Sewing equipment

Abstract

The present invention provides a sewing device, comprising a frame, a sewing table, a motor, a presser foot and a controller; the sewing table is arranged on the frame and used to place sewing materials; the motor is fixed to the frame and used to drive the presser foot to move in a vertical direction; the controller is electrically connected to the motor and used to control the rotation of the motor; the controller is used to control the motor to press down to a first position for pressing the sewing materials, and is used to adjust the output current of the motor to a working current according to a set pressure value, and to keep the output current of the motor as the working current during the sewing process, and to control the motor to move up to a second position away from the sewing materials after the sewing is completed. The sewing device provided by the present invention has the advantages of accurately adjusting the pressure of the presser foot on the sewing materials, short adjustment time, and simple user operation.

Description

Technical Field

[0001] The present invention relates to the technical field of sewing equipment, in particular to sewing equipment. Background Art

[0002] A sewing machine is a machine that uses one or more sewing threads to form one or more stitches on the sewing material, so that one or more layers of sewing material are interwoven or sewn together.

[0003] The sewing machine of the related art includes a frame, on which a motor, a presser foot and a sewing table are arranged. The sewing table can slide on the frame along the X and Y directions. The sewing material is placed on the sewing table and can move with the sewing table. When sewing starts, the motor drives the presser foot to move down so that the sewing material is pressed tightly on the sewing table.

[0004] However, the pressure applied by the presser foot to the sewing material is uncontrolled, and the user needs to repeatedly adjust the downward stroke of the presser foot to adjust the pressure applied by the presser foot to the sewing material. Summary of the invention

[0005] The embodiment of the present invention provides a sewing device to solve the problem that the pressure applied by the presser foot to the sewing material is uncontrolled and the user needs to repeatedly adjust the downward stroke of the presser foot to adjust the pressure applied by the presser foot to the sewing material.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] One aspect of an embodiment of the present invention provides a sewing device, including a frame, on which a sewing table, a motor, a presser foot assembly, a transmission mechanism and a controller are installed; the sewing table is arranged on the frame and is used to place sewing materials; the presser foot assembly is located above the sewing table; the motor drives the presser foot assembly to move in a vertical direction through the transmission mechanism; the transmission mechanism is tightly connected to the presser foot assembly and is used to convert the rotation of the motor into a linear motion of the presser foot assembly; the controller is electrically connected to the motor and is used to control the rotation of the motor; the controller is also used to control the motor to rotate forward so that the presser foot assembly moves down to a first position for pressing the sewing materials; the controller is also used to adjust the output current of the motor to a working current according to a pressure value set by a user, and maintain the output current of the motor as the working current unchanged during the sewing process, and control the motor to reverse after sewing is completed so that the presser foot assembly moves up to a second position that is separated from the sewing materials. In one possible implementation, it also includes an angle detector for detecting the forward rotation angle of the motor; the input end of the controller is electrically connected to the angle detector, and the output end of the controller is electrically connected to the motor, and the controller is used to determine the forward rotation angle change rate according to the forward rotation angle measured by the angle detector, and when the forward rotation angle change rate is less than or equal to a preset value, control the motor to maintain the current forward rotation angle so that the presser foot assembly remains in the first position.

[0008] In one possible implementation manner, the angle detector is an encoder arranged at one end of the motor.

[0009] In one possible implementation, it also includes a current detector for detecting the output current of the motor; the input end of the current detector is electrically connected to the output end of the motor, and the output end of the current detector is electrically connected to the controller; the controller is used to determine the working current corresponding to the current pressure value set by the user according to the mapping relationship between the pressure value set by the user and the working current; the controller is also used to feedback adjust the output current to the working current according to the output current measured by the current detector.

[0010] In one possible implementation manner, the current detector is a current loop.

[0011] In one possible implementation, the controller is further used to maintain the current output current of the motor unchanged when the output current is the working current, and control the sewing table to move horizontally or vertically according to a sewing pattern set by a user.

[0012] In one possible implementation, the controller is also used to determine the final reversal angle corresponding to the lifting height currently set by the user according to the mapping relationship between the lifting height set by the user and the final reversal angle after sewing is completed, and control the motor to reverse.

[0013] In one possible implementation, it also includes an angle detector for detecting the reversal angle of the motor, and the output end of the angle detector is electrically connected to the controller; the controller is used to feedback-adjust the motor according to the reversal angle measured by the angle detector until the reversal angle is the final reversal angle.

