Method and system for driving control of injection mold hot runner valve pin, device

Abstract

The application discloses a kind of injection mold hot runner valve needle drive control method and system, device, hot runner valve needle is accompanied with rotation in up and down movement, can make hot runner valve needle hole and glue injection port automatic alignment, avoid because eccentricity brings glue mouth defect, let hot runner valve needle be accompanied with rotation in up and down movement, avoid the jamming problem that hot runner valve needle moves in hot runner valve needle sleeve, using hot runner valve needle pressure real-time correction system, adjustable torque is output by oil pressure gear motor, the thrust of hot runner valve needle is corrected, avoid the problem that hot runner valve needle thrust is insufficient and thrust is too large because of unstable thrust.

Description

Technical Field

[0001] This invention relates to the field of injection molding, and in particular to a method, system, and device for driving and controlling a hot runner valve pin in an injection mold. Background Technology

[0002] Existing injection mold hot runner valve pins are driven by hydraulic / pneumatic / servo electric cylinders, resulting in linear motion. This can easily cause the hot runner valve pins to become off-center, leading to burrs at the product gate. Furthermore, the linear motion of existing hot runner valve pins driven by hydraulic / pneumatic / electric cylinders can easily cause them to jam, affecting production. The use of external system pressure for hot runner valve pins is also problematic; excessive pressure can damage the mold and cause bulging, while insufficient pressure can lead to leakage. The working pressure of existing hot runner valve pins is affected by changes in external air / oil pressure, impacting the sealing thrust and causing unstable production quality. The existing hot runner valve pin drive system is mounted on a manifold, resulting in a large size and increased mold thickness. The current hot runner system using a manifold as a distribution solution is costly and bulky.

[0003] In summary, there is a need for a driving control method, system, and device for the hot runner valve needle of injection molds to address the shortcomings of existing technologies. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a driving control method, system, and device for hot runner valve pins in injection molds, aiming to solve the aforementioned problems.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a method for controlling dyeing and printing parameters in a textile production line, comprising the following steps:

[0006] Step S1: Power on the system and initialize it. Reset the electrically adjustable relief valve to the open state to release the system oil pressure and read the preset target pressure value.

[0007] Step S2: Receive the injection signal from the injection molding machine, control the oil circuit solenoid valve to open, drive the hydraulic gear motor to rotate in the forward direction, drive the external gear nut fixed to the valve needle to move counterclockwise spiral upward along the fixed screw, so that the hot runner valve needle can synchronously perform a linear rotation and disengage from the injection port, opening the runner;

[0008] Step S3: Receive the stop injection signal from the injection molding machine, switch the oil circuit control, drive the hydraulic gear motor to rotate in the opposite direction, and drive the external gear nut to move clockwise spirally downward along the fixed screw, so that the hot runner valve needle can synchronously perform a linear rotation until its front end contacts and blocks the injection port.

[0009] Step S4: After the valve needle completes the sealing action, the sealing pressure is collected in real time by the pressure sensor installed on the drive end to obtain the actual pressure value Pactual.

[0010] Step S5: In automatic operation mode, compare Pactual with the preset target pressure value Ptarget, calculate the deviation ΔP, and adjust the output torque of the hydraulic gear motor by adjusting the set pressure of the electric adjustable relief valve according to the direction and magnitude of the deviation, thereby correcting the valve needle thrust.

[0011] Optionally, step S1 is implemented in the following manner:

[0012] Step A1: After the system completes its power-on self-test, the PLC immediately outputs the minimum effective signal to the electrically adjustable relief valve, forcing it to fully open and release pressure, so that the hydraulic circuit can quickly drop to a pressure-free safe state.

[0013] Step A2: After the overflow valve pressure relief operation is completed, the PLC initialization program will immediately read the previously stored Ptarget value from its non-volatile memory. This value is loaded into the PLC's working memory for subsequent automatic operation control logic to call at any time.

[0014] Optionally, step S2 is implemented in the following manner:

[0015] Step B1: Signal reception and recognition. The programmable controller continuously monitors the digital output signal of the injection molding machine control system. This signal is connected to the designated digital input port of the PLC through hard-wiring. When the injection molding machine completes mold closing and enters the injection stage, its controller will set this signal to a high level.

