A device and method for automatically tensioning cloth

Abstract

The application provides a device and method for automatically tensioning cloth, and belongs to the field of industrial automatic sewing. The device comprises a support, a support frame and a tabletop are sequentially arranged on the front side of the support from top to bottom; a lifting mechanism is arranged on the support frame, a lifting compression plate is arranged below the support frame, the lifting mechanism can drive the lifting compression plate to move up and down, the lifting compression plate can drive a tensioning jig to move up and down, and a plurality of tensioning units are arranged on the tensioning jig; and a tabletop jig bottom plate is arranged on the tabletop. The application realizes automatic tensioning of materials, reduces manual work, and improves production efficiency.

Description

Technical Field

[0001] This invention belongs to the field of industrial automated sewing, specifically relating to a device and method for automatically tensioning fabric. Background Technology

[0002] Inside the car manufacturing plant, materials (including overlapping cotton and leather) need to be stretched, then the stretched materials are sewn together, and finally the sewn materials are spliced ​​together to form the outer layer of the car seat.

[0003] The current method for tensioning materials is as follows: Material 55 is manually placed on the base plate of the tensioning fixture. The base plate of the tensioning fixture is a plate-like structure with one or more material placement holes. The material is placed above the material placement holes and slightly stretched outwards. At the same time, multiple clips or tacks are used to fix the edges of the material to the periphery of the material placement holes. In this way, material 55 is fixed on the base plate of the tensioning fixture, thus obtaining the tensioned material.

[0004] However, existing tensioning methods require a large amount of manual labor, resulting in low production efficiency. Furthermore, manual tensioning may lead to inconsistent tension at each point, making it impossible to guarantee uniform quality. Summary of the Invention

[0005] The purpose of this invention is to solve the problems existing in the prior art and provide a device for automatically tensioning fabric, which can realize the automatic tensioning of materials, reduce manual labor, and improve production efficiency.

[0006] This invention is achieved through the following technical solution:

[0007] In a first aspect, the present invention provides an apparatus for automatically tensioning fabric, the apparatus comprising: a support frame and a tabletop arranged sequentially from top to bottom on the front side of the support frame;

[0008] A lifting mechanism is provided on the support frame, and a lifting pressure plate is provided below the support frame. The lifting mechanism can drive the lifting pressure plate to move up and down, and the lifting pressure plate can drive the tensioning fixture to move up and down. Multiple tensioning units are provided on the tensioning fixture.

[0009] A desktop fixture base plate is provided on the desktop.

[0010] Preferably, at least one material placement hole is provided on the bottom plate of the desktop fixture;

[0011] Multiple fabric support plates are arranged around the edge of each material placement hole.

[0012] Preferably, the lifting and pressing plate includes a lifting plate, and a plurality of pressing components and a plurality of pressing components disposed on the lifting plate;

[0013] Each pressing assembly includes: a pressing cylinder and a hexagonal cap nut; the central axis of the piston rod of the pressing cylinder is perpendicular to the lifting plate, and the lower end of the piston rod passes through the lifting plate and is connected to the hexagonal cap nut;

[0014] Each clamping assembly includes: a flat-head snap ring pin, a clamping spring, a clamping washer, and a snap ring; a snap ring pin hole is provided on the lifting plate, through which the flat-head snap ring pin passes; a snap ring is installed at the upper end of the flat-head snap ring pin, the snap ring being located above the lifting plate; the clamping washer and the clamping spring are sleeved on the outside of the flat-head snap ring pin; an annular flange is provided at the lower end of the flat-head snap ring pin, and the clamping spring is located between the clamping washer and the annular flange.

[0015] Preferably, a working hole is provided on the lifting plate, and the working hole corresponds one-to-one with the material placement hole on the bottom plate of the desktop fixture;

[0016] Multiple pressing components and multiple clamping components surround the edge of each working hole.

[0017] Preferably, multiple clamping components are also provided on the edge of the lifting plate;

[0018] Each clamping assembly includes: a clamping cylinder and a lifting pin;

[0019] The central axis of the piston rod of the clamping cylinder is parallel to the lifting plate, and the front end of the piston rod is connected to the lifting pin through a connecting plate. The central axis of the lifting pin is parallel to the central axis of the piston rod.

[0020] Preferably, a plurality of limiting plates and limiting plate fixing blocks are provided on the lower end surface of the lifting plate;

[0021] The limiting plate fixing block is fixedly installed on the lower end face of the lifting plate. A threaded hole is opened on the limiting plate fixing block, and the central axis of the threaded hole is parallel to the lifting plate.

[0022] An elongated hole is provided at the upper end of the limiting plate.

[0023] Preferably, the tensioning fixture includes a tensioning base plate with at least one large hole.

