A low-stress automatic clamping system and clamping method for thin-walled parts

Abstract

The present invention discloses a low-stress automatic clamping system and clamping method for thin-walled parts, which relate to the fields of machine tool manufacturing and fixture technology, comprising: a base, on which two lifting mechanisms are slidably arranged; two clamping mechanisms, respectively arranged on the lifting mechanisms, the clamping mechanism comprising a bracket and two cams, the middle part of the bracket is hinged to the telescopic end of the lifting mechanism, one end of the bracket is hingedly connected to the lifting mechanism, the cam is rotatably arranged on the bracket, the two cams rotate with different positions of the bracket as the axis, and the two cams are respectively used to fit the surfaces of different positions of the thin-walled parts; a control unit, which is control-connected to the lifting mechanism and the clamping mechanism; the automatic clamping system can achieve precise control of the clamping force, and can be suitable for clamping and positioning of different curved workpieces through the two freely rotating cams, can adaptively clamp the surfaces of workpieces with different curvature radii, and can effectively reduce clamping stress.

Description

Technical Field

[0001] The present invention belongs to the technical field of machine tool manufacturing and fixtures, and more specifically, relates to a low-stress automatic clamping system and a clamping method for thin-walled parts. Background Art

[0002] The modern aerospace and high-speed rail industries frequently use thin-walled parts made of titanium alloys, aluminum alloys, and composite materials as structural supports. These parts are complex in shape and easily deform during the clamping process, impacting machining results and yield. This problem stems from two factors: first, the inherent strength and rigidity of thin-walled workpieces are poor; second, traditional fixtures struggle to precisely control clamping force. Currently, the industry's common approach is to design specialized fixtures supplemented by manual adjustments. This results in low clamping efficiency and is only suitable for specific workpiece types, lacking versatility. Summary of the Invention

[0003] The purpose of the present invention is to address the deficiencies in the prior art and provide a low-stress automatic clamping system and clamping method for thin-walled parts. The automatic clamping system can achieve precise control of the clamping force, and through two freely rotating cams, it can be suitable for clamping and positioning of different curved workpieces, can adaptively clamp the surfaces of workpieces with different curvature radii, and can effectively reduce clamping stress.

[0004] In order to achieve the above object, the present invention provides a low-stress automatic clamping system for thin-walled parts, comprising:

[0005] A base, on which two lifting mechanisms are slidably provided;

[0006] Two clamping mechanisms are respectively provided on the lifting mechanism, the clamping mechanism comprising a bracket and two cams, the middle portion of the bracket is hinged to the telescopic end of the lifting mechanism, one end of the bracket is hingedly connected to the lifting mechanism, the cams are rotatably provided on the bracket, the two cams rotate about different positions of the bracket as the axis, and the two cams are respectively used to fit the profiles of different positions of the thin-walled part;

[0007] A control unit is control-connected to the lifting mechanism and the clamping mechanism.

[0008] Optionally, the lifting mechanism includes:

[0009] A support seat, slidably arranged on the base;

[0010] A telescopic cylinder, the middle portion of which is hingedly connected to the support base, and the output end of the telescopic cylinder is connected to the middle portion of the bracket via a hinged joint;

[0011] A pair of tapered roller bearings is arranged at one end of the top of the support seat, and the end of the bracket is arranged between the pair of tapered roller bearings.

[0012] Optionally, an end cover is provided on the outer side of the tapered roller bearing, and a limit block is provided on the other end of the top of the support seat, and the limit block cooperates with the output end of the telescopic cylinder.

[0013] Optionally, the base is connected to the lifting mechanism via a transverse feeding mechanism, and the transverse feeding mechanism includes:

[0014] A ball screw, both ends of which are connected to the base via bearing supports, and the lifting mechanism is slidably arranged on the ball screw;

[0015] a first motor, disposed at an end of the base, wherein an output end of the first motor is connected to the ball screw via a coupling, and a first reducer is disposed between the first motor and the coupling;

[0016] A linear guide rail is arranged along the length direction of the base, and the linear guide rail is arranged on both sides of the ball screw.

