A sewing machine with adjustable pricking stroke and control method thereof

Abstract

The application provides a sewing machine with adjustable fabric penetrating stroke and a control method thereof. The sewing machine with adjustable fabric penetrating stroke comprises a main shaft, a needle bar, a connecting column fixed on the needle bar, a needle bar connecting rod, an adjusting driving motor, an eccentric part fixed on the end of the main shaft, a stroke adjuster, and a stroke adjusting assembly. One end of the needle bar connecting rod is hinged to the connecting column. The eccentric part is provided with an eccentric shaft part eccentric to the rotation center of the main shaft. The stroke adjuster is rotatably installed on the eccentric shaft part. The adjusting driving motor is connected to the stroke adjuster through the stroke adjusting assembly. The other end of the needle bar connecting rod is hinged to the stroke adjuster. The connecting points of the stroke adjuster and the stroke adjusting assembly, the connecting points of the stroke adjuster and the eccentric shaft part, and the connecting points of the stroke adjuster and the needle bar connecting rod are distributed in dislocation. The application can switch different fabric penetrating strokes on a single sewing machine to achieve better sewing effect, expand the sewing adaptation range of the single sewing machine, and improve the use experience of the whole machine.

Description

A sewing machine with adjustable needle-punch stroke and its control method Technical Field

[0001] This invention relates to sewing machines, and more particularly to a sewing machine with adjustable needle-punching stroke and its control method. Background Technology

[0002] A sewing machine is a machine that uses one or more sewing threads to create one or more stitches on fabric, allowing one or more layers of fabric to interweave or sew together. A sewing machine mainly includes a housing, a feed dog mechanism, a needle bar mechanism (also known as a needle insertion mechanism), a thread hook mechanism, a presser foot mechanism, and a thread trimming mechanism. These mechanisms work together to complete the sewing process.

[0003] Currently, the needle bar mechanism of a sewing machine is installed at the left end of the main shaft, which is driven by a main motor. The needle bar mechanism adopts a crank-slider structure, mainly including a needle bar crank fixed to the left end of the main shaft, a needle bar extending vertically, a connecting post fixed to the needle bar, and a needle bar connecting rod. One end of the needle bar connecting rod is hinged to the needle bar crank, and the other end is hinged to the connecting post. For example, a sewing machine disclosed in Chinese invention patent CN110565283B. When the sewing machine is running, the main shaft rotates, driving the needle bar to move up and down reciprocally through the crank-slider structure composed of the needle bar crank, needle bar connecting rod, and connecting post. The needle at the lower end of the needle bar moves up and down synchronously with the needle bar, performing the needle-piercing action.

[0004] Clearly, the movement of the needle bar through the fabric (i.e., the needle bar stroke) is determined by the parameters of the needle bar mechanism. A fixed sewing machine model corresponds to a fixed needle bar stroke; that is, the needle bar stroke of existing sewing machines is not adjustable. However, common flatbed sewing machines require different needle bar strokes when sewing thin, medium, and thick materials. Specifically, there are derivative models of flatbed sewing machines with different needle bar strokes for thin, medium, and thick materials. When changing fabrics, a corresponding model needs to be changed, which is inconvenient for customers who frequently change fabrics and materials. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a sewing machine with adjustable needle-punch stroke, which can conveniently adjust the needle-punch stroke.

[0006] To achieve the above objectives, the present invention provides a sewing machine with adjustable needle bar stroke, comprising a main shaft rotatably supported in a sewing machine housing, a needle bar extending vertically, a connecting column fixed to the needle bar, a needle bar connecting rod, an adjustment drive motor, an eccentric component fixed to the end of the main shaft, a stroke adjuster, and a stroke adjustment assembly. One end of the needle bar connecting rod is hinged to the connecting column. An eccentric shaft portion eccentrically disposed on the eccentric component is fixedly arranged with respect to the rotation center of the main shaft. The stroke adjuster is rotatably mounted on the eccentric shaft portion. The adjustment drive motor is connected to the stroke adjuster through the stroke adjustment assembly. The other end of the needle bar connecting rod is hinged to the stroke adjuster. The connection points between the stroke adjuster and the stroke adjustment assembly, the connection points between the stroke adjuster and the eccentric shaft portion, and the connection points between the stroke adjuster and the needle bar connecting rod are staggered.

[0007] Furthermore, the stroke adjustment assembly includes an adjustment crank and an adjustment connecting rod. The adjustment crank is connected to and driven to rotate by the adjustment drive motor. The two ends of the adjustment connecting rod are respectively hinged to the adjustment crank and the stroke adjuster.