[0024] Multiple tensioning units are provided at the edge of each large hole;

[0025] Each tensioning unit includes: a moving mechanism and a needle insertion mechanism;

[0026] The moving mechanism includes a guide rail, a slider, a spring fixing block, and a moving spring; the guide rail and the spring fixing block are fixedly installed on the tensioning base plate, and the slider can move back and forth along the guide rail; a moving block is connected above the slider, and the moving block is connected to the spring fixing block through the moving spring; an inclined surface is provided on the upper part of the moving block;

[0027] The needle-sticking mechanism includes a connecting block, a double-ended threaded pin, a steel needle connecting plate, and a steel needle. The lower end of the connecting block is connected to the front end of the moving block. A longitudinal through hole is formed in the connecting block, and the lower end of the double-ended threaded pin passes through the hole and connects to the steel needle connecting plate. A transverse groove is formed in the middle of the lower end of the connecting block, and the rear end of the steel needle connecting plate is located in the groove, while the front end extends out of the groove and connects to the steel needle. The central axis of the steel needle is parallel to the central axis of the double-ended threaded pin. A needle-sticking spring is fitted on the double-ended threaded pin.

[0028] Preferably, multiple needle-holding units are also provided at the edge of each large hole, with the multiple needle-holding units located at a portion of the edge of the large hole and multiple tensioning units located at another portion of the edge of the large hole;

[0029] Each of the needle-piercing units includes: a mounting block, a double-ended threaded pin, a steel needle connecting plate, and a steel needle;

[0030] The lower end of the mounting block is fixed to the tensioning base plate; a longitudinal through hole is opened at the front of the mounting block, and the lower end of the double-ended threaded pin passes through the hole and is connected to the steel needle connecting plate.

[0031] A transverse groove is formed in the middle of the lower end of the mounting block. The rear end of the steel needle connecting plate is located in the groove, and the front end extends out of the groove and is connected to the steel needle.

[0032] The central axis of the steel needle is parallel to the central axis of the double-threaded pin.

[0033] A pin spring is fitted onto the double-ended threaded pin.

[0034] Preferably, a lifting pin plate is also provided on the tensioning base plate;

[0035] The lifting pin plate has a pin hole, into which the lifting pin can be inserted.

[0036] A second aspect of the present invention provides a method for automatically tensioning fabric, the method comprising:

[0037] (1) Place the material on the material placement hole on the bottom plate of the table fixture, and the edge of the material is supported by each fabric support piece;

[0038] (2) Use flat-head snap ring pins to press and position the material, use the pin unit to fix the material, and use the tensioning unit to tension the material.

[0039] Compared with the prior art, the beneficial effects of the present invention are: the present invention realizes automatic tensioning of materials, reduces manual labor, and improves production efficiency. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of the automatic fabric tensioning device of the present invention in its initial state;

[0041] Figure 2 This is a schematic diagram of the structure of the automatic fabric tensioning device of the present invention in the state where the tensioning fixture is disengaged from the lifting pressure plate after tensioning is completed;

[0042] Figure 3 This is a left view of the device for automatically tensioning fabric according to the present invention in its initial state;

[0043] Figure 4-1 This is an assembly diagram of the lifting and pressing plate in the automatic fabric tensioning device of the present invention;

[0044] Figure 4-2 This is an assembly diagram of the limiting plate and the limiting plate fixing block in the device for automatically tensioning fabric according to the present invention.

[0045] Figure 4-3 This is a schematic diagram of the pressing component in the automatic fabric tensioning device of the present invention;

[0046] Figure 5 This is an assembly diagram of the tensioning fixture in the automatic fabric tensioning device of the present invention;

[0047] Figure 6 This is a three-dimensional structural diagram of the fixed needle unit in the automatic fabric tensioning device of the present invention.

[0048] Figure 7 This is an assembly diagram of the fixing needle unit in the automatic fabric tensioning device of the present invention;

[0049] Figure 8 This is a three-dimensional structural diagram of the tensioning unit in the automatic fabric tensioning device of the present invention;

[0050] Figure 9 This is an assembly diagram of the tensioning unit in the automatic fabric tensioning device of the present invention;

[0051] Figure 10 This is a schematic diagram of the fabric support plate in the device for automatically tensioning fabric according to the present invention. Detailed Implementation

[0052] The present invention will now be described in further detail with reference to the accompanying drawings:

[0053] like Figures 1 to 10 As shown, the present invention provides a device for automatically tensioning fabric. The device includes: a bracket 1, a support frame and a tabletop 2 arranged sequentially from top to bottom on the front side of the bracket 1, the support frame and the tabletop 2 being parallel, and both the support frame and the tabletop 2 being perpendicular to the bracket 1.

[0054] A lifting mechanism is provided on the support frame, and a lifting pressure plate 51 is provided below the support frame. The lifting mechanism can drive the lifting pressure plate 51 to move up and down, and the lifting pressure plate 51 can drive the tensioning fixture 52 to move up and down.

[0055] A desktop fixture base plate 3 is provided on the desktop 2, and at least one material placement hole is provided on the desktop fixture base plate 3. The shape and number of the material placement hole can be designed according to actual needs, for example, it can be designed as one or more rectangular material placement holes, or one or more elliptical material placement holes, etc. Figure 1 In the embodiment shown, two U-shaped material placement holes are provided.

