A method for controlling a presser foot of an embroidery machine

Abstract

This invention provides a method for controlling the presser foot of an embroidery machine. The method includes the following steps: the embroidery machine spindle rotates to 100°, and the control system sets a preset pressure value for the presser foot; the control system reads the current pressure sensor data and sets the pressure value to zero; embroidery begins, and the presser foot motor is controlled by the needle bar motion control system to drive the presser foot. For each step the presser foot takes, the control system reads the pressure sensor data to obtain the current pressure value; the control system compares the current pressure value with the preset pressure value and calibrates based on the comparison result. If the current pressure value is less than the preset pressure value, the control system controls the presser foot motor to continue driving the presser foot until the current pressure value reaches the preset pressure value, at which point the control system stops the presser foot motor; the control system records the current pulse value of the presser foot motor, converts the pulse value into presser foot height data, and displays it visually. This invention can promptly and accurately detect whether the presser foot is pressing on the fabric surface and whether the amount of fabric pressed is excessive.

Description

Technical Field

[0001] This invention relates to a control method for an embroidery machine, specifically a control method for the presser foot of an embroidery machine, and belongs to the technical field of embroidery machine equipment. Background Technology

[0002] With the continuous development of the embroidery machine industry, consumers have increasingly higher requirements for embroidery products. Because the presser foot height of traditional embroidery machines is mechanical, it cannot be dynamically adjusted after mechanical adjustment. In actual embroidery, the thickness of the fabric is not uniform, especially for three-dimensional embroidery products. Since the presser foot height cannot be dynamically adjusted, it will cause the presser foot to squeeze and deform the completed pattern, resulting in pattern deformation.

[0003] Currently, some embroidery machines use motors to independently control the raising and lowering of the presser feet, and the fabric thickness can be set. The motor automatically controls and adjusts the presser feet, eliminating the need for manual mechanical adjustments, thus improving processing efficiency and significantly enhancing the quality of the embroidery.

[0004] However, existing embroidery machine presser foot control technology requires all height parameters to be manually set in advance, which is complex. Furthermore, the actual height is difficult to measure after the fabric is in place, often leading to discrepancies between the set and actual values, affecting the final result. Existing technologies have also employed methods that detect the motor's current during operation to determine if the presser foot is pressing against the fabric. If excessive current is detected, the presser foot height is raised, achieving automatic adjustment. However, in practical use, this technology suffers from several drawbacks. Because the motor current is dynamically adjusted and fluctuates significantly, precise measurement is difficult. Additionally, the high frequency of presser foot movement introduces a delay in current detection, making it impossible to measure the actual presser foot pressure in real time. This results in discrepancies between the detection results and the actual presser foot condition, failing to accurately and promptly detect whether the presser foot is pressing against the fabric or whether excessive fabric is being pressed. Summary of the Invention

[0005] Based on the above background, the purpose of this invention is to provide a method for controlling the presser foot of an embroidery machine, which can detect in a timely and accurate manner whether the presser foot is pressing on the fabric surface and whether the amount of fabric pressed is excessive.

[0006] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0007] A method for controlling the presser foot of an embroidery machine, used in an embroidery machine with a pressure sensor, the pressure sensor being disposed at the bottom of the needle plate of the embroidery machine, the needle plate being located below the presser foot of the embroidery machine, the method comprising the following steps:

[0008] When the main shaft of the embroidery machine rotates to 100°, the pressure value of the presser foot pressing the fabric is set through the control system.

[0009] The control system reads the current pressure sensor data and sets the pressure value to zero;

[0010] When embroidery begins, the needle bar motion control system controls the presser foot motor to drive the presser foot, which moves in a pulse-driven manner toward the fabric. Each time the presser foot moves one step, the control system reads the data from the pressure sensor to obtain the current pressure value.

[0011] The control system compares the current pressure value with the set pressure value and calibrates according to the comparison result. If the current pressure value is less than the set pressure value, the control system drives the presser foot motor to continue stepping until the current pressure value reaches the set pressure value, at which point the control system stops the presser foot motor from rotating.