[0008] Furthermore, the sewing machine with adjustable needle-punch stroke also includes a presser foot, a presser foot lifting assembly connected to the presser foot, and a presser foot lifting transmission unit. The adjustment drive motor is connected to the presser foot lifting assembly through the presser foot lifting transmission unit.

[0009] The operating range of the adjustable drive motor includes an independent piercing zone and a presser foot lifting zone. When the adjustable drive motor operates within the piercing zone, the presser foot lifting transmission unit has no power transmission.

[0010] Furthermore, the presser foot transmission unit includes a presser foot transmission cam, a presser foot transmission lever with a fixed swing fulcrum, and a presser foot transmission ball rotatably mounted on one end of the presser foot transmission lever. The presser foot transmission cam is connected to an adjustment drive motor and is driven to rotate by the adjustment drive motor. The other end of the presser foot transmission lever is connected to the presser foot assembly.

[0011] When the adjustment drive motor operates within the piercing zone, the lifting foot transmission ball is separated from the lifting foot transmission cam, or the lifting foot transmission ball and the lifting foot transmission cam are in contact with each other on their equal diameter surfaces.

[0012] When the adjustment drive motor operates within the pressure foot lifting range, the pressure foot lifting transmission ball engages with the variable diameter surface of the pressure foot lifting transmission cam.

[0013] Furthermore, the presser foot lifting assembly includes a presser foot lifting plate, a vertically extending pressure rod, and a pressure rod guide fixed on the pressure rod. The presser foot lifting transmission lever is hinged to the upper end of the presser foot lifting plate. The presser foot lifting plate is provided with a lifting hook. The pressure rod guide is provided with a connecting protrusion that engages with the lifting hook. The presser foot is installed at the lower end of the pressure rod.

[0014] Furthermore, the sewing machine with adjustable needle-punch stroke also includes a presser foot spring coaxially arranged with the presser bar, and a pressure adjustment assembly installed on the sewing machine housing. The upper and lower ends of the presser foot spring abut against the pressure adjustment assembly and the presser bar, respectively.

[0015] Furthermore, the adjustment drive motor is fixed at the head of the sewing machine housing.

[0016] The present invention also provides a control method for a sewing machine with adjustable needle-punch stroke as described above, comprising the following steps:

[0017] S1. An electronic control module that is communicatively connected to the adjustment drive motor is configured in the sewing machine, and the electronic control module stores the needle-piercing interval of the adjustment drive motor;

[0018] S2. After the sewing machine is powered on, the electronic control module controls and adjusts the rotation angle value X1 within the piercing section of the drive motor;

[0019] S3. When the electronic control module receives the instruction to adjust the barbed wire stroke, the electronic control module controls the adjustment drive motor to operate within the barbed wire range, so that the adjustment drive motor outputs the target rotation angle value X2 within the barbed wire range, and the target rotation angle value X2 matches the adjusted target barbed wire stroke; the adjustment drive motor changes the position angle of the stroke adjuster through the stroke adjustment component, thereby changing the transmission efficiency between the main shaft and the connecting column.

[0020] S4. The sewing machine starts sewing normally.

[0021] Furthermore, the sewing machine with adjustable needle-punch stroke also includes a presser foot, a presser foot lifting assembly connected to the presser foot, and a presser foot lifting transmission unit. The adjustment drive motor is connected to the presser foot lifting assembly through the presser foot lifting transmission unit.

[0022] The sewing machine control method further includes the following steps:

[0023] S5. The electronic control module stores the lifting presser foot interval for adjusting the drive motor, and the piercing interval and the lifting presser foot interval are independent of each other.

[0024] S6. When the electronic control module controls the adjustment drive motor to operate in the piercing fabric zone, the lifting presser foot transmission unit has no power transmission, the lifting presser foot assembly does not move, and the presser foot remains in the lowered state.

[0025] S7. When the electronic control module receives the command to lift the pressure foot, the electronic control module controls the adjustment drive motor to rotate from the current angle value to the starting point of the pressure foot lifting interval, and then rotate from the starting point of the pressure foot lifting interval to the ending point, so that the adjustment drive motor outputs the angle value P within the pressure foot lifting interval, the pressure foot lifting transmission unit has power transmission, and the adjustment drive motor drives the pressure foot lifting assembly to move through the pressure foot lifting transmission unit, so that the pressure foot moves upward.

