Automatic sewing machine with sewing material thickness detection function

Abstract

The invention belongs to the technical field of automatic sewing machines, and particularly relates to an automatic sewing machine with a sewing material thickness detection function. The automatic sewing machine comprises a full-automatic longitudinal towel sewing machine, and an overlocking machine is fixedly installed on the full-automatic longitudinal towel sewing machine. By arranging a double-detection structure of the compression thickness detection assembly and the bulkiness detection assembly, the problem that only the overall thickness of a towel can be measured and the thickness of a base and the thickness of a pile ring layer cannot be distinguished in the prior art is accurately solved, and the compression thickness detection assembly is matched with a detection conveying wheel through a thickness detection hollow wheel; in combination with linkage detection of a pressure sensor and a laser displacement sensor, the compression thickness of a towel before sewing can be accurately obtained, and data support is provided for basic adjustment of the height of a presser foot of the serger; the bulkiness detection assembly senses the reactive force of the pile loop of the cloth through a piezoelectric film sensor, a Keyence displacement sensor is matched to monitor the moving distance of a bulkiness detection height reflecting block, the height of a pile loop layer is obtained, and accurate quantification of the height of the pile loop and the bulkiness is achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automatic sewing machines, in particular to an automatic sewing machine with fabric thickness detection function. BACKGROUND

[0002] At present, as the core equipment in the field of textile processing, the automatic sewing machine greatly improves the efficiency and consistency of sewing operation by virtue of its automatic feeding, cutting and edge sewing functions, and is widely used in batch production scenes of various fabrics such as towels, clothes and home textiles. Especially in towel sewing, it can realize continuous operations such as side edge sewing, horizontal cutting and edge processing of raw fabric, and meet the needs of industrial production for process standardization and high efficiency.

[0003] However, the existing automatic sewing machine lacks precise thickness detection mechanism when facing different thickness of towel fabric. For this kind of special fabric, the towel is composed of pile layer and base, with high loft and significant thickness fluctuation. The thickness difference of different types of towels such as washcloths, bath towels and towel quilts can reach 2-5 times. Even though a few devices integrate simple thickness measurement function, they are mostly simple contact type detection such as mechanical touch pressure sensor and infrared distance sensor, which can only measure the overall thickness of the towel and cannot distinguish the thickness of the base and the pile layer, nor can it capture the loft difference of the pile layer. The loft of the pile directly determines the sewing resistance and adaptive parameters, and the adjustment based on the overall thickness will inevitably have deviations, which makes it difficult to accurately adapt the sewing parameters. When sewing thick towels according to thin towel parameters, it is easy to cause skipping lines and loose stitches due to insufficient presser foot pressure and insufficient needle stroke. When sewing thin towels according to thick towel parameters, problems such as pile collapse (forming hard edges), fabric tearing and pile falling off will occur, which seriously affects the hand feeling and appearance of the towel. In batch production, the parameters need to be adjusted frequently by manual operation, which limits the efficiency and quality stability. In view of the above technical defects, a solution is proposed. SUMMARY

[0004] To solve the above problems, the present application provides the following technical scheme: An automatic sewing machine with fabric thickness detection function, comprising a full-automatic longitudinal sewing towel machine, a hemming machine is fixedly installed on the full-automatic longitudinal sewing towel machine, a connecting bracket is fixedly installed on the full-automatic longitudinal sewing towel machine, a fabric thickness detection box is fixedly installed on the connecting bracket, a control display device is fixedly installed on the fabric thickness detection box, and the automatic sewing machine with fabric thickness detection function further comprises A compression thickness detection assembly is arranged on the right side inside the fabric thickness detection box, which detects the thickness of the towel fabric about to enter the hemming machine for sewing, so as to adjust the presser foot of the hemming machine according to the thickness of the entering towel; The loft detection assembly is arranged on the left side inside the cloth thickness detection box, and is used for detecting the loft of the terry cloth after thickness detection. The terry cloth loft can be used to adjust the needle distance, presser foot pressure, and needle lowering height of the overlock machine, so as to avoid the terry loop from being collapsed and hooked off.

[0005] Further, the compression thickness detection assembly comprises a detection conveying wheel, a mounting plate is rotatably connected to the detection conveying wheel, the bottom of the mounting plate is fixedly installed inside the cloth thickness detection box, a suspended thickness detection hollow wheel is arranged on the detection conveying wheel, a support strip is arranged inside the thickness detection hollow wheel, a pressure sensor is arranged at the bottom of the support strip, a stress conduction plate is bonded at the bottom of the pressure sensor, the bottom of the stress conduction plate is slidably connected to the inner wall of the thickness detection hollow wheel through a ball, and a thickness linkage display piece is arranged on the front and back surfaces of the thickness detection hollow wheel.

[0006] Further, the thickness linkage display piece comprises a linkage plate, the linkage plate is arranged outside the thickness detection hollow wheel, a fixed rod is connected to the linkage plate, the thickness detection hollow wheel is rotatably connected to the fixed rod through a circular ring, the inner side of the fixed rod extends into the inside of the thickness detection hollow wheel and is fixedly inserted into the support strip, a limit moving block is connected to the top of the linkage plate, a support plate is fixedly installed at the top of the cloth thickness detection box, and a laser displacement sensor is fixedly installed at the bottom of the support plate.

[0007] Further, the pressure compensation piece comprises a micro pre-pressing spring, the micro pre-pressing spring is connected in the support strip, the micro pre-pressing spring is connected to the pressure sensor, and a pressure feedback device is attached between the micro pre-pressing spring and the pressure sensor.