[0012] The control system records the current pulse value of the presser foot motor, converts the pulse value into presser foot height data, and displays it in a visual manner.

[0013] This embroidery machine presser foot control method directly measures the pressure of the presser foot on the fabric using a pressure sensor, thereby achieving real-time monitoring and closed-loop control of the presser foot pressure. It can accurately detect the motor position when the presser foot presses on the fabric, and uses stepper drive and pulse control to control the presser foot movement, achieving fine adjustment of the presser foot pressure. This method performs pressure calibration by comparing the pressure set value and the feedback value, ensuring the accuracy of presser foot pressure control during embroidery, thereby improving the quality of embroidery and the degree of automation in embroidery.

[0014] Preferably, the control system for the movement of the needle bar, which controls the presser foot motor to drive the presser foot, includes:

[0015] When the embroidery machine spindle rotates to 115°, the control presser foot motor drives the presser foot to step towards the fabric and reach the working position. Keeping the presser foot motor stationary, the embroidery machine spindle rotates to 245°, and the control presser foot motor drives the presser foot to step away from the fabric. When the embroidery machine spindle rotates to 180°, the control system reads the data from the pressure sensor to obtain the current pressure value.

[0016] Preferably, the method further includes the following steps before starting the embroidery:

[0017] The control system sets the set height value of the presser foot pressing the fabric, sets the minimum and maximum allowable pressure values ​​for the fabric, sets the maximum number of times the pressure limit is exceeded, and sets the maximum number of times the presser foot height can be continuously adjusted.

[0018] Depending on the fabric and embroidery pattern, different minimum and maximum allowable pressure values ​​can be set for the fabric.

[0019] Preferably, the control system compares the current pressure value with the set pressure value and performs calibration based on the comparison result, including:

[0020] If the current pressure value reaches the set pressure value but is not greater than the set pressure value, the number of times the pressure limit is exceeded and the number of times the presser foot height is continuously adjusted will be set to zero.

[0021] If the current pressure value is greater than the set pressure value, record the number of times the pressure limit is exceeded. If the number of times the pressure limit is exceeded is less than the maximum number of times the pressure limit is exceeded, maintain the current set height value of the presser foot pressing cloth. If the number of times the pressure limit is exceeded is greater than or equal to the maximum number of times the pressure limit is exceeded, adjust the current set height value of the presser foot pressing cloth to form a new set height value of the presser foot pressing cloth.

[0022] Preferably, the control system further includes comparing the current pressure value with the set pressure value and calibrating based on the comparison result:

[0023] The control system compares the current pressure value with the minimum and maximum allowable pressure values ​​for the fabric.

[0024] If the current pressure value is less than the minimum allowable pressure on the fabric, the presser foot is not fully pressing down on the fabric. Adjust the presser foot height.

[0025] If the current pressure value is greater than the maximum allowable pressure on the fabric, the presser foot is pressing the fabric too hard. Adjust the height of the presser foot.

[0026] After adjustment, reset the number of times the pressure limit was exceeded to zero and record the number of consecutive adjustments to the presser foot height.

[0027] Preferably, after setting the new presser foot pressure cloth height value, the method further includes the following steps:

[0028] Set the number of times the pressure limit was exceeded to zero, and record the number of times the presser foot height was continuously adjusted.

[0029] If the number of consecutive presser foot height adjustments is less than the maximum number of consecutive presser foot height adjustments, the control system will proceed with the subsequent embroidery work according to the new presser foot fabric pressing height setting value;

[0030] If the number of consecutive presser foot height adjustments is greater than or equal to the maximum number of consecutive presser foot height adjustments, the control system will indicate an abnormality in the presser foot motor and issue an alarm, and will reset the number of times the pressure limit is exceeded and the number of consecutive presser foot height adjustments to zero.

