Device and method for automatically tensioning cloth

Abstract

The invention provides a device and method for automatically tensioning cloth, and belongs to the field of industrial automatic sewing. The device comprises a support, and a supporting frame and a table top are sequentially arranged on the front side of the support from top to bottom; a lifting mechanism is arranged on the supporting frame, a lifting pressing plate is arranged below the supporting frame, the lifting mechanism can drive the lifting pressing plate to move up and down, the lifting pressing plate can drive a tensioning jig to move up and down, and a plurality of tensioning units are arranged on the tensioning jig. A table top jig bottom plate is arranged on the table top. By means of the automatic tensioning device, automatic tensioning of materials is achieved, labor is reduced, and production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the field of industrial automated sewing, and in particular relates to a device and method for automatically tensioning cloth. Background Art

[0002] In the automobile manufacturing factory, the materials (including the overlapping cotton materials and leather materials) need to be stretched, and then the stretched materials are sewn, and finally the sewn materials 55 are spliced ​​into the outer layer of the automobile seat.

[0003] At present, the material is tensioned in the following manner: the material 55 is manually placed on the tensioning jig bottom plate. The tensioning jig bottom plate is a plate-like structure with one or more material placement holes opened thereon, the material is placed above the material placement hole, and the material is slightly stretched outward, and at the same time, the edge of the material is fixed to the periphery of the material placement hole by using multiple clips or thumbtacks, so that the material 55 is fixed on the tensioning jig bottom plate, and the tensioned material is obtained.

[0004] However, the existing tensioning method requires a lot of manual participation, resulting in low production efficiency. In addition, due to manual tensioning, the tensioning force at each point may be different, which makes it impossible to ensure uniform quality. Summary of the invention

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

[0006] The present invention is achieved through the following technical solutions:

[0007] A first aspect of the present invention provides a device for automatically tensioning a cloth, the device comprising: a bracket, a support frame and a table top being arranged in sequence from top to bottom on the front side of the bracket;

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

[0009] A desktop fixture bottom plate is arranged on the desktop.

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

[0011] A plurality of cloth supporting pieces are arranged around the edge of each material placement hole.

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

[0013] Each pressing assembly comprises: 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-headed retaining spring pin, a retaining spring, a retaining gasket and a retaining spring; a retaining spring pin hole is opened on the lifting plate, and the flat-headed retaining spring pin passes through the retaining spring pin hole; a retaining spring is installed on the upper end of the flat-headed retaining spring pin, and the retaining spring is located above the lifting plate; the retaining gasket and the retaining spring are sleeved on the outside of the flat-headed retaining spring pin; an annular flange is provided at the lower end of the flat-headed retaining spring pin, and the retaining spring is located between the retaining gasket and the annular flange.

[0015] Preferably, working holes are provided on the lifting plate, and the working holes correspond one-to-one with the material placement holes on the bottom plate of the desktop fixture;

[0016] A plurality of pressing components and a plurality of clamping components are arranged around the edge of each working hole.

[0017] Preferably, a plurality of clamping assemblies 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, the front end of the piston rod is connected to the lifting pin through the connecting plate, and the central axis of the lifting pin is parallel to the central axis of the piston rod.

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

[0021] The limit plate fixing block is fixedly installed on the lower end surface of the lifting plate, and a threaded hole is opened on the limit plate fixing block, and the central axis of the threaded hole is parallel to the lifting plate;

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

[0023] Preferably, the tensioning jig comprises a tensioning base plate, and at least one large hole is formed on the tensioning base plate;

[0024] A plurality of tensioning units are arranged at the edge of each large hole;

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

[0026] The moving mechanism comprises a guide rail, a slider, a spring fixing block, and a moving spring; the guide rail and the spring fixing block are fixedly mounted on the tensioning base plate, and the slider can move forward and backward 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 arranged on the upper part of the moving block;

[0027] The needle-piercing mechanism includes a connecting block, a double-headed 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 opened on the connecting block, and the lower end of the double-headed thread is connected to the steel needle connecting plate after passing through the hole; a transverse groove is opened in the middle of the lower end of the connecting 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-headed threaded pin; a needle-piercing spring is sleeved on the double-headed threaded pin.