[0008] Further, a micro telescopic motor is built in the support strip, the micro telescopic motor is connected to the pressure sensor to control it, the pressure feedback device is electrically connected to a control display device, and the micro telescopic motor is directly triggered to compensate the mechanical pressure by sensing whether the contact pressure is in a preset range.

[0009] Further, the bulkiness detection assembly comprises an electric push rod fixedly installed on the cloth thickness detection box, a pushing plate fixedly installed at the telescopic end of the electric push rod, a plastic light plate slidably connected to the bottom of the pushing plate, a piezoelectric film sensor bonded to the bottom of the plastic light plate, a bulkiness detection height embodiment block connected to the plastic light plate, and a Kion displacement sensor fixedly installed on the pushing plate.

[0010] Further, the support comprises a sealing plate fixedly installed on the cloth thickness detection box, a fixed plate connected to the sealing plate, and a support stress plate connected to the top of the fixed plate, which serves to keep the towel cloth parallel during the bulkiness detection.

[0011] Further, both sides of the cloth thickness detection box are connected with a hanging plate, and parallel wheels are rotatably connected to the inner side of the hanging plate, which are used to keep the towel cloth parallel during the thickness detection and the bulkiness detection.

[0012] Further, the cloth tensioning piece comprises a semicircular plate connected to the bottom of the pushing plate, a center rod movably connected to the inside of the semicircular plate, two movable plates connected to the center rod, and a silica gel tensioning wheel movably connected between the two symmetrical movable plates, which is used to tension the cloth at the bottom of the plastic light plate to the two sides when the pushing plate is lowered, so as to prevent the cloth from being wrinkled and affecting the bulkiness precision.

[0013] Further, a torsional spring is connected to the center rod, and the other end of the torsional spring is connected to the bottom of the pushing plate.

[0014] Compared with the prior art, the present application has the following advantages: 1. In the present application, the double detection architecture of the compression thickness detection assembly and the bulkiness detection assembly is set, which accurately solves the problem that the existing technology can only measure the overall thickness of the towel and cannot distinguish the thickness of the base and the loop layer, wherein the compression thickness detection assembly can accurately obtain the compression thickness of the towel before sewing by means of the cooperation of the thickness detection hollow wheel and the detection conveying wheel, combined with the linkage detection of the pressure sensor and the laser displacement sensor, and provides data support for the basic adjustment of the presser foot height of the overlock machine; the bulkiness detection assembly can know the height of the loop layer by sensing the reaction force of the cloth loop through the piezoelectric film sensor and monitoring the moving distance of the bulkiness detection height embodiment block through the Kion displacement sensor, so as to realize the accurate quantification of the loop height and the bulkiness; 2. In the present application, based on the accurate data output of the double detection assembly, the sewing parameters of the overlock machine can be dynamically adapted, effectively solving the product quality problems caused by the parameter adaptation deviation of the prior art; the presser foot height can be accurately adjusted according to the compression thickness detection result, avoiding the feeding slip caused by improper presser foot height; the stitch length, presser foot pressure and needle drop height of the overlock machine can be simultaneously optimized according to the loft detection data, preventing problems such as pile collapse, hard edge, fabric tearing and pile shedding when sewing thin towels according to thick towel parameters, and avoiding defects such as skipping and loose stitches when sewing thick towels according to thin towel parameters, significantly improving the finished product quality of towel sewing. BRIEF DESCRIPTION OF DRAWINGS

[0015] In order to facilitate those skilled in the art to understand, the present application will be further described below in conjunction with the drawings; Figure 1 is a schematic diagram of the three-dimensional structure of the present application; Figure 2 is a schematic diagram of the three-dimensional structure of the cloth thickness detection box in the present application; Figure 3 is a schematic diagram of the three-dimensional structure of the compression thickness detection assembly in the present application; Figure 4 is a schematic diagram of the three-dimensional structure of the support in the present application; Figure 5 is a schematic diagram of the three-dimensional structure of the thickness linkage display in the present application; Figure 6 is a schematic diagram of the three-dimensional structure of the loft detection assembly in the present application; Figure 7 is a schematic diagram of the front view of the cloth thickness detection box in the present application; Figure 8 is a schematic diagram of the three-dimensional structure of the cloth tensioning piece in the present application. Figure 5 Figure 9 is a schematic diagram of the three-dimensional structure of the cloth tensioning piece in the present application.

[0016] ​Figures: 1, full-automatic longitudinal seam towel machine; 2, overlock machine; 3, connecting bracket; 4, cloth thickness detection box; 5, control display device; 6, compressed thickness detection assembly; 61, detection conveying wheel; 62, mounting plate; 63, thickness detection hollow wheel; 64, support strip; 65, pressure sensor; 66, stress conduction plate; 67, thickness linkage display piece; 671, linkage plate; 672, fixed rod; 673, limit moving block; 674, support plate; 675, laser displacement sensor; 68, pressure compensation piece; 681, miniature pre-compression spring; 682, pressure feedback device; 683, miniature telescopic motor; 7, bulkiness detection assembly; 71, electric push rod; 72, push plate; 73, plastic light plate; 74, piezoelectric film sensor; 75, bulkiness detection height embodiment block; 76, Keyence displacement sensor; 77, support piece; 771, sealing plate; 772, fixed plate; 773, support stress plate; 78, cloth tensioning piece; 781, semicircular plate; 782, center rod; 783, movable plate; 784, silica gel tensioning wheel; 785, torsional spring; 8, hanging plate; 9, parallel wheel. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0018] As shown in Figures 1 to 9 The present application provides an automatic sewing machine with seam thickness detection function, comprising a full-automatic longitudinal seam towel machine 1, an overlock machine 2 fixedly installed on the full-automatic longitudinal seam towel machine 1, a connecting bracket 3 fixedly installed on the full-automatic longitudinal seam towel machine 1, a cloth thickness detection box 4 fixedly installed on the connecting bracket 3, and a control display device 5 fixedly installed on the cloth thickness detection box 4, further comprising: A compressed thickness detection assembly 6 is arranged on the right side inside the cloth thickness detection box 4, which detects the thickness of the towel cloth about to enter the overlock machine 2 for sewing, so as to adjust the presser foot of the overlock machine 2 according to the thickness of the entering towel; A bulkiness detection assembly 7 is arranged on the left side inside the cloth thickness detection box 4, which detects the bulkiness of the detected cloth pile, and can adjust the needle spacing, presser foot pressure and needle lowering height of the overlock machine 2 according to the bulkiness of the towel cloth, so as to avoid the pile being pressed down and broken.