[0056] Multiple fabric support pieces 4 are arranged around the edge of each material placement hole. The number and position of the fabric support pieces 4 are determined according to the tension point of the fabric. Specifically, multiple grooves are provided around the edge of the material placement hole, each groove corresponding to a fabric support piece 4, with one fabric support piece 4 installed in one groove. Figure 10 As shown, each fabric support piece 4 has a Y-shaped structure. Two branches of the Y-shaped structure are fixed in the groove by bolts, and the other branch of the Y-shaped structure extends into the material placement hole, and a U-shaped groove is opened on the branch.

[0057] Specifically, such as Figure 1 As shown, the lifting mechanism includes a lifting cylinder 16 disposed above the support frame. The central axis of the piston rod of the lifting cylinder 16 is perpendicular to the plane on which the support frame is located. The lower end of the piston rod is fixedly connected to the upper end face of the lifting pressure plate 51. Thus, when the piston rod of the lifting cylinder 16 moves up and down, the piston rod drives the lifting pressure plate 51 to move up and down.

[0058] To facilitate the installation of the lifting cylinder 16, a lifting cylinder fixing plate 15 is provided on the support frame. The lower end of the cylinder body of the lifting cylinder 16 is connected to the lifting cylinder fixing plate 15, and the piston rod passes through the lifting cylinder fixing plate 15 and is connected to the lifting pressure plate 51.

[0059] Furthermore, to ensure the stability of the lifting and pressing plate 51's movement, the lifting mechanism further includes multiple guide shafts 14 and multiple linear bearings 13. Each linear bearing 13 corresponds to one guide shaft 14. The lower end of each guide shaft 14 is connected to the upper end face of the lifting and pressing plate 51, and the upper end of the guide shaft 14 passes through the linear bearing 13. Thus, during the up-and-down movement of the lifting and pressing plate 51 driven by the piston rod, the guide shaft 14 moves up and down along the linear bearing 13. For mounting the linear bearings, multiple linear bearing mounting plates 12 are provided on the support frame, and the linear bearings 13 are mounted on their respective mounting plates 12. Preferably, four linear bearings 13 are provided on the support frame, located at the four vertices of a rectangle, with the central axis of the lifting cylinder 16 located at the center of the rectangle. This improves the stability of the lifting and pressing plate 51 during its up-and-down movement.

[0060] like Figure 2 As shown, the lifting and pressing plate 51 includes a lifting plate 17, and multiple pressing components and multiple clamping components disposed on the lifting plate 17. Multiple clamping components are also disposed on the edge of the lifting plate 17.

[0061] Specifically, such as Figure 3 As shown in Figure 4, each pressing assembly includes a pressing cylinder 22 and a hexagonal cap nut 23. The pressing cylinder 22 is positioned above the lifting plate 17, and the hexagonal cap nut 23 is positioned below the lifting plate 17. The central axis of the piston rod of the pressing cylinder 22 is perpendicular to the lifting plate 17, and the lower end of the piston rod passes through the lifting plate 17 and connects to the hexagonal cap nut 23. When the piston rod of the pressing cylinder 22 moves up and down, it drives the hexagonal cap nut 23 to move up and down.

[0062] like Figure 4-1 and Figure 4-3As shown, each clamping assembly includes: a flat-head snap ring pin 24, a clamping spring 25, a clamping washer 26, and a snap ring 27. A snap ring pin hole is formed on the lifting plate 17, through which the flat-head snap ring pin 24 passes. A snap ring groove is provided at the upper end of the flat-head snap ring pin 24, and a snap ring 27 is installed in the snap ring groove. The snap ring 27 is located above the lifting plate 17, ensuring that the flat-head snap ring pin 24 will not dislodge from the snap ring pin hole on the lifting plate 17. The clamping washer 26 and the clamping spring 25 are sleeved on the outside of the flat-head snap ring pin 24, with the clamping washer 26 located below the lifting plate 17 and above the clamping spring 25. An annular flange is provided at the lower end of the flat-head snap ring pin 24, and the clamping spring 25 is located between the clamping washer 26 and the annular flange. When the lifting and pressing plate 51 moves downward, the lower end of the flat-head snap ring pin 24 contacts the fabric first. When it presses on the fabric, the flat-head snap ring pin 24 moves upward relative to the lifting and pressing plate 51. At this time, the pressing spring 25 is squeezed by the pressing pad 26 and the annular flange to press and position the fabric. When the lifting and pressing plate 51 moves upward, the pressing spring 25 returns to its original state. The pressing spring 25 pushes the flat-head snap ring pin 24 downward through the annular flange, thus returning to its initial state.

[0063] Preferably, the lifting plate 17 is provided with two working holes, which correspond one-to-one with the material placement holes on the tabletop fixture base plate 3. Multiple pressing components and multiple clamping components are arranged around the edge of each working hole, with the pressing components located on the outer ring and the clamping components located on the inner ring (the inner ring is closer to the center of the working hole, and the outer ring is farther from the center of the working hole).