[0028] Preferably, a plurality of needle-piercing units are arranged at the edge of each large hole, the plurality of needle-piercing units are located at a portion of the edge of the large hole, and the plurality of tensioning units are located at another portion of the edge of the large hole;

[0029] Each of the needle-piercing units comprises: 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 on the tensioning base plate; a longitudinal through hole is opened at the front of the mounting block, and the lower end of the double-headed threaded pin passes through the hole and is connected to the steel needle connecting plate;

[0031] A transverse groove is provided 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-ended threaded pin;

[0033] A needle spring is sleeved on the double-ended threaded pin.

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

[0035] A pin hole is formed on the lifting pin plate, and the lifting pin can be inserted into the pin hole.

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

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

[0038] (2) The material is compressed and positioned using a flat-head retaining pin, and the material is fixed using a needle-piercing unit, and the material is tensioned using a tensioning unit.

[0039] Compared with the prior art, the beneficial effects of the present invention are: the present invention realizes automatic tensioning of materials, reduces labor and improves production efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic structural diagram of the device for automatically tensioning cloth in the initial state of the present invention;

[0041] Figure 2 It is a structural schematic diagram of the device for automatically tensioning cloth according to the present invention, in which the tensioning jig is separated from the lifting and pressing plate after tensioning is completed;

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

[0043] Figure 4-1 This is an assembly diagram of a lifting and pressing plate in a device for automatically tensioning cloth according to the present invention;

[0044] Figure 4-2 It is an assembly diagram of a limit plate and a limit plate fixing block in the device for automatically tensioning cloth of the present invention;

[0045] Figure 4-3 It is a schematic structural diagram of a pressing assembly in a device for automatically tensioning cloth according to the present invention;

[0046] Figure 5 This is an assembly diagram of a tensioning jig in a device for automatically tensioning cloth according to the present invention;

[0047] Figure 6 It is a schematic diagram of the three-dimensional structure of the fixed needle-piercing unit in the device for automatically tensioning cloth according to the present invention;

[0048] Figure 7 This is an assembly diagram of a fixed needle-piercing unit in a device for automatically tensioning cloth according to the present invention;

[0049] Figure 8 It is a schematic diagram of the three-dimensional structure of the tensioning unit in the device for automatically tensioning cloth according to the present invention;

[0050] Fig. 9 The figure is an assembly diagram of a tensioning unit in a device for automatically tensioning cloth according to the present invention;

[0051] Fig.10 The present invention is a schematic structural diagram of a cloth support in a device for automatically tensioning cloth. DETAILED DESCRIPTION

[0052] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0053] like Figures 1 to 10 As shown, the present invention provides a device for automatically tensioning cloth, the device comprising: a bracket 1, a support frame and a table top 2 are arranged on the front side of the bracket 1 from top to bottom, the support frame is parallel to the table top 2, and the support frame and the table top 2 are both perpendicular to the bracket 1.

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

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

[0056] A plurality of cloth support pieces 4 are arranged around the edge of each material placement hole, and the number and position of the cloth support pieces 4 are arranged according to the tension point of the cloth. Specifically, a plurality of grooves are arranged on the edge of the material placement hole, and the grooves correspond to the cloth support pieces 4 one by one, and one cloth support piece 4 is installed in one groove. Fig.10 As shown, each cloth support piece 4 is in 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, Figure 1 As shown, the lifting mechanism includes a lifting cylinder 16 arranged above the support frame, the central axis of the piston rod of the lifting cylinder 16 is perpendicular to the plane where the support frame is located, and the lower end of the piston rod is fixedly connected to the upper end surface of the lifting and clamping plate 51. In this way, when the piston rod of the lifting cylinder 16 moves up and down, the piston rod drives the lifting and clamping plate 51 to move up and down.

[0058] In order 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 clamping plate 51.

[0059] Furthermore, in order to ensure the stability of the movement of the lifting and clamping plate 51, the lifting mechanism further includes a plurality of guide shafts 14 and a plurality of linear bearings 13. The linear bearings 13 correspond to the guide shafts 14 one by one. The lower end of each guide shaft 14 is connected to the upper end surface of the lifting and clamping plate 51. The upper end of the guide shaft 14 passes through the linear bearing 13. In this way, when the piston rod drives the lifting and clamping plate 51 to move up and down, the guide shaft 14 moves up and down along the linear bearing 13. In order to install the linear bearings, a plurality of linear bearing mounting plates 12 are provided on the support frame, and the linear bearings 13 are installed on the corresponding linear bearing mounting plates 12. Preferably, four linear bearings 13 are provided on the support frame, and the four linear bearings 13 are located at the four vertices of the rectangle. The central axis of the lifting cylinder 16 is located at the center of the rectangle, which improves the stability of the lifting and clamping plate 51 when it moves up and down.

