Internal pushing type clamping device for numerical control pipe bending machine

Abstract

The internal pushing type clamping device for the numerical control pipe bending machine comprises a fixing sleeve, a pushing and clamping sleeve is arranged at the front end of the fixing sleeve, a clamp is inserted into the pushing and clamping sleeve from front to back, and the front end of the clamp is provided with a reducing section with the external diameter being reduced backwards and capable of being contracted in the radial direction. The outer wall of the reducing section is in contact with the inner wall of the pushing and clamping sleeve; the rear end of the clamp is connected with a pull rod, and the clamp and the pull rod are arranged in the fixing sleeve in an axial moving mode through an oil cylinder. The problems that in the prior art, a pipe clamped by a clamp has limitation, if the diameter of the pipe is small, an original clamp cannot be used, and the clamp needs to be detached and replaced with a corresponding clamp, so that the adaptability is poor, and a large amount of time needs to be consumed are solved.

Description

Technical Field

[0001] The invention relates to the technical field of mechanical processing fixtures, in particular to an inner push type clamping device for a numerical control pipe bending machine. Background Art

[0002] CNC pipe bending machine is a machine tool specially used for processing various metal pipes. Its biggest feature is that it can realize the bending processing of metal pipes. During the processing, a clamping device is needed. The clamping device mainly includes an elastic clamp, a cylinder, a push sleeve and a rotating rod. The specific process is to put the bent pipe into the middle of the elastic clamp, start the cylinder to drive the rotating rod to push and move inward, drive the elastic clamp to contact with the push sleeve to achieve clamping.

[0003] For example, the invention with the publication number CN105750384A discloses an improved inner push-type clamping device for a CNC pipe bending machine, which belongs to the field of CNC pipe bending machines. It solves the problem that the rotary seal of the existing clamping device for CNC pipe bending machines is poor and prone to oil leakage when the oil cylinder rotates, and the service life is short. The invention includes an elastic chuck, an oil cylinder, and a component connecting the elastic chuck and the oil cylinder. The component connecting the elastic chuck and the oil cylinder includes a push chuck sleeve and a rotating rod; the oil cylinder includes a cylinder body and a piston rod arranged in the cylinder body, the push chuck sleeve is arranged at the protruding end of the piston rod, the push chuck sleeve is relatively fixed with the piston rod axially, and can rotate relatively around the axis; the rotating rod is arranged in the piston rod, and the rotating rod is connected to the push chuck sleeve by a connection method that can rotate synchronously and move relative to the axial direction; the elastic chuck is arranged at one end of the rotating rod. The invention can avoid the problem of oil leakage due to poor rotary seal of the oil cylinder, thereby improving the working stability of the clamping device and extending the service life.

[0004] In the above-mentioned prior art, the staff puts the pipe fitting into the clamp and starts the cylinder. The cylinder pulls the connecting structure, the connecting structure pulls the rotating rod, the rotating rod drives the clamp to move, and the clamp and the push sleeve are squeezed to clamp and fix the pipe fitting. However, the pipe fittings clamped by the existing clamp have limitations. If the diameter of the pipe fitting is small, the original clamp cannot be used and the clamp needs to be disassembled and replaced with a corresponding clamp. Therefore, the adaptability is poor and it takes a lot of time. Summary of the invention

[0005] The purpose of the invention is to provide an inner push clamping device for a CNC pipe bending machine, which can solve the problem that the pipes clamped by the clamps in the prior art have limitations. If the diameter of the pipe is small, the original clamp cannot be used and the clamp needs to be disassembled and replaced with a corresponding clamp. Therefore, the adaptability is poor and a lot of time is required.

[0006] The technical solution adopted by the present invention is as follows: An inner push clamping device for a CNC pipe bending machine comprises a fixed sleeve, a push clamp sleeve is provided at the front end of the fixed sleeve, a clamp is inserted into the push clamp sleeve from front to rear, the front end of the clamp has a reducing section whose outer diameter is reduced backwards and is radially contractible, the outer wall of the reducing section is in contact with the inner wall of the push clamp sleeve; a pull rod is connected to the rear end of the clamp, and the clamp and the pull rod are axially movable in the fixed sleeve through an oil cylinder.

