When it is detected that the back electromotive force has no change or the state where the back electromotive force is lower than the preset threshold value, it indicates that the rotational speed of the motor is abnormal, and thus it can be accurately judged that the drive motor is blocked. Description of the Drawings

[0020] Figure 1 It is an external structure diagram of the flushing head handle with the syringe fixed.

[0021] Figure 2 It is an exploded structure diagram of the flushing head handle.

[0022] Figure 3 It is a schematic circuit connection diagram of the controller and the stall detection module.

[0023] Figure 4 It is a schematic circuit connection diagram of the drive motor coil and the stall detection module. Detailed Embodiments

[0024] The following further details the present invention in combination with specific embodiments.

[0025] The irrigation head handle 1 is shown in Figure 1 , the outer shell 2 is formed by splicing a left shell 21 and a right shell 22. An installation seat 3, a fixing seat 4 and a slider 9 are successively arranged on the upper part of the outer shell 2 from front to back. An injection head 5 is detachably installed in the installation seat 3, a syringe 6 is fixed in the fixing seat 4, the front end and the rear end of the injection head 5 are connected, the front end is used for treating the human body and the rear end is aligned with and connected to the liquid outlet of the syringe; the syringe 6 is filled with a treatment liquid, and the treatment liquid is first injected from the syringe 6 to the injection head 5 under the push of the slider 9, and then injected from the injection head 5 to the part of the human body to be treated for treatment.

[0026] See Figure 2 , a driving motor 7 is installed in the outer shell 2, the driving rod (not shown in the figure) of the driving motor 7 extends backward, and is fixedly connected to a screw rod 82 through a coupling 81; a guide groove is opened at the rear of the fixing seat 4 on the top of the outer shell 2, the guide groove penetrates downward through the outer shell 2 and communicates with the inside of the outer shell 2, the above-mentioned slider 9 is installed in the guide groove, the upper part of the slider 9 is exposed and the lower part extends into the inside of the outer shell 2 through the guide groove and is screwed on the screw rod 82. The driving motor 7 is connected with a driving rod and a controller as shown in Figure 3 . The driving rod is used to connect the piston push rod of the syringe. The driving motor rotates forward and backward under the control of the controller, so as to drive the driving rod to drive the connected piston push rod to move back and forth along the guide groove.

[0027] As shown in Figure 4 , the driving motor M is specifically a bipolar stepper motor. The driving motor includes a coil and two power switch tubes respectively connected to the front and rear of the coil. The handle further includes a stall detection module electrically connected to the controller and the coil. The stall detection module includes a detection circuit and a driver. The driver is specifically a microstep stepper motor driver of model NCV70522, and the driver is electrically connected to the controller through an SPI interface. The detection circuit is used to detect the current of the coil in the driving motor, and the driver is used to judge the zero-crossing direction of the current of the coil when the current is zero. After a short time period when the detection circuit detects that the current of the coil is zero, the detection circuit samples the terminal voltage of the coil, and outputs the sampled terminal voltage as the back electromotive force generated by the coil with zero current to the controller. The controller is used to output a stall signal according to the state that the back electromotive force is lower than a preset threshold, such as 1.5V. The controller judges whether the stepper motor of the handle is stalled through the back electromotive force, and stops using the driving motor in case of stall.

[0028] Among them, the short time period refers to: along the zero-crossing direction of the current judged by the driver, the time period required for the power switch tube located downstream of the coil with zero current to switch from the off state to the on state.

[0029] When the flushing head handle is powered on, the controller is initialized, the driver is reset and initial parameter settings are made for the coil current and the stepping mode. The driver sends NXT pulses to the controller to control the rotation of the motor. A detection circuit is connected to the coil of the drive motor to detect the coil current. When the detected coil current is zero, the driver determines the zero-crossing direction of the coil current at zero current and samples the terminal voltage at the back end in this direction, using the sampled voltage as the back electromotive force. Since the back electromotive force of the drive motor refers to the induced electromotive force generated during the operation of the drive motor due to its rotation, the magnitude of this induced electromotive force is proportional to the rotational speed of the drive motor. When the rotational speed of the drive motor increases, the back electromotive force also increases; conversely, when the rotational speed of the drive motor decreases, the back electromotive force also decreases accordingly. When it is detected that the back electromotive force has no change or the back electromotive force is in a state lower than the preset threshold value, it indicates that the rotational speed of the motor is abnormal, and thus it is possible to accurately determine that the drive motor is blocked.

[0030] See Figure 2 , the U-shaped body of the fixing seat 4 is made of an elastic material and detachably clamps the side wall of the syringe 6 to fix the syringe 6. The syringe 6 has a hollow injection cavity (not shown in the figure) for accommodating the treatment fluid. The front end of the syringe 6 is provided with a liquid outlet communicating with the injection cavity, and the rear end is provided with a liquid filling port communicating with the injection cavity (not shown in the figure). A piston push rod 62 extending backward is installed at the liquid filling port. When the piston push rod 62 moves forward relative to the injection cavity, the treatment fluid in the injection cavity is pushed toward the liquid outlet 61 of the syringe 6 for liquid discharge.

[0031] See Figure 2 , a mounting cavity 23 with an upward-facing cavity opening is formed at the top of the housing 2. The mounting seat 3 is detachably installed and accommodated in the mounting cavity 23 and protrudes above the housing. The front top of the left housing 21 is partially recessed to form the left half of the mounting cavity 23, and the front top of the right housing 22 is partially recessed to form the right half of the mounting cavity 23. The tops of the left housing 21 and the right housing 22 of the housing 2 are locked and installed through a locking block 23, which is convenient for installation and disassembly.