[0014] In one possible implementation, the controller includes a memory, an input end of which is electrically connected to the angle detector and is used to record the forward rotation angle of the presser foot assembly when it is in the first position as an initial angle.

[0015] In one possible implementation manner, the set lifting height is 0 to 17 mm.

[0016] The sewing device provided by the present invention controls the motor to be pressed down to a first position for pressing the sewing material through a controller, and adjusts the output current of the motor to a working current according to a set pressure value, and keeps the output current of the motor at the working current unchanged during the sewing process, and controls the motor to move up to a second position for separating from the sewing material after sewing is completed, thereby more accurately adjusting the pressure of the presser foot on the sewing material, which is beneficial to reducing the user's adjustment time and simplifying the user's operation.

[0017] In addition to the technical problems solved by the embodiments of the present invention described above, the technical features that constitute the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions, other technical problems that can be solved by the embodiments of the present invention, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further described in detail in the specific implementation methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0019] Figure 1 A schematic diagram of a sewing device of related art;

[0020] Figure 2 A schematic diagram of a sewing device provided by an embodiment of the present invention;

[0021] Figure 3 A first flow chart of a sewing device provided by an embodiment of the present invention;

[0022] Figure 4 A second flow diagram of a sewing device provided by an embodiment of the present invention;

[0023] Figure 5 A third flow chart of a sewing device provided by an embodiment of the present invention;

[0024] Figure 6 A fourth process diagram of a sewing device provided by an embodiment of the present invention.

[0025] Description of reference numerals:

[0026] 1- rack;

[0027] 2-sewing table;

[0028] 3-motor; 31-output shaft;

[0029] 4-presser foot assembly; 41, presser foot; 42, press rod;

[0030] 5-Connecting rod assembly;

[0031] 6-sewing material;

[0032] 101-frame; 102-sewing table; 103-sewing material; 104-presser foot; 105-pressing rod; 106-spring; 107-connecting rod assembly; 108-motor.

[0033] The above drawings have shown clear embodiments of the present invention, which will be described in more detail below. These drawings and text descriptions are not intended to limit the scope of the present invention in any way, but to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0034] Figure 1 Schematic diagram of a sewing device of related art. Figure 1 In the sewing equipment of the related art, it includes a frame 101, a sewing platform 102, a presser foot 104, a presser rod 105, a connecting rod assembly 107 and a motor 108. An embroidery needle is installed on the presser foot 104, and the embroidery needle can slide up and down relative to the presser foot 104. The needle hole of the embroidery needle is penetrated with sewing thread. The presser foot 104 is fixed on the presser rod 105, and the connecting rod assembly 107 is transmission-connected between the presser rod 105 and the output shaft of the motor 108. The motor 108 drives the connecting rod assembly 107 to rotate, so that the presser rod 105 moves vertically, and then the presser foot 104 fixed to the presser rod 105 moves in the vertical direction.

[0035] Before sewing, the motor 108 drives the presser foot 104 to move downward, so that the sewing material 103 is pressed on the sewing platform 102 by the presser foot 104. During sewing, the sewing platform 102 performs translational movement in the X direction and / or the Y direction relative to the presser foot 104, and the sewing material 103 on the sewing platform 102 moves with the sewing platform 102 relative to the presser foot 104, and the embroidery needle reciprocates through the sewing material 103 in the vertical reverse direction to form a sewing pattern on the sewing material 103 under the presser foot 104. After sewing is completed, the motor 108 drives the presser foot 104 to move upward, so that the presser foot 104 is separated from the sewing material 103, so that the sewing material 103 can be taken out.

[0036] However, the pressure of the presser foot 104 on the sewing material 103 should not be too large or too small. If the pressure of the presser foot 104 on the sewing material 103 is too large, the friction between the sewing material 103 and the presser foot 104 will be large, making it difficult for the sewing material 103 to move horizontally. If the pressure of the presser foot 104 on the sewing material 103 is too small, part of the sewing material 103 will swing relative to the sewing platform 102 and be uneven. Therefore, before sewing, the pressure of the presser foot 104 on the sewing material 103 should be adjusted to a suitable pressure.