[0060] like Figure 2 As shown, the lifting and clamping plate 51 includes a lifting plate 17 , and a plurality of pressing assemblies and a plurality of clamping assemblies arranged on the lifting plate 17 , and a plurality of clamping assemblies are also arranged on the edge of the lifting plate 17 .

[0061] Specifically, 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 arranged above the lifting plate 17, and the hexagonal cap nut 23 is arranged 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 is connected to the hexagonal cap nut 23. When the piston rod of the pressing cylinder 22 moves up and down, the hexagonal cap nut 23 is driven to move up and down.

[0062] like Figure 4-1 and Figure 4-3As shown, each clamping assembly includes: a flat-headed circlip pin 24, a clamping spring 25, a clamping gasket 26 and a clamping spring 27. A clamping spring pin hole is provided on the lifting plate 17, and the flat-headed circlip pin 24 passes through the clamping spring pin hole. A clamping spring groove is provided at the upper end of the flat-headed circlip pin 24, and a clamping spring 27 is installed in the clamping spring groove. The clamping spring 27 is located above the lifting plate 17, and the clamping spring 27 can ensure that the flat-headed circlip pin 24 will not fall out of the clamping spring pin hole on the lifting plate 17. The clamping gasket 26 and the clamping spring 25 are sleeved on the outside of the flat-headed circlip pin 24, and the clamping gasket 26 is located below the lifting plate 17 and above the clamping spring 25. An annular flange is provided at the lower end of the flat-headed circlip pin 24, and the clamping spring 25 is located between the clamping gasket 26 and the annular flange. When the lifting and pressing plate 51 moves downward, the lower end of the flat-headed retaining spring pin 24 first contacts the cloth. When pressed on the cloth, the flat-headed retaining spring pin 24 will move upward relative to the lifting and pressing plate 51. At this time, the compression spring 25 is squeezed by the compression gasket 26 and the annular flange to compress and position the cloth. When the lifting and pressing plate 51 moves upward, the compression spring 25 is restored, and the compression spring 25 pushes the flat-headed retaining spring pin 24 downward through the annular flange, thereby returning to its original state.

[0063] Preferably, two working holes are provided on the lifting plate 17, and the working holes correspond to the material placement holes on the bottom plate 3 of the desktop fixture. A plurality of pressing components and a plurality of clamping components are arranged around the edge of each working hole, wherein the plurality of pressing components are arranged in the outer circle, and the plurality of clamping components are arranged in the inner circle (the inner circle is close to the center of the working hole, and the outer circle is far 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 arranged above the lifting plate 17, 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, the piston rod drives the lifting pin 21 to move outward (i.e., move away from the lifting plate 17); when the piston rod of the clamping cylinder 18 retracts, the piston rod drives the lifting pin 21 to move inward (i.e., move closer to the lifting plate 17). Figure 2 In the illustrated embodiment, 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 at the same time, the four lifting pins 21 can clamp the tensioning jig 52, and when the lifting pins 21 of the four clamping assemblies move outward at the same time, the tensioning jig 52 can be released.

[0067] Further, such as Figure 4-1 and Figure 4-2 As shown, a plurality of limit plates 49 and limit plate fixing blocks 50 are arranged on the lower end surface of the lifting plate 17. The limit plates 49 correspond to the limit plate fixing blocks 50 one by one. The limit plate fixing blocks 50 are fixedly mounted on the lower end surface of the lifting plate 17. Two threaded holes are provided on the limit plate fixing blocks 50, and the central axis of the threaded holes is parallel to the lifting plate 17. An oblong hole is provided on the upper end of the limit plate 49. The limit plate 49 can be fixed below the lifting plate 17 by screwing a screw into the oblong hole. The oblong hole has a certain length, so the position of the limit plate 49 can be adjusted. After adjusting the position of the limit plate 49, tighten the screw in the oblong hole so that the limit plate 49 is fixed on the lifting plate 17. At the same time, a long bolt is screwed into the threaded hole of the limit plate fixing block 50 so that the front end of the long bolt supports the limit plate 49, thereby playing a limiting role.