[0007] Optionally, the diameter-changing section is provided with at least one clamping groove opening axially forward. When there are more than two clamping grooves, the diameter-changing section is divided into a plurality of clamping heads by the clamping grooves, and a first friction groove is provided on the inner front part of the clamping head.

[0008] Optionally, a detachable adapting clamp is provided on the inner side of the clamp, the outer wall of the adapting clamp is in contact with the inner wall of the clamp, and a second friction groove is provided on the inner front part of the adapting clamp.

[0009] Optionally, the adapting clamping plate includes a plurality of pieces arranged circumferentially on the inner side of the clamp.

[0010] Optionally, the inner wall of the front end portion of the clamp is provided with a first limit groove opened axially, and first clamping grooves are opened on both circumferential sides of the first limit groove; a limit block is provided at the front end of the outer wall of the adapter splint, and the limit block can move axially along the first limit groove, and both ends of the two sides of the limit block are provided with outward receiving grooves, the interior of the receiving groove is fixedly connected with a first spring, and the outer end of the first spring is fixedly connected with a clamping block, and the clamping block can slide in the receiving groove; when the receiving groove is aligned with the first clamping slot, the clamping block moves outward into the first clamping slot.

[0011] Optionally, a first limiting step is provided in the clamp, and a plurality of second limiting grooves are provided on the first limiting step along the circumferential direction; a limiting plate is fixedly connected to the bottom end of the adapter clamp near the second limiting groove, and the limiting plate is clamped in the second limiting groove.

[0012] Optionally, a positioning plane is provided in the clamp, and an extrusion component is provided between the rear end of the adapting clamp and the front side of the positioning plane.

[0013] Optionally, the extrusion assembly includes a support rod, one end of which is connected to the rear end of the adapter splint via a connector, the rear portion of the support rod is slidably connected to a support tube, a second spring is provided in the support tube, and the front end portion of the second spring is in contact with the support rod; a fixing groove is provided on the front end surface of the positioning plane, and the rear end of the support tube is located in the fixing groove.

[0014] Optionally, the inner wall of the front end portion of the adapter splint is provided with a third limit groove opened along the axial direction, and second clamping grooves are opened on both sides of the circumferential direction of the third limit groove; the adapter splint is provided with a second limit step, and the second limit step is provided with a fourth limit groove opened along the circumferential direction.

[0015] Optionally, a rotation groove is provided at the rear end of the pull rod, the internal rotation of the rotation groove is connected to a limit ring, the limit ring is fixedly connected to a connecting sleeve, and the connecting sleeve is fixedly connected to the moving end of the oil cylinder.

[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The present invention provides an inner push clamping device for a CNC pipe bending machine. The staff installs the adapter splint according to the diameter of the bent pipe. During installation, the adapter splint is installed on the inner wall of the chuck, and the limit plate is inserted into the corresponding second limit groove or fourth limit groove. The limit block is located inside the first limit groove or the third limit groove, so that the adapter splint is completely attached to the inner wall of the chuck. During clamping, the second friction groove contacts the bent pipe to increase the friction force, making the clamping of the bent pipe more stable. When the clamp drives the adapter splint to rotate, the limit plate and the limit block can limit the adapter splint, so that the adapter splint drives the rotation of the bent pipe more stably.

[0017] 2. The present invention provides an inner push clamping device for a CNC pipe bending machine. When installing the adapter splint, the support tube is inserted into the fixed groove to push the adapter splint. The adapter splint drives the connecting head to move. The connecting head squeezes the support rod. The support rod drives the fixed plate to move. The support rod squeezes the second spring. At this time, the second spring is compressed, and then the adapter splint is pressed down and slowly loosened. The adapter splint gradually slides along the inner wall of the clamp under the elastic force of the second spring. Since the limit plate is inclined, the limit plate slides into the second limit groove or the fourth limit groove, and the limit block is located inside the third limit groove or the first limit groove. At this time, the adapter splint is installed, and under the continuous squeezing of the second spring, the adapter splint is fixed to the inner wall of the clamp or the bottom adapter splint.