[0019] Specifically, the fully automatic longitudinal sewing towel machine 1 uses the Metek CSMTK-1H model, and the control display device 5 adopts a touch screen display, model Kunlun Tongtai KG-HMI70-24MT-V3.0, which supports parameter preset, real-time data display, and command output. The core sewing process of the fully automatic longitudinal sewing towel machine 1 is as follows: the towel fabric is conveyed to the fabric thickness detection box 4 through the feeding mechanism, and after detection, it enters the working area of ​​the overlock machine 2. The overlock machine 2 completes the overlocking and overlocking processing of the towel side through the cooperation of the needle and the bottom and top threads, realizing the locking and fixing of the raw edges. The fully automatic longitudinal sewing towel machine 1 is an existing mature and known product, and the fabric thickness detection box 4 is integrated into the fully automatic longitudinal sewing towel machine through the connecting bracket 3. The feeding path of machine 1 and overlock machine 2 form a continuous link for sewing detection. The compression thickness detection component 6 serves as a preliminary basic detection, which can accurately obtain the thickness of the towel in its compressed state before it enters overlock machine 2. This provides basic data for adjusting the presser foot height of overlock machine 2, avoiding slippage caused by excessive presser foot height or compression of the loops due to excessive presser foot height. The loft detection component 7 serves as a precise adaptation detection, which further locks the actual height and loft of the loop layer. This provides a basis for the fine adjustment of stitch length, presser foot pressure, and needle height of overlock machine 2. It fundamentally solves the problems of loop collapse, hook breakage, or loose stitches caused by adjusting parameters only based on overall thickness in the existing technology, ensuring the consistency of sewing quality for towels with different loft levels.

[0020] like Figures 1 to 4 As shown, the compression thickness detection component 6 includes a detection conveyor wheel 61, on which a mounting plate 62 is rotatably connected. The bottom of the mounting plate 62 is fixedly installed inside the fabric thickness detection box 4. A suspended thickness detection hollow wheel 63 is provided on the detection conveyor wheel 61. A support bar 64 is provided inside the thickness detection hollow wheel 63. A pressure sensor 65 is provided at the bottom of the support bar 64. A force transmission plate 66 is bonded to the bottom of the pressure sensor 65. The bottom of the force transmission plate 66 is slidably connected to the inner wall of the thickness detection hollow wheel 63 by ball bearings. Thickness linkage display components 67 are provided on both the front and back of the thickness detection hollow wheel 63. The mechanical pressure is compensated by a pressure compensation component 68 inside the support bar 64.

[0021] Specifically, the pressure sensor 65 is a Honeywell 24PC series miniature pressure sensor 65 with a range of 0-0.1MPa and an accuracy of ±0.001MPa. It is suitable for detecting slight thrust in fabric contact and compressing the thickness detection component 6. Driven by the feeding mechanism of the fully automatic longitudinal stitching towel machine 1, the towel fabric enters the gap between the detection conveying wheel 61 and the thickness detection hollow wheel 63 on the right side of the fabric thickness detection box 4. The thickness of the fabric will push the suspended thickness detection hollow wheel 63 upward. When the thickness detection hollow wheel 63 is raised, its inner wall will generate an upward pushing force on the pressure sensor 65 through the force transmission plate 66, triggering the pressure sensor 65 to act. The core function of the pressure sensor 65 here is not to directly measure the thickness, but to act as a system wake-up and position sensing unit. When the pressure sensor 65 first senses the thrust of the force transmission plate 66, it determines that towel fabric has entered the fabric thickness detection box 4, and then wakes up the entire detection system, including the laser displacement sensor 675, control display device 5, etc., to enter the working state. During the detection process, the pressure sensor 65 continuously senses the thrust signal. If the signal is stable, it indicates that the towel fabric is in a continuous feeding and detection state. If the thrust signal disappears, it is determined that the towel fabric has completely passed through the compression thickness detection component 6, meaning that sewing is about to be completed or the fabric feeding is interrupted. The system can trigger subsequent finishing actions such as parameter reset and alarm prompts accordingly. At the same time, the lifting action of the thickness detection hollow wheel 63 will synchronously drive the thickness linkage display component 67 to move, providing a mechanical linkage basis for the accurate acquisition of subsequent thickness data. This detection module realizes the accurate detection of the compressed thickness of the towel fabric. The hollow nylon structure of the thickness detection hollow wheel 63 and the uniform force transmission design of the force transmission plate 66 ensure that the pressure sensor 65 accurately senses the position of the fabric. The high resolution characteristics of the laser displacement sensor 675 enable the accurate capture of minute displacements, providing reliable data support for the subsequent adjustment of the presser foot height of the overlock machine 2, avoiding feeding slippage or loop compression damage caused by thickness detection deviation, adapting to the detection needs of towels of different thicknesses, and improving the versatility and stability of the detection system.