[0031] Preferably, the pressure sensor is a strain gauge pressure sensor, a piezoresistive pressure sensor, a capacitive pressure sensor, or a piezoelectric pressure sensor.

[0032] Compared with the prior art, the present invention has the following advantages:

[0033] This invention discloses a presser foot control method for an embroidery machine. It directly measures the pressure of the presser foot on the fabric using a pressure sensor, achieving a detection accuracy of 0.1g. This enables real-time, precise monitoring and closed-loop control of the presser foot pressure, allowing for high-precision detection of the motor position when the presser foot presses onto the fabric. The method employs stepper drive and pulse control to control the presser foot movement, achieving fine adjustment of the presser foot pressure. Furthermore, the method performs pressure calibration by comparing the pressure setpoint and feedback value, ensuring the accuracy of presser foot pressure control during embroidery, thereby improving the quality of the embroidery and the degree of automation in the embroidery process. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0035] Figure 1 This is a three-dimensional structural diagram of the embroidery machine in this invention;

[0036] Figure 2 This is a schematic diagram of the control flow of the embroidery machine presser foot control method of the present invention;

[0037] Figure 3 This is a schematic diagram of the calibration process for the presser foot control method of the embroidery machine of the present invention.

[0038] In the diagram: 1. Head; 2. Presser foot; 3. Needle plate; 4. Pressure sensor; 5. Shuttle box. Detailed Implementation

[0039] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any modifications and / or alterations made to the present invention will fall within the protection scope of the present invention.

[0040] In this invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used are commercially available or commonly used in the art. Unless otherwise specified, the methods in the following embodiments are conventional methods in the art. Unless otherwise specified, the components or equipment in the following embodiments are general standard parts or components known to those skilled in the art, and their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0041] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In this detailed description, numerous specific details are set forth to facilitate explanation and provide a thorough understanding of the embodiments of the present invention. However, one or more embodiments may be practiced by those skilled in the art without these specific details.

[0042] An embodiment of the present invention discloses a method for controlling the presser foot of an embroidery machine, the method comprising the following steps:

[0043] When the main shaft of the embroidery machine rotates to 100°, the pressure value of the presser foot pressing the fabric is set through the control system.

[0044] The control system reads the current pressure sensor data and sets the pressure value to zero;

[0045] When embroidery begins, the needle bar motion control system controls the presser foot motor to drive the presser foot, which moves in a pulse-driven manner toward the fabric. Each time the presser foot moves one step, the control system reads the data from the pressure sensor to obtain the current pressure value.

[0046] The control system compares the current pressure value with the set pressure value and calibrates according to the comparison result. If the current pressure value is less than the set pressure value, the control system drives the presser foot motor to continue stepping until the current pressure value reaches the set pressure value, at which point the control system stops the presser foot motor from rotating.

[0047] The control system records the current pulse value of the presser foot motor, converts the pulse value into presser foot height data, and displays it in a visual manner.

[0048] The control of the presser foot motor to drive the presser foot in conjunction with the needle bar motion control system includes: the embroidery machine spindle rotates to 115°, the presser foot motor is controlled to drive the presser foot to step towards the fabric to reach the working position, the presser foot motor is kept stationary, the embroidery machine spindle rotates to 245°, the presser foot motor is controlled to drive the presser foot to step away from the fabric, the embroidery machine spindle rotates to 180°, and the control system reads the data from the pressure sensor to obtain the current pressure value.

[0049] Before beginning the embroidery, the method also includes the following steps:

[0050] The control system allows setting the presser foot's fabric pressing height, the minimum and maximum allowable fabric pressure, the maximum number of times the pressure limit is exceeded, and the maximum number of consecutive presser foot height adjustments. Different minimum and maximum allowable fabric pressure values ​​can be set according to different fabrics and embroidery patterns.

[0051] The control system compares the current pressure value with the set pressure value and performs calibration based on the comparison result, including:

[0052] If the current pressure value reaches the set pressure value but is not greater than the set pressure value, the number of times the pressure limit is exceeded and the number of times the presser foot height is continuously adjusted will be set to zero.