[0026] S8. After the pressure foot is lifted, the electronic control module controls and adjusts the drive motor to rotate in the opposite direction to the current angle value before lifting the pressure foot.

[0027] As described above, the sewing machine with adjustable needle-punch stroke and its control method according to the present invention have the following beneficial effects:

[0028] In this application, when it is necessary to adjust the needle bar's reciprocating motion of the needle insertion stroke, the rotation of the drive motor shaft is adjusted, and the position angle of the variable stroke adjuster is changed through the stroke adjustment component. Thus, during subsequent sewing, the stroke of the connecting column driven by the main shaft through the eccentric component, stroke adjuster, and needle bar connecting rod changes, thereby altering the transmission efficiency between the main shaft and the connecting column. The needle bar's synchronous reciprocating motion with the connecting column also changes, resulting in a change in the needle insertion stroke. Therefore, this application allows for switching between different needle insertion strokes on a single sewing machine, adapting the needle insertion stroke to the fabric for better sewing results. This effectively expands the sewing adaptability of a single sewing machine and improves the overall user experience. Attached Figure Description

[0029] Figures 1 and 2 are schematic diagrams of the sewing machine in this application from different perspectives.

[0030] Figure 3 is a schematic diagram of the transmission structure from the drive motor to the stroke adjuster and from the spindle to the needle bar in this application.

[0031] Figure 4 is a schematic diagram of the transmission structure of the adjustment drive motor to the lifting foot assembly in this application.

[0032] Figure 5 is a schematic diagram of the connection between the adjusting crank, adjusting connecting rod, stroke adjuster, eccentric part and needle bar connecting rod in this application.

[0033] Figure 6 is a schematic diagram of the principle of the needle-punch fabric stroke adjustment in this application.

[0034] Figure 7 is a schematic diagram of the structure of the adjusting crank and the lifting foot transmission cam being an integral component in this application.

[0035] Figure 8 is a schematic diagram of the distribution of the adjustable drive motor operating range in this application.

[0036] Figure 9 is a graph showing the relationship between the angle φ of the adjusting crank and the stroke H of the puncture in this application.

[0037] Figure 10 is a flowchart of the control method of the sewing machine with adjustable needle-punch stroke in this application.

[0038] Component designation explanation

[0039] 10 spindles

[0040] 20 needle bar

[0041] 30 Connecting Post

[0042] 40 needle bar connecting rod

[0043] 50 Adjust the drive motor

[0044] 60 Eccentric parts

[0045] 70 Stroke Regulator

[0046] 80 Stroke Adjustment Component

[0047] 81 Adjusting crank

[0048] 82 Adjusting rod

[0049] 90 Presser foot assembly

[0050] 91 Lift the presser foot lifting plate

[0051] 911 Lifting Hook

[0052] 92 Compression bar

[0053] 93 Pressure bar guide frame

[0054] 931 Connecting protrusion

[0055] 110 Presser Foot Transmission Unit

[0056] 111 Presser foot drive cam

[0057] 112 Lifting the presser foot transmission lever

[0058] 113 Lifting foot drive ball bearing

[0059] 120 pressure foot spring

[0060] 130 Voltage Regulator

[0061] 140 Limit slider Detailed Implementation

[0062] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification.

[0063] It should be understood that the structures, proportions, sizes, etc., depicted in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of the invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness and objectives of the invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms "upper," "lower," "left," "right," "middle," and "one" used in this specification are merely for clarity and not intended to limit the scope of the invention. Changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention's implementation.

[0064] This application provides a sewing machine with adjustable needle-punch stroke, hereinafter referred to as the sewing machine; the sewing machine is a flatbed sewing machine. For ease of description, in the following embodiments, the directions are defined as follows: the length direction of the sewing machine is defined as the left-right direction, and the direction towards the head of the sewing machine is the left direction, and the direction towards the tail of the sewing machine is the right direction. The left-right direction is also the axial direction of the main shaft 10 in the sewing machine; the height direction of the sewing machine is defined as the up-down direction, the width direction of the sewing machine is defined as the front-back direction, and the direction of fabric movement when the sewing machine is sewing forward is the front direction.