[0018] 3. The present invention provides an inner push clamping device for a CNC pipe bending machine. When the limit block enters the first limit groove or the third limit groove, the clamping block is squeezed into the receiving groove and squeezes the first spring. When the clamping block is aligned with the first clamping groove or the second clamping groove, the first spring rebounds and pushes the clamping block into the first clamping groove or the second clamping groove, thereby clamping the limit block and increasing the stability of the limit block. When the adapter splint drives the limit block to move, the clamping block will enter the receiving groove again, thereby causing the limit block to lose its clamping connection, which is convenient for the disassembly of the adapter splint. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 It is a structural schematic diagram of an inner push type clamping device for a CNC pipe bending machine; Figure 2 A schematic diagram of the cross-sectional structure of a fixed sleeve of an inner push-type clamping device for a CNC pipe bending machine; Figure 3 It is a schematic diagram of the exploded structure of an inner push type clamping device for a CNC pipe bending machine; Figure 4 A schematic diagram of a connecting sleeve structure of an inner push-type clamping device for a CNC pipe bending machine; Figure 5 It is a schematic diagram of the assembly of a clamp and an adapter clamp plate of an inner push clamping device for a CNC pipe bending machine; Figure 6 A schematic diagram of a clamp structure of an inner push type clamping device for a CNC pipe bending machine; Figure 7 A schematic diagram of the structure of an adaptor clamping plate of an inner push-type clamping device for a CNC pipe bending machine; Figure 8 It is a schematic diagram of the clamping structure of an inner push type clamping device for a CNC pipe bending machine; Legend: 1-fixed sleeve, 11-pull rod, 111-fixed column, 112-first fixed thread, 12-pushing sleeve, 13-second fixed thread, 14-connecting sleeve, 141-limiting ring, 15-fixed bolt, 16-first thread groove, 17-rotating groove, 2-oil cylinder, 31-clamp, 311-clamp groove, 312-second thread groove, 313-chuck, 314-first friction groove, 315-first limit groove, 316 -first card slot, 317-second limiting slot, 318-fixing slot, 32-adapting splint, 321-second friction slot, 322-third limiting slot, 323-second card slot, 324-limiting plate, 325-fourth limiting slot, 33-support rod, 331-connecting head, 332-support tube, 333-fixing plate, 334-second spring, 34-limiting block, 341-storage slot, 342-first spring, 343-card block. DETAILED DESCRIPTION

[0020] The present invention will be described in detail below in conjunction with the accompanying drawings.

[0021] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0022] Any feature disclosed in this specification, unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0023] An inner push clamping device for a CNC pipe bending machine, such as Figure 1-8 As shown, it includes a fixed sleeve 1, a push-clamp sleeve 12 is provided at the front end of the fixed sleeve 1, a clamp 31 is inserted into the push-clamp sleeve 12 from front to back, and the front end of the clamp 31 has a reducing section whose outer diameter is reduced backward and is radially contractible, and the outer wall of the reducing section is in contact with the inner wall of the push-clamp sleeve 12; the rear end of the clamp 31 is connected to a pull rod 11, and the clamp 31 and the pull rod 11 are axially movable in the fixed sleeve 1 through the cylinder 2.