[0037] The existing debugging method is to adjust the pressure of the presser foot 104 on the sewing material 103 to a suitable pressure by adjusting the position of the presser foot 104. For example, the thickness of the sewing material 103 is 3 mm, and the height from the upper end surface of the sewing material 103 to the sewing platform 102 is 3 mm. When the distance between the lower end surface of the presser foot 104 and the sewing platform 102 is 1 mm, the pressure of the presser foot 104 on the sewing material 103 is F1. When the distance between the lower end surface of the presser foot 104 and the sewing platform 102 is 2 mm, the pressure of the presser foot 104 on the sewing material 103 is F2. Obviously, F2 is greater than F1.

[0038] In addition, when the stroke of the presser foot 104 driven by the motor 108 to fall is too large, the user adjusts the pressure of the presser foot 104 pressing the sewing material 103 by the spring 106 sleeved on the pressure rod 105. When the stroke of the presser foot 104 driven by the motor 108 to fall is too small or just right, the user needs to overcome the tension of the spring 106. It is understandable that, since it is uncertain what position the presser foot 104 is in and how much the deformation of the spring 106 is, the user needs to conduct repeated tests to obtain the appropriate pressure. Therefore, the current control method of adjusting the presser foot 104 to press the sewing material 103 by adjusting the stroke of the presser foot 104 has high requirements for the operator, is not convenient to adjust, and is not practical.

[0039] In addition, the appropriate pressure corresponding to the sewing materials 103 of different thicknesses may be the same or different. The same pressure is applied to the sewing materials 103 of different thicknesses, and the position of the presser foot 104 is also different. In the actual sewing process, it may be necessary to sew the sewing materials 103 of different thicknesses together, or different positions of a piece of sewing material 103 have different thicknesses. In this case, the user needs to adjust the position of the presser foot 104 corresponding to the sewing materials 103 of different thicknesses according to the different thicknesses, which causes the user to operate cumbersomely and the processing time is long. In addition, the appropriate pressure obtained by adjusting the position of the presser foot 104 of the sewing materials 103 of different thicknesses may be different, which has just caused the different forces used to move the sewing platform 102, and the speed of the sewing platform 102 moving is different, which then causes the sewing traces on the sewing materials 103 of different thicknesses to be different, affecting the sewing pattern.

[0040] In view of this, the inventor has found that in addition to changing the pressure of the presser foot on the sewing material by adjusting the position of the presser foot, the presser foot can also be stopped at a certain position, and the pressure of the presser foot on the sewing material can be changed by changing the output torque of the motor. The position where the presser foot stops is a place where it can contact the sewing material and can have a certain pressure on the sewing material, so as to ensure that the presser foot can have pressure on the sewing material no matter how the output torque of the motor is adjusted. Since the sewing material is flexible, simply determining the stopping position by the position of the presser foot cannot ensure that the presser foot has pressure on the sewing material. Exemplarily, the thickness of the sewing material is 3mm. Since the sewing material is flexible, the presser foot may have pressure on the sewing material when the distance between the lower end surface of the presser foot and the seam platform is 1mm, that is, when the presser foot causes the sewing material to sink 2mm.

[0041] In order to ensure that the position where the presser foot stops can exert pressure on the sewing material, the present invention can lower the presser foot to a first position where it cannot be lowered any further, and the presser foot is restricted by the sewing platform and cannot be lowered any further when the presser foot is in the first position. When the presser foot is in the first position, the sewing material pressed by the presser foot is in the maximum position where its elastic deformation occurs, that is, the sewing material is pressed and compacted. The presser foot in the first position must exert pressure on the sewing material. In order to obtain the first position where the presser foot compacts the sewing material, it can be obtained through a closed-loop control system of a motor.

[0042] In addition, after the presser foot is lowered to the first position, the pressure of the presser foot on the sewing material is changed to a set pressure value by changing the torque of the motor, and the set pressure value is maintained during the sewing process. That is to say, when the present invention is used, only the user needs to input the pressure value, and the system can automatically adjust the position of the presser foot and the pressure of the presser foot on the sewing material to the set pressure value. Compared with the existing method of adjusting the position of the presser foot to adjust the pressure of the presser foot on the sewing material, the present invention has the advantage of simple operation.

[0043] In addition, when sewing materials of different thicknesses together, or when different positions of a piece of sewing material have different thicknesses, the pressure of the presser foot on materials of different thicknesses can all be a set pressure value. This means that even if the thickness of the sewing materials varies greatly, the pressure of the presser foot on materials of different thicknesses is the same or close. This reduces the difference in force used to move the sewing table, thereby ensuring the consistency of the stitches.