[0053] If the current pressure value is greater than the set pressure value, record the number of times the pressure limit is exceeded. If the number of times the pressure limit is exceeded is less than the maximum number of times the pressure limit is exceeded, maintain the current set height value of the presser foot pressing cloth. If the number of times the pressure limit is exceeded is greater than or equal to the maximum number of times the pressure limit is exceeded, adjust the current set height value of the presser foot pressing cloth to form a new set height value of the presser foot pressing cloth.

[0054] The control system compares the current pressure value with the set pressure value and calibrates based on the comparison result. This also includes:

[0055] The control system compares the current pressure value with the minimum and maximum allowable pressure values ​​for the fabric.

[0056] If the current pressure value is less than the minimum allowable pressure on the fabric, the presser foot is not fully pressing down on the fabric. Adjust the presser foot height.

[0057] If the current pressure value is greater than the maximum allowable pressure on the fabric, the presser foot is pressing the fabric too hard. Adjust the height of the presser foot.

[0058] After adjustment, reset the number of times the pressure limit was exceeded to zero and record the number of consecutive adjustments to the presser foot height.

[0059] After establishing the set height value for the new presser foot and presser fabric, the method further includes the following steps:

[0060] Set the number of times the pressure limit was exceeded to zero, and record the number of times the presser foot height was continuously adjusted.

[0061] If the number of consecutive presser foot height adjustments is less than the maximum number of consecutive presser foot height adjustments, the control system will proceed with the subsequent embroidery work according to the new presser foot fabric pressing height setting value;

[0062] If the number of consecutive presser foot height adjustments is greater than or equal to the maximum number of consecutive presser foot height adjustments, the control system will indicate an abnormality in the presser foot motor and issue an alarm, and will reset the number of times the pressure limit is exceeded and the number of consecutive presser foot height adjustments to zero.

[0063] This embroidery machine presser foot control method directly measures the pressure of the presser foot on the fabric using a pressure sensor, thereby achieving real-time monitoring and closed-loop control of the presser foot pressure. It can accurately detect the motor position when the presser foot presses on the fabric, and uses stepper drive and pulse control to control the presser foot movement, achieving fine adjustment of the presser foot pressure. This method performs pressure calibration by comparing the pressure set value and the feedback value, ensuring the accuracy of presser foot pressure control during embroidery, thereby improving the quality of embroidery and the degree of automation in embroidery.

[0064] The following section provides a detailed explanation using the specific application of this presser foot control method in embroidery machines as an example.

[0065] This method is applied to embroidery machines equipped with pressure sensors, such as... Figure 1 As shown, the embroidery machine includes a machine head 1, a main shaft (not shown), a main shaft motor (not shown), a presser foot 2, a presser foot motor (not shown), a needle plate 3, a pressure sensor 4, a shuttle box 5, and a control system (not shown). The control system controls the rotation of the main shaft by controlling the main shaft motor and controls the presser foot motor to move the presser foot closer to and away from the needle plate. The presser foot is located at the bottom of the machine head, and the needle plate is located below the machine head and below the presser foot. There is a gap between the needle plate and the presser foot. A portion of the fabric is laid on the needle plate, and the bottom of the needle plate is fixedly connected to the shuttle box via a pressure sensor. The pressure sensor is located at the bottom of the needle plate of the embroidery machine. The pressure sensor can be a strain gauge pressure sensor, a piezoresistive pressure sensor, a capacitive pressure sensor, or a piezoelectric pressure sensor.

[0066] As the presser foot moves downwards, it eventually presses down on the fabric. Simultaneously, the fabric transmits the pressure to the needle plate. This pressure is detected by a pressure sensor at the bottom of the needle plate and transmitted to the control system. The control system then controls the presser foot's movement based on the detected pressure value and the specified control method. Figure 2 As shown, the control flow is as follows:

[0067] S10, Parameter Settings

[0068] Rotate the spindle to the original position 100 degrees, and then enter the presser foot height setting interface of the control system. First, set the pressure value required for pressing the fabric. Before setting, ensure that the fabric has been placed on the frame and fixed. Then click the presser foot height (i.e. fabric height) one-click setting button.