[0016] Step B2: Oil circuit solenoid valve control. After the PLC detects that the injection glue signal is valid, it immediately executes the output command and sets the corresponding digital output point inside to a high level. This digital output point is connected to the forward working coil of the oil circuit direction control solenoid valve through hard wiring. After the solenoid valve is energized, it switches to the forward oil supply working position.

[0017] Step B3: Hydraulic power transmission. After the solenoid valve switches, the high-pressure oil output by the hydraulic pump is guided to the forward oil inlet of the hydraulic gear motor. The return oil inlet of the motor is connected to the oil tank, and the output shaft of the gear motor begins to rotate in the forward direction.

[0018] Step B4: Mechanical motion conversion. The output shaft of the gear motor drives the external gear nut, which is fixed to it, to rotate, which is converted into linear motion upward along the screw axis, causing it to spiral upward. The combined rotational and linear motion of the external gear nut is transmitted to the valve needle, causing it to synchronously execute the rotational linear motion of the spiral trajectory. The front end of the valve needle gradually separates from the glue injection port sealing surface inside the hot runner nozzle core, opening the flow channel.

[0019] Optionally, step S3 is implemented in the following manner:

[0020] Step C1: Signal reception and recognition. The programmable controller continuously monitors the stop injection digital output signal from the injection molding machine control system. This signal is connected to the designated digital input port of the PLC through hard wiring. When the injection molding machine completes mold closing and enters the injection stage, its controller will set this signal to a high level.

[0021] Step C2: Switching the direction of the hydraulic circuit. After the PLC detects that the stop dispensing signal is valid, it disconnects the forward hydraulic circuit solenoid valve coil that was previously used to open the valve needle, and turns on the reverse hydraulic circuit solenoid valve coil to switch the direction of the hydraulic circuit, so that the high-pressure oil enters from the return port of the hydraulic gear motor.

[0022] Step C3: The motor reverses its drive. Under the action of reverse hydraulic pressure, the output shaft of the hydraulic gear motor begins to rotate in the reverse direction.

[0023] Step C4: The helical pair motion is converted. The motor output shaft drives the external gear nut fixed to it to rotate in the opposite direction, which is converted into a linear downward motion along the screw axis, forming a clockwise helical downward trajectory, gradually approaching and finally closely contacting the injection port sealing surface in the hot runner nozzle core, cutting off the flow channel.

[0024] Optionally, step S4 is implemented in the following manner:

[0025] The pressure sensor collects analog signals of sealing thrust pressure at a fixed sampling period, performs analog-to-digital conversion to convert them into digital quantities, and uses a digital filtering algorithm to smooth multiple consecutive sampled values. The filtered values ​​are then converted into actual pressure values ​​(Pactual) through calibration coefficients.

[0026] Optionally, step S5 is implemented in the following manner:

[0027] Step D1: The PLC first checks whether the system is in automatic operation mode, and after confirmation, reads the target pressure value Ptarget calibrated and saved in the manual debugging stage from the memory;

[0028] Step D2: Deviation calculation. After the valve needle completes the sealing action, the PLC obtains the filtered actual pressure value Pactual and calculates the pressure deviation ΔP.

[0029] Step D3: Deviation threshold judgment. The absolute value of the pressure deviation is compared with the pressure tolerance threshold set by the system. If the pressure deviation is less than or equal to the pressure tolerance threshold, the current sealing force is considered qualified; otherwise, the pressure correction process is triggered.

[0030] Step D4: Generate and adjust the adjustment command. Determine the adjustment direction based on the direction of the pressure deviation ΔP. If the pressure deviation ΔP is greater than zero, reduce the system pressure and decrease the output signal. Conversely, increase the system pressure and increase the output signal. Dynamically adjust the opening pressure and correct the valve needle thrust.

[0031] A drive control system for a hot runner valve pin in an injection mold, employing the drive control method for the hot runner valve pin in the injection mold, is characterized by comprising a controller module, a hydraulic power module, an oil circuit control module, an actuator module, a pressure feedback module, and a pressure regulation module;

[0032] The controller module is used for system power-on initialization and self-test, receiving injection molding machine signals, controlling the output of solenoid valves and overflow valves, reading / storing target pressure Ptarget, collecting and processing pressure sensor data, and executing deviation calculation and closed-loop regulation logic.

[0033] The hydraulic power module provides a stable hydraulic source to drive the gear motor in both forward and reverse directions.

[0034] The oil circuit control module is used to switch the oil circuit direction according to PLC instructions, and control the gear motor to open the valve when rotating forward or close the valve when rotating in reverse.