[0044] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0045] Figure 2 A schematic diagram of a sewing device provided by an embodiment of the present invention. Figure 2 The sewing device provided by the present invention comprises a frame 1, a sewing table 2, a motor 3, a presser foot assembly 4 and a controller. The frame 1 is placed on the ground, and the sewing table 2 is installed on the frame 1 so that the sewing table 2 has a certain distance from the ground. The upper end surface of the sewing table 2 is used to place the sewing material 5. The upper surface of the sewing table 2 can be a flat surface to facilitate the placement of the sewing material 5.

[0046] The motor 3 can be installed on the frame 1 above the sewing table 2, and the motor 3 can have a certain height with the sewing table 2 to prevent the vibration generated by the motor 3 from affecting the sewing table 2. The motor 3 can be powered by an external power supply or by a rechargeable battery. The output shaft 31 of the motor 3 can be connected to the connecting rod assembly 5, and the end of the connecting rod assembly 5 away from the output shaft 31 of the motor 3 can be connected to the presser foot assembly 4. The presser foot assembly 4 can include a press rod 42 arranged in the vertical direction and a presser foot 41 arranged in the horizontal direction, and the presser foot 41 is fixed to the lower end of the press rod 42. The upper end of the press rod 42 is tightly connected to the connecting rod assembly 5. The motor 3 can rotate by driving the connecting rod assembly 5, thereby realizing the lifting and lowering of the presser foot 41. The presser foot 41 can be provided with an embroidery needle that has been threaded (the embroidery needle is not shown in the figure). The embroidery needle can be driven to and fro by the controller to sew a pattern on the sewing material 5.

[0047] It should be noted that, compared with the prior art connection through a spring, the fastening connection between the connecting rod assembly 5 and the presser foot assembly 4 not only reduces the number of parts, but also enables the output force of the output shaft 31 of the motor 3 to directly act on the press rod 42 through the connecting rod assembly 5, and then act on the presser foot 41, which is beneficial to the control of the pressure of the presser foot 41 by the motor 3. The structure of the connecting rod assembly 5 is prior art and will not be described in detail here.

[0048] During the sewing process, the sewing table 2 can move in the horizontal direction (laterally and / or longitudinally) relative to the frame 1, and the sewing material 5 on the sewing table 2 moves with the movement of the sewing table 2. Of course, during the sewing process, the sewing table 2 can also be stationary relative to the frame 1, and the sewing material 5 can be dragged by a person's hand and slide on the sewing table 2. The present invention takes the case where the sewing table 2 can move in the horizontal direction during sewing, the sewing material 5 is stationary relative to the sewing table 2, and moves with the movement of the sewing table 2 as an example to illustrate the controller of the sewing device provided by the embodiment of the present invention. For the case where the sewing material 5 is dragged by a person's hand, it can be obtained by referring to the following, and it will not be repeated here.

[0049] refer to Figure 3-Figure 6 The controller is used to control the motor to lower the presser foot to a first position for compacting the sewing material before sewing the pattern, and to adjust the pressure of the presser foot on the sewing material when the presser foot is in the first position to reach the pressure value set by the user; the controller is also used to control the motor to raise the presser foot to a second position to separate from the sewing material after sewing the pattern.

[0050] The following is a description of the process of the controller controlling the sewing equipment in four parts: Part 1: the presser foot moves down from a certain position to the first position for compacting the sewing material; Part 2: the output torque of the motor is adjusted to the working torque; Part 3: sewing the pattern; Part 4: the presser foot is raised to the second position.

[0051] Figure 3 A first flow chart of a sewing device provided by an embodiment of the present invention. Figure 3 To describe the process of the first part, the controller includes a controller capable of receiving signals, storing signals, processing signals and outputting signals.

[0052] S101, the input terminal sends a start instruction to the controller;

[0053] Specifically, the input terminal is a device for exchanging information between the user and the controller. The start instruction may be an instruction for causing the sewing device to work. The start instruction may be input into the controller via an input terminal such as a keyboard, a button, a handwriting input board, or a voice input.