[0064] like Figure 2 and Figure 4-1 As shown, each clamping assembly includes a clamping cylinder 18 and a lifting pin 21. The clamping cylinder 18 is disposed above the lifting plate 17, and the central axis of the piston rod of the clamping cylinder 18 is parallel to the lifting plate 17. The front end of the piston rod is connected to the lifting pin 21 through a connecting plate, and the central axis of the lifting pin 21 is parallel to the central axis of the piston rod.

[0065] When the piston rod of the clamping cylinder 18 extends, it drives the lifting pin 21 to move outward (i.e., away from the lifting plate 17). When the piston rod of the clamping cylinder 18 retracts, it drives the lifting pin 21 to move inward (i.e., closer to the lifting plate 17). Figure 2 In the embodiment shown, the connecting plate includes a first connecting plate 19 and a second connecting plate 20. The upper end of the first connecting plate 19 is connected to the end of the piston rod of the clamping cylinder 18, and the lower end is connected to one end of the second connecting plate 20. The other end of the second connecting plate 20 is connected to one end of the lifting pin 21, and the other end of the lifting pin 21 is suspended.

[0066] Preferably, a clamping assembly is provided at each of the four corners of the lifting plate 17. When the lifting pins 21 of the four clamping assemblies move inward simultaneously, the four lifting pins 21 can clamp the tensioning fixture 52; when the lifting pins 21 of the four clamping assemblies move outward simultaneously, the tensioning fixture 52 can be released.

[0067] Furthermore, such as Figure 4-1 and Figure 4-2 As shown, multiple limiting plates 49 and limiting plate fixing blocks 50 are provided on the lower end surface of the lifting plate 17. Each limiting plate 49 corresponds to one limiting plate fixing block 50, and the limiting plate fixing block 50 is fixedly installed on the lower end surface of the lifting plate 17. Two threaded holes are opened on the limiting plate fixing block 50, and the central axis of the threaded holes is parallel to the lifting plate 17. An elongated hole is opened at the upper end of the limiting plate 49. Screws are screwed into the elongated hole to fix the limiting plate 49 below the lifting plate 17. The elongated hole has a certain length, thus allowing adjustment of the position of the limiting plate 49. After adjusting the position of the limiting plate 49, the screws in the elongated hole are tightened to fix the limiting plate 49 on the lifting plate 17. Simultaneously, a long bolt is screwed into the threaded hole of the limiting plate fixing block 50, so that the front end of the long bolt abuts against the limiting plate 49, thereby achieving the limiting function.

[0068] like Figure 5 As shown, the tensioning fixture 52 includes a tensioning base plate 28, on which at least one large hole is formed, corresponding one-to-one with the working holes on the lifting plate 17. Multiple tensioning units 53 are arranged at the edge of each large hole, and these units are used to tension the material 55.

[0069] In practical use, since the entire fabric can be tensioned as long as a portion of the material 55 is fixed and the other portion is tensioned, tensioning units only need to be set on a portion of the edge of the large hole, thus saving costs. Therefore, this invention sets multiple tensioning units 53 and multiple needle-holding units 54 on the edge of each large hole, that is, multiple needle-holding units are located at a portion of the edge of the large hole, and multiple tensioning units are located at another portion of the edge of the large hole. The needle-holding units 54 are used to fix a portion of the material 55, and the tensioning units 53 are used to tension the other portion of the material 55. The arrangement of the needle-holding units 54 and the tensioning units 53 is determined according to the shape of the fabric. The steel needles in the tensioning units 53 can move back and forth, while the steel needles in the needle-holding units 54 cannot move back and forth. Figure 5 In the embodiment shown, multiple tensioning units 53 are set in the small arc segment of the large hole, and multiple needle-sticking units 54 are set in the large arc segment of the large hole. In this way, a part of the material 55 is fixed by the multiple needle-sticking units 54 in the large arc segment, and another part of the material 55 is tensioned by the multiple tensioning units 53 in the small arc segment, thereby achieving tensioning of the entire material 55.

[0070] Furthermore, a lifting pin plate 29 is also provided on the tensioning base plate 28. Each lifting pin plate 29 corresponds one-to-one with a lifting pin 21 in the clamping assembly. A pin hole is formed on the lifting pin plate 29, into which the lifting pin 21 can be inserted. When multiple lifting pins 21 move inward simultaneously, they are simultaneously inserted into the pin holes of their respective lifting pin plates 29. This connects the tensioning base plate 28 to the lifting plate 17 via the multiple lifting pins 21, allowing the lifting plate 17 to move the tensioning base plate 28 up and down. When the tensioning base plate 28 does not need to be moved, the multiple lifting pins 21 move outward simultaneously, exiting from their pin holes. The tensioning base plate 28 separates from the lifting plate 17 and no longer moves up and down with it. Preferably, lifting pin plates 29 are provided at each of the four corners of the tensioning base plate 28.