[0069] S11. Read the current pressure value and set it to zero.

[0070] First, read the current pressure sensor data and set the current value to zero.

[0071] S12, Presser foot motor starts

[0072] After the sensor data is reset to zero, the control system starts the presser foot motor at a low speed. Each time the system sends a pulse, the motor moves one step towards the fabric.

[0073] S13. Real-time reading of pressure data from the pressure sensor.

[0074] After each step the presser foot motor takes, the control system reads the sensor data once.

[0075] S14, Pressure Detection Comparison

[0076] The read data is compared with the set pressure value. If the pressure value is less than the set value, it means the presser foot has not yet reached the required position. The motor continues to rotate one step, and the reading and comparison are repeated. When the pressure data reaches the set value, it means the presser foot has pressed onto the fabric surface and exactly meets the set requirements.

[0077] S15 / S16, Presser foot data read and save

[0078] Once the pressure reaches the set value, the system stops the motor and records the current real-time position of the motor. The current pulse value is saved and converted into presser foot height data. The presser foot height data is displayed on the control system's screen. After manual confirmation, the data is automatically saved to the corresponding parameter column.

[0079] During the operation of the pressure foot, there is also an automatic calibration process, such as... Figure 3 As shown, the calibration process includes:

[0080] S20, Related Parameter Setting Procedure

[0081] Before operation, you need to set the presser foot height parameter, then set the actual pressure range parameter (including minimum and maximum values) on the fabric surface during operation, then set the parameter K1 for the number of times the measurement exceeds the range, and also set the parameter K2 for the number of times the presser foot height can be continuously adjusted.

[0082] S21 / S22 After the machine starts embroidery, the presser foot descends, the spindle angle is about 115 degrees, the presser foot height reaches the set value, then the presser foot motor remains stationary, and then begins to rise after the spindle angle reaches 245 degrees. After the presser foot stabilizes, the current pressure value is detected when the spindle is at 180 degrees.

[0083] S23 / S24 After detecting the pressure value, the system compares the collected pressure value with the parameter setting value. If the pressure value is normal, the pressure foot height parameter is not adjusted. The number of consecutive failures K1 is set to zero, and the number of consecutive pressure foot height adjustments K2 is set to zero. If the pressure value is out of range, proceed to S25.

[0084] S25. After one instance of pressure exceeding the tolerance is detected, the number of consecutive unqualified tests, K1, is incremented by 1.

[0085] S26. The number of consecutive non-conforming items K1 is compared with the set value. If K1 is less than the set value, the presser foot height is not adjusted this time. Once K1 is greater than or equal to the set value, the presser foot height data is finely adjusted.

[0086] S27. The system compares the detected pressure value with the set value. If the measured value is less than the set minimum value, it means the presser foot is not fully pressing the fabric, and the presser foot height needs to be adjusted downwards. The amount of adjustment is calculated based on the difference in pressure. If the measured value is greater than the set value, it means the presser foot is applying too much pressure to the fabric, and the presser foot height needs to be increased. After adjustment, the number of consecutive non-conforming tests K1 is reset to zero. At the same time, the number of consecutive adjustments K2 is incremented by 1.

[0087] S28. The control system compares the continuously adjustable parameter K2 with the set value. If the continuously adjustable parameter is greater than the set value, the control system reports an abnormality in the presser foot motor, and simultaneously sets both K1 and K2 data to zero. If the continuously adjustable parameter K2 is less than the set value, the control system will use the adjusted presser foot height data for the next stitch.

