Automatic bending device for supporting legs of folding ladder

Abstract

The invention discloses an automatic folding ladder supporting leg bending device which comprises a heating part and a bending part, the heating part can conduct dynamic heating, and the bending part is used for splitting stress. When the square tube is pushed to the heating mechanism, the square tube is pressed through the pressing device, the mounting plate is pushed to move through the telescopic air cylinder after being pressed until one end of the heating device abuts against the square tube, the heating device is started, the heating amplitude of the heating device on the right side of the square tube is larger than that on the left side of the square tube, then the mounting plate continues to be pushed, and under the action of the connecting rod mechanism, the square tube is heated. In addition, the lengths of the connecting rods are set differently, namely, the length of the second connecting rod is reduced, and the lengths of the third connecting rod and the fourth connecting rod are increased, so that the initial heating angle is consistent, and the heating effect is improved. The same pushing form enables the swing amplitude of the heating device to be distinguished so as to adapt to the difference of core heating areas at the top and the bottom of the square pipe, so that small gradient heating and key area key heating are realized, the internal stress after pipe bending is reduced, and wrinkles are avoided; besides, swing rods are arranged on the two sides, push-pull is conducted on the two sides of each swing device through a push-pull rod, double-side driving is conducted in the push-pull process, axial force is borne by the swing rods, force in all directions is split, and the problem that local parts are prone to damage when swing is conducted through a single arm is effectively avoided.

Description

Technical Field

[0001] The present invention relates to a bending device, in particular to an automatic bending device for the support legs of a folding ladder. Background Art

[0002] A folding ladder is a common portable climbing tool, named as such because its shape resembles the Chinese character "person" when unfolded. It usually consists of two equal-length ladder poles connected at the top by a hinge, equipped with crossbars for people to step on, and the bottom can be freely opened to form a stable triangular support structure.

[0003] During manufacturing, its support legs are usually made of square tubes. The top of the square tube needs to be bent into an arc and flattened for connection, so a bending device is required. The press-wheel type bending device bends the square tube by swinging along a die using the pressure of the press wheel. However, there are two problems during the bending process: First, since the square tube has a hollow structure and a limited wall thickness, it is extremely easy to form wrinkles during bending; Second, currently, the press wheel is generally driven by a hydraulic device. The axial tension and rotational force of the driving structure are applied through the same structure, and the load at the hydraulic output end is too large, and it is extremely easy to be damaged at the rotational position of the press wheel. Summary of the Invention

[0004] In view of the problems in the prior art, the technical problem to be solved by the present invention is to provide an automatic bending device for the support legs of a folding ladder.

[0005] The technical solution adopted by the present invention to solve the above technical problems is as follows: An automatic bending device for the support legs of a folding ladder, comprising: A machine table, on which a feeding area is provided, and an installation space is provided between both ends of the feeding area; A limiting device, which is arranged on both sides of the feeding area for limiting the pipe; A downward pressing device, which is arranged above the machine table and is used for pressing the pipe tightly; A heating mechanism, which is arranged at the installation space and includes two sets that are symmetrically arranged up and down. Each set includes: A mounting plate; A telescopic cylinder, whose output end is connected to the mounting plate; Telescopic rods, which include two and are both arranged on the mounting plate; A link mechanism, which includes two sets. Each set includes a first link, a second link, a third link, and a fourth link. The first link and the second link are spaced apart and hinged to the telescopic rod. The third link is hinged to the ends of the first link and the second link. One end of the fourth link is coaxially hinged to the second link with the third link, and the other end of the fourth link is hinged to the mounting plate. The angle between the third link and the fourth link on one side of the second link is greater than 180 degrees; The heating device is mounted on two first connecting rods, and its initial state is at an angle of less than 90 degrees to the horizontal plane with its left side lower than its right side; A bending device is located at the rear of the machine tool; Among the two heating mechanisms, when the telescopic cylinder pushes the heating device at the top of the set with the same stroke, the swing amplitude is smaller than that of the bottom set.