[0068] like Figure 5 As shown, the tensioning fixture 52 includes a tensioning base plate 28, on which at least one large hole is opened, and the large hole corresponds to the working hole on the lifting plate 17. A plurality of tensioning units 53 are arranged at the edge of each large hole, and the plurality of tensioning units 53 are used to tension the material 55.

[0069] In actual use, as long as a part of the material 55 is fixed and the other part is tensioned, the entire fabric can be tensioned, so it is sufficient to set a tensioning unit on a part of the edge of the large hole, which can save costs. Therefore, the present invention sets multiple tensioning units 53 and multiple needle units 54 on the edge of each large hole, that is, multiple needle units are located at a part of the edge of the large hole, and multiple tensioning units are located at another part of the edge of the large hole. The needle unit 54 is used to fix a part of the material 55, and the tensioning unit 53 is used to tension the other part of the material 55. The arrangement of the needle unit 54 and the tensioning unit 53 is determined according to the shape of the fabric. The steel needles in the tensioning unit 53 can move forward and backward, and the steel needles in the needle unit 54 cannot move forward and backward. Figure 5 In the illustrated embodiment, a plurality of tensioning units 53 are arranged in the small arc section of the large hole, and a plurality of needle-piercing units 54 are arranged in the large arc section of the large hole, so that a part of the material 55 is fixed by the plurality of needle-piercing units 54 of the large arc section, and another part of the material 55 is tensioned by the plurality of tensioning units 53 of the small arc section, thereby achieving tensioning of the entire material 55.

[0070] Furthermore, a lifting pin plate 29 is also provided on the tensioning base plate 28. The lifting pin plate 29 corresponds to the lifting pin 21 in the clamping assembly one by one. A pin hole is provided on the lifting pin plate 29, and the lifting pin 21 can be inserted into the pin hole. When multiple lifting pins 21 move inward at the same time, multiple lifting pins 21 are simultaneously inserted into the pin holes of the corresponding lifting pin plates 29, so that the tensioning base plate 28 can be connected to the lifting plate 17 through multiple lifting pins 21, and the lifting plate 17 can drive the tensioning base plate 28 to move up and down. When the tensioning base plate 28 does not need to be moved, multiple lifting pins 21 move outward at the same time, and the lifting pins 21 withdraw from the pin holes, and the tensioning base plate 28 is separated from the lifting plate 17 and no longer moves up and down with the lifting plate 17. Preferably, lifting pin plates 29 are respectively provided at 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 jig base plate 3. The positioning sleeve 30 corresponds to the positioning shaft 7 one by one, and the positioning shaft 7 is fixed to the desktop jig base plate 3 by bolts. The positioning shaft 7 can be inserted into the positioning sleeve 30, and the positioning of the tensioning jig 52 is achieved by 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 jig bottom plate 3, and a drag shaft 5 is provided on the drag shaft fixing plate 6. Preferably, the drag shaft 5 and the drag shaft fixing plate 6 are provided at both ends of the front side of the desktop jig bottom plate 3. The drag shaft fixing plate 6 is fixed to the desktop jig bottom plate 3 with bolts, and the drag shaft 5 is fixed to the drag shaft fixing plate 6. After tensioning is completed, the desktop jig bottom plate 3 can be dragged by the drag shaft 5.

[0073] In order to position the tensioning jig, at least two jig positioning assemblies are provided at the rear end of the desktop jig base plate 3, each jig positioning assembly includes a positioning cylinder 10, a jig positioning block 8 and a positioning cylinder bracket 9, the jig positioning block 8 is fixed on the desktop 2 and is located on the rear side of the desktop jig base plate 3, the jig positioning block 8 is provided with a U-shaped groove with an opening facing forward, the positioning cylinder bracket 9 is installed above the jig 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, and the central axis of the piston rod of the positioning cylinder 10 is perpendicular to the desktop. Correspondingly, a jig bottom plate positioning block 48 is provided at the rear end of the desktop jig bottom plate 3, and the jig bottom plate positioning block 48 can be inserted into the U-shaped groove of the jig 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 the jig bottom plate positioning block 48, thereby pressing the entire desktop jig bottom plate 3. When the piston rod retracts upward, it drives the positioning pin 11 to move upward, and releases the desktop jig bottom plate 3.