[0065] As shown in Figures 1 to 3, the sewing machine with adjustable needle travel involved in this application includes a main shaft 10 extending horizontally, a needle bar 20 extending vertically, a connecting column 30 fixed and locked to the needle bar 20 by screws, a needle bar connecting rod 40, an adjusting drive motor 50, an eccentric part 60, a travel adjuster 70, and a travel adjusting assembly 80. The main shaft 10 is rotatably supported in the sewing machine housing. The adjustment drive motor 50 is fixed to the sewing machine housing. The eccentric part 60 is fixed and locked to the left end of the main shaft 10 by screws. An eccentric shaft part is fixed on the eccentric part 60, which is eccentrically set to the rotation center of the main shaft 10. The eccentric shaft part extends straight to the left from the left end face of the eccentric part 60. Therefore, the eccentric shaft part is parallel to the main shaft 10. The stroke adjuster 70 is rotatably installed on the eccentric shaft part. The adjustment drive motor 50 is connected to the stroke adjuster 70 through the stroke adjustment assembly 80. One end of the needle bar connecting rod 40 is hinged to the connecting post 30, and the other end of the needle bar connecting rod 40 is hinged to the stroke adjuster 70. Furthermore, as shown in Figure 5, the connection points O1 between the stroke adjuster 70 and the stroke adjustment assembly 80, O2 between the stroke adjuster 70 and the eccentric shaft, and O3 between the stroke adjuster 70 and the needle bar connecting rod 40 are staggered. In this embodiment, the connection point O1 between the stroke adjuster 70 and the stroke adjustment assembly 80 is located at the front end of the stroke adjuster 70, the connection point O2 between the stroke adjuster 70 and the eccentric shaft is located at the middle end of the stroke adjuster 70, and the connection point O3 between the stroke adjuster 70 and the needle bar connecting rod 40 is located at the rear end of the stroke adjuster 70. Within the range of 360° rotation of the adjustment drive motor 50, as shown in Figure 8, the operating range of the adjustment drive motor 50 includes the piercing section T1, where the starting angle and ending angle of the piercing section T1 are θ1 and θ2, respectively.

[0066] The present invention also provides a control method for the above-mentioned sewing machine with adjustable needle-punch stroke, as shown in Figure 10. The control method includes the following steps:

[0067] S1. An electronic control module is configured in the sewing machine to communicate with the adjustment drive motor 50. The electronic control module stores the needle-punching interval T1 of the adjustment drive motor 50.

[0068] S2. After the sewing machine is powered on, the electronic control module controls the adjustment drive motor 50 to output the angle value X1 within the piercing interval T1. Therefore, θ1≤X1≤θ2. Under the action of the adjustment drive motor 50 and the stroke adjustment component 80, the stroke adjuster 70 is reliably maintained at the current position angle. Then, during sewing, the main motor drives the main shaft 10 to rotate, and the eccentric component 60 rotates with the main shaft 10. The eccentric component 60 drives the connecting column 30 to move up and down reciprocally through the stroke adjuster 70 and the needle bar connecting rod 40. The needle bar 20 and the needle at its lower end move up and down synchronously with the connecting column 30, performing the piercing action. The stroke of the needle bar 20 moving up and down is the piercing stroke.

[0069] S3. When the electronic control module receives the instruction to adjust the needle bar stroke, it controls the main motor to stop running. Simultaneously, the electronic control module controls the adjustment drive motor 50 to operate within the needle bar section T1, causing the adjustment drive motor 50 to output the target rotation angle value X2 within the needle bar section T1, where θ1≤X2≤θ2, but X2≠X1. The target rotation angle value X2 matches the adjusted target needle bar stroke. During the rotation of the motor shaft of the adjustment drive motor 50 from X1 to X2, the adjustment drive motor 50 acts on the stroke adjuster 70 through the stroke adjustment component 80, changing the position angle of the stroke adjuster 70. Thus, during subsequent sewing, the stroke of the main shaft 10 driving the connecting column 30 to move up and down through the eccentric part 60, the stroke adjuster 70, and the needle bar connecting rod 40 changes, thus altering the transmission efficiency between the main shaft 10 and the connecting column 30. Consequently, the stroke of the needle bar 20 moving up and down synchronously with the connecting column 30 changes, resulting in a change in the needle bar stroke.

[0070] S4. The sewing machine starts sewing normally.

[0071] Therefore, the sewing machine involved in this application realizes automatic adjustment of the needle-punch stroke; when sewing fabrics with large differences in thickness, this application can switch different needle-punch strokes on a single sewing machine, so that the needle-punch stroke is adapted to the fabric, achieving better sewing results, effectively expanding the sewing adaptability range of a single sewing machine, and improving the overall user experience of the machine.