[0088] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for controlling the presser foot of an embroidery machine, characterized in that: This embroidery machine presser foot control method is used in embroidery machines equipped with pressure sensors. The pressure sensors are located at the bottom of the needle plate of the embroidery machine, which is situated below the presser foot. The embroidery machine presser foot control method includes the following steps: When the main shaft of the embroidery machine rotates to 100°, the pressure value of the presser foot pressing the fabric is set through the control system. The control system reads the current pressure sensor data and sets the pressure value to zero; When embroidery begins, the needle bar motion control system controls the presser foot motor to drive the presser foot, which moves in a pulse-driven manner toward the fabric. Each time the presser foot moves one step, the control system reads the data from the pressure sensor to obtain the current pressure value. The control system compares the current pressure value with the set pressure value and calibrates according to the comparison result. If the current pressure value is less than the set pressure value, the control system drives the presser foot motor to continue stepping until the current pressure value reaches the set pressure value, at which point the control system stops the presser foot motor from rotating. The control system records the current pulse value of the presser foot motor, converts the pulse value into presser foot height data, and displays it in a visual manner; Before beginning the embroidery, the method also includes the following steps: The control system sets the set height value of the presser foot pressing the cloth, sets the minimum and maximum allowable pressure on the cloth, sets the maximum number of times the pressure limit is exceeded, and sets the maximum number of times the presser foot height can be continuously adjusted. The control system compares the current pressure value with the set pressure value and calibrates based on the comparison result, including: If the current pressure value reaches the set pressure value but is not greater than the set pressure value, the number of times the pressure limit is exceeded and the number of times the presser foot height is continuously adjusted will be set to zero. If the current pressure value is greater than the set pressure value, record the number of times the pressure limit is exceeded. If the number of times the pressure limit is exceeded is less than the maximum number of times the pressure limit is exceeded, maintain the current set pressure height value of the presser foot and the presser cloth. If the number of times the pressure limit is exceeded is greater than or equal to the maximum number of times the pressure limit is exceeded, adjust the current set pressure height value of the presser foot and the presser cloth to form a new set pressure height value of the presser foot and the presser cloth. The control system, which compares the current pressure value with the set pressure value and calibrates based on the comparison result, also includes: The control system compares the current pressure value with the minimum and maximum allowable pressure values ​​for the fabric. If the current pressure value is less than the minimum allowable pressure on the fabric, the presser foot is not fully pressing down on the fabric. Adjust the presser foot height. If the current pressure value is greater than the maximum allowable pressure on the fabric, the presser foot is pressing the fabric too hard. Adjust the height of the presser foot. After adjustment, reset the number of times the pressure limit was exceeded to zero and record the number of consecutive adjustments to the presser foot height; After establishing the set height value for the new presser foot and presser fabric, the method further includes the following steps: Set the number of times the pressure limit was exceeded to zero, and record the number of times the presser foot height was continuously adjusted. If the number of consecutive presser foot height adjustments is less than the maximum number of consecutive presser foot height adjustments, the control system will proceed with the subsequent embroidery work according to the new presser foot fabric pressing height setting value; If the number of consecutive presser foot height adjustments is greater than or equal to the maximum number of consecutive presser foot height adjustments, the control system will indicate an abnormality in the presser foot motor and issue an alarm, and will reset the number of times the pressure limit is exceeded and the number of consecutive presser foot height adjustments to zero.

2. The method of controlling a presser foot of a embroidery machine according to claim 1, characterized in that: The aforementioned control system for the movement of the needle bar controls the motor driving of the presser foot, including: When the embroidery machine spindle rotates to 115°, the control presser foot motor drives the presser foot to step towards the fabric and reach the working position. Keeping the presser foot motor stationary, the embroidery machine spindle rotates to 245°, and the control presser foot motor drives the presser foot to step away from the fabric. When the embroidery machine spindle rotates to 180°, the control system reads the data from the pressure sensor to obtain the current pressure value.

3. The method of controlling a presser foot of a embroidery machine according to claim 1, wherein: The pressure sensor is a strain gauge pressure sensor, a piezoresistive pressure sensor, a capacitive pressure sensor, or a piezoelectric pressure sensor.

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