[0074] Specifically, Figure 7 As shown, each of the needle-piercing units 54 includes: a mounting block 31, a double-headed threaded pin 35, a steel needle connecting plate 32 and a steel needle 33. The lower end of the mounting block 31 is fixed on the tensioning base plate 28. A longitudinal through hole is provided at the front of the mounting block 31, the upper end of the double-headed threaded pin 35 is located above the hole, and the lower end passes through the hole and is connected to the steel needle connecting plate 32 located below the hole. A transverse groove is provided at 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, the front end extends out of the groove and is connected to the steel needle 33, and the steel needle connecting plate 23 can move up and down in the groove. The central axis of the steel needle 33 is parallel to the central axis of the double-headed threaded pin 35. A needle-piercing spring 40 is sleeved on the double-headed threaded pin 35, and the needle-piercing spring 40 is located above the mounting block 31. When the double-headed threaded pin 35 is pressed downward, the needle spring 40 is compressed, the double-headed 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, thereby achieving the steel needle 33 being inserted into the material 55. When the double-headed threaded pin 35 is released, the needle spring 40 is restored, driving the double-headed threaded pin 35 to move upward, and the steel needle connecting plate 32 then drives the steel needle 33 to move upward. When working, the steel needle 33 is located directly above the U-shaped groove of the cloth support plate 4, so that when the steel needle 33 moves downward, it can penetrate the material 55.

[0075] In order to facilitate the installation of the needle spring 40, each needle unit 54 further includes an upper gasket 36, an upper bolt 37, and a lower gasket 38; a threaded hole is opened at the upper end of the double-headed threaded pin 35, and the upper gasket 36 is installed at the upper end of the double-headed threaded pin 35. The lower end of the upper bolt 37 is screwed into the threaded hole at the upper end of the double-headed threaded pin 35 to fix the upper gasket 36. A lower gasket 38 is arranged above the hole of the mounting block 31, and the upper and lower ends of the needle spring 40 respectively support the upper gasket 36 and the lower gasket 38, thereby ensuring that the needle spring 40 will not fall off the double-headed threaded pin 35.

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

[0077] In order to further limit the steel needle connecting plate 32, a longitudinal pin hole is opened at the rear part of the mounting block 31, and a longitudinal pin hole is also opened at the rear end of the steel needle connecting plate 32. The mounting block locating 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 locating pin 34 and the pin hole on the steel needle connecting plate 32 are tightly fitted, and the locating pin 34 and the pin hole on the mounting block 31 are slidingly fitted. Therefore, the mounting block locating pin 34 can move along the pin hole on the mounting block 31.

[0078] like Figure 8 As shown, each of the tensioning units 53 includes: a moving mechanism and a needle-piercing mechanism, and the moving mechanism can drive the needle-piercing mechanism to move forward and backward.

[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, and the slider 45 matches the guide rail 46 and can move forward and backward 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 a moving spring. Figure 8 In the illustrated embodiment, first driving bolts are provided on both sides of the movable block 44, and second driving bolts 42 are provided on both sides of the spring fixing block 42. Both ends of a movable spring 43 are respectively connected to the first driving bolt and the second driving bolt 42 on the left side, and both ends of another movable spring 43 are respectively connected to the first driving bolt and the second driving bolt 42 on the right side. When the movable block 44 moves forward and backward 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 moving block 44, and the limiting plate 49 corresponds to the tensioning unit 53 one by one, and can push the moving block 44 of the tensioning unit 53 to move, specifically as follows: when the limiting plate 49 on the lower end surface of the lifting plate 17 contacts the inclined surface of the moving block 44, as the lifting plate 17 descends, the limiting plate 49 pushes the moving block 44 to move forward (the direction close to the center of the working hole is forward, and the reverse direction is backward), the moving spring 43 is stretched, and the moving block 44 drives the needle-piercing mechanism to move forward. When the lifting plate 17 rises, the limiting plate 49 is no longer in contact with the moving block 44, the moving spring 43 retracts, and drives the moving block 44 back to its original position, and the needle-piercing mechanism also moves backward back to its original position.

[0081] The structure of the needle sticking mechanism is similar to that of the needle sticking 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 provided on the connecting block 47, the upper end of the double-headed threaded pin 35 is located above the hole, and the lower end passes through the hole and is connected to the steel needle connecting plate 32 located below the hole. A transverse groove is provided 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, the front end extends out of the groove and is connected to the steel needle 33, and the steel needle connecting plate 23 can move up and down in the groove. The central axis of the steel needle 33 is parallel to the central axis of the double-headed threaded pin 35. A needle spring 40 is sleeved on the double-headed threaded pin 35, and the needle spring 40 is located above the connecting block 47. When the double-headed threaded pin 35 is pressed downward, the needle spring 40 is compressed, the double-headed 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, thereby achieving the steel needle 33 piercing into the material 55. When the double-ended threaded pin 35 is loosened, the needle spring 40 is restored, driving the double-ended threaded pin 35 to move upward, and the steel needle connecting plate 32 then drives the steel needle 33 to move upward. When in use, the steel needle 33 is located just above the U-shaped groove of the cloth support sheet 4, so that the steel needle 33 can pass through the material 55 when it moves downward.