[0072] Further, as shown in Figures 3, 5, and 6, the stroke adjustment assembly 80 includes an adjustment crank 81 and an adjustment connecting rod 82. The adjustment crank 81 is connected to and driven to rotate by the adjustment drive motor 50. The two ends of the adjustment connecting rod 82 are hinged to the adjustment crank 81 and the stroke adjuster 70, respectively. In this embodiment, the adjustment crank 81 is directly fixed and locked to the motor shaft of the adjustment drive motor 50 by screws. The electronic control module controls the rotation angle of the motor shaft of the adjustment drive motor 50, which in turn controls the angle φ of the adjustment crank 81, as shown in Figure 6. The angle φ is the angle between the adjustment crank 81 and the horizontal plane, and this angle φ has a roughly linear relationship with the piercing stroke H, as shown in Figure 9. Specifically, when the adjustment drive motor 50 changes the angle φ of the adjustment crank 81, the adjustment crank 81 changes the position angle of the stroke adjuster 70 through the adjustment connecting rod 82, causing the eccentric member 60 to rotate and the transmission efficiency transmitted to the connecting column 30, which is manifested as a change in the piercing stroke. In one specific embodiment, as shown in Figure 9, when the angle φ of the adjusting crank 81 increases from 0° to 20°, the needle-punch stroke H correspondingly decreases from 35mm corresponding to H3 to 30.8mm corresponding to H1.

[0073] Preferably, as shown in Figures 2 and 3, the sewing machine further includes a fixedly installed limiting guide rail and a limiting slider 140 that slides with the limiting guide rail. The limiting slider 140 is movably installed in the limiting groove of the limiting guide rail. The limiting guide rail is not shown in the figure. The limiting slider 140, the lower end of the needle bar connecting rod 40, and the connecting post 30 are coaxially hinged by a left-right extending pin.

[0074] Furthermore, the adjusting drive motor 50 also serves as the drive for automatically lifting the presser foot. Specifically, as shown in Figures 1 and 2, the sewing machine also includes a presser foot, a presser foot lifting assembly 90 connected to the presser foot, and a presser foot lifting transmission unit 110. The adjusting drive motor 50 is connected to the presser foot lifting assembly 90 through the presser foot lifting transmission unit 110. As shown in Figure 8, the operating range of the adjusting drive motor 50 also includes the presser foot lifting interval T2. The starting angle value and the ending angle value of the presser foot lifting interval T2 are θ3 and θ4, respectively. The needle insertion interval T1 and the presser foot lifting interval T2 are two independent working intervals. In this embodiment, the starting angle value θ3 of the presser foot lifting interval T2 is equal to the ending angle value θ2 of the needle insertion interval T1. Along the rotation direction of the motor shaft of the adjusting drive motor 50 when lifting the presser foot (i.e., the counterclockwise direction in the view of Figure 8), θ1 < θ2 = θ3 < θ4, and the remaining area is an inactive interval. In particular, when the adjustment drive motor 50 is running in the piercing line interval T1, the presser foot lifting transmission unit 110 has no power transmission, so the presser foot lifting assembly 90 does not move and the presser foot remains in the lowered state, thus realizing that the piercing line stroke adjustment function and the presser foot lifting function do not interfere with each other.

[0075] Further, the preferred structure of the presser foot lifting transmission unit 110 is as follows: As shown in Figures 1, 2, and 4, the presser foot lifting transmission unit 110 includes a presser foot lifting transmission cam 111, a presser foot lifting transmission lever 112 with a fixed swing fulcrum, and a presser foot lifting transmission ball 113 rotatably mounted on the right end of the presser foot lifting transmission lever 112. The presser foot lifting transmission cam 111 is connected to and driven to rotate by the adjustment drive motor 50. The left end of the presser foot lifting transmission lever 112 is connected to the presser foot assembly 90. In this embodiment, the presser foot lifting transmission cam 111 is directly fixed and locked to the motor shaft of the adjustment drive motor 50 by screws. The presser foot lifting transmission lever 112 is rotatably mounted to the sewing machine housing by a shaft screw extending forward and backward, which constitutes the fixed swing fulcrum of the presser foot lifting transmission lever 112. When the adjustment drive motor 50 operates within the quilting section T1, the presser foot transmission ball 113 separates from the presser foot transmission cam 111, or the presser foot transmission ball 113 contacts the equal-diameter surface on the outer periphery of the presser foot transmission cam 111. The presser foot transmission lever 112 does not rotate, and the presser foot assembly 90 does not move. When the adjustment drive motor 50 operates within the presser foot section T2, the presser foot transmission ball 113 contacts the variable-diameter surface on the outer periphery of the presser foot transmission cam 111. At this time, the presser foot transmission cam 111 drives the presser foot transmission lever 112 to rotate around its fixed pivot point via the presser foot ball. The presser foot transmission lever 112 drives the presser foot assembly 90 to move, causing the presser foot to move upward, thus achieving automatic presser foot lifting.