[0035] The actuator module is used to convert the rotational motion of the motor into a rotary-linear compound motion of the valve needle through a helical pair, so as to accurately open or close the glue injection port;

[0036] The pressure feedback module is used to collect the actual thrust pressure Pactual during valve needle sealing in real time, and after filtering and calibration, it is used for closed-loop control.

[0037] The pressure regulation module is used to fully open and release pressure when powered on, and dynamically adjusts the system set pressure according to ΔP during operation, thereby changing the motor output.

[0038] A drive control device for a hot runner valve needle in an injection mold, employing the same drive control method, includes a hot runner plate for the mold. A drive system base is mounted on the hot runner plate and fixedly connected to it. A valve needle mechanism is mounted on the upper part of the drive system base and fixedly connected to it. A hydraulic gear motor is mounted on one side of the drive system base and fixedly connected to the hot runner plate. The hydraulic gear motor is connected to the valve needle mechanism via a hydraulic gear motor drive shaft and transmission gears. A flow channel tube is mounted on the drive system base and fixedly connected to it. A hot nozzle sleeve is mounted on the flow channel tube and fixedly connected to it.

[0039] Optionally, the valve needle mechanism includes a nut, a screw rod is disposed inside the nut and threadedly connected to the nut, the screw rod is fixedly connected to the drive system base, a hot runner valve needle is disposed on the nut and fixedly connected to the nut by a pin, a driven gear is disposed on the outside of the nut and fixedly connected to the nut, and a pressure sensor is disposed between the nut and the drive system base and fixedly connected to the drive system base.

[0040] Optionally, a flow divider pipe is provided on one side of the drive system base, and the flow divider pipe is fixedly connected to the drive system base. The flow divider pipe is a pipe-type flow divider pipe.

[0041] The beneficial effects of this invention are:

[0042] 1. In this invention, the hot runner valve needle rotates during its up-and-down movement, which automatically aligns the hot runner valve needle hole and the glue inlet, avoiding glue inlet defects caused by eccentricity. The rotational movement of the hot runner valve needle during its up-and-down movement also prevents the hot runner valve needle from getting stuck in the hot runner valve needle sleeve. The hot runner valve needle pressure real-time correction system uses an adjustable torque output by a hydraulic gear motor to correct the thrust of the hot runner valve needle, avoiding problems of insufficient or excessive thrust caused by unstable thrust.

[0043] 2. In this invention, two modes are adopted: manual adjustment and automatic adjustment. Manual adjustment is used in the debugging stage, and automatic adjustment is used in the mass production stage. This effectively reduces the height of the hot runner valve needle drive system, thereby reducing the thickness of the mold steel. On the one hand, it reduces the mold cost, and on the other hand, it allows the mold to be produced on a smaller tonnage injection molding machine, thus improving energy efficiency.

[0044] 3. In this invention, the hot runner valve needle rotates during its up-and-down movement, which automatically aligns the front end of the hot runner valve needle with the injection hole, avoiding defects in the injection port caused by eccentricity. The rotational movement of the hot runner valve needle during its up-and-down movement also prevents the hot runner valve needle from getting stuck during movement. The real-time pressure correction system for the hot runner valve needle uses the adjustable torque output of the hydraulic gear motor to correct the ejection pressure of the hot runner valve needle, avoiding problems of insufficient or excessive thrust caused by unstable thrust of the hot runner valve needle. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of a method flow of the present invention.

[0046] Figure 2 This is a schematic diagram of step S1 of the present invention.

[0047] Figure 3 This is a schematic diagram of step S2 of the present invention.

[0048] Figure 4 This is a schematic diagram of step S3 of the present invention.

[0049] Figure 5 This is a schematic diagram of step S5 of the present invention.

[0050] Figure 6 This is a schematic diagram of a system structure according to the present invention.

[0051] Figure 7 This is a diagram illustrating the forward and reverse rotation control operation of a hydraulic gear motor according to the present invention.

[0052] Figure 8 This is a waveform diagram of the output torque of a hydraulic gear motor and the thrust of a hot runner valve needle according to the present invention.

[0053] Figure 9 This is a cross-sectional structural diagram of a device according to the present invention.

[0054] Figure 10 This is a top view of a device according to the present invention.