[0071] Furthermore, a positioning sleeve 30 is provided on the tensioning base plate 28, and a positioning shaft 7 is provided on the desktop fixture base plate 3. The positioning sleeve 30 and the positioning shaft 7 correspond one-to-one, and the positioning shaft 7 is fixed to the desktop fixture base plate 3 by bolts. The positioning shaft 7 can be inserted into the positioning sleeve 30, and the positioning of the tensioning fixture 52 is achieved through the cooperation between the positioning shaft 7 and the positioning sleeve 30.

[0072] A drag shaft fixing plate 6 is also provided on the desktop fixture base plate 3, and a drag shaft 5 is provided on the drag shaft fixing plate 6. Preferably, a drag shaft 5 and a drag shaft fixing plate 6 are provided at both ends of the front side of the desktop fixture base plate 3. The drag shaft fixing plate 6 is fixed to the desktop fixture base plate 3 with bolts, and the drag shaft 5 is fixed to the drag shaft fixing plate 6. After tensioning, the desktop fixture base plate 3 can be dragged by the drag shaft 5.

[0073] To position the tensioning fixture, at least two fixture positioning components are provided at the rear end of the tabletop fixture base plate 3. Each fixture positioning component includes a positioning cylinder 10, a fixture positioning block 8, and a positioning cylinder bracket 9. The fixture positioning block 8 is fixed on the tabletop 2 and located on the rear side of the tabletop fixture base plate 3. The fixture positioning block 8 has a U-shaped groove with its opening facing forward. The positioning cylinder bracket 9 is installed above the fixture positioning block 8. The positioning cylinder 10 is installed above the positioning cylinder bracket 9. The piston rod of the positioning cylinder 10 passes through the positioning cylinder bracket 9 and is connected to the positioning pin 11. The positioning pin 11 is located above the U-shaped groove. The central axis of the piston rod of the positioning cylinder 10 is perpendicular to the tabletop. Correspondingly, a fixture base plate positioning block 48 is provided at the rear end of the desktop fixture base plate 3. The fixture base plate positioning block 48 can be inserted into the U-shaped groove of the fixture positioning block 8. After insertion, when the piston rod of the positioning cylinder 10 extends downward, the piston rod drives the positioning pin 11 to move downward, and the positioning pin 11 presses against the fixture base plate positioning block 48, thereby pressing against the entire desktop fixture base plate 3. When the piston rod retracts upward, it drives the positioning pin 11 to move upward, releasing the desktop fixture base plate 3.

[0074] Specifically, such as Figure 7 As shown, each needle-sticking unit 54 includes: a mounting block 31, a double-ended threaded pin 35, a steel needle connecting plate 32, and a steel needle 33. The lower end of the mounting block 31 is fixed to the tensioning base plate 28. A longitudinal through hole is formed at the front of the mounting block 31. The upper end of the double-ended threaded pin 35 is located above the hole, and the lower end passes through the hole and connects to the steel needle connecting plate 32 located below the hole. A transverse groove is formed in the middle of the lower end of the mounting block 31. The rear end of the steel needle connecting plate 32 is located in the groove, and the front end extends out of the groove and connects to the steel needle 33. The steel needle connecting plate 32 can move up and down within the groove. The central axis of the steel needle 33 is parallel to the central axis of the double-ended threaded pin 35. A needle-sticking spring 40 is fitted on the double-ended threaded pin 35, and the needle-sticking spring 40 is located above the mounting block 31. When the double-ended threaded pin 35 is pressed down, the needle-piercing spring 40 is compressed. The double-ended threaded pin 35 drives the steel needle connecting plate 32 to move downward, and the steel needle connecting plate 32 drives the steel needle 33 to move downward, thus allowing the steel needle 33 to penetrate the material 55. When the double-ended threaded pin 35 is released, the needle-piercing spring 40 returns to its original position, driving the double-ended threaded pin 35 to move upward, and the steel needle connecting plate 32 subsequently drives the steel needle 33 to move upward. During operation, the steel needle 33 is located directly above the U-shaped groove of the fabric support plate 4, so that when the steel needle 33 moves downward, it can penetrate the material 55.

[0075] To facilitate the installation of the needle spring 40, each needle unit 54 further includes an upper washer 36, an upper bolt 37, and a lower washer 38. A threaded hole is formed at the upper end of the double-ended threaded pin 35. The upper washer 36 is installed at the upper end of the double-ended threaded pin 35, and the lower end of the upper bolt 37 is screwed into the threaded hole at the upper end of the double-ended threaded pin 35 to fix the upper washer 36 in place. A lower washer 38 is provided above the hole in the mounting block 31. The upper and lower ends of the needle spring 40 respectively abut against the upper washer 36 and the lower washer 38, thus ensuring that the needle spring 40 will not come off the double-ended threaded pin 35.

[0076] To facilitate the installation of the steel needle connecting plate 32, a threaded hole is also provided at the lower end of the double-ended threaded pin 35. The lower bolt 39 passes through the steel needle connecting plate 32 from bottom to top and is then screwed into the threaded hole at the lower end of the double-ended threaded pin 35.