[0022] like Figures 1 to 4 As shown, the thickness linkage display component 67 includes a linkage plate 671, which is disposed outside the thickness detection hollow wheel 63. A fixing rod 672 is connected to the linkage plate 671. The thickness detection hollow wheel 63 is rotatably connected to the fixing rod 672 via a ring. The inner side of the fixing rod 672 extends into the interior of the thickness detection hollow wheel 63 and is inserted and fixedly connected to the support bar 64. A limit moving block 673 is connected to the top of the linkage plate 671. A support plate 674 is fixedly installed on the top of the fabric thickness detection box 4. A laser displacement sensor 675 is fixedly installed on the bottom of the support plate 674.

[0023] like Figures 5 to 8As shown, a miniature preload spring 681 is connected inside the support bar 64. The miniature preload spring 681 is connected to the pressure sensor 65, and a pressure feedback device 682 is attached between the miniature preload spring 681 and the pressure sensor 65.

[0024] Specifically, the core function of the pressure feedback device 682 is to directly sense whether the contact pressure is within the preset range of 0.02N±0.001N. When the thickness detection hollow wheel 63 is pushed up by the fabric, and the thrust transmitted through the force transmission plate 66 compresses the micro preload spring 681, the pressure feedback device 682 only needs to determine whether the current pressure exceeds the range. Once it exceeds the range, it immediately sends a trigger signal to the control display device 5 to provide direct instructions for subsequent mechanical pressure compensation, ensuring the simplicity and reliability of pressure sensing.

[0025] like Figures 5 to 8 As shown, the support bar 64 has a built-in miniature telescopic motor 683, which is connected to the pressure sensor 65 for control. The pressure feedback device 682 is electrically connected to the control display device 5. By sensing whether the contact pressure is within the preset range, the miniature telescopic motor 683 is directly triggered to perform mechanical pressure compensation.

[0026] Specifically, the miniature telescopic motor 683 is a TECMOTION™ 17 series miniature DC motor, completely integrated inside the support bar 64 and fixed to the support bar 64 via a motor mount. This miniature telescopic motor 683 has a bidirectional fixed stroke fine-tuning function, with a single fine-tuning amount of 0.01mm and a maximum telescopic stroke of ±0.5mm. When the pressure feedback device 682 sends a signal to the control display device 5 indicating that the pressure exceeds the preset range, the control display device 5 directly outputs a drive signal in the corresponding direction to the miniature telescopic motor 683. If the pressure is lower than the preset lower limit (<0.019N), the miniature telescopic motor 683 is driven to extend... The retracting shaft extends, pushing the pressure sensor 65 downward and compressing the miniature pre-compression spring 681 to increase the contact pressure. If the pressure exceeds the preset upper limit by more than 0.021N, the miniature telescopic motor 683 drives the telescopic shaft to retract, releasing the compression of the miniature pre-compression spring 681 to reduce the contact pressure. After each fine adjustment, the pressure feedback device 682 senses the pressure status in real time until the pressure returns to the preset range. The control display device 5 immediately sends a stop signal, ensuring the constant contact pressure during compression thickness detection and avoiding thickness detection deviation caused by pressure fluctuations. This makes the fabric compression thickness data obtained by the laser displacement sensor 675 more accurate.

[0027] Specifically, the laser displacement sensor 675 is a Keyence LK-G5000 series sensor, suitable for detecting minute displacements. The support bar 64 also has a hexagonal groove. The inner side of the fixing rod 672 is integrally formed with a hexagonal block that mates with the hexagonal groove on the support bar 64. This hexagonal groove and hexagonal block mating structure ensures no relative rotation between the fixing rod 672 and the support bar 64, allowing the thickness detection hollow wheel 63 to rotate on the fixing rod 672 via a ring. This ensures the proper feeding of the towel fabric by the thickness detection hollow wheel 63 and the detection conveyor wheel 61. Furthermore, it ensures that the support bar 64 will not shift within the thickness detection hollow wheel 63 as the wheel 63 rotates, ensuring that the pressure sensor 65 continuously detects the conveying status of the towel fabric downwards. The core detection logic of the laser displacement sensor 675 is as follows: when the thickness detection hollow wheel 63 is pushed upwards by the towel fabric, it will drive the linkage plate 671 to move upwards synchronously through the fixing rod 672. The limit moving block 673 at the top of the linkage plate 671 will rise and fall synchronously. The laser displacement sensor 675 monitors the limit in real time. The lifting distance of the moving block 673 can indirectly obtain the distance between the thickness detection hollow wheel 63 and the detection conveying wheel 61. This distance is the actual thickness of the towel fabric in the compressed state. Because the cooperation between the thickness detection hollow wheel 63 and the detection conveying wheel 61 can generate a constant slight pressure on the towel, the consistency of thickness detection is ensured. After the detection is completed, the laser displacement sensor 675 transmits the collected thickness data to the control display device 5 in real time through the signal transmission line. The interface of the control display device 5 will simultaneously display the specific value of the current fabric thickness in mm, and at the same time generate the corresponding presser foot height adjustment command and transmit it to the control system of the overlock machine 2. After receiving the command, the overlock machine 2 can drive the presser foot lifting mechanism to adjust the presser foot height to a position that matches the current fabric thickness through the built-in servo motor. Alternatively, the corresponding presser foot height adjustment command on the control display device 5 can be viewed manually, and the presser foot height can be manually calibrated through the manual adjustment knob of the overlock machine 2 to ensure that the presser foot is always adapted to the fabric thickness and to avoid slippage or damage to the loops.