[0055] 1. Hot runner valve needle; 2. Nut; 3. Screw; 4. Pin; 5. Driven gear; 6. Hydraulic gear motor; 61. Hydraulic gear motor drive shaft; 62. Hydraulic gear motor drive gear; 7. Pressure sensor; 8. Drive system base; 9. Diverter pipe; 10. Runner pipe; 11. Hot nozzle sleeve; 12. Mold hot runner plate. Detailed Implementation

[0056] To more clearly illustrate the technical solutions in the embodiments of the invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0057] like Figures 1 to 5 As shown, a method for controlling dyeing and printing parameters in a textile production line includes the following:

[0058] Step S1: Power on the system and initialize it. Reset the electrically adjustable relief valve to the open state to release the system oil pressure and read the preset target pressure value.

[0059] Implemented in the following ways:

[0060] Step A1: After the system completes its power-on self-test, the PLC immediately outputs the minimum effective signal to the electrically adjustable relief valve, forcing it to fully open and release pressure, so that the hydraulic circuit can quickly drop to a pressure-free safe state.

[0061] Step A2: After the overflow valve pressure relief operation is completed, the PLC initialization program will immediately read the previously stored Ptarget value from its non-volatile memory. This value is loaded into the PLC's working memory for subsequent automatic operation control logic to call at any time.

[0062] Step S2: Receive the injection signal from the injection molding machine, control the oil circuit solenoid valve to open, drive the hydraulic gear motor to rotate in the forward direction, drive the external gear nut fixed to the valve needle to move counterclockwise spiral upward along the fixed screw, so that the hot runner valve needle can synchronously perform a linear rotation and disengage from the injection port, opening the runner;

[0063] Implemented in the following ways:

[0064] Step B1: Signal reception and recognition. The programmable controller continuously monitors the digital output signal of the injection molding machine control system. This signal is connected to the designated digital input port of the PLC through hard-wiring. When the injection molding machine completes mold closing and enters the injection stage, its controller will set this signal to a high level.

[0065] Step B2: Oil circuit solenoid valve control. After the PLC detects that the injection glue signal is valid, it immediately executes the output command and sets the corresponding digital output point inside to a high level. This digital output point is connected to the forward working coil of the oil circuit direction control solenoid valve through hard wiring. After the solenoid valve is energized, it switches to the forward oil supply working position.

[0066] Step B3: Hydraulic power transmission. After the solenoid valve switches, the high-pressure oil output by the hydraulic pump is guided to the forward oil inlet of the hydraulic gear motor. The return oil inlet of the motor is connected to the oil tank, and the output shaft of the gear motor begins to rotate in the forward direction.

[0067] Step B4: Mechanical motion conversion. The output shaft of the gear motor drives the external gear nut, which is fixed to it, to rotate, which is converted into linear motion upward along the screw axis, causing it to spiral upward. The combined rotational and linear motion of the external gear nut is transmitted to the valve needle, causing it to synchronously execute the rotational linear motion of the spiral trajectory. The front end of the valve needle gradually separates from the glue injection port sealing surface inside the hot runner nozzle core, opening the flow channel.

[0068] Step S3: Receive the stop injection signal from the injection molding machine, switch the oil circuit control, drive the hydraulic gear motor to rotate in the opposite direction, and drive the external gear nut to move clockwise spirally downward along the fixed screw, so that the hot runner valve needle can synchronously perform a linear rotation until its front end contacts and blocks the injection port.

[0069] Implemented in the following ways:

[0070] Step C1: Signal reception and recognition. The programmable controller continuously monitors the stop injection digital output signal from the injection molding machine control system. This signal is connected to the designated digital input port of the PLC through hard wiring. When the injection molding machine completes mold closing and enters the injection stage, its controller will set this signal to a high level.

[0071] Step C2: Switching the direction of the hydraulic circuit. After the PLC detects that the stop dispensing signal is valid, it disconnects the forward hydraulic circuit solenoid valve coil that was previously used to open the valve needle, and turns on the reverse hydraulic circuit solenoid valve coil to switch the direction of the hydraulic circuit, so that the high-pressure oil enters from the return port of the hydraulic gear motor.

[0072] Step C3: The motor reverses its drive. Under the action of reverse hydraulic pressure, the output shaft of the hydraulic gear motor begins to rotate in the reverse direction.

[0073] Step C4: The helical pair motion is converted. The motor output shaft drives the external gear nut fixed to it to rotate in the opposite direction, which is converted into a linear downward motion along the screw axis, forming a clockwise helical downward trajectory, gradually approaching and finally closely contacting the injection port sealing surface in the hot runner nozzle core, cutting off the flow channel.