[0024] Specifically, the fixed sleeve 1 is the basic part of the device, which plays a supporting and positioning role. The push sleeve 12 is fixed at the front end of the fixed sleeve 1, and is a key component for fixing and guiding the clamp 31. Its inner wall is in contact with the outer wall of the reducing section of the clamp 31. The front end of the clamp 31 has a reducing section design with an outer diameter that shrinks backwards, and is radially shrinkable. This means that the reducing section can be adjusted according to the diameter of the pipe fitting. The outer wall of the reducing section is in contact with the inner wall of the push sleeve 12. When the oil cylinder 2 acts, the push sleeve 12 squeezes the reducing section to shrink radially, thereby adapting to pipe fittings of different diameters. The oil cylinder 2 is the power source for driving the clamp 31 to contract and expand radially by axially moving the clamp 31 and the pull rod 11. The pull rod 11 is connected to the rear end of the clamp 31 and is used to transmit the axial force of the oil cylinder 2. In this scheme, when the pipe fitting is in place, the oil cylinder 2 starts to work and pulls the pull rod 11 to move backward. As the pull rod 11 moves, the clamp 31 is also pulled toward the front end of the push sleeve 12, and the outer wall of the reducing section contacts the inner wall of the push sleeve 12. Since the inner wall of the push sleeve 12 is fixed, the reducing section of the clamp 31 is squeezed by the oil cylinder 2, causing it to shrink radially. The radial contraction of the reducing section reduces its diameter, thereby tightly clamping the inner wall of the pipe fitting and allowing the clamping device to adapt to pipe fittings of different diameters. During the pipe bending process, the oil cylinder 2 continuously provides force to ensure that the reducing section of the clamp 31 is always in close contact with the inner wall of the pipe fitting to prevent the pipe fitting from slipping out or shifting during bending. After the pipe bending is completed, the oil cylinder 2 works in the reverse direction, the pull rod 11 pushes the clamp 31 forward, and the reducing section returns to its original state under the action of the inner wall of the push sleeve 12, thereby releasing the pipe fitting.

[0025] Optionally, the front end of the pull rod 11 includes a fixing column 111, and the outer periphery of the fixing column 111 is provided with a first fixing thread 112; the rear end of the clamp 31 is provided with a second thread groove 312, and the clamp 31 is connected to the first fixing thread 112 through the second thread groove 312. The front end of the fixing sleeve 1 is provided with a first thread groove 16, and the rear part of the push clamp sleeve 12 is provided with a second fixing thread 13, and the push clamp sleeve 12 is threadedly connected to the first thread groove 16 through the second fixing thread 13. In other embodiments, the above connection method can also adopt a detachable connection method such as bolts and buckles.

[0026] As another specific embodiment, the reducing section is provided with at least one clamping groove 311 which opens forward in the axial direction. When there are more than two clamping grooves 311, the reducing section is divided into a plurality of clamps 313 by the clamping grooves 311. The inner front part of the clamps 313 is provided with a first friction groove 314. Due to the existence of the clamping grooves 311, the radial contraction of the reducing section can be controlled by changing the spacing between the clamps 313. When the distance between the clamps 313 decreases, the reducing section radially contracts, and vice versa. The first friction groove 314 inside the clamps 313 contacts the surface of the pipe fitting, providing additional friction to prevent the pipe fitting from sliding during the bending process. When clamping, the oil cylinder 2 starts to work, pushing the pull rod 11 to move the reducing section of the clamp 31 forward, and starts to reduce the spacing between the clamps 313. As the spacing decreases, the clamps 313 start to contract radially and tightly clamp the pipe fitting. The first friction groove 314 inside the clamps 313 contacts the surface of the pipe fitting, providing additional friction to prevent the pipe fitting from sliding during the bending process. Since the spacing between the clamps 313 can be adjusted, this design allows the clamping device to adapt to pipes of different diameters. The spacing between the clamps 313 is adjusted accordingly according to the size of the pipe diameter to ensure uniform and stable clamping.

[0027] As another specific embodiment, a detachable adapter splint 32 is provided on the inner side of the clamp 31, and the outer wall of the adapter splint 32 fits the inner wall of the clamp 31, and a second friction groove 321 is provided on the inner front of the adapter splint 32. The adapter splint 32 is a detachable component, and a suitable adapter splint 32 can be selected according to the size and material of the pipe fitting and installed on the inner side of the clamp 31, thereby improving the versatility and adaptability of the equipment. The outer wall of the adapter splint 32 fits tightly with the inner wall of the clamp 31, ensuring that there is no relative movement between the splint and the clamp 31 during operation, thereby maintaining the stability of the clamping. The second friction groove 321 is located at the inner front of the adapter splint 32, and is used to increase the friction between the splint and the pipe fitting, further ensuring the stability of the pipe fitting during the bending process.