[0006] Preferably, the mounting plate has a cylindrical body with slots on both sides. A backing plate and a spring are slidably mounted inside the cylindrical body. The backing plate has screws extending from the slots on both sides, and nuts for locking are provided on the screws. One end of the spring abuts against the backing plate, and the other end of the spring abuts against the end of the telescopic rod to apply elastic force to the telescopic rod. The end of the telescopic rod is provided with a limiting plate for the spring to abut against.

[0007] Preferably, the bending device includes: The mold is slidably mounted at the end of the machine base and is driven to rise and fall by a lifting drive device. It has an arc-shaped forming surface and a lower forming groove on the forming surface. The pressure roller is positioned above the mold and has an upper forming groove. The swinging device includes two sets, which are respectively set on the front and rear sides of the machine. Both sets are connected to the pressure roller to drive the pressure roller to swing along the forming surface.

[0008] Preferably, the swing device includes: A swing arm, one end of which is rotatably connected to the machine base, and a pressure roller is rotatably mounted at the other end; The first push-pull rod is hinged between the two ends of the swing rod; The first sliding rod is vertically slidable and its top end is hinged to the bottom end of the first push-pull rod, and a limiting post is provided on it; The second push-pull rod is hinged between the two ends of the swing rod and is symmetrical to the first push-pull rod about the swing rod. The second sliding rod is vertically slidable and its top end is hinged to the bottom end of the second push-pull rod, and a limiting post is provided on it; The swing frame has a central part that is rotatably connected to the ground. Its bottom is provided with a left and right symmetrical inclined surface. The central part is provided with a horizontal limiting hole. The limiting post extends into the limiting hole. When the swing frame swings, it drives the first sliding rod and the second sliding rod to move in opposite directions in the vertical direction, so that the two push-pull rods push and pull the swing rod, thereby driving the pressure roller to rotate around the forming surface. A sliding block, which is slidably set on the ground and located below the swing frame, has two top blocks on its top; The drive cylinder is located on the ground and its output end is connected to the sliding block. When the drive cylinder pushes the sliding block to slide, the two top blocks act on the left and right inclined planes respectively to drive the swing frame to swing.

[0009] Preferably, the limiting device includes several limiting wheel sets, each including a fixed wheel set and an adjustable wheel set. The fixed wheel set includes two fixed limiting wheels, and the adjustable wheel set includes a fixed limiting wheel and a limiting wheel that is slidably connected and elastically supported by an elastic element. The adjustable wheel set includes at least two sets, and both the front and rear sides of the pushing area are provided with fixed limiting wheels and slidable limiting wheels.

[0010] Compared with the prior art, the present invention has the following advantages: In this application, when the square tube is pushed to the heating mechanism, it is pressed by a pressing device. After pressing, the mounting plate is moved by a telescopic cylinder until one end of the heating device abuts against the square tube, and the heating device is turned on. At this time, the heating device heats the right side of the square tube more than the left side. Then, the mounting plate is pushed further, and under the action of the linkage mechanism, the heating device moves upward to one side and to the left, thereby increasing the heating force on the left side of the square tube. In addition, by differentiating the lengths of the linkages—reducing the length of the second linkage and increasing the lengths of the third and fourth linkages—the heating device can achieve the following advantages: The length allows for a consistent initial heating angle, while the same pushing motion creates variations in the amplitude of the heating device's swing. This adapts to the differences in the core heating areas at the top and bottom of the square tube, enabling small-gradient heating and focused heating of key areas. This reduces internal stress after bending and prevents wrinkles. Furthermore, this application uses swing rods on both sides, with push-pull rods on both sides of each swing device. The push-pull process is driven from both sides, and the axial force is borne by the swing rods, effectively distributing the force in each direction and avoiding the problem of localized damage that occurs when swinging with a single arm. Attached Figure Description

[0011] The present invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments. However, those skilled in the art will understand that these drawings are drawn only for the purpose of explaining the preferred embodiments and therefore should not be regarded as a limitation on the scope of the present invention. In addition, unless otherwise specified, the drawings are not necessarily drawn to scale.