[0074] Step S4: After the valve needle completes the sealing action, the sealing pressure is collected in real time by the pressure sensor installed on the drive end to obtain the actual pressure value Pactual.

[0075] Implemented in the following ways:

[0076] The pressure sensor collects analog signals of sealing thrust pressure at a fixed sampling period, performs analog-to-digital conversion to convert them into digital quantities, and uses a digital filtering algorithm to smooth multiple consecutive sampled values. The filtered values ​​are then converted into actual pressure values ​​(Pactual) through calibration coefficients.

[0077] Step S5: In automatic operation mode, compare Pactual with the preset target pressure value Ptarget, calculate the deviation ΔP, and adjust the output torque of the hydraulic gear motor by adjusting the set pressure of the electric adjustable relief valve according to the direction and magnitude of the deviation, thereby correcting the valve needle thrust.

[0078] Implemented in the following ways:

[0079] Step D1: The PLC first checks whether the system is in automatic operation mode, and after confirmation, reads the target pressure value Ptarget calibrated and saved in the manual debugging stage from the memory;

[0080] Step D2: Deviation calculation. After the valve needle completes the sealing action, the PLC obtains the filtered actual pressure value Pactual and calculates the pressure deviation ΔP.

[0081] Step D3: Deviation threshold judgment. The absolute value of the pressure deviation is compared with the pressure tolerance threshold set by the system. If the pressure deviation is less than or equal to the pressure tolerance threshold, the current sealing force is considered qualified; otherwise, the pressure correction process is triggered.

[0082] Step D4: Generate and adjust the adjustment command. Determine the adjustment direction based on the direction of the pressure deviation ΔP. If the pressure deviation ΔP is greater than zero, reduce the system pressure and decrease the output signal. Conversely, increase the system pressure and increase the output signal. Dynamically adjust the opening pressure and correct the valve needle thrust.

[0083] like Figures 6 to 8 As shown, a drive control system for a hot runner valve pin of an injection mold, employing the drive control method for the hot runner valve pin of the injection mold, is characterized by comprising a controller module, a hydraulic power module, an oil circuit control module, an actuator module, a pressure feedback module, and a pressure regulation module;

[0084] The controller module is used for system power-on initialization and self-test, receiving injection molding machine signals, controlling the output of solenoid valves and overflow valves, reading / storing target pressure Ptarget, collecting and processing pressure sensor data, and executing deviation calculation and closed-loop regulation logic.

[0085] The hydraulic power module provides a stable hydraulic source to drive the gear motor in both forward and reverse directions.

[0086] The oil circuit control module is used to switch the oil circuit direction according to PLC instructions, and control the gear motor to open the valve when rotating forward or close the valve when rotating in reverse.

[0087] The actuator module is used to convert the rotational motion of the motor into a rotary-linear compound motion of the valve needle through a helical pair, so as to accurately open or close the glue injection port;

[0088] The pressure feedback module is used to collect the actual thrust pressure Pactual during valve needle sealing in real time, and after filtering and calibration, it is used for closed-loop control.

[0089] The pressure regulation module is used to fully open and release pressure when powered on, and dynamically adjusts the system set pressure according to ΔP during operation, thereby changing the motor output.

[0090] like Figure 9 and Figure 10As shown, a drive control device for a hot runner valve needle in an injection mold, employing the same drive control method, includes a hot runner plate for the mold. A drive system base is mounted on the hot runner plate and fixedly connected to it. A valve needle mechanism is mounted on the upper part of the drive system base and fixedly connected to it. A hydraulic gear motor is mounted on one side of the drive system base and fixedly connected to the hot runner plate. The hydraulic gear motor is connected to the valve needle mechanism via a hydraulic gear motor drive shaft and a hydraulic gear motor drive gear. A flow channel tube is mounted on the drive system base and fixedly connected to it. A hot nozzle sleeve is mounted on the flow channel tube and fixedly connected to it.

[0091] The valve needle mechanism includes a nut, a screw rod inside the nut, the screw rod being threadedly connected to the nut, and the screw rod being fixedly connected to the drive system base. A hot runner valve needle is mounted on the nut and fixedly connected to the nut by a pin. A driven gear is mounted on the outside of the nut and fixedly connected to the nut. A pressure sensor is mounted between the nut and the drive system base and fixedly connected to the drive system base. A flow divider pipe is mounted on one side of the drive system base and fixedly connected to the drive system base. The flow divider pipe is a pipe-type flow divider pipe.