[0028] As another specific embodiment, the adapting splint 32 includes a plurality of pieces arranged circumferentially on the inner side of the clamp 31. The adapting splint 32 is composed of a plurality of pieces, each of which is evenly distributed circumferentially along the inner side of the clamp 31. A uniform clamping force can be provided to reduce deformation or damage of the pipe during the bending process. Preferably, the adapting splint 32 and the chuck 313 match. During the clamping process, the chuck 313 can accurately dock with the adapting splint 32 to form a closed clamping structure. When the chuck 313 is actuated, the chuck 313 and the adapting splint 32 work together to radially clamp the pipe to ensure that the pipe does not slide during the bending process.

[0029] As another specific embodiment, the inner wall of the front end of the clamp 31 is provided with a first limiting groove 315 opened in the axial direction, and the first limiting groove 315 is provided with first clamping grooves 316 on both sides of the circumferential direction; the front end of the outer wall of the adapting clamp 32 is provided with a limiting block 34, and the limiting block 34 can move axially along the first limiting groove 315, and both ends of the two sides of the limiting block 34 are provided with outward receiving grooves 341, and the inside of the receiving groove 341 is fixedly connected with a first spring 342, and the outer end of the first spring 342 is fixedly connected with a clamping block 343, and the clamping block 343 can slide in the receiving groove 341; when the receiving groove 341 is aligned with the first clamping groove 316, the clamping block 343 moves outward into the first clamping groove 316. The adapting clamp 32 moves axially along the first limiting groove 315 and is installed to the inner side of the clamp 31, and the limiting block 34 is located in the first limiting groove 315. As the limit block 34 moves, the receiving groove 341 is aligned with the first clamping groove 316. Under the action of the first spring 342, the clamping block 343 is pushed out and clamped into the first clamping groove 316, thereby fixing the position of the adapter clamp 32. After the pipe bending is completed, the oil cylinder 2 acts in the opposite direction, the limit block 34 retreats along the first limit groove 315, and the clamping block 343 returns to the receiving groove 341 under the action of the spring force, and the adapter clamp 32 and the reducing section of the clamp 31 return to the original state, and the pipe fitting is released. Through this solution, the adapter clamp 32 can be accurately positioned by using the cooperation of the clamping block 343 and the first clamping groove 316 to ensure the stability of the clamping. The clamping block 343 is automatically fixed in the first clamping groove 316 under the action of the spring, which simplifies the operation process. After the pipe bending operation is completed, the clamping block 343 can quickly return to the receiving groove 341, which is convenient for the quick release of the pipe fitting. Preferably, an arc-shaped chamfer is provided on the clamping block 343 to facilitate the clamping block 343 to exit the first clamping slot 316 .

[0030] As another specific embodiment, the clamp 31 is provided with a first limiting step, and the first limiting step is provided with a plurality of second limiting grooves 317 opened in the circumferential direction; the bottom end of the adapting clamp 32 is fixedly connected to a limiting plate 324 near the second limiting groove 317, and the limiting plate 324 is engaged with the second limiting groove 317. The adapting clamp 32 is installed inside the clamp 31, and the limiting plate 324 at the bottom end thereof is aligned with the first limiting step and the second limiting groove 317 in the clamp 31. The limiting plate 324 is engaged with the second limiting groove 317, so that the adapting clamp 32 is limited in both the axial direction and the circumferential direction and cannot move relative to the clamp 31. This ensures the stability of the adapting clamp 32 during the clamping process and prevents the adapting clamp 32 from falling off or shifting due to external force during the clamping process.

[0031] As another specific embodiment, a positioning plane is provided in the clamp 31, and an extrusion assembly is provided between the rear end of the adapter splint 32 and the front side of the positioning plane. The positioning plane is located behind the extrusion assembly, and provides a stable support surface to ensure that the thrust of the extrusion assembly can be effectively transmitted to the adapter splint 32. The extrusion assembly is located between the rear end of the adapter splint 32 and the front side of the positioning plane, and is used to generate a thrust to push the adapter splint 32 forward to maintain a certain pressure. When the workpiece is not clamped, the extrusion assembly is in a relaxed state, and the adapter splint 32 is also in an unstressed state. When the workpiece begins to be clamped, the extrusion assembly is activated, generating a forward thrust to push the adapter splint 32 forward. The thrust generated by the extrusion assembly enables the adapter splint 32 to maintain a certain pressure on the workpiece, ensuring that the workpiece will not move due to external force or vibration during the processing.