[0017] Optionally, the bracket is a vertically arranged plate-shaped structure, the two cams are respectively arranged on both sides of the bracket, and the rotation axes of the two cams are parallel to each other.

[0018] Optionally, the clamping mechanism further comprises:

[0019] Two second motors are respectively arranged on both sides of the bracket;

[0020] Two second reducers, one end of which is connected to the output end of the second motor, and the other end of which is connected to the cam via a transmission shaft, wherein the transmission shaft passes through the bracket;

[0021] Lock the cover to fix the cam on the transmission shaft.

[0022] Optionally, the two cams are respectively arranged at the middle of the bracket and the other end of the bracket.

[0023] Optionally, the profile of the cam is a variable diameter arc.

[0024] Optionally, a grating ruler is provided on the base, and a probe of the grating ruler faces the ball screw.

[0025] The present invention also provides a method for automatically clamping thin-walled parts with low stress, using the above-mentioned automatic clamping system for thin-walled parts with low stress, the method comprising:

[0026] Adjusting the distance between the two lifting mechanisms according to the size of the thin-walled part;

[0027] The two clamping mechanisms are opened, and the thin-walled part is placed between the two lifting mechanisms;

[0028] The two clamping mechanisms clamp, and the two cams rotate to clamp the profiles at different positions of the thin-walled part.

[0029] The present invention provides a low-stress automatic clamping system and clamping method for thin-walled parts, which have the following beneficial effects: the low-stress automatic clamping system for thin-walled parts can be controlled by a machine tool numerical control system to achieve action coordination with the machine tool host, complete functions such as fully automatic clamping of thin-walled parts and automatic avoidance of the spindle during processing, with strong adaptability and high processing efficiency; the lateral feed mechanism can achieve arbitrary point positioning, adapt to the clamping requirements of workpieces of different sizes, and improve the adaptability of the tooling system; the lifting mechanism is controlled by the machine tool numerical control system to automatically switch between the standby position and the clamping position, providing the necessary conditions for automatically avoiding the spindle and the tool; the cam in the clamping mechanism is optimized to adapt to the outer walls of workpieces with different contour diameters and improve the stress condition of the workpiece at the clamping point; at the same time, the automatic clamping system adopts a modular design, and the number of clamping systems can be increased according to the length of the workpiece to adapt to the clamping requirements of workpieces of different sizes and specifications.

[0030] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and other objects, features and advantages of the present invention will become more apparent through a more detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings, wherein like reference numerals generally represent like components throughout the exemplary embodiments of the present invention.

[0032] Figure 1 A schematic structural diagram of a low-stress automatic clamping system for thin-walled parts according to an embodiment of the present invention is shown.

[0033] Figure 2 A structural schematic diagram of a lifting mechanism according to an embodiment of the present invention is shown.

[0034] Figure 3 Shown Figure 2 Right view of .

[0035] Figure 4 Shown Figure 2 Stereoscopic image.

[0036] Figure 5 A structural schematic diagram of a transverse feeding mechanism according to an embodiment of the present invention is shown.

[0037] Figure 6A structural schematic diagram of a clamping mechanism according to an embodiment of the present invention is shown.

[0038] Figure 7 Shown Figure 6 Schematic diagram of the back.

[0039] Figure 8 A schematic diagram showing the position of a cam when a thin-walled workpiece with an inner arc surface is clamped by a low-stress automatic clamping system for thin-walled parts according to an embodiment of the present invention.

[0040] Figure 9 A schematic diagram of the modular configuration of a low-stress automatic clamping system for thin-walled parts according to an embodiment of the present invention is shown.

[0041] Description of reference numerals:

[0042] 1. Base; 2. Lifting mechanism; 3. Clamping mechanism; 4. Horizontal feed mechanism; 5. Bracket; 6. Cam; 7. Support seat; 8. Telescopic cylinder; 9. Articulated head; 10. Tapered roller bearing; 11. End cover; 12. Limit block; 13. Ball screw; 14. Bearing support; 15. First motor; 16. Coupling; 17. First reducer; 18. Linear guide; 19. Second motor; 20. Second reducer; 21. Drive shaft; 22. Locking cover. DETAILED DESCRIPTION

[0043] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. Instead, these embodiments are provided to make the present invention more thorough and complete and to fully convey the scope of the present invention to those skilled in the art.