[0077] To further limit the positioning of the steel needle connecting plate 32, a longitudinal pin hole is provided at the rear of the mounting block 31, and a longitudinal pin hole is also provided at the rear end of the steel needle connecting plate 32. The mounting block positioning pin 34 passes through the pin hole on the mounting block 31 from top to bottom and is inserted into the pin hole at the rear end of the steel needle connecting plate 32. The positioning pin 34 and the pin hole on the steel needle connecting plate 32 are in a tight fit, and the positioning pin 34 and the pin hole on the mounting block 31 are in a sliding fit. Therefore, the mounting block positioning pin 34 can move along the pin hole on the mounting block 31.

[0078] like Figure 8 As shown, each tensioning unit 53 includes a moving mechanism and a needle-piercing mechanism, wherein the moving mechanism can drive the needle-piercing mechanism to move back and forth.

[0079] Specifically, the moving mechanism includes a guide rail 46, a slider 45, a spring fixing block 42, and a moving spring 43. The guide rail 46 and the spring fixing block 42 are fixedly mounted on the tensioning base plate 28. The slider 45 matches the guide rail 46 and can move back and forth along the guide rail 46. A moving block 44 is connected above the slider 45, and the moving block 44 is connected to the spring fixing block 42 through the moving spring. Figure 8 In the embodiment shown, first locking bolts are provided on both the left and right sides of the movable block 44, and second locking bolts 42 are provided on both the left and right sides of the spring fixing block 42. The two ends of a movable spring 43 are respectively connected to the first locking bolt and the second locking bolt 42 on the left side, and the two ends of another movable spring 43 are respectively connected to the first locking bolt and the second locking bolt 42 on the right side. When the movable block 44 moves back and forth along the guide rail 46, the two movable springs 43 extend or retract simultaneously.

[0080] Furthermore, an inclined surface is provided on the upper part of the movable block 44, and the limiting plate 49 corresponds one-to-one with the tensioning unit 53, which can push the movable block 44 of the tensioning unit 53 to move, specifically as follows: When the limiting plate 49 on the lower end face of the lifting plate 17 contacts the inclined surface of the movable block 44, as the lifting plate 17 descends, the limiting plate 49 pushes the movable block 44 forward (forward is the direction closer to the center of the working hole, and backward is the opposite), the moving spring 43 is stretched, and the movable block 44 drives the needle-sticking mechanism to move forward. When the lifting plate 17 rises, the limiting plate 49 and the movable block 44 no longer contact each other, the moving spring 43 retracts, and drives the movable block 44 back to its original position, and the needle-sticking mechanism also moves backward to its original position.

[0081] The structure of the needle-piercing mechanism is similar to that of the needle-piercing unit 54, except that the mounting block 31 is replaced by a connecting block 47. Figure 8As shown, the lower end of the connecting block 47 is connected to the front end of the moving block 44. A longitudinal through hole is formed in the connecting block 47. The upper end of the double-ended threaded pin 35 is located above the hole, and the lower end passes through the hole and connects to the steel needle connecting plate 32 located below the hole. A transverse groove is formed in the middle of the lower end of the connecting block 47. The rear end of the steel needle connecting plate 32 is located in the groove, and the front end extends out of the groove and connects to the steel needle 33. The steel needle connecting plate 32 can move up and down within the groove. The central axis of the steel needle 33 is parallel to the central axis of the double-ended threaded pin 35. A needle-piercing spring 40 is fitted on the double-ended threaded pin 35, and the needle-piercing spring 40 is located above the connecting block 47. When the double-ended threaded pin 35 is pressed downwards, the needle-piercing spring 40 is compressed, the double-ended threaded pin 35 drives the steel needle connecting plate 32 to move downwards, and the steel needle connecting plate 32 drives the steel needle 33 to move downwards, thereby enabling the steel needle 33 to penetrate the material 55. When the double-ended threaded pin 35 is released, the needle spring 40 returns to its original position, causing the double-ended threaded pin 35 to move upward, and the steel needle connecting plate 32 subsequently moves the steel needle 33 upward. In use, the steel needle 33 is positioned directly above the U-shaped groove of the fabric support plate 4, so that when the steel needle 33 moves downward, it can pass through the material 55.

[0082] To facilitate the installation of the needle spring 40, each needle-attaching mechanism further includes an upper washer 36, an upper bolt 37, and a lower washer 38. A threaded hole is formed at the upper end of the double-ended threaded pin 35. The upper washer 36 is installed at the upper end of the double-ended threaded pin 35, and the lower end of the upper bolt 37 is screwed into the threaded hole at the upper end of the double-ended threaded pin 35 to fix the upper washer in place. A lower washer 38 is provided above the hole in the connecting block 47. The upper and lower ends of the needle spring 40 respectively abut against the upper washer 36 and the lower washer 38, thus ensuring that the needle spring 40 will not detach from the double-ended threaded pin 35.