[0032] As another specific embodiment, the extrusion assembly includes a support rod 33, one end of which is connected to the rear end of the adapter clamp 32 through a connector 331, and a support tube 332 is slidably connected to the rear of the support rod 33, and a second spring 334 is arranged in the support tube 332, and the front end of the second spring 334 contacts the support rod 33; a fixing groove 318 is provided on the front end surface of the positioning plane, and the rear end of the support tube 332 is located in the fixing groove 318. When the extrusion assembly is not activated, the second spring 334 is in a compressed state, the rear end of the support tube 332 is restricted by the fixing groove 318, and the support rod 33 and the adapter clamp 32 are in a relaxed state. When the workpiece needs to be clamped, the extrusion assembly is activated, and the second spring 334 begins to stretch, pushing the support rod 33 to move forward. As the second spring 334 stretches, the support rod 33 transmits the thrust to the adapter clamp 32, causing it to move forward and press the workpiece. The elastic force of the second spring 334 enables the adapter clamp 32 to maintain a certain pressure on the workpiece, ensuring stable clamping of the workpiece even under the influence of external force or vibration. The fixing groove 318 limits the rear end position of the support tube 332, ensuring the accurate position of the extrusion assembly, thereby improving the clamping accuracy.

[0033] As another specific embodiment, the inner wall of the front end of the adapter splint 32 is provided with a third limiting groove 322 opened in the axial direction, and the second clamping groove 323 is opened on both sides of the circumferential direction in the third limiting groove 322; the adapter splint 32 is provided with a second limiting step, and the second limiting step is provided with a fourth limiting groove 325 opened in the circumferential direction. In this scheme, through the positioning structure inside the adapter splint 32 that is the same as the clamp 31, the large adapter splint 32 can be placed on the smaller adapter splint 32, and the position of the small adapter splint 32 is ensured to be fixed. Its matching mode is the same as the matching mode between the adapter splint 32 and the clamp 31, so as to realize the positioning of the smaller adapter splint 32. Specifically, the limiting block 34 is located inside the third limiting groove 322, the clamping block 343 of the small adapter splint 32 is clamped with the second clamping groove 323, and the limiting plate 324 of the small adapter splint 32 is inserted into the fourth limiting groove 325 corresponding to the large adapter splint 32. Adaptive clamps 32 of different sizes can be placed in an overlapping manner in the adaptable clamp 32, so as to adapt to various workpiece sizes and improve the versatility of the clamping system. By overlapping the adaptable clamps 32, the number of required adaptable clamps 32 is reduced, making the structure more compact. It is possible to quickly adapt to workpieces of different sizes without replacing the main body of the clamp 31, thereby improving production efficiency and flexibility.

[0034] As another specific embodiment, a rotation groove 17 is provided at the rear end of the pull rod 11, and a limit ring 141 is rotatably connected inside the rotation groove 17. The limit ring 141 is fixedly connected with a connecting sleeve 14, and the connecting sleeve 14 is fixedly connected to the moving end of the oil cylinder 2. The pull rod 11 is rotatably connected with the connecting sleeve 14, and the connecting sleeve 14 is fixed to the oil cylinder 2 by a fixing bolt 15. When the oil cylinder 2 is extended or retracted, the connecting sleeve 14 is driven to move, and the connecting sleeve 14 drives the pull rod 11 to move. By rotating the limit ring 141, the circumferential movement of the pull rod 11 and the limit ring 141 can be adapted. The limit ring 141 can prevent the pull rod 11 from being damaged due to excessive pushing and pulling of the oil cylinder 2, thereby increasing the reliability of the system. Specifically, the limit ring 141 can match the rear end of the fixed sleeve 1 to prevent it from moving too far backward and leaving the fixed sleeve 1. The design of the rotation groove 17 and the limit ring 141 facilitates the connection and disassembly between the pull rod 11 and the oil cylinder 2, and simplifies maintenance work. The fixed connection of the connecting sleeve 14 ensures the stable connection between the pull rod 11 and the oil cylinder 2, and reduces the vibration and displacement during the working process. Among them, the middle part of the connecting sleeve 14 is threadedly connected with a fixing bolt 15, and the fixing bolt 15 is threadedly connected to the oil cylinder 2.