[0054] S102, the controller generates a forward rotation signal according to the start instruction; S103, the controller sends a forward rotation signal to the motor; S104, the motor rotates the output shaft of the motor in a first direction according to the forward rotation signal to drive the presser foot to move down;

[0055] Specifically, the output ends of the controller are electrically connected to the input ends of the motor, respectively, and are used to control the rotation of the motor. The controller receives a start instruction and outputs a forward rotation signal to the motor. The motor receives the forward rotation signal and rotates in a first direction. It should be noted that the controller can control the motor to rotate forward or reverse. In the first part, the controller only controls the motor to rotate forward, that is, controls the motor to rotate in the first direction.

[0056] S105, the angle detector detects the forward rotation angle of the motor and generates a positive angle signal;

[0057] Specifically, an angle detector is a sensor that converts rotational displacement into a digital pulse signal. The angle detector can be an encoder that can be installed at one end of the motor. The encoder can be incremental or absolute. The incremental encoder converts the displacement into a periodic electrical signal, and then converts the electrical signal into a counting pulse, using the number of pulses to represent the magnitude of the displacement. In other words, the incremental encoder and the counter can obtain the forward rotation angle of the motor. Each position of the absolute encoder corresponds to a certain digital code, so its indication is only related to the starting and ending positions of the measurement, but not to the intermediate process of the measurement. In other words, the absolute encoder can directly obtain the forward rotation angle of the motor.

[0058] S106. The angle detector sends a positive angle signal to the controller; S107. The controller receives the positive angle signal and calculates the rate of change of the forward rotation angle; the controller generates a forward rotation signal when the rate of change of the forward rotation angle is greater than the preset frequency; the controller generates an angle holding signal when the rate of change of the forward rotation angle is less than or equal to the preset frequency. S108. The controller sends a forward rotation signal or an angle holding signal to the motor. S109. According to the forward rotation signal, the output shaft of the motor continues to rotate in the first direction to drive the presser foot to move down; or, according to the angle holding signal, the output shaft of the motor stops rotating and remains at the current rotation angle so that the presser foot remains in the first position for compacting the sewing material.

[0059] Specifically, the input end of the controller is electrically connected to the output end of the angle detector. The positive rotation angle change rate refers to the angle of the output shaft of the motor that rotates forward per unit time.

[0060] When the output shaft of the motor just starts to rotate in the first direction, the rotation speed of the output shaft of the motor is a fixed value, and the rate of change of the positive rotation angle of the output shaft of the motor is a fixed value. And the fixed value is greater than the preset value. At this time, the controller sends a positive rotation signal to the motor so that the output shaft of the motor continues to rotate in the first direction.

[0061] When the presser foot starts to press the sewing material, the sewing material is deformed, and the presser foot is supported by the sewing material, and the speed of pressing down is slowed down. The rate of change of the positive rotation angle of the output shaft of the motor is gradually reduced. However, the rate of change of the positive rotation angle is still greater than the preset value, so the controller still sends a positive rotation signal to the motor, so that the output shaft of the motor continues to rotate in the first direction.

[0062] When the presser foot compacts the sewing material, that is, when the presser foot is in the first position, the deformation of the sewing material is the largest, and the presser foot is restricted by the sewing table and cannot move down further, so that the output shaft of the motor can no longer rotate in the first direction. When the positive rotation angle change rate is less than or equal to the preset value, the controller sends an angle holding signal to the motor, so that the output shaft of the motor remains in the rotation position and the presser foot remains in the first position.

[0063] It is worth noting that the controller includes a memory, an input end of which is electrically connected to the angle detector and is used to record the forward rotation angle of the presser foot assembly when it is in the first position as the initial angle, so as to obtain the data required for the presser foot rise mentioned below.

[0064] Figure 4 A second flow chart of a sewing device provided by an embodiment of the present invention. Figure 4 Let’s describe the process of the second part.

[0065] S110, the input end sends the pressure value set by the user to the controller; S111, the controller determines the working current corresponding to the pressure value set by the user according to the mapping relationship between the pressure value set by the user and the working current, and feeds back to adjust the input current of the motor;

[0066] Specifically, the user can input the pressure value set by the user according to the material and thickness of the sewing material to be processed. Alternatively, the user can input the material and thickness of the sewing material to be processed, and the controller automatically configures the pressure value set by the user. It should be noted that the user can input the set pressure value before inputting the start command.