[0083] To facilitate the installation of the steel needle connecting plate 32, a threaded hole is also provided at the lower end of the double-ended threaded pin 35. The lower bolt 39 passes through the steel needle connecting plate 32 from bottom to top and is then screwed into the threaded hole at the lower end of the double-ended threaded pin 35.

[0084] To further limit the positioning of the steel needle connecting plate 32, a longitudinal pin hole is provided at the rear of the connecting block 47, and a longitudinal pin hole is also provided at the rear end of the steel needle connecting plate 32. The mounting block positioning pin 34 passes through the pin hole on the connecting block 47 from top to bottom and is inserted into the pin hole at the rear end of the steel needle connecting plate 32. The positioning pin 34 and the pin hole on the steel needle connecting plate 32 are in a tight fit, while the positioning pin 34 and the pin hole on the connecting block 47 are in a sliding fit. Therefore, the mounting block positioning pin 34 can move along the pin hole on the connecting block 47.

[0085] Preferably, in order to save space, two needle-sticking units 54 can be connected to the front end of the moving block 44 of a moving mechanism. In this way, when the moving block 44 of the moving mechanism moves back and forth, it can simultaneously drive the two needle-sticking units 54 to move back and forth.

[0086] The hexagonal cap nut 23 in the pressing assembly corresponds one-to-one with the double-ended threaded pin 35 in the needle-pinning unit 54 and the tensioning unit 53, and can press down on its corresponding double-ended threaded pin 35.

[0087] The present invention also provides a method for automatically tensioning fabric, the method comprising:

[0088] (1) Place the material 55 (including stacked leather and cotton) on the material placement hole on the base plate 3 of the table fixture. The edges of the material 55 are supported by the fabric support pieces 4. In actual use, the material 55 can be placed on the material placement hole manually or by a robot.

[0089] (2) The material 55 is pressed and positioned using a flat-head snap ring pin, and the material 55 is fixed using a needle unit 54. At the same time, the material 55 is tensioned using a tensioning unit 53. Specifically, the lifting cylinder 16 drives the lifting pressing plate 51 to clamp the tensioning fixture 52 and move it downward. The flat-head snap ring pin 24 first contacts the fabric and presses and positions the fabric. The lifting pressing plate 51 continues to move downward, and the tensioning fixture 52 contacts the table fixture base plate 3. The tensioning plate positioning shaft 7 and the positioning sleeve 30 cooperate to position the tensioning fixture 52. At this time, each limit plate 49 on the lifting pressing plate 51 presses against each corresponding moving block 44, so that each steel needle 33 in the tensioning unit 53 is at the foremost position. Then, the piston rod of the press cylinder 22 drives the hexagonal cap nut 23 to move downward, pressing the double-ended threaded pin 35 in the needle-sticking unit 54 and the tensioning unit 53, causing the double-ended threaded pin 35 to move downward, and the double-ended threaded pin 35 drives the steel needle 33 in the needle-sticking unit 54 and the tensioning unit 53 to insert into the material 55; then, the clamping cylinder 18 is activated, causing the lifting pin 21 to disengage from the second connecting plate 20, and the tensioning fixture 52 to disengage from the lifting pressure plate 51. At this time, the lifting and pressing plate 51 moves upward, and the hexagonal cap nut 23 also moves upward with the lifting and pressing plate 51, thus no longer contacting the double-ended threaded pin 35. Under the action of the needle spring 40, the steel needles 33 of the needle unit 54 and the tensioning unit 53 simultaneously drive the material 55 to move upward a short distance. The part of the material 55 that is pierced by the needle unit 54 remains in this position. At the same time, the limiting plate 49 also moves upward with the lifting and pressing plate 51. The limiting plate 49 no longer contacts the moving block 44. Under the action of the moving spring 43, the moving block 44 drives the steel needle 33 to move backward, driving the part of the material 55 that is pierced by the tensioning unit 53 to move backward. In this way, the needle unit 54 fixes the material 55, and the tensioning unit 53 achieves tension on the material 55.

[0090] After tensioning the material 55, transfer the tensioning fixture 52 and the tabletop fixture base plate 3 together onto the sewing machine for sewing.

[0091] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0092] In the description of this invention, unless otherwise stated, the terms "upper," "lower," "left," "right," "inner," "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0093] The above technical solution is only one embodiment of the present invention. For those skilled in the art, based on the principles disclosed in the present invention, it is easy to make various types of improvements or modifications, and not limited to the technical solutions described in the specific embodiments of the present invention. Therefore, the foregoing description is only a preferred option and is not restrictive.