[0035] The present invention provides an inner push clamping device for a CNC pipe bender, and its working process is as follows: First, during installation, the connecting sleeve 14 is sleeved on the oil cylinder 2, and the connecting sleeve 14 is fixedly connected to the oil cylinder 2 by the fixing bolt 15, and then the pushing sleeve 12 is connected to the first thread groove 16 by the second fixing thread 13, and the pushing sleeve 12 is installed, and the clamp 31 is passed through the pushing sleeve 12 and installed on the fixing column 111 through the second thread groove 312, and the clamp 31 is installed and fixed. When clamping, the staff puts the bent pipe into the middle of the clamp 313, and starts the oil cylinder 2. One end of the oil cylinder 2 is shortened to drive the connecting sleeve 14 to move, and the connecting sleeve 14 drives the pull rod 11 to move through the limit ring 141, and the pull rod 11 drives the fixing column 111 and the first fixing thread 112 to move, and the fixing column 111 and the first fixing thread 112 drive the clamp 31 to move, and the clamp 31 moves gradually. The clamp 31 gradually slides along the diameter of the push sleeve 12, so that the clamp 31 gradually clamps the bent pipe. The first friction groove 314 is set to stably clamp the bent pipe. When the pull rod 11 rotates, the clamp 31 can be driven to rotate, thereby driving the bent pipe to rotate. The setting of the connecting sleeve 14 can avoid the oil cylinder 2, thereby avoiding oil leakage of the oil cylinder 2. When the diameter of the bent pipe becomes smaller, the number of the adapter splints 32 can be increased. When installing the adapter splint 32, the adapter splint 32 is installed on the inner wall of the clamp 313, and the support tube 332 is inserted into the fixing groove 318. The adapter splint 32 is pushed, and the adapter splint 32 drives the connecting head 331 to move. The connecting head 331 squeezes the support rod 33, and the support rod 33 drives the fixing plate 333 to move. The support rod 33 squeezes the second spring 334. At this time The second spring 334 is compressed, and then the adapter splint 32 is pressed down and slowly loosened. The adapter splint 32 gradually slides along the inner wall of the clamp 31 under the elastic force of the second spring 334. Since the limit plate 324 is inclined, the limit plate 324 slides into the second limit groove 317 or the fourth limit groove 325, and the limit block 34 is located inside the third limit groove 322 or the first limit groove 315. At this time, the adapter splint 32 is installed. Under the continuous compression of the second spring 334, the adapter splint 32 is fixed to the inner wall of the clamp 31 or the bottom adapter splint 32. When the limit block 34 enters the first limit groove 315 or the third limit groove 322, the block 343 is squeezed into the receiving groove 341 and presses the first spring 34 When the clamping block 343 is aligned with the first clamping groove 316 or the second clamping groove 323, the first spring 342 rebounds and pushes the clamping block 343 into the first clamping groove 316 or the second clamping groove 323, thereby clamping the limit block 34 and increasing the stability of the limit block 34. When the adapting clamping plate 32 drives the limit block 34 to move, the clamping block 343 will enter the receiving groove 341 again, thereby causing the limit block 34 to lose the clamping connection, which is convenient for the disassembly of the adapting clamping plate 32. Therefore, according to the diameter of the bent pipe and the number of installed adapting clamping plates 32, when clamping, the second friction groove 321 contacts the bent pipe to increase the friction force, making the bent pipe clamping more stable. When the clamp 31 drives the adapting clamping plate 32 to rotate, the limit plate 324 and the limit block 34 can limit the adapting clamping plate 32.This makes the adapter clamp 32 drive the elbow to rotate more stably.