[0044] The present invention provides a low-stress automatic clamping system for thin-walled parts, comprising:

[0045] A base, on which two lifting mechanisms are slidably arranged;

[0046] Two clamping mechanisms are respectively provided on the lifting mechanism. The clamping mechanism includes a bracket and two cams. The middle portion of the bracket is hinged to the telescopic end of the lifting mechanism. One end of the bracket is hinged to the lifting mechanism. The cam is rotatably provided on the bracket. The two cams rotate with different positions of the bracket as the axis. The two cams are respectively used to fit the surfaces at different positions of the thin-walled part.

[0047] The control unit is connected to the lifting mechanism and the clamping mechanism.

[0048] Specifically, this automatic clamping system supports and secures the surface of thin-walled parts via rotating cams within the clamping mechanism. To clamp a part, the distance between the two lifting mechanisms is adjusted based on the part's size. The bracket is then rotated open, placing the clamping mechanism in a standby position. The part is placed between the two lifting mechanisms, and the bracket is then rotated closed. Simultaneously, the two cams rotate, supporting the cams and the part's surface according to the part's shape, applying force to the workpiece at the contact point. This switches the clamping mechanism to the clamping position. This automatic clamping system can adjust the cam's rotation angle and distance based on the actual thin-walled part, improving versatility.

[0049] Optionally, the lifting mechanism includes:

[0050] A support seat is slidably arranged on the base;

[0051] The telescopic cylinder is hingedly connected to the support base in the middle, and the output end of the telescopic cylinder is connected to the middle part of the bracket through a hinge joint;

[0052] A pair of tapered roller bearings is arranged at one end of the top of the support seat, and the end of the bracket is arranged between the pair of tapered roller bearings.

[0053] Specifically, the lifting mechanism is used to realize the switching of the clamping mechanism between the standby position and the clamping position; the support seat serves as the bracket part of the lifting structure, connecting the base with the clamping mechanism, and driving the clamping mechanism to slide according to the size of the part; the bracket is hingedly connected to the support seat through a pair of tapered roller bearings, and a rotating shaft is arranged between the tapered roller bearings, so that the bracket rotates around the rotating shaft as the axis; in addition, the telescopic cylinder is rotatably arranged on the support seat, and the telescopic rod in the telescopic cylinder drives the bracket to rotate through telescopic movement; in this way, the bracket in the lifting mechanism is driven by the telescopic cylinder to drive the two cams to press toward the corresponding surface on the part.

[0054] Optionally, an end cover is provided on the outer side of the tapered roller bearing, and a limit block is provided on the other end of the top of the support seat, and the limit block cooperates with the output end of the telescopic cylinder.

[0055] Specifically, the bracket is installed between the tapered roller bearings and is sealed and fixed with end covers to ensure that the inside of the tapered roller bearings is clean and the bracket rotates more smoothly; in order to realize the switching of the clamping mechanism between the standby position and the clamping position, the bracket needs to be rotated, and the telescopic cylinder will also cooperate with the rotation of the bracket to perform telescopic work. In order to realize the linkage between the bracket and the telescopic cylinder, the telescopic cylinder will also rotate relative to the support seat. When the bracket is switched to the clamping position, the side of the bracket away from the tapered roller bearing will move downward. When the telescopic rod of the telescopic cylinder moves with the bracket, the limit block can clamp the telescopic rod of the telescopic cylinder to limit it, so as to avoid the bracket from rotating too much and causing damage to the automatic clamping system.

[0056] Optionally, the base is connected to the lifting mechanism via a transverse feed mechanism, and the transverse feed mechanism includes:

[0057] The ball screw is connected to the base at both ends through bearing supports, and the lifting mechanism is slidably arranged on the ball screw;

[0058] a first motor disposed at an end of the base, wherein an output end of the first motor is connected to the ball screw via a coupling, and a first reducer is disposed between the first motor and the coupling;

[0059] The linear guide rails are arranged along the length direction of the base and are arranged on both sides of the ball screw.