[0082] In order to facilitate the installation of the needle spring 40, each of the needle piercing mechanisms further includes an upper gasket 36, an upper bolt 37, and a lower gasket 38; a threaded hole is opened at the upper end of the double-headed threaded pin 35, and the upper gasket 36 is installed at the upper end of the double-headed threaded pin 35. The lower end of the upper bolt 37 is screwed into the threaded hole at the upper end of the double-headed threaded pin 35 to fix the upper gasket. A lower gasket 38 is arranged above the hole of the connecting block 47, and the upper and lower ends of the needle spring 40 respectively support the upper gasket 36 and the lower gasket 38, thereby ensuring that the needle spring 40 will not fall off from the double-headed threaded pin 35.

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

[0084] In order to further limit the position of the steel needle connecting plate 32, a longitudinal pin hole is opened at the rear of the connecting block 47, and a longitudinal pin hole is also opened at the rear end of the steel needle connecting plate 32. The mounting block locating 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 locating pin 34 and the pin hole on the steel needle connecting plate 32 are tightly matched, and the locating pin 34 and the pin hole on the connecting block 47 are slidingly matched. Therefore, the mounting block locating pin 34 can move along the pin hole on the connecting block 47.

[0085] Preferably, in order to save space, two needle-piercing units 54 can be connected to the front end of a moving block 44 of a moving mechanism, so that when the moving block 44 of the moving mechanism moves forward and backward, the two needle-piercing units 54 can be driven to move forward and backward at the same time.

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

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

[0088] (1) Place the material 55 (including stacked leather and cotton) on the material placement hole on the bottom plate 3 of the table fixture, and 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) Use the flat-headed retaining spring pin to compress and position the material 55, and use the needle-piercing unit 54 to fix the material 55, and use the tensioning unit 53 to tension the material 55. Specifically, the lifting cylinder 16 drives the lifting and pressing plate 51 to clamp the tensioning fixture 52 and move downward, and the flat-headed retaining spring pin 24 first contacts the fabric to compress and position the fabric, and the lifting and pressing plate 51 continues to move downward, and the tensioning fixture 52 contacts the bottom plate 3 of the desktop fixture, and the tensioning plate positioning shaft 7 cooperates with the positioning sleeve 30 to position the tensioning fixture 52. At this time, each limit plate 49 on the lifting and pressing plate 51 presses against each corresponding moving block 44, so that each steel needle 33 in the tensioning unit 53 is located at the front end. Then, the piston rod of the cylinder 22 is pressed to drive the hexagonal cap nut 23 to move downward, and the double-headed threaded pin 35 in the needle-piercing unit 54 and the tensioning unit 53 is pressed to move the double-headed threaded pin 35 downward, and the double-headed threaded pin 35 drives the steel needle 33 in the needle-piercing unit 54 and the tensioning unit 53 to penetrate into the material 55; then, the clamping cylinder 18 is started to disengage the lifting pin 21 from the second connecting plate 20, and the tensioning fixture 52 is separated from the lifting and clamping 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, and no longer contacts the double-headed threaded pin 35. Under the action of the needle spring 40, the needle unit 54 and the steel needle 33 of the tensioning unit 53 simultaneously drive the material 55 to move upward a short distance, and the part of the material 55 pierced by the needle unit 54 remains in this position. At the same time, the limit plate 49 also moves upward with the lifting and pressing plate 51, and the limit 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, and drives the part of the material 55 pierced by the tensioning unit 53 to move backward. In this way, the needle unit 54 is used to fix the material 55, and the tensioning unit 53 is used to achieve the tensioning of the material 55.

[0090] After the material 55 is tensioned, the tensioning jig 52 and the desktop jig bottom plate 3 are transferred to the sewing machine for sewing.