[0092] The flow channel pipe 9 is fixed to the drive system base 8, the flow channel pipe 7 is fixed to the drive system base 8, the screw 3 is fixed to the drive system base 8, the pressure sensor 7 is sleeved on the screw 3 and fixed to the drive system base 8, the hot runner valve needle 1 passes through the nut 2 and is fixed to the nut 2 by the pin 4. The assembly of the hot runner valve needle fixed to the nut by the pin is rotated on the screw 3 by the thread, the driven gear 5 is connected to the nut 2 by the key pin, the hydraulic gear motor drive gear 62 is connected to the hydraulic gear motor drive shaft 61 by the key pin, the hydraulic gear motor 6 is mounted on the mold hot runner plate 12, and the entire hot runner system is mounted on the mold hot runner plate 12.

[0093] The injection machine transmits the injection switch signal to the hot runner programmable controller. The programmable controller then transmits the injection switch signal to the second solenoid valve in the hydraulic circuit. The hydraulic oil in the second solenoid valve flows to the hydraulic gear motor 6, driving the hydraulic gear motor 6 to rotate. The hydraulic gear motor 6 drives the hydraulic gear motor transmission gear 62, which in turn drives the driven gear 5. The driven gear 5 drives the assembly of nut 2 and hot runner valve needle 1. The assembly of nut 2 and hot runner valve needle 1 rotates and rises around the screw 3, opening the injection port of the runner. The injection molding machine's stop injection switch signal is transmitted to the programmable controller (PLC). The PLC then transmits the injection switch signal to the first solenoid valve in the hydraulic circuit, which is now open. The PLC adjusts the electrically adjustable overflow valve to control the hydraulic pressure. The controllable hydraulic pressure flows through the second valve in the hydraulic circuit to the hydraulic gear motor 6, driving the hydraulic gear motor 6 to rotate in the opposite direction. The hydraulic gear motor 6 drives the hydraulic gear motor transmission gear 62, which in turn drives the driven gear 5. The driven gear 5 actuates the assembly of nut 2 and hot runner valve needle 1. The assembly of nut 2 and hot runner valve needle 1 rotates around the screw 3 and falls, blocking the hot runner injection port.

[0094] During the commissioning phase, first close oil circuit valve two. The injection molding machine stops dispensing, and the switch signal is sent to the programmable controller (PLC). The PLC then sends the dispensing switch signal to oil circuit solenoid valve one, opening the circuit. The PLC adjusts the electrically adjustable relief valve to control the oil circuit pressure. The controllable oil pressure flows through oil circuit valve two to the hydraulic gear motor 6, driving it to rotate in the opposite direction. The hydraulic gear motor 6 drives the hydraulic gear motor transmission gear 62, which in turn drives the driven gear 5. The driven gear 5 actuates the assembly of nut 2 and hot runner valve needle 1. The assembly of nut 2 and hot runner valve needle 1 rotates around screw 3 and falls. The pressure applied by the nut is transmitted to the pressure sensor, which sends the pressure to the PLC, displaying it on the human-machine interface. By manually rotating the manually adjustable relief valve, the output torque of the hydraulic gear motor is adjusted by regulating the oil circuit pressure, thereby adjusting the thrust of the hot runner valve needle. Through debugging, the pressure value displayed on the human-machine interface reached the target value, which is the minimum thrust required for the hot runner valve needle to seal the injection port plus 200N. After completing the manual target value calibration, close oil circuit valve one and open oil circuit valve two.

[0095] During the automated production phase, the calibrated target thrust value obtained through manual adjustment is input into the automatic pressure setpoint on the human-machine interface. The programmable controller (PLC) then operates automatically based on this target thrust value. The PLC does not correct for pressure variations within ±100N input from the pressure sensor. When the pressure signal from the pressure sensor exceeds 100N, the PLC adjusts the oil circuit pressure by controlling the electrically adjustable relief valve, correcting the output torque of the hydraulic gear motor. Each correction is 50N.