[0012] Figure 1 This is a side view of this application; Figure 2 This is a perspective view of the present application; Figure 3 This is a perspective view of the present application; Figure 4 This is a perspective view of the present application; Figure 5 This is an exploded view of the heating mechanism; Figure 6 A three-dimensional view of the oscillating device; In the diagram: 10. Machine base; 20. Limiting device; 30. Pressing device; 40. Heating mechanism; 401. Telescopic cylinder; 402. Mounting plate; 4031. Cylinder; 40311. Slot hole; 4032. Spring; 4033. Abutting plate; 40331. Screw; 4034. Telescopic rod; 404. First connecting rod; 405. Second connecting rod; 406. Third connecting rod; 407. Fourth connecting rod; 408. Heating device; 50. Bending device; 501. Mold; 502. Pressure roller; 503. Swing rod; 504. First push-pull rod; 505. Second push-pull rod; 506. First sliding rod; 507. Second sliding rod; 508. Swing frame; 5081. Limiting hole; 5082. Inclined surface; 509. Sliding block; 5091. Top block; 510. Drive cylinder. Detailed Implementation

[0013] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Those skilled in the art will appreciate that these descriptions are merely descriptive and exemplary and should not be construed as limiting the scope of protection of the present invention.

[0014] It should be noted that similar labels in the following figures indicate similar items; therefore, once an item is defined in one figure, it may not be further defined and explained in subsequent figures. Example

[0015] This embodiment mainly describes the title of the automatic bending device for the support legs of a folding ladder, as follows: Automatic bending device for folding ladder support legs, such as Figure 1-6 As shown, including, The machine 10 has a material pushing area, and there is an installation space between the two ends of the material pushing area; The limiting device 20 is disposed on both sides of the pushing area to limit the pipe material; A pressing device 30 is disposed above the machine base 10 and is used to press the pipe; Heating mechanism 40, which is disposed in the installation space and comprises two sets symmetrically arranged vertically, each set comprising: Mounting plate 402; Telescopic cylinder 401, the output end of which is connected to mounting plate 402; Telescopic rod 4034, which includes two rods, both of which are mounted on mounting plate 402; The linkage mechanism includes two sets, each set including a first link 404, a second link 405, a third link 406 and a fourth link 407. The first link 404 and the second link 405 are hinged at intervals to the telescopic rod 4034. The third link 406 is hinged to the ends of the first link 404 and the second link 405. One end of the fourth link 407 is coaxially hinged to the second link 405 with the third link 406. The other end of the fourth link 407 is hinged to the mounting plate 402. The angle between the third link 406 and the fourth link 407 on one side of the second link 405 is greater than 180 degrees. Heating device 408 is mounted on two first connecting rods 404. Its initial state is at an angle of less than 90 degrees to the horizontal plane and its left side is lower than its right side. A bending device 50 is located at the rear of the machine base 10; Among the two sets of heating mechanisms 40, when the telescopic cylinder 401 pushes the heating device 408 on the top set with the same stroke, the swing amplitude is smaller than that of the bottom set. In this design, when the square tube is pushed to the heating mechanism 40, it is pressed by the pressing device 30. After pressing, the mounting plate 402 is moved by the telescopic cylinder 401 until one end of the heating device 408 abuts against the square tube, and the heating device 408 is turned on. At this time, the heating device 408 heats the right side of the square tube more than the left side. Then, the mounting plate 402 is pushed further. Under the action of the linkage mechanism, the heating device 408 moves upward to one side and to the left, thereby increasing the heating intensity on the left side of the square tube. In addition, by setting different linkage lengths—reducing the length of the second linkage 405 and increasing the lengths of the third linkage 406 and the fourth linkage 407—the initial heating angle can be made consistent, while pushing the same stroke makes the swing amplitude of the heating device 408 different, thereby adapting to the difference in the core heating areas at the top and bottom of the square tube, thus achieving small gradient heating and focusing on heating the key areas at the center of the bend, thereby reducing the internal stress after bending the tube and avoiding wrinkles.