[0076] Furthermore, the preferred structure of the presser foot lifting assembly 90 is as follows: as shown in Figures 1, 2 and 4, the presser foot lifting assembly 90 includes a presser foot lifting plate 91, a vertically extending pressure rod 92, and a pressure rod guide 93 fixed and locked to the pressure rod 92 by screws. The left end of the presser foot transmission lever 112 is hinged to the upper end of the presser foot lifting plate 91. The presser foot lifting plate 91 is provided with a lifting hook 911, and the pressure rod guide 93 is provided with a connecting protrusion 931 that engages with the lifting hook 911. The presser foot is installed at the lower end of the pressure rod 92.

[0077] Preferably, as shown in Figures 1, 2, and 4, the sewing machine with adjustable needle-punch stroke further includes a presser foot spring 120 coaxially arranged with the presser bar 92, and a pressure adjusting assembly 130 installed on the sewing machine housing. The upper and lower ends of the presser foot spring 120 abut against the pressure adjusting assembly 130 and the presser bar 92, respectively. The presser foot spring 120 applies a spring force to the presser bar 92, and the spring force is transmitted to the presser foot at the lower end of the presser bar 92, so that the presser foot reliably presses against the fabric and cooperates with the feed dog in the sewing machine to perform the feeding action. The pressure adjusting assembly 130 is preferably a bolt assembly. Under the action of the feed dog assembly, the upper end of the presser foot spring 120 is adjusted to adjust the compression of the presser foot spring 120, which in turn adjusts the spring force applied by the presser foot spring 120 to the presser bar 92.

[0078] Furthermore, the adjustment drive motor 50 is a high-performance stepper motor or servo motor to improve control accuracy. The adjustment drive motor 50 is fixed at the head of the sewing machine housing, specifically at the left end of the sewing machine housing, near the needle bar 20 and the pressure rod 92 in the presser foot assembly 90. This shortens the transmission chain between the adjustment drive motor 50, the stroke adjuster 70, and the presser foot assembly 90, simplifying the structure and improving transmission reliability. Additionally, the adjustment crank 81 and the presser foot transmission cam 111 can be separate components, forming a fixed angle in the circumferential direction, as shown in Figures 1 and 2. In other embodiments, the adjustment crank 81 and the presser foot transmission cam 111 can also be an integrated component, as shown in Figure 7. Moreover, the needle insertion and presser foot functions at the entire sewing machine head can be integrated into an independent needle insertion and presser foot module, facilitating subsequent modular technology integration and making it well-suited for modular sewing machines.

[0079] Furthermore, the sewing machine is also equipped with an operation panel that communicates with the electronic control module. The operation panel has a display screen and input buttons, which realizes digital adjustment and display of the needle insertion stroke and the presser foot height.

[0080] In summary, as shown in Figure 10, the control method for a sewing machine with the above structure also includes the following steps.

[0081] Step 1: In the electronic control module, set the piercing stroke range T1 and presser foot lifting range T2 of the adjustment drive motor 50. The motor shaft rotation angle range of the piercing stroke range T1 is θ1~θ2, and the motor shaft rotation angle range of the presser foot lifting range T2 is θ3~θ4, where θ2 and θ3 are equal. Set a first mapping table in the electronic control module between the piercing stroke and the motor shaft rotation angle of the adjustment drive motor 50, as shown in Table 1; set a second mapping table in the electronic control module between the presser foot lifting height and the motor shaft rotation angle of the adjustment drive motor 50, as shown in Table 2.

[0082] Table 1. First mapping table of needle-punching stroke and motor shaft rotation angle of adjustment drive motor 50

[0083] The motor shaft rotation angles D0θ1……D1θ2 of the quilting stroke adjustment drive motor 50 surface

[0084] Table 2. Second mapping table of presser foot height and motor shaft rotation angle of adjustment drive motor 50

[0085] The motor shaft rotation angle of the pressure foot height adjustment drive motor 50 is G0θ3……G1θ4 surface

[0086] Step 2: After the sewing machine is powered on, the electronic control module controls and adjusts the drive motor 50 to output the angle value X1 within the needle-punching interval T1.