[0028] like Figures 4 to 7 As shown, the bulkiness detection component 7 includes an electric push rod 71, which is fixedly installed on the fabric thickness detection box 4. A push plate 72 is fixedly installed on the telescopic end of the electric push rod 71. A plastic lightweight plate 73 is slidably connected to the bottom of the push plate 72. A piezoelectric film sensor 74 is bonded to the bottom of the plastic lightweight plate 73. A bulkiness detection height indicator block 75 is connected to the plastic lightweight plate 73. A Keyence displacement sensor 76 is fixedly installed on the push plate 72. A support member 77 is provided at the bottom of the push plate 72 to support the fabric in order to prevent the fabric from bending during bulkiness detection. The bottom of the push plate 72 is tightened by a fabric tensioning member 78 to prevent the fabric from wrinkling and affecting the bulkiness detection.

[0029] Specifically, the complete process and effect of the loft detection are as follows: After the towel fabric has undergone compression thickness detection, it continues to be conveyed to the loft detection area on the left side of the fabric thickness detection box 4. At this time, the control display device 5 confirms that the fabric has arrived according to the signal from the pressure sensor 65, triggering the electric push rod 71 to move. The electric push rod 71 drives the push plate 72 to move downward, causing the plastic lightweight plate 73 and the piezoelectric film sensor 74 at the bottom to move closer to the towel fabric simultaneously, until the piezoelectric film sensor 74 contacts the loop layer of the towel. Since the plastic lightweight plate 73 and the push plate 72 are slidably connected, when the piezoelectric film sensor 74 contacts the loop, the reaction force of the loop will push the plastic lightweight plate 73 to slide upward relative to the push plate 72, while simultaneously causing the loft to move. The loft detection height indicator 75 moves upwards synchronously. It's important to note that the control display device 5 has a pre-set loft reaction force requirement line. Based on the common loop characteristics of towels, real-time calculation is unnecessary; the loft level is directly defined by the reaction force range. High-loft fabric: reaction force ≤ 0.008N corresponds to thin face towels, high-loft beauty towels, etc., with loose loops and good elasticity, requiring low compression force. Medium-loft fabric: 0.008N < reaction force ≤ 0.015N corresponds to regular face towels, bath towels, etc., with moderate loop density and balanced elasticity. Low-loft fabric: reaction force > 0.015N corresponds to thick towels, compacted work towels, etc., with dense loops and poor elasticity, requiring high compression force. During this testing process, the piezoelectric film sensor 74, model Murata Picoleaf™ series FMPSABB015, with a thickness ≤0.3mm and a force sensitivity of 35mV / N, is adapted for detecting minute reaction forces. It synchronously transmits the real-time sensed reaction force data analog signal to the control and display device 5. The control and display device 5 directly compares the real-time data with a preset force requirement line to initially determine the fabric's loft level range. Simultaneously, the control and display device 5 tracks the change in reaction force: in the initial contact stage, the reaction force increases with the elastic deformation of the loops; when the reaction force rises to the corresponding loft level range, and is continuously sampled for 5 cycles at a sampling rate of 1kHz (i.e., within 5ms), the value is recorded. When the fluctuation is ≤0.001N, it indicates that the reaction force has reached the stable value of the current loop layer. Continuing to press down will cause the loop to collapse irreversibly, exceeding the elastic deformation range. At this time, the control display device 5 immediately sends a stop command to the electric push rod 71. The electric push rod 71 is a Mingzhi MLT28 series miniature electric cylinder. The selected Mingzhi MLT28 series miniature electric cylinder is a mature product. Its initial state is the fully retracted position. The distance between the plastic light plate 73 and the towel fabric is preset to 30mm. The effective stroke of 50mm covers the detection requirements of all towel loop heights of 1-5mm. The remaining stroke is a safety redundancy. The descent speed during detection is set to 5mm / s and a high-precision ball screw drive is used to ensure that the error of the push rod descent displacement is ≤0.The Keyence displacement sensor 76 uses the Keyence CL-3000 series CL-L007N sensor head with a diameter of 8mm and repeatability ≤0.1μm. It is adapted for loop height detection and can be precisely started and stopped through the digital signal output by the control display device 5. The electric push rod 71 then stops driving the push plate 72 to move downward, avoiding excessive compression and damage to the loop, while ensuring that the current loft level corresponding to the reaction force is the true state. At this time, the distance that the loft detection height display block 75 moves upward, which is monitored in real time by the Keyence displacement sensor 76, is the actual height of the loop layer under the corresponding loft level. The Keyence displacement sensor 76 transmits the loop height data to the control display device 5, forming a double verification with the previously determined loft level to avoid occasional deviations from the single reaction force data. Subsequently, the control display device 5 directly generates targeted adjustment commands according to the preset loft level and sewing parameter correspondence. If the fabric is determined to be high-loft: control the overlock machine 2 to reduce the presser foot pressure by 0.05-0.08 MPa, increase the stitch length by 4-5 mm, and raise the stitch height by 8-10 mm to avoid crushing the loops or breaking the pile threads; if the fabric is determined to be medium-loft: control the overlock machine 2 to set the presser foot pressure to medium (0.08-0.12 MPa), the standard stitch length to 3-4 mm, and the appropriate stitch height to 6-8 mm, balancing stitch strength and loop integrity; if the fabric is determined to be low-loft: control the overlock machine 2 to increase the presser foot pressure by 0.12-0.18 MPa, reduce the stitch length by 2-3 mm, and lower the stitch height by 4-6 mm to ensure the stitches are firm and not loose. This ensures the accuracy of the loft level determination and avoids damage to the loops during the testing process, providing real-time feedback on sewing parameters. The adaptation provides a reliable basis, completely solving the parameter adaptation deviation problem caused by the inability to distinguish the state of the loops in the existing technology, and ensuring the consistency of sewing quality of towels with different loft. After the test is completed, the control display device 5 sends a reset command to the electric push rod 71, driving the push plate 72 and the plastic light plate 73 to rise back to the initial position and wait. It should be noted that the electric push rod 71 after the reset will no longer be triggered by the continuously running monitoring pressure sensor 65. This is because the pressure sensor 65 only continuously senses the signal during the fabric conveying process to determine the conveying status. Only when the batch of fabric has completely passed through, the push signal of the pressure sensor 65 disappears, and the next batch of fabric enters the fabric thickness detection box 4 again and triggers the pressure sensor 65 will the entire detection process be restarted.