[0016] Preferably, the mounting plate 402 is provided with a cylindrical body 4031, with slots 40311 on both sides of the cylindrical body 4031. A stop plate 4033 and a spring 4032 are slidably disposed inside the cylindrical body 4031. Screws 40331 extending from the slots 40311 are provided on both sides of the stop plate 4033, and nuts for locking are provided on the screws 40331. One end of the spring 4032 abuts against the stop plate 4033, and the other end abuts against the end of the telescopic rod 4034, applying a spring force to the telescopic rod 4034. A limiting plate is provided at the end of the telescopic rod 4034 for the spring 4032 to abut against. This design is used to adjust the initial position of the telescopic rod 4034 so that the angle of the heating device 408 can be adjusted as needed during use.

[0017] Preferably, the bending device 50 includes: The mold 501 is slidably disposed at the end of the machine base 10. It is driven to rise and fall by a lifting drive device. It has an arc-shaped forming surface and a lower forming groove is provided on the forming surface. The pressure roller 502 is positioned above the mold 501 and has an upper forming groove on it; The swinging device includes two sets, which are respectively set on the front and rear sides of the machine base 10. Both sets are connected to the pressure roller 502 to drive the pressure roller 502 to swing along the forming surface.

[0018] Preferably, the swing device includes: The swing arm 503 is rotatably connected to the machine base 10 at one end, and the pressure roller 502 is rotatably mounted at the other end; The first push-pull rod 504 is hinged between the two ends of the swing rod 503; The first sliding rod 506 is vertically slidable and its top end is hinged to the bottom end of the first push-pull rod 504, and a limiting post is provided on it; The second push-pull rod 505 is hinged between the two ends of the swing rod 503 and is symmetrical to the first push-pull rod 504 about the swing rod 503. The second sliding rod 507 is vertically slidable and its top end is hinged to the bottom end of the second push-pull rod 505, and a limiting post is provided on it; The swing frame 508 has its middle part rotatably connected to the ground. Its bottom is provided with a left inclined surface and a right inclined surface 5082 that are symmetrical. The middle part is provided with a horizontal limiting hole 5081. The limiting post extends into the limiting hole 5081. When the swing frame 508 swings, it drives the first sliding rod 506 and the second sliding rod 507 to move in opposite directions in the vertical direction, so that the two push-pull rods push and pull the swing rod 503, thereby driving the pressure roller 502 to rotate around the forming surface. A sliding block 509 is slidably disposed on the ground and located below the swing frame 508, and has two top blocks 5091 on its top; The drive cylinder 510 is mounted on the ground, and its output end is connected to the sliding block 509. When the drive cylinder 510 pushes the sliding block 509 to slide, the two top blocks 5091 act on the left and right inclined surfaces 5082 respectively to drive the swing frame 508 to swing. In this design, the swing rod 503 bears the axial force of the pressure roller 502, and the push-pull rod applies the swing force. Separating the two can avoid local damage and improve the stability of operation. In addition, by setting the swing frame 508 and setting a 45-degree inclined surface 5082 at its bottom to cooperate with the two top blocks 5091 on the sliding block 509 for support, the sliding block 508 is driven to swing when the slider slides, thereby driving the sliding rod to rise and fall, and finally driving the push-pull rod to push and pull the swing rod 503. This structure not only makes the actions on both sides work synchronously and enhances the swing force of the swing rod 503, but also ensures that the entire structure will not fail immediately in the event of local damage.

[0019] Preferably, the limiting device 20 includes several limiting wheel sets, which include fixed wheel sets and adjustable wheel sets. The fixed wheel sets include two fixed limiting wheels, and the adjustable wheel sets include one fixed limiting wheel and one slidingly connected limiting wheel supported by an elastic element. The adjustable wheel sets include at least two sets, and both the front and rear sides of the pushing area are equipped with fixed and sliding limiting wheels. The limiting device 20 is used to limit the movement of the square tube, ensuring its forward positioning. Additionally, the elastically supported limiting wheels provide a certain clamping effect on the square tube in the horizontal direction.

[0020] In the description of this invention, it should be noted that the terms "upper," "lower," "front," "rear," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed when in use. They are 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 limiting this invention.