[0032] Since the mounting seat 3 and the fixing seat 4 are not integrally formed with the housing 2 but are installed on the housing 2 of the handle 1 in a detachable manner, the processing is relatively convenient; in addition, the mounting seat 3 and the fixing seat 4 with determined sizes can only install the injection head 5 and the syringe 6 with corresponding sizes. If it is necessary to install an injection head 5 of other sizes, the operator can first remove the mounting seat 3 and the fixing seat 4 already installed on the housing 2, install the mounting seat 3 and the fixing seat 4 of other sizes on the housing 2, and then install the injection head 5 of other sizes on the replaced and matching mounting seat 3 and fixing seat 4.

[0033] The slider 9 is driven by the driving rod and moves back and forth along the guide groove, thereby pushing the piston push rod to move back and forth. The specific process is described as follows: When the syringe 6 is installed on the mounting base 3, the piston push rod 62 of the syringe 6 is located above the guide groove. When the driving rod of the driving motor 7 rotates forward around its own axis, it drives the screw rod 82 to rotate forward through the coupling 81, thereby driving the slider 9 to move forward along the guide groove and pushing the piston push rod 62 forward, and the syringe 6 thus discharges liquid; after the liquid discharge is completed, the driving rod of the driving motor 7 rotates reversely around its own axis, driving the screw rod 82 to rotate reversely, thereby driving the slider 9 to move backward along the guide groove and return to its original position. In this embodiment, the driving motor 7 is used as the driving motor to drive the slider 9 to move through the screw rod 82; in other embodiments, the driving motor can be changed to a stepping telescopic motor, and the lower part of the slider 9 is directly installed on the telescopic rod of the stepping telescopic motor, and is driven by the telescopic rod to move back and forth along the guide groove.

[0034] The above is only the implementation mode of the present invention, and does not limit the scope of patent protection. Those skilled in the art make non-substantive changes or substitutions on the basis of the present invention, and still fall within the scope of patent protection.

Claims

1. A flushing head handle with a stall detection module, comprising a housing, a fixing seat provided above the housing for fixing a syringe, and a driving motor provided inside the housing; a guiding groove is formed behind the fixing seat above the housing, the guiding groove penetrates downward through the housing and communicates with the inside of the housing, the driving motor is connected with a driving rod and a controller, the driving rod is used for connecting the piston push rod of the syringe, and the driving motor rotates forward and backward under the control of the controller, so as to drive the driving rod to drive the connected piston push rod to move back and forth along the guiding groove; It is characterized in that The driving motor includes a coil, and the handle further includes a stall detection module electrically connected to the controller and the coil. The stall detection module includes a detection circuit and a driver. The detection circuit is used for detecting the current of the coil in the driving motor, and the driver is used for judging the current zero-crossing direction of the coil when the current is zero. After a short time period when the detection circuit detects that the current of the coil is zero, the detection circuit samples the terminal voltage of the coil, and outputs the sampled terminal voltage as the back electromotive force generated by the coil with zero current to the controller. The controller is used for outputting a stall signal according to the state that the back electromotive force is lower than a preset threshold.

2. The rinsing head handle according to claim 1, characterized in that, The driving motor is specifically a bipolar stepper motor.

3. The rinsing head handle according to claim 2, wherein, The driver is specifically a microstep stepper motor driver of model NCV70522, and the driver is electrically connected to the controller through an SPI interface.

4. The flushing head handle according to claim 3, wherein, The preset threshold is 1.5V.

5. The flushing head handle according to claim 1, characterized in that, The driving motor includes two power switch tubes respectively connected to the front and rear of the coil. The short time period refers to the time period required for the power switch tube located downstream of the coil with zero current to switch from the off state to the on state along the current zero-crossing direction judged by the driver.

6. The flushing head handle according to claim 1, characterized in that, A slider is installed in the guiding groove. The upper and lower parts of the slider are respectively connected to the piston push rod and the driving rod. Specifically, the upper part of the slider is exposed, and the lower part extends into the housing through the guiding groove and is installed on the driving rod of the driving motor. The piston push rod is located above the guiding groove. When the slider is driven by the driving rod to move back and forth along the guiding groove, the piston push rod is pushed to realize the back-and-forth movement.

7. The rinsing head handle according to claim 1, characterized in that, Including the syringe, the syringe has a hollow injection cavity for accommodating a treatment liquid. The front end of the syringe is provided with a liquid outlet communicating with the injection cavity, and the rear end is provided with a liquid filling port communicating with the injection cavity. A piston push rod extending backward is installed at the liquid filling port. When the piston push rod moves forward relative to the injection cavity, the treatment liquid in the injection cavity is pushed to the liquid outlet of the syringe for liquid discharge.

8. The rinsing head handle according to claim 7, characterized in that: An installation seat is provided above the housing, and the installation seat is located in front of the fixing seat; an injection head is detachably installed in the installation seat, and the front end and the rear end of the injection head are connected. The front end is used for treating the human body, and the rear end is aligned with and connected to the liquid outlet of the syringe.

9. The flushing head handle according to claim 8, characterized in that, An installation cavity with an upward-facing cavity opening is formed at the top of the housing, and the installation seat is detachably installed and accommodated in the installation cavity.

10. The flushing head handle according to claim 7 or 8, characterized in that, The main body of the fixing seat is U-shaped and made of an elastic material, and can detachably clamp the side wall of the syringe for fixing.

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