[0060] Specifically, according to the size of the part, the lateral feed mechanism will drive the lifting mechanism to move on the base, so that the cams of the two relative clamping mechanisms can fit and fix with the clamping surface of the part after clamping; two ball screws are arranged on the base, respectively located near the two ends of the base, and each ball screw is equipped with a first motor, which drives the ball screw to rotate through the first reducer and the coupling, so that the lifting mechanism moves in the length direction of the base. In addition, linear guide rails are arranged on both sides of the ball screw to ensure that the lifting mechanism slides more smoothly and stably.

[0061] Optionally, the bracket is a vertically arranged plate-shaped structure, the two cams are respectively arranged on both sides of the bracket, and the rotation axes of the two cams are parallel to each other.

[0062] Optionally, the profile of the cam is a variable diameter arc.

[0063] Specifically, cams are provided on both sides of the bracket, and the cams can rotate arbitrarily on the bracket. The rotation axes of the two cams are set not to overlap with each other, so that the requirements of multi-point clamping of workpieces with different sizes and contours can be adapted by controlling the rotation angle; at the same time, the outer contour of the cam is designed as a variable diameter arc with the axis of the rotating shaft as the center, so that as the cam rotating assembly is tightened, the clamping force can be precisely controlled.

[0064] In one embodiment, when the automatic clamping system positions and clamps a thin-walled workpiece with an inner arc surface, the supporting surfaces of the two cams rotate in opposite directions, thereby expanding and fixing the workpiece.

[0065] Optionally, the clamping mechanism further comprises:

[0066] Two second motors are respectively arranged on both sides of the bracket;

[0067] Two second reducers, one end of which is connected to the output end of the second motor, and the other end of which is connected to the cam via a transmission shaft, which passes through the bracket;

[0068] Tighten the cover to secure the cam to the drive shaft.

[0069] Specifically, in the clamping mechanism, a second motor, a second reducer and a transmission shaft are respectively arranged on both sides of the bracket. The second motor and the second reducer are arranged on the same side, and then the power is transmitted to the cam on the other side through the transmission shaft. This can avoid setting the driving parts on the same side and avoid the limitations of the cam position design.

[0070] Optionally, the two cams are respectively arranged at the middle of the bracket and the other end of the bracket.

[0071] Specifically, in addition to ensuring that the rotation axes of the two cams are parallel to each other, it is best to set the cams in the middle of the bracket and at the end away from the tapered roller bearing. When clamping thin-walled parts, the lifting mechanisms at both ends are moved and adjusted according to the size of the parts, so that the space between the two clamping mechanisms can be used to place the parts. The cam of each clamping mechanism can fit and support the end surface of the part; when there is a thin arc surface at the end of the part, the two cams of each clamping mechanism can internally support and fix the arc surface, thereby achieving clamping and fixation of the part; when the part to be clamped is replaced, it is only necessary to adjust the distance between the two clamping mechanisms, and control the rotation angle of the cam and the extension distance of the telescopic cylinder, so as to adapt to the positioning and clamping of parts of different sizes.

[0072] Optionally, a grating ruler is provided on the base, and a probe of the grating ruler faces the ball screw.

[0073] Specifically, when the lifting mechanism slides on the base, the grating ruler can measure the distance the lifting mechanism on the ball screw moves, and can more accurately control the positioning accuracy.

[0074] The present invention also provides a method for automatically clamping thin-walled parts with low stress, using the above-mentioned automatic clamping system for thin-walled parts with low stress, the method comprising:

[0075] Adjust the distance between the two lifting mechanisms according to the size of the thin-walled parts;

[0076] The two clamping mechanisms open and the thin-walled parts are placed between the two lifting mechanisms;

[0077] The two clamping mechanisms clamp, and the two cams rotate to clamp the surfaces at different positions of the thin-walled parts.