Claims

1. A device for automatically tensioning fabric, characterized in that: The device includes: a bracket, with a support frame and a desktop arranged sequentially from top to bottom on the front side of the bracket; A lifting mechanism is provided on the support frame, and a lifting pressure plate is provided below the support frame. The lifting mechanism can drive the lifting pressure plate to move up and down, and the lifting pressure plate can drive the tensioning fixture to move up and down. Multiple tensioning units are provided on the tensioning fixture. A desktop fixture base plate is provided on the desktop; The lifting and pressing plate includes a lifting plate; multiple limiting plates and limiting plate fixing blocks are provided on the lower end surface of the lifting plate; the limiting plate fixing blocks are fixedly installed on the lower end surface of the lifting plate, and threaded holes are opened on the limiting plate fixing blocks, with the central axis of the threaded holes parallel to the lifting plate; an oblong hole is opened at the upper end of the limiting plate. The tensioning fixture includes a tensioning base plate with at least one large hole. Multiple tensioning units are arranged around the edge of each large hole. Each tensioning unit includes a moving mechanism and a needle-attaching mechanism. The moving mechanism includes a guide rail, a slider, a spring fixing block, and a moving spring. The guide rail and spring fixing block are fixedly mounted on the tensioning base plate, and the slider can move back and forth along the guide rail. A moving block is connected above the slider, and the moving block is connected to the spring fixing block via the moving spring. An inclined surface is provided on the upper part of the moving block, and a limiting plate corresponds to each tensioning unit, enabling the moving block of the tensioning unit to move. The needle-sticking mechanism includes a connecting block, a double-ended threaded pin, a steel needle connecting plate, and a steel needle. The lower end of the connecting block is connected to the front end of the moving block. A longitudinal through hole is formed in the connecting block, and the lower end of the double-ended threaded pin passes through the hole and connects to the steel needle connecting plate. A transverse groove is formed in the middle of the lower end of the connecting block, and the rear end of the steel needle connecting plate is located in the groove, while the front end extends out of the groove and connects to the steel needle. The central axis of the steel needle is parallel to the central axis of the double-ended threaded pin. A needle-sticking spring is fitted on the double-ended threaded pin.

2. The device for automatically tensioning fabric according to claim 1, characterized in that: At least one material placement hole is provided on the base plate of the desktop fixture; Multiple fabric support plates are arranged around the edge of each material placement hole.

3. The device for automatically tensioning fabric according to claim 1, characterized in that: The lifting and pressing plate includes a lifting plate, and multiple pressing components and multiple pressing components disposed on the lifting plate; Each pressing assembly includes: a pressing cylinder and a hexagonal cap nut; the central axis of the piston rod of the pressing cylinder is perpendicular to the lifting plate, and the lower end of the piston rod passes through the lifting plate and is connected to the hexagonal cap nut; Each clamping assembly includes: a flat-head snap ring pin, a clamping spring, a clamping washer, and a snap ring; a snap ring pin hole is provided on the lifting plate, through which the flat-head snap ring pin passes; a snap ring is installed at the upper end of the flat-head snap ring pin, the snap ring being located above the lifting plate; the clamping washer and the clamping spring are sleeved on the outside of the flat-head snap ring pin; an annular flange is provided at the lower end of the flat-head snap ring pin, and the clamping spring is located between the clamping washer and the annular flange.

4. The device for automatically tensioning fabric according to claim 3, characterized in that: The lifting plate is provided with working holes, which correspond one-to-one with the material placement holes on the bottom plate of the desktop fixture; Multiple pressing components and multiple clamping components surround the edge of each working hole.

5. The device for automatically tensioning fabric according to claim 3, characterized in that: Multiple clamping components are also provided on the edge of the lifting plate; Each clamping assembly includes: a clamping cylinder and a lifting pin; The central axis of the piston rod of the clamping cylinder is parallel to the lifting plate, and the front end of the piston rod is connected to the lifting pin through a connecting plate. The central axis of the lifting pin is parallel to the central axis of the piston rod.

6. The device for automatically tensioning fabric according to claim 1, characterized in that: Multiple needle-holding units are also provided at the edge of each large hole, with multiple needle-holding units located at one part of the edge of the large hole and multiple tensioning units located at the other part of the edge of the large hole; Each of the needle-piercing units includes: a mounting block, a double-ended threaded pin, a steel needle connecting plate, and a steel needle; The lower end of the mounting block is fixed to the tensioning base plate; a longitudinal through hole is opened at the front of the mounting block, and the lower end of the double-ended threaded pin passes through the hole and is connected to the steel needle connecting plate. A transverse groove is formed in the middle of the lower end of the mounting block. The rear end of the steel needle connecting plate is located in the groove, and the front end extends out of the groove and is connected to the steel needle. The central axis of the steel needle is parallel to the central axis of the double-threaded pin. A pin spring is fitted onto the double-ended threaded pin.

7. The device for automatically tensioning fabric according to claim 1, characterized in that: A lifting pin plate is also provided on the tensioning base plate; The lifting pin plate has a pin hole, into which the lifting pin can be inserted.

8. A method for automatically tensioning fabric, using the apparatus as described in any one of claims 1-7, characterized in that: The method includes: (1) Place the material on the material placement hole on the bottom plate of the table fixture, and the edge of the material is supported by each fabric support piece; (2) Use flat-head snap ring pins to press and position the material, use the pinning unit to fix the material, and use the tensioning unit to tension the material.

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