[0036] The present invention is not limited to the above-mentioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. An inner push clamping device for a CNC pipe bending machine, characterized in that: A fixed sleeve (1), wherein a push-clamp sleeve (12) is provided at the front end of the fixed sleeve (1), a clamp (31) is inserted into the push-clamp sleeve (12) from front to rear, the front end of the clamp (31) has a reducing section whose outer diameter is reduced backwards and is radially contractible, and the outer wall of the reducing section is in contact with the inner wall of the push-clamp sleeve (12); the rear end of the clamp (31) is connected to a pull rod (11), and the clamp (31) and the pull rod (11) are axially movable in the fixed sleeve (1) through an oil cylinder (2).

2. The inner push clamping device for a CNC pipe bender according to claim 1, characterized in that: The diameter-changing section is provided with at least one clamping groove (311) opening forward in the axial direction. When there are more than two clamping grooves (311), the diameter-changing section is divided into a plurality of clamping heads (313) by the clamping grooves (311). The inner front part of the clamping head (313) is provided with a first friction groove (314).

3. The inner push clamping device for a CNC pipe bender according to claim 1, characterized in that: A detachable adapting clamp (32) is provided on the inner side of the clamp (31), the outer wall of the adapting clamp (32) is in contact with the inner wall of the clamp (31), and a second friction groove (321) is provided on the inner front part of the adapting clamp (32).

4. The inner push clamping device for a CNC pipe bender according to claim 3, characterized in that: The adapting clamping plate (32) comprises a plurality of pieces which are arranged on the inner side of the clamp (31) along the circumferential direction.

5. The inner push clamping device for a CNC pipe bender according to claim 3, characterized in that: The inner wall of the front end portion of the clamp (31) is provided with a first limiting groove (315) opened in the axial direction, and first clamping grooves (316) are opened on both circumferential sides of the first limiting groove (315); a limiting block (34) is provided at the front end of the outer wall of the adapter clamp (32); the limiting block (34) can move axially along the first limiting groove (315), and both ends of both sides of the limiting block (34) are provided with outward receiving grooves (341); the inside of the receiving groove (341) is fixedly connected with a first spring (342), and the outer end of the first spring (342) is fixedly connected with a clamping block (343), and the clamping block (343) can slide in the receiving groove (341); when the receiving groove (341) is aligned with the first clamping groove (316), the clamping block (343) moves outward into the first clamping groove (316).

6. The inner push clamping device for a CNC pipe bender according to claim 3, characterized in that: The clamp (31) is provided with a first limiting step, and the first limiting step is provided with a plurality of second limiting grooves (317) opened in the circumferential direction; the bottom end of the adapting clamp (32) is fixedly connected to a limiting plate (324) near the second limiting groove (317), and the limiting plate (324) is clamped with the second limiting groove (317).

7. The inner push clamping device for a CNC pipe bender according to claim 3, characterized in that: A positioning plane is provided inside the clamp (31), and an extrusion component is provided between the rear end of the adapting clamp (32) and the front side of the positioning plane.

8. The inner push clamping device for a CNC pipe bender according to claim 7, characterized in that: The extrusion assembly comprises a support rod (33), one end of which is connected to the rear end of the adapter clamp (32) via a connector (331); the rear part of the support rod (33) is slidably connected to a support tube (332); a second spring (334) is provided in the support tube (332); the front end of the second spring (334) is in contact with the support rod (33); a fixing groove (318) is provided on the front end surface of the positioning plane, and the rear end of the support tube (332) is located in the fixing groove (318).

9. The inner push clamping device for a CNC pipe bender according to claim 3, characterized in that: The inner wall of the front end of the adapter clamp (32) is provided with a third limiting groove (322) opened in the axial direction, and the third limiting groove (322) is provided with second clamping grooves (323) on both sides of the circumference; the adapter clamp (32) is provided with a second limiting step, and the second limiting step is provided with a fourth limiting groove (325) opened in the circumferential direction.

10. The inner push clamping device for a CNC pipe bender according to claim 1, characterized in that: A rotation groove (17) is provided at the rear end of the pull rod (11), the interior of the rotation groove (17) is rotatably connected to a limit ring (141), the limit ring (141) is fixedly connected to a connecting sleeve (14), and the connecting sleeve (14) is fixedly connected to the movable end of the oil cylinder (2).

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