[0078] Specifically, this low-stress automatic clamping system for thin-walled parts can freely configure the number of systems according to the length of the workpiece, and the height of the support seat can also be modified, thus realizing clamping of different positions of the workpiece; the clamping system can be connected to the CNC system, and under the unified and coordinated control of the system, it can realize functions such as fully automatic clamping of thin-walled parts and automatic avoidance of the spindle during processing. When preparing to clamp and fix the part, the shape and size of the part are scanned in advance, and the distance between the two lifting mechanisms is adjusted in a targeted manner. The part is then placed between the two clamping mechanisms. Driven by the telescopic cylinder, the brackets at both ends approach the part and, by rotating the protrusions, the protrusions fit and support the different surfaces of the part. Two protrusions are used at each end of the part to achieve positioning and clamping at different positions. Example

[0079] like Figures 1 to 9 As shown, the present invention provides a low-stress automatic clamping system for thin-walled parts, comprising:

[0080] A base 1, on which two lifting mechanisms 2 are slidably arranged;

[0081] Two clamping mechanisms 3 are respectively provided on the lifting mechanism 2. The clamping mechanism 3 includes a bracket 5 and two cams 6. The middle portion of the bracket 5 is hinged to the telescopic end of the lifting mechanism 2. One end of the bracket 5 is hingedly connected to the lifting mechanism 2. The cams 6 are rotatably provided on the bracket 5. The two cams 6 rotate about different positions of the bracket 5 as the axis. The two cams 6 are respectively used to fit the surfaces at different positions of the thin-walled part.

[0082] The control unit is controlled and connected with the lifting mechanism 2 and the clamping mechanism 3.

[0083] In this embodiment, the lifting mechanism 2 includes:

[0084] A support seat 7 is slidably arranged on the base 1;

[0085] The telescopic cylinder 8 is hingedly connected to the support base 7 in the middle, and the output end of the telescopic cylinder 8 is connected to the middle of the bracket 5 through the hinge joint 9;

[0086] A pair of tapered roller bearings 10 is disposed at one end of the top of the support seat 7 , and an end portion of the bracket 5 is disposed between the pair of tapered roller bearings 10 .

[0087] In this embodiment, an end cover 11 is provided on the outer side of the tapered roller bearing 10 , and a limit block 12 is provided on the other end of the top of the support seat 7 , and the limit block 12 cooperates with the output end of the telescopic cylinder 8 .

[0088] In this embodiment, the base 1 is connected to the lifting mechanism 2 via a transverse feed mechanism 4, which includes:

[0089] The ball screw 13 is connected to the base 1 at both ends through bearing supports 14, and the lifting mechanism 2 is slidably set on the ball screw 13;

[0090] A first motor 15 is provided at the end of the base 1 . The output end of the first motor 15 is connected to the ball screw 13 via a coupling 16 . A first reducer 17 is provided between the first motor 15 and the coupling 16 .

[0091] The linear guide rails 18 are arranged along the length direction of the base 1 and are arranged on both sides of the ball screw 13 .

[0092] In this embodiment, the bracket 5 is a vertically arranged plate-shaped structure, and the two cams 6 are respectively arranged on both sides of the bracket 5 , and the rotation axes of the two cams 6 are parallel to each other.

[0093] In this embodiment, the clamping mechanism 3 further includes:

[0094] Two second motors 19 are respectively arranged on both sides of the bracket 5;

[0095] Two second reducers 20, one end of which is connected to the output end of the second motor 19, and the other end of the second reducer 20 is connected to the cam 6 through a transmission shaft 21, and the transmission shaft 21 passes through the bracket 5;

[0096] Lock the cover 22 and fix the cam 6 on the transmission shaft 21.

[0097] In this embodiment, two cams 6 are respectively provided at the middle portion of the bracket 5 and the other end of the bracket 5 .

[0098] In this embodiment, the profile of the cam 6 is a variable diameter arc.

[0099] In this embodiment, a grating ruler is provided on the base 1 , and a probe of the grating ruler faces the ball screw 13 .

[0100] The present invention also provides a method for automatically clamping thin-walled parts with low stress, using the above-mentioned automatic clamping system for thin-walled parts with low stress, the method comprising:

[0101] Adjust the distance between the two lifting mechanisms 2 according to the size of the thin-walled parts;

[0102] The two clamping mechanisms 3 are opened, and the thin-walled parts are placed between the two lifting mechanisms 2;

[0103] The two clamping mechanisms 3 clamp, and the two cams 6 rotate to clamp the profiles at different positions of the thin-walled part.