[0067] The torque of the motor (the output force of the motor) is related to the output current of the motor. Changing the output current of the motor can change the torque of the motor, and then change the pressure of the presser foot on the sewing material. The controller can store a mapping table, which is a correspondence table between the pressure value set by the user and the working current. That is, when the controller obtains a pressure value set by the user, it can obtain a working current corresponding to the pressure value set by the user through the mapping table. The working current is the output current of the motor when the pressure of the presser foot on the sewing material is the set pressure value.

[0068] The controller can change the output current of the motor by adjusting the input current of the motor. For example, the controller can change the input current of the motor by connecting a sliding resistor, a MOS tube, or a triode in series in the power supply circuit of the motor.

[0069] In addition, the mapping table can be stored in the controller before leaving the factory. In order to obtain the mapping table, a pressure device can be installed on the sewing table during the development stage of the equipment. The pressure device can detect the pressure of the sewing table caused by different motor output currents. When the sewing equipment is delivered, it can be equipped with no pressure device to reduce costs.

[0070] S113, the current detector detects the output current of the motor and generates a current detection signal; S114, the current detector sends the current detection signal to the controller;

[0071] Specifically, the input end of the detector can be connected in series with the motor, and the output end of the detector can be electrically connected to the input end of the controller. The detector can be a device such as a current loop that can detect the output current of the motor.

[0072] S115, the controller receives the current detection signal, and when the current detection signal is not equal to the working current, continues to adjust the input current of the motor; when the current detection signal is equal to the working current, maintains the current output current of the motor and generates a working signal;

[0073] Specifically, when the presser foot is pressed down to the first position, the pressure value of the presser foot on the sewing material is the initial pressure. The initial pressure of the presser foot can be the same each time. For example, at the first time, the initial pressure is 100%, so the output torque of the motor is 100%. The set pressure value is 80%, and the controller adjusts the output current of the motor so that the output torque of the motor is 80%. After the presser foot leaves the sewing material, the controller needs to adjust the output torque of the motor to 100%, so that at the second time, the initial pressure is 100%.

[0074] Of course, the initial pressure of the presser foot can also be the pressure value set last time. Exemplarily, when the first time, the set pressure value is 60%, then when the second time, the initial pressure of the presser foot is 60%.

[0075] In addition, when the current detection signal is equal to the working current, the controller maintains the output current of the motor at this time, so that the motor maintains the current output torque, and further the presser foot maintains the current pressure on the sewing material.

[0076] Figure 5 A third flow chart of a sewing device provided by an embodiment of the present invention. Figure 5 To describe the process of the third part.

[0077] S201, the controller sends a working signal to the driver; S202, the driver drives the sewing table and the embroidery needle to move according to the working signal; S203, the controller generates an end signal after sewing is completed; S204, the controller sends an end signal to the controller and the driver; S205, the driver stops driving the sewing table and the embroidery needle to move according to the end signal;

[0078] Specifically, when the pressure of the presser foot on the sewing material is the pressure value set by the user, the controller controls the driver to move the sewing table and the embroidery needle to form a sewing pattern on the sewing material. The part about the controller controlling the movement of the sewing table and the embroidery needle is an existing technology and will not be repeated here.

[0079] Figure 6 A fourth flow chart of a sewing device provided by an embodiment of the present invention. Figure 6 To describe the process of the fourth part.

[0080] S301, the controller records that when the presser foot is in the first position, the forward rotation angle of the motor is recorded as the initial angle;

[0081] Specifically, when the motor drives the presser foot to rise, and the motor is powered on again after a sudden power failure, the controller can find the position of the presser foot when the power is off according to the initial angle of the motor. The initial angle can be the forward rotation angle of the motor when the presser foot is pressed down to the first position.

[0082] In addition, if a position sensor is used to detect the position of the presser foot and feed the position of the presser foot back to the controller, not only will the cost increase, but the sewing material is flexible and it is difficult for the position sensor to detect whether the presser foot is separated from the sewing material.

[0083] S302, the input terminal sends the lifting height set by the user to the controller; S303, the controller determines the final reversal angle corresponding to the lifting height set by the user according to the mapping relationship between the lifting height set by the user and the final reversal angle, and generates a reversal signal; S304, the controller sends a reversal signal;

[0084] The set lifting height can be 0-17 mm. The lifting height refers to the height of the presser foot lifted upward from the first position. That is, the first position is the initial position.