[0096] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for driving and controlling a hot runner valve pin in an injection mold, characterized in that, Includes the following steps: Step S1: Power on the system and initialize it. Reset the electrically adjustable relief valve to the open state to release the system oil pressure and read the preset target pressure value. Step S2: Receive the injection signal from the injection molding machine, control the oil circuit solenoid valve to open, drive the hydraulic gear motor to rotate in the forward direction, drive the external gear nut fixed to the valve needle to move counterclockwise spiral upward along the fixed screw, so that the hot runner valve needle can synchronously perform a linear rotation and disengage from the injection port, opening the runner; Step S3: Receive the stop injection signal from the injection molding machine, switch the oil circuit control, drive the hydraulic gear motor to rotate in the opposite direction, and drive the external gear nut to move clockwise spirally downward along the fixed screw, so that the hot runner valve needle can synchronously perform a linear rotation until its front end contacts and blocks the injection port. Step S4: After the valve needle completes the sealing action, the sealing pressure is collected in real time by the pressure sensor installed on the drive end to obtain the actual pressure value Pactual. Step S5: In automatic operation mode, compare Pactual with the preset target pressure value Ptarget, calculate the deviation ΔP, and adjust the output torque of the hydraulic gear motor by adjusting the set pressure of the electric adjustable relief valve according to the direction and magnitude of the deviation, thereby correcting the valve needle thrust. Implemented in the following ways: Step D1: The PLC first checks whether the system is in automatic operation mode, and after confirmation, reads the target pressure value Ptarget calibrated and saved in the manual debugging stage from the memory; Step D2: Deviation calculation. After the valve needle completes the sealing action, the PLC obtains the filtered actual pressure value Pactual and calculates the pressure deviation ΔP. Step D3: Deviation threshold judgment. The absolute value of the pressure deviation is compared with the pressure tolerance threshold set by the system. If the pressure deviation is less than or equal to the pressure tolerance threshold, the current sealing force is considered qualified; otherwise, the pressure correction process is triggered. Step D4: Generate and adjust the adjustment command. Determine the adjustment direction based on the direction of the pressure deviation ΔP. If the pressure deviation ΔP is greater than zero, reduce the system pressure and decrease the output signal. Conversely, increase the system pressure and increase the output signal. Dynamically adjust the opening pressure and correct the valve needle thrust.

2. The driving control method for the hot runner valve pin of an injection mold according to claim 1, characterized in that, Step S1 is implemented in the following manner: Step A1: After the system completes its power-on self-test, the PLC immediately outputs the minimum effective signal to the electrically adjustable relief valve, forcing it to fully open and release pressure, so that the hydraulic circuit can quickly drop to a pressure-free safe state. Step A2: After the overflow valve pressure relief operation is completed, the PLC initialization program will immediately read the previously stored Ptarget value from its non-volatile memory. This value is loaded into the PLC's working memory for subsequent automatic operation control logic to call at any time.

3. The driving control method for the hot runner valve pin of an injection mold according to claim 1, characterized in that, Step S2 is implemented in the following manner: Step B1: Signal reception and recognition. The programmable controller continuously monitors the digital output signal of the injection molding machine control system. This signal is connected to the designated digital input port of the PLC through hard-wiring. When the injection molding machine completes mold closing and enters the injection stage, its controller will set this signal to a high level. Step B2: Oil circuit solenoid valve control. After the PLC detects that the injection glue signal is valid, it immediately executes the output command and sets the corresponding digital output point inside to a high level. This digital output point is connected to the forward working coil of the oil circuit direction control solenoid valve through hard wiring. After the solenoid valve is energized, it switches to the forward oil supply working position. Step B3: Hydraulic power transmission. After the solenoid valve switches, the high-pressure oil output by the hydraulic pump is guided to the forward oil inlet of the hydraulic gear motor. The return oil inlet of the motor is connected to the oil tank, and the output shaft of the gear motor begins to rotate in the forward direction. Step B4: Mechanical motion conversion. The output shaft of the gear motor drives the external gear nut, which is fixed to it, to rotate, which is converted into linear motion upward along the screw axis, causing it to spiral upward. The combined rotational and linear motion of the external gear nut is transmitted to the valve needle, causing it to synchronously execute the rotational linear motion of the spiral trajectory. The front end of the valve needle gradually separates from the glue injection port sealing surface inside the hot runner nozzle core, opening the flow channel.