[0091] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0092] In the description of the present invention, unless otherwise specified, the terms "upper", "lower", "left", "right", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

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

Claims

1. A device for automatically tensioning cloth, characterized in that: The device comprises: a bracket, on the front side of which a support frame and a tabletop are arranged in sequence from top to bottom; A lifting mechanism is provided on the support frame, and a lifting and pressing plate is provided below the support frame. The lifting mechanism can drive the lifting and pressing plate to move up and down, and the lifting and pressing plate can drive the tensioning fixture to move up and down. A plurality of tensioning units are provided on the tensioning fixture. A desktop fixture bottom plate is arranged on the desktop.

2. The device for automatically tensioning cloth according to claim 1, characterized in that: At least one material placement hole is provided on the bottom plate of the desktop fixture; A plurality of cloth supporting pieces are arranged around the edge of each material placement hole.

3. The device for automatically tensioning cloth according to claim 1, characterized in that: The lifting and pressing plate comprises a lifting plate, and a plurality of pressing components and a plurality of pressing components arranged on the lifting plate; Each pressing assembly comprises: 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-headed retaining spring pin, a retaining spring, a retaining gasket and a retaining spring; a retaining spring pin hole is opened on the lifting plate, and the flat-headed retaining spring pin passes through the retaining spring pin hole; a retaining spring is installed on the upper end of the flat-headed retaining spring pin, and the retaining spring is located above the lifting plate; the retaining gasket and the retaining spring are sleeved on the outside of the flat-headed retaining spring pin; an annular flange is provided at the lower end of the flat-headed retaining spring pin, and the retaining spring is located between the retaining gasket and the annular flange.

4. The device for automatically tensioning cloth 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; A plurality of pressing components and a plurality of clamping components are arranged around the edge of each working hole.

5. The device for automatically tensioning cloth according to claim 3, characterized in that: A plurality of clamping components are also arranged 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, the front end of the piston rod is connected to the lifting pin through the connecting plate, and the central axis of the lifting pin is parallel to the central axis of the piston rod.

6. The device for automatically tensioning cloth according to claim 3, characterized in that: A plurality of limit plates and limit plate fixing blocks are arranged on the lower end surface of the lifting plate; The limit plate fixing block is fixedly installed on the lower end surface of the lifting plate, and a threaded hole is opened on the limit plate fixing block, and the central axis of the threaded hole is parallel to the lifting plate; An oblong hole is provided at the upper end of the limiting plate.

7. The device for automatically tensioning cloth according to claim 1, characterized in that: The tensioning fixture comprises a tensioning base plate, on which at least one large hole is opened; A plurality of tensioning units are arranged at the edge of each large hole; Each tensioning unit includes: a moving mechanism and a needle-piercing mechanism; The moving mechanism comprises a guide rail, a slider, a spring fixing block, and a moving spring; the guide rail and the spring fixing block are fixedly mounted on the tensioning base plate, and the slider can move forward and backward 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 arranged on the upper part of the moving block; The needle-piercing mechanism includes a connecting block, a double-headed 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 opened on the connecting block, and the lower end of the double-headed thread is connected to the steel needle connecting plate after passing through the hole; a transverse groove is opened in the middle of the lower end of the connecting 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-headed threaded pin; a needle-piercing spring is sleeved on the double-headed threaded pin.

8. The device for automatically tensioning cloth according to claim 7, characterized in that: A plurality of needle-piercing units are also arranged at the edge of each large hole, wherein the plurality of needle-piercing units are located at a portion of the edge of the large hole, and the plurality of tensioning units are located at another portion of the edge of the large hole; Each of the needle-piercing units comprises: 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 on the tensioning base plate; a longitudinal through hole is opened at the front of the mounting block, and the lower end of the double-headed threaded pin passes through the hole and is connected to the steel needle connecting plate; A transverse groove is provided 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-ended threaded pin; A needle spring is sleeved on the double-ended threaded pin.

9. The device for automatically tensioning cloth according to claim 7, characterized in that: A lifting pin plate is also provided on the tensioning bottom plate; A pin hole is formed on the lifting pin plate, and the lifting pin can be inserted into the pin hole.

10. A method for automatically tensioning a cloth, characterized in that: The method comprises: (1) Place the material on the material placement hole on the bottom plate of the desktop fixture, and the edges of the material are supported by each fabric support piece; (2) The material is compressed and positioned using a flat-head retaining pin, and the material is fixed using a needle-piercing unit, and the material is tensioned using a tensioning unit.

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