[0087] Step 3: When the piercing stroke needs adjustment, the worker can input the target piercing stroke through the operation panel. After receiving the instruction to adjust the piercing stroke, the electronic control module controls the main motor to stop running. Simultaneously, the electronic control module controls the adjustment drive motor 50 to operate within the piercing zone T1, causing the adjustment drive motor 50 to rotate from the angle value X1 to the target angle value X2 within the piercing zone T1. The target angle value X2 matches the adjusted target piercing stroke. During this process, the position angle φ of the adjusting crank 81 is adjusted and rotated to the corresponding position, thereby changing the transmission efficiency between the main shaft 10 and the connecting column 30, thus realizing the change of the piercing stroke.

[0088] Step 4: The sewing machine begins sewing normally.

[0089] Step 5: When the electronic control module receives the presser foot lifting command, it controls the adjustment drive motor 50 to rotate from the current angle value within the quilting section T1 to the starting point θ3 of the presser foot lifting section T2, and then from the starting point θ3 to the ending point θ4, causing the adjustment drive motor 50 to output the angle value P within the presser foot lifting section T2, where θ3 < P ≤ θ4. When the adjustment drive motor 50 rotates within the presser foot lifting section T2, the presser foot lifting transmission unit 110 receives power. The adjustment drive motor 50 drives the presser foot lifting assembly 90 through the presser foot lifting transmission unit 110, causing the presser foot to move upward, thus achieving automatic presser foot lifting. Furthermore, by outputting different angle values ​​within the presser foot lifting section T2, the adjustment drive motor 50 can lift the presser foot to different heights to meet different sewing needs.

[0090] Step 6: After the pressure foot is lifted, the electronic control module controls the adjustment drive motor 50 to rotate in the opposite direction to the current angle value before lifting the pressure foot.

[0091] Step 7: The sewing machine begins sewing normally.

[0092] In summary, the sewing machine of this application uses a single motor for adjusting and controlling the needle insertion stroke and driving the presser foot. It can automatically switch between different needle insertion strokes according to the different thicknesses of the fabric being sewn, improving the sewing machine's versatility and greatly enhancing its adaptability to different fabrics. It also improves the user experience of automatically lifting the presser foot, further enhancing the product's competitiveness. Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial applicability.

[0093] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A sewing machine with adjustable needle insertion stroke, comprising a main shaft (10) rotatably supported in a sewing machine housing, a vertically extending needle bar (20), a connecting post (30) fixed on the needle bar (20), and a needle bar connecting rod (40), one end of the needle bar connecting rod (40) being hinged to the connecting post (30), characterized in that: It also includes an adjustment drive motor (50), an eccentric component (60) fixed to the end of the main shaft (10), a stroke adjuster (70), a stroke adjustment assembly (80), a presser foot, a presser foot lifting assembly (90) connected to the presser foot, and a presser foot lifting transmission unit (110). The eccentric component (60) is fixed with an eccentric shaft portion that is eccentrically set to the rotation center of the main shaft (10). The stroke adjuster (70) is rotatably mounted on the eccentric shaft portion. The adjustment drive motor (50) is connected to the stroke adjuster (70) through the stroke adjustment assembly (80). The other end of the needle bar connecting rod (40) is connected to the stroke adjuster (70). The connection points of the stroke adjuster (70) and the stroke adjustment assembly (80), the connection points of the stroke adjuster (70) and the eccentric shaft, and the connection points of the stroke adjuster (70) and the needle bar connecting rod (40) are staggered. The adjustment drive motor (50) is connected to the presser foot assembly (90) through the presser foot lifting transmission unit (110). The operating range of the adjustment drive motor (50) includes the independent needle-punching zone (T1) and the presser foot lifting zone (T2). When the adjustment drive motor (50) operates in the needle-punching zone (T1), the presser foot lifting transmission unit (110) has no power transmission.

2. The sewing machine with adjustable needle-punch stroke according to claim 1, characterized in that: The stroke adjustment assembly (80) includes an adjustment crank (81) and an adjustment connecting rod (82). The adjustment crank (81) is connected to the adjustment drive motor (50) and is driven to rotate by the adjustment drive motor (50). The two ends of the adjustment connecting rod (82) are respectively hinged to the adjustment crank (81) and the stroke adjuster (70).