[0085] S305, the motor rotates in the second direction according to the reversal signal to drive the presser foot to move upward; S306, the angle detector detects the reversal angle of the motor and generates a reverse angle signal; S307, the angle detector sends a reverse angle signal; S308, the controller receives the reverse angle signal; when the reversal angle is not equal to the final reversal angle, the controller generates a reversal signal; when the reversal angle is equal to the final reversal angle, the controller generates a stop signal; S309, the controller sends a reversal signal or a stop signal;

[0086] S310, the motor output shaft continues to rotate in the second direction according to the reversal signal to drive the presser foot to move upward; the motor output shaft stops rotating according to the stop signal, and the presser foot is in the second position away from the sewing material.

[0087] It should be noted that the set lifting height mentioned in S302 can be obtained by user input or calculated by the controller. Exemplarily, when the output shaft of the motor rotates in the first direction, the controller can record the rotation position of the output shaft of the motor as the change position when the rate of change of the forward rotation angle begins to change. After the output shaft of the motor rotates in the second direction to the change position, it continues to rotate in the second direction by a certain angle. At this time, the presser foot is in the second position of being separated from the sewing material.

[0088] The terms "upper" and "lower" etc. are used to describe the relative position relationship of each structure in the accompanying drawings, which is only for the convenience of description and is not intended to limit the scope of implementation of the present invention. Changes or adjustments to the relative relationship shall be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0089] It should be noted that: in the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0090] In addition, in the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected, or indirectly connected through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0091] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0092] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A sewing device, characterized in that: It comprises a frame, on which a sewing table, a motor, a presser foot assembly, a transmission mechanism and a controller are installed; The sewing platform is arranged on the frame and is used to place sewing materials; the presser foot assembly is located above the sewing platform; the motor drives the presser foot assembly to move in a vertical direction through the transmission mechanism; the transmission mechanism is tightly connected to the presser foot assembly and is used to convert the rotation of the motor into a linear motion of the presser foot assembly; The controller is electrically connected to the motor and is used to control the rotation of the motor; the controller is also used to control the motor to rotate forward, so that the presser foot assembly moves down to a first position to press the sewing material, and the first position is a position where the presser foot is lowered and cannot be lowered any further; the controller is also used to adjust the output current of the motor to a working current according to a pressure value set by a user, and maintain the output current of the motor as the working current unchanged during the sewing process, and control the motor to reverse after the sewing is completed, so that the presser foot assembly moves up to a second position to separate from the sewing material; Also included is an angle detector for detecting the forward rotation angle of the motor; The input end of the controller is electrically connected to the angle detector, and the output end of the controller is electrically connected to the motor. The controller is used to determine the rate of change of the forward rotation angle according to the forward rotation angle measured by the angle detector, and when the rate of change of the forward rotation angle is less than or equal to a preset value, control the motor to maintain the current forward rotation angle so that the presser foot assembly is maintained at the first position; The controller comprises a memory, an input end of which is electrically connected to the angle detector and is used to record the forward rotation angle of the presser foot assembly when it is in the first position as an initial angle.

2. The sewing device according to claim 1, characterized in that The angle detector is an encoder arranged at one end of the motor.

3. The sewing device according to claim 1, characterized in that: It also includes a current detector for detecting the output current of the motor; the input end of the current detector is electrically connected to the output end of the motor, and the output end of the current detector is electrically connected to the controller; The controller is used to determine the working current corresponding to the current pressure value set by the user according to the mapping relationship between the pressure value set by the user and the working current; The controller is also used for feedback-regulating the output current to the operating current according to the output current measured by the current detector.

4. The sewing device according to claim 3, characterized in that: The current detector is a current loop.

5. The sewing device according to claim 1, characterized in that: The controller is also used to maintain the current output current of the motor unchanged when the output current is the working current, and control the sewing table to move horizontally or vertically according to the sewing pattern set by the user.

6. The sewing device according to any one of claims 1 to 5, characterized in that: The controller is also used to determine the final reversal angle corresponding to the current lifting height set by the user according to the mapping relationship between the lifting height set by the user and the final reversal angle after sewing is completed, and control the motor to reverse.

7. The sewing device according to claim 6, characterized in that It also includes an angle detector for detecting the reverse angle of the motor, wherein the output end of the angle detector is electrically connected to the controller; The controller is used for feedback-adjusting the motor according to the reversal angle measured by the angle detector until the reversal angle reaches the final reversal angle.

8. The sewing device according to claim 6, characterized in that The set lifting height is 0-17 mm.

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