4. The driving control method for the hot runner valve pin of an injection mold according to claim 1, characterized in that, Step S3 is implemented in the following manner: Step C1: Signal reception and recognition. The programmable controller continuously monitors the stop injection digital output signal from the injection molding machine control system. This signal is connected to the designated digital input port of the PLC through hard wiring. When the injection molding machine completes mold closing and enters the injection stage, its controller will set this signal to a high level. Step C2: Switching the direction of the hydraulic circuit. After the PLC detects that the stop dispensing signal is valid, it disconnects the forward hydraulic circuit solenoid valve coil that was previously used to open the valve needle, and turns on the reverse hydraulic circuit solenoid valve coil to switch the direction of the hydraulic circuit, so that the high-pressure oil enters from the return port of the hydraulic gear motor. Step C3: The motor reverses its drive. Under the action of reverse hydraulic pressure, the output shaft of the hydraulic gear motor begins to rotate in the reverse direction. Step C4: The helical pair motion is converted. The motor output shaft drives the external gear nut fixed to it to rotate in the opposite direction, which is converted into a linear downward motion along the screw axis, forming a clockwise helical downward trajectory, gradually approaching and finally closely contacting the injection port sealing surface in the hot runner nozzle core, cutting off the flow channel.

5. The driving control method for the hot runner valve pin of an injection mold according to claim 1, characterized in that, Step S4 is implemented in the following manner: The pressure sensor collects analog signals of sealing thrust pressure at a fixed sampling period, performs analog-to-digital conversion to convert them into digital quantities, and uses a digital filtering algorithm to smooth multiple consecutive sampled values. The filtered values ​​are then converted into actual pressure values ​​(Pactual) through calibration coefficients.

6. A drive control system for a hot runner valve pin in an injection mold, employing the drive control method for a hot runner valve pin in an injection mold as described in any one of claims 1-5, characterized in that, It includes a controller module, a hydraulic power module, an oil circuit control module, an actuator module, a pressure feedback module, and a pressure regulation module; The controller module is used for system power-on initialization and self-test, receiving injection molding machine signals, controlling the output of solenoid valves and overflow valves, reading / storing target pressure Ptarget, collecting and processing pressure sensor data, and executing deviation calculation and closed-loop regulation logic. The hydraulic power module provides a stable hydraulic source to drive the gear motor in both forward and reverse directions. The oil circuit control module is used to switch the oil circuit direction according to PLC instructions, and control the gear motor to open the valve when rotating forward or close the valve when rotating in reverse. The actuator module is used to convert the rotational motion of the motor into a rotary-linear compound motion of the valve needle through a helical pair, so as to accurately open or close the glue injection port; The pressure feedback module is used to collect the actual thrust pressure Pactual during valve needle sealing in real time, and after filtering and calibration, it is used for closed-loop control. The pressure regulation module is used to fully open and release pressure when powered on, and dynamically adjusts the system set pressure according to ΔP during operation, thereby changing the motor output.

7. A drive control device for a hot runner valve pin in an injection mold, employing the drive control method for a hot runner valve pin in an injection mold as described in any one of claims 1-5, characterized in that, The system includes a mold hot runner plate, a drive system base mounted on the hot runner plate, the drive system base being fixedly connected to the mold hot runner plate, a valve needle mechanism mounted on the upper part of the drive system base, the valve needle mechanism being fixedly connected to the drive system base, a hydraulic gear motor mounted on one side of the drive system base, the hydraulic gear motor being fixedly connected to the mold hot runner plate, the hydraulic gear motor being connected to the valve needle mechanism via a hydraulic gear motor drive shaft and hydraulic gear motor drive gear, a flow channel pipe mounted on the drive system base, the flow channel pipe being fixedly connected to the drive system base, and a hot nozzle sleeve mounted on the flow channel pipe, the hot nozzle sleeve being fixedly connected to the flow channel pipe.

8. The driving control device for the hot runner valve pin of the injection mold according to claim 7, characterized in that, The valve needle mechanism includes a nut, a screw rod is disposed inside the nut and threadedly connected to the nut, the screw rod is fixedly connected to the drive system base, a hot runner valve needle is disposed on the nut and fixedly connected to the nut by a pin, a driven gear is disposed on the outside of the nut and fixedly connected to the nut, and a pressure sensor is disposed between the nut and the drive system base and fixedly connected to the drive system base.

9. The driving control device for the hot runner valve pin of the injection mold according to claim 7, characterized in that, A flow channel pipe is provided on one side of the drive system base. The flow channel pipe is fixedly connected to the drive system base and is a pipe-type flow channel pipe.

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