3. The sewing machine with adjustable needle-punch stroke according to claim 1, characterized in that: The presser foot lifting transmission unit (110) includes a presser foot lifting transmission cam (111), a presser foot lifting transmission lever (112) with a fixed swing fulcrum, and a presser foot lifting transmission ball (113) rotatably mounted on one end of the presser foot lifting transmission lever (112). The presser foot lifting transmission cam (111) is connected to and driven to rotate by the adjustment drive motor (50). The other end of the presser foot lifting transmission lever (112) is connected to the presser foot lifting assembly (90). When the adjustment drive motor (50) operates in the presser foot interval (T1), the presser foot transmission ball (113) is separated from the presser foot transmission cam (111), or the presser foot transmission ball (113) and the presser foot transmission cam (111) are in contact with each other on equal diameter surfaces; when the adjustment drive motor (50) operates in the presser foot interval (T2), the presser foot transmission ball (113) and the presser foot transmission cam (111) are in contact with each other on variable diameter surfaces.

4. The sewing machine with adjustable needle-punch stroke according to claim 3, characterized in that: The presser foot assembly (90) includes a presser foot lifting plate (91), a vertically extending pressure rod (92), and a pressure rod guide (93) fixed on the pressure rod (92). The presser foot transmission lever (112) is hinged to the upper end of the presser foot lifting plate (91). The presser foot lifting plate (91) is provided with a lifting hook (911), and the pressure rod guide (93) is provided with a connecting protrusion (931) that engages with the lifting hook (911). The presser foot is installed at the lower end of the pressure rod (92).

5. The sewing machine with adjustable needle-punch stroke according to claim 4, characterized in that: It also includes a presser foot spring (120) coaxially arranged with the presser bar (92) and a pressure adjustment assembly (130) installed on the sewing machine housing. The upper and lower ends of the presser foot spring (120) abut against the pressure adjustment assembly (130) and the presser bar (92) respectively.

6. The sewing machine with adjustable needle-punch stroke according to claim 1, characterized in that: The adjustable drive motor (50) is fixed at the head of the sewing machine housing.

7. A control method for a sewing machine with adjustable needle-punch stroke as described in claim 1, characterized in that: Includes the following steps: S1. An electronic control module is configured in the sewing machine to communicate with the adjustment drive motor (50). The electronic control module stores the needle-punch interval (T1) of the adjustment drive motor (50). S2. After the sewing machine is powered on, the electronic control module controls the adjustment drive motor (50) to output the angle value X1 in the needle-punch interval (T1). S3. When the electronic control module receives the instruction to adjust the needle-punch stroke, the electronic control module controls the adjustment drive motor (50) to operate in the needle-punch interval (T1), so that the adjustment drive motor (50) outputs the target angle value X2 in the needle-punch interval (T1), which matches the target needle-punch stroke. The adjustment drive motor (50) changes the position angle of the stroke adjuster (70) through the stroke adjustment component (80), thereby changing the transmission efficiency between the main shaft (10) and the connecting column (30). S4. The sewing machine starts sewing normally.

8. The control method for a sewing machine according to claim 7, characterized in that: The control method of the sewing machine further includes the following steps: S5, the electronic control module stores the presser foot lifting interval (T2) of the adjustment drive motor (50), and the needle-punching interval (T1) and the presser foot lifting interval (T2) are independent; S6, when the electronic control module controls the adjustment drive motor (50) to operate in the needle-punching interval (T1), the presser foot lifting transmission unit (110) has no power transmission, the presser foot lifting assembly (90) does not move, and the presser foot remains in a lowered state; S7, when the electronic control module receives the presser foot lifting command, the electronic control module controls the adjustment drive motor (50) to operate in the needle-punching interval (T1), the presser foot lifting assembly (90) does not move, and the presser foot remains in a lowered state; The motor (50) rotates from the current angle value to the starting point of the lifting foot interval (T2), and then rotates from the starting point of the lifting foot interval (T2) to the ending point, so that the adjustment drive motor (50) outputs the angle value P in the lifting foot interval (T2). The lifting foot transmission unit (110) has power transmission. The adjustment drive motor (50) drives the lifting foot assembly (90) to move through the lifting foot transmission unit (110), so that the pressing foot moves up. S8. After the lifting foot is completed, the electronic control module controls the adjustment drive motor (50) to rotate in the opposite direction to the current angle value before lifting the pressing foot.

Images