[0030] like Figures 4 to 7 As shown, the support member 77 includes a sealing plate 771, which is fixedly installed on the fabric thickness detection box 4. A fixing plate 772 is connected to the sealing plate 771, and a support plate 773 is connected to the top of the fixing plate 772.

[0031] Specifically, the sealing plate 771 serves two purposes: first, it seals the back of the fabric thickness detection box 4, effectively preventing lint and dust generated during towel sewing from entering the interior of the fabric thickness detection box 4, thus avoiding contamination of precision components such as the pressure sensor 65 and the piezoelectric film sensor 74, and ensuring the stability of detection accuracy; second, the sealing plate 771 is detachable, allowing for direct removal of the sealing plate 771 without disassembling the entire fabric thickness detection box 4 when maintenance, calibration, or replacement of the detection components is required, significantly improving maintenance convenience. The fixing plate 772 serves as the load-bearing foundation for the supporting plate 773, ensuring the support force through its connection with the sealing plate 771. The installation stability of plate 773: The top surface of the support plate 773 is parallel to the towel conveying path. When the towel enters the fluffiness detection area, the support plate 773 supports the towel from below, keeping the towel flat and preventing bending due to the weight of the fabric or slight shaking during conveying. If the fabric bends, it will cause uneven contact force between the piezoelectric film sensor 74 and the loop, which will lead to a deviation in the height of the loop detected by the Keyence displacement sensor 76. Therefore, the flat support function of the support plate 773 is a key prerequisite for ensuring the accuracy of fluffiness detection, and indirectly provides a guarantee for the accurate adjustment of subsequent sewing parameters.

[0032] like Figures 1 to 4 As shown, both sides of the fabric thickness detection box 4 are connected to hanging plates 8, and parallel wheels 9 are rotatably connected to the inner side of the hanging plates 8.

[0033] Specifically, the parallel wheels 9 are installed on both sides of the inlet and outlet of the fabric thickness detection box 4 via the hanging plate 8. Before the towel fabric enters the fabric thickness detection box 4, it needs to pass between the parallel wheels 9 on both sides. During the conveying process, the parallel wheels 9 on both sides can limit and guide the edge of the towel. Since the parallel wheels 9 can rotate, they will not affect the normal conveying of the towel. At the same time, they can ensure that the towel remains in a horizontally parallel state throughout the entire detection process. By ensuring the parallel stability of the towel conveying, the parallel wheels 9 can reduce mechanical interference during the detection process and ensure that the detection data of the compression thickness detection component 6 and the bulkiness detection component 7 are accurate and reliable, providing stable basic data for the precise adjustment of the sewing parameters of the overlock machine 2.

[0034] like Figures 6 to 9 As shown, the fabric tensioning member 78 includes a semi-circular plate 781, which is connected to the bottom of the push plate 72. A central rod 782 is movably connected inside the semi-circular plate 781. Two movable plates 783 are connected to the central rod 782. A silicone tensioning wheel 784 is movably connected between the two symmetrical movable plates 783.

[0035] Specifically, the surface of the silicone tensioning wheel 784 is covered with a fine anti-slip texture. This texture provides sufficient elasticity to avoid damaging the towel loops while also enhancing friction with the fabric surface to prevent slippage during tensioning. When the push plate 72 is driven downward by the electric push rod 71, the silicone tensioning wheel 784 contacts the towel fabric surface before the piezoelectric film sensor 74. As the push plate 72 continues to move downward, the silicone tensioning wheel 784, under the reaction force of the fabric, drives the movable plate 783 to rotate and unfold around the central rod 782. The symmetrical expansion force evenly tensions the fabric to both sides laterally. The tensioning force is automatically adjusted by the elasticity of the silicone material to avoid excessive stretching that could deform the fabric. This effectively eliminates slight wrinkles on the fabric surface caused by conveying, ensuring uniform contact between the piezoelectric film sensor 74 and the loop layer. It also avoids distortion in reaction force detection caused by wrinkles, providing effective assurance for the accuracy of loft detection.

[0036] like Figure 9 As shown, a torsion spring 785 is connected to the center rod 782, and the other end of the torsion spring 785 is connected to the bottom of the push plate 72.