[0104] In summary, when clamping parts, the low-stress automatic clamping system for thin-walled parts selects the lateral feed mechanism 4 as a single group setting or a symmetrical arrangement according to the size and shape characteristics of the clamped parts. In addition, a corresponding number of low-stress automatic clamping systems for thin-walled parts are set on the periphery of the parts, and then the distance between the lifting mechanisms 2 is adjusted according to the size of the parts. The parts are placed between the lifting mechanisms 2, and then the clamping mechanism 3 is driven by the telescopic cylinder 8 to rotate. At the same time, the cam rotates an angle under the drive of the second motor 19, and the cam rotation angle is used to form a multi-point clamping fit with the parts, thereby realizing fully automatic clamping of thin-walled parts, automatic avoidance of the spindle during processing, and other functions.

[0105] While various embodiments of the present invention have been described above, the above description is intended to be illustrative, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A low-stress automatic clamping system for thin-walled parts, characterized in that: include: A base, on which two lifting mechanisms are slidably provided; Two clamping mechanisms are respectively provided on the lifting mechanism, the clamping mechanism comprising a bracket and two cams, the middle portion of the bracket is hinged to the telescopic end of the lifting mechanism, one end of the bracket is hingedly connected to the lifting mechanism, the cams are rotatably provided on the bracket, the two cams rotate about different positions of the bracket as the axis, and the two cams are respectively used to fit the profiles of different positions of the thin-walled part; a control unit, in control connection with the lifting mechanism and the clamping mechanism; The bracket is a vertically arranged plate-shaped structure, and the two cams are respectively arranged on both sides of the bracket, and the rotation axes of the two cams are parallel to each other; The clamping mechanism further comprises: Two second motors are respectively arranged on both sides of the bracket; Two second reducers, one end of which is connected to the output end of the second motor, and the other end of which is connected to the cam via a transmission shaft, wherein the transmission shaft passes through the bracket; A locking cover is provided to fix the cam on the transmission shaft; The two cams are respectively arranged at the middle of the bracket and the other end of the bracket; The profile of the cam is a variable diameter arc.

2. The low-stress automatic clamping system for thin-walled parts according to claim 1 is characterized in that: The lifting mechanism comprises: A support seat, slidably arranged on the base; A telescopic cylinder, the middle portion of which is hingedly connected to the support base, and the output end of the telescopic cylinder is connected to the middle portion of the bracket via a hinged joint; A pair of tapered roller bearings is arranged at one end of the top of the support seat, and the end of the bracket is arranged between the pair of tapered roller bearings.

3. The low-stress automatic clamping system for thin-walled parts according to claim 2 is characterized in that: An end cover is provided on the outer side of the tapered roller bearing, and a limit block is provided on the other end of the top of the support seat, and the limit block cooperates with the output end of the telescopic cylinder.

4. The low-stress automatic clamping system for thin-walled parts according to claim 1 is characterized in that: The base is connected to the lifting mechanism via a transverse feeding mechanism, and the transverse feeding mechanism comprises: A ball screw, both ends of which are connected to the base via bearing supports, and the lifting mechanism is slidably arranged on the ball screw; a first motor, disposed at an end of the base, wherein an output end of the first motor is connected to the ball screw via a coupling, and a first reducer is disposed between the first motor and the coupling; A linear guide rail is arranged along the length direction of the base, and the linear guide rail is arranged on both sides of the ball screw.

5. The low-stress automatic clamping system for thin-walled parts according to claim 4 is characterized in that: A grating ruler is provided on the base, and a probe of the grating ruler faces the ball screw.

6. A method for automatically clamping thin-walled parts with low stress, using the automatic clamping system for thin-walled parts with low stress according to any one of claims 1 to 5, characterized in that: The method includes: Adjusting the distance between the two lifting mechanisms according to the size of the thin-walled part; The two clamping mechanisms are opened, and the thin-walled part is placed between the two lifting mechanisms; The two clamping mechanisms clamp, and the two cams rotate to clamp the profiles at different positions of the thin-walled part.

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