Claims

1. An automatic bending device for the support legs of a folding ladder, characterized in that, include, The machine has a material pushing area, and there is an installation space between the two ends of the material pushing area; A limiting device is installed on both sides of the pushing area to limit the movement of the pipe. A pressing device, which is located above the machine base and is used to press the pipes together; The heating mechanism is located in the installation space and comprises two sets symmetrically arranged vertically, each set including: Mounting plate; A telescopic cylinder, the output end of which is connected to a mounting plate; The telescopic rod consists of two rods, both of which are mounted on a mounting plate. The linkage mechanism comprises two sets, each set including a first link, a second link, a third link, and a fourth link. The first link and the second link are hinged to the telescopic rod at intervals. The third link is hinged to the ends of the first link and the second link. One end of the fourth link is coaxially hinged to the second link with the third link, and the other end of the fourth link is hinged to the mounting plate. The angle between the third link and the fourth link on one side of the second link is greater than 180 degrees. The heating device is mounted on two first connecting rods, and its initial state is at an angle of less than 90 degrees to the horizontal plane with its left side lower than its right side; A bending device is located at the rear of the machine tool; Among the two heating mechanisms, when the telescopic cylinder pushes the heating device at the top of the set with the same stroke, the swing amplitude is smaller than that of the bottom set.

2. The automatic bending device for the support legs of a folding ladder according to claim 1, characterized in that, The mounting plate has a cylindrical body with slots on both sides. A backing plate and a spring are slidably mounted inside the cylindrical body. The backing plate has screws extending from the slots on both sides, and nuts for locking are mounted on the screws. One end of the spring abuts against the backing plate, and the other end of the spring abuts against the end of the telescopic rod to apply elastic force to the telescopic rod. The end of the telescopic rod has a limiting plate for the spring to abut against.

3. The automatic bending device for the support legs of a folding ladder according to claim 1, characterized in that, The bending device includes: The mold is slidably mounted at the end of the machine base and is driven to rise and fall by a lifting drive device. It has an arc-shaped forming surface and a lower forming groove on the forming surface. The pressure roller is positioned above the mold and has an upper forming groove. The swinging device includes two sets, which are respectively set on the front and rear sides of the machine. Both sets are connected to the pressure roller to drive the pressure roller to swing along the forming surface.

4. The automatic bending device for the support legs of a folding ladder according to claim 1, characterized in that, The swing device includes: A swing arm, one end of which is rotatably connected to the machine base, and a pressure roller is rotatably mounted at the other end; The first push-pull rod is hinged between the two ends of the swing rod; The first sliding rod is vertically slidable and its top end is hinged to the bottom end of the first push-pull rod, and a limiting post is provided on it; The second push-pull rod is hinged between the two ends of the swing rod and is symmetrical to the first push-pull rod about the swing rod. The second sliding rod is vertically slidable and its top end is hinged to the bottom end of the second push-pull rod, and a limiting post is provided on it; The swing frame has a central part that is rotatably connected to the ground. Its bottom is provided with a left and right symmetrical inclined surface. The central part is provided with a horizontal limiting hole. The limiting post extends into the limiting hole. When the swing frame swings, it drives the first sliding rod and the second sliding rod to move in opposite directions in the vertical direction, so that the two push-pull rods push and pull the swing rod, thereby driving the pressure roller to rotate around the forming surface. A sliding block, which is slidably set on the ground and located below the swing frame, has two top blocks on its top; The drive cylinder is located on the ground and its output end is connected to the sliding block. When the drive cylinder pushes the sliding block to slide, the two top blocks act on the left and right inclined planes respectively to drive the swing frame to swing.

5. The automatic bending device for the support legs of a folding ladder according to claim 1, characterized in that, The limiting device includes several sets. The limiting wheel set includes a fixed wheel set and an adjustable wheel set. The fixed wheel set includes two fixed limiting wheels. The adjustable wheel set includes a fixed limiting wheel and a limiting wheel that is slidably connected and elastically supported by an elastic element. The adjustable wheel set includes at least two sets, and both the front and rear sides of the pushing area are provided with fixed limiting wheels and slidable limiting wheels.

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