[0037] Specifically, the torsion spring 785 is initially in a slightly pre-tensioned state. One end is fixed to the central groove of the central rod 782 by a buckle, and the other end is embedded in the pre-set limiting hole at the bottom of the push plate 72. The core function of the torsion spring 785 is reflected in two aspects: first, the reset function. After the fluffiness detection is completed, the control display device 5 triggers the electric push rod 71 to drive the push plate 72 to rise, and the silicone tensioning wheel 784 disengages from the fabric surface. At this time, the torsion spring 785 releases the pre-tension force, driving the central rod 782 to rotate in the opposite direction, driving the movable plate 783 and the silicone tensioning wheel 784 to retract to the initial contracted state. Prepare for the next batch of fabric testing. The entire reset process does not require additional drive components and is achieved solely through mechanical elasticity. Secondly, it has a limiting function. The preload of the torsion spring 785 can limit the rotation angle of the center rod 782 within a preset range, so that the silicone tensioning wheel 784 remains in a horizontal position parallel to the plastic lightweight plate 73 when not in operation. This avoids the tensioning wheel from shifting up and down due to equipment vibration or conveying interference, ensuring that the silicone tensioning wheel 784 can contact the fabric at a uniform height and angle during each test, achieving a stable and consistent tensioning effect, and further ensuring the repeatability and reliability of the bulkiness test.

[0038] The working principle of this invention: The feeding mechanism of the fully automatic longitudinal stitching towel machine 1 transports the towel fabric to the fabric thickness detection box 4. Parallel wheels 9 on both sides of the hanging plates 8 limit and guide the fabric, maintaining a horizontally parallel state to avoid bending stress and ensure detection stability. The fabric first enters the compression thickness detection component 6 on the right side of the fabric thickness detection box 4. A conveying channel is formed by the cooperation of the detection conveying wheel 61 and the thickness detection hollow wheel 63. The fabric thickness pushes the thickness detection hollow wheel 63 to rise, and its inner wall triggers the pressure sensor 65 through the force transmission plate 66. A micro pre-compression spring 681 provides a constant pre-pressure. The pressure feedback device 682 judges in real time whether the pressure exceeds the specified range. Once the pressure exceeds the limit, a micro telescopic electric current is immediately triggered. Machine 683 performs bidirectional fixed stroke fine adjustment, and compensates for contact pressure through the telescopic shaft to ensure constant pressure. This sensor serves as a system wake-up and position sensing unit. When the thrust is sensed for the first time, it wakes up the entire system. It continuously senses the stable thrust to determine that the fabric is continuously conveyed. When the thrust disappears, it triggers parameter reset or alarm. At the same time, the thickness detection hollow wheel 63 drives the linkage plate 671 and the limit moving block 673 to rise and fall through the hexagonal cooperation structure of the fixed rod 672 and the support bar 64. The laser displacement sensor 675 detects the lifting distance to obtain the fabric compression thickness. After the data is transmitted to the control display device 5, a presser foot height adjustment command is generated. The overlock machine 2 can automatically adjust or be manually calibrated by the knob to avoid feeding slippage or loop compression. After the fabric thickness is measured, it enters the left-side bulkiness measurement area. Once the pressure sensor 65 confirms the fabric is in place, the control display device 5 triggers the electric push rod 71, causing the plastic lightweight plate 73 and the piezoelectric film sensor 74 at the bottom to move downwards. The fabric tensioning component 78 and the plastic lightweight plate 73 also move downwards. The silicone tensioning wheel 784 contacts the fabric before the piezoelectric film sensor 74. Upon contact, the reaction force with the fabric causes the movable plate 783 to unfold around the central rod 782, evenly tensioning the fabric to both sides to eliminate minor wrinkles until the fabric is pressed down. The piezoelectric thin-film sensor 74 contacts the towel loop layer for detection; the reaction force of the loop pushes the plastic lightweight plate 73 upward and causes the fluffiness detection height display block 75 to rise and fall. The piezoelectric thin-film sensor 74 transmits the real-time reaction force signal to the control display device 5, which is directly compared with the preset fluffiness level. When the reaction force fluctuates ≤0.001N within 5ms and reaches a stable value, the electric push rod 71 immediately stops to prevent the loop from collapsing; subsequently, the Keyence displacement sensor 76 detects the moving distance of the fluffiness detection height display block 75 to obtain the true height of the loop, and compares it with the reaction force. The data forms a dual verification. The control display device 5 adjusts the presser foot pressure, stitch length, and needle height of the overlock machine 2 according to the preset correspondence, taking into account both the stitch strength and the integrity of the loops. After the inspection is completed, the control display device 5 sends a reset command, driving the electric push rod 71 to push the push plate 72 and the plastic light plate 73 to rise. The torsion spring 785 releases the preload force to drive the center rod 782 to rotate in the opposite direction, driving the movable plate 783 and the silicone tensioning wheel 784 to reset to the initial state. At the same time, the preload force limits the silicone tensioning wheel 784 to maintain its position relative to the plastic light plate. 73. Parallel to the initial position and wait; it should be clarified that the reset electric push rod 71 will not be triggered by the continuously monitored pressure sensor 65. The entire detection process will only restart when the current batch of fabric has completely passed through, the push signal of the pressure sensor 65 disappears, and the next batch of fabric re-enters the fabric thickness detection box 4 and triggers the pressure sensor 65. This ensures that the detection and conveying rhythm are precisely matched, completely solving the problems of loop collapse, hook breakage, or loose stitches caused by adjusting parameters only according to the overall thickness in the existing technology, and ensuring the consistency and stability of sewing quality.

[0039] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to any specific implementation. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The invention is limited only by the claims and their full scope and equivalents.

Claims

1. An automatic sewing machine with fabric thickness detection function, characterized in that, Including full-automatic longitudinal seam towel machine (1), the full-automatic longitudinal seam towel machine (1) is fixedly installed with overlock machine (2), the full-automatic longitudinal seam towel machine (1) is fixedly installed with connecting bracket (3), the connecting bracket (3) is fixedly installed with cloth thickness detection box (4), the cloth thickness detection box (4) is fixedly installed with control display device (5), further includes Compression thickness detection assembly (6), the compression thickness detection assembly (6) is set up in the right side inside cloth thickness detection box (4), the towel cloth that will enter overlock machine (2) sewing is carried out thickness detection, so as to adjust the presser foot of overlock machine (2) according to the thickness of entering towel; Loft detection assembly (7), the loft detection assembly (7) is set up in the left side inside cloth thickness detection box (4), for detecting the loft of the cloth pile after thickness detection, to adjust the stitch length, presser foot pressure and needle drop height of overlock machine (2) according to the loft of towel cloth, avoid the pile being pressed down, hooked off.

2. The automatic sewing machine having a fabric thickness detection function according to claim 1, characterized in that, The compression thickness detection assembly (6) includes detection conveying wheel (61), the detection conveying wheel (61) is rotatably connected with mounting plate (62), the bottom of the mounting plate (62) is fixedly installed with the inside of cloth thickness detection box (4), the detection conveying wheel (61) is provided with the thickness detection hollow wheel (63) of suspension, the inside of the thickness detection hollow wheel (63) is provided with support strip (64), the bottom of the support strip (64) is provided with pressure sensor (65), the bottom of the pressure sensor (65) is bonded with force conduction plate (66), the bottom of the force conduction plate (66) is slidably connected with the inner wall of the thickness detection hollow wheel (63) through ball, the front and back of the thickness detection hollow wheel (63) are provided with thickness linkage display piece (67), the support strip (64) is compensated by pressure compensator (68) for mechanical pressure.

3. The automatic sewing machine having a fabric thickness detecting function according to claim 2, wherein The thickness linkage display piece (67) includes linkage plate (671), the linkage plate (671) is set up outside the thickness detection hollow wheel (63), the linkage plate (671) is connected with fixed rod (672), the thickness detection hollow wheel (63) is rotatably connected on the fixed rod (672), the inner side of the fixed rod (672) extends to the inside of the thickness detection hollow wheel (63) and is inserted with the support strip (64) Fixed, the top of the linkage plate (671) is connected with limit moving block (673), the top of the cloth thickness detection box (4) is fixedly installed with support plate (674), the bottom of the support plate (674) is fixedly installed with laser displacement sensor (675).

4. The automatic sewing machine having a fabric thickness detecting function according to claim 2, wherein The pressure compensator (68) includes micro pre-compression spring (681), the micro pre-compression spring (681) is connected in the support strip (64), the micro pre-compression spring (681) is connected with the pressure sensor (65), the micro pre-compression spring (681) and pressure sensor (65) are attached with pressure feedback device (682).

5. The automatic sewing machine having a fabric thickness detecting function according to claim 4, wherein The support strip (64) is internally provided with a micro telescopic motor (683), the micro telescopic motor (683) is opposite to the pressure sensor (65) and controls the pressure sensor (65), the pressure feedback device (682) is electrically connected with the control display device (5), whether the contact pressure is in the preset interval is sensed, and the micro telescopic motor (683) is directly triggered to carry out mechanical pressure compensation.

6. The automatic sewing machine having a fabric thickness detecting function according to claim 1, wherein The loft detection assembly (7) comprises an electric push rod (71), the electric push rod (71) is fixedly installed on the cloth thickness detection box (4), a push plate (72) is fixedly installed at the telescopic end of the electric push rod (71), a plastic light plate (73) is slidably connected to the bottom of the push plate (72), a piezoelectric film sensor (74) is bonded to the bottom of the plastic light plate (73), a loft detection height embodiment block (75) is connected to the plastic light plate (73), a gage sensor (76) is fixedly installed on the push plate (72), and a supporting piece (77) is arranged at the bottom of the push plate (72) to support the cloth, so that the cloth bending phenomenon in the loft detection is prevented. The cloth to be detected is tightened by the cloth tensioning piece (78) to prevent the cloth from being wrinkled and affecting the loft detection phenomenon.

7. The automatic sewing machine having a fabric thickness detecting function according to claim 6, wherein The supporting piece (77) comprises a sealing plate (771), the sealing plate (771) is fixedly installed on the cloth thickness detection box (4), a fixed plate (772) is connected to the sealing plate (771), and a supporting stress plate (773) is connected to the top of the fixed plate (772). The supporting stress plate (773) plays a role in keeping the towel cloth parallel during the loft detection.

8. The automatic sewing machine having a fabric thickness detecting function according to claim 1, wherein Both sides of the cloth thickness detection box (4) are connected with a hanging plate (8), and parallel wheels (9) are rotatably connected to the inner side of the hanging plate (8), so that the towel cloth in the thickness detection and the loft detection is kept parallel.

9. The automatic sewing machine having a fabric thickness detecting function according to claim 7, wherein The cloth tensioning piece (78) comprises a semicircular plate (781), the semicircular plate (781) is connected to the bottom of the push plate (72), a center rod (782) is movably connected to the inside of the semicircular plate (781), two movable plates (783) are connected to the center rod (782), and a silica gel tensioning wheel (784) is movably connected between the two symmetrical movable plates (783). When the push plate descends, the silica gel tensioning wheel (784) is used to tension the cloth at the bottom of the plastic light plate (73) to the two sides, so that the cloth is not easy to wrinkle and affect the loft accuracy.

10. The automatic sewing machine having a fabric thickness detecting function according to claim 9, wherein The center rod (782) is connected with a torsional spring (785), and the other end of the torsional spring (785) is connected with the bottom of the push plate (72).

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