阅读说明：本技术 并联轨道式智能机器人复合弯曲成形加工方法及装置 (Parallel-track type intelligent robot composite bending forming processing method and device ) 是由 刘春梅 黄祖树 郭训忠 郑�硕 孙振彪 于 2021-07-30 设计创作，主要内容包括：本发明公开了一种并联轨道式智能机器人复合弯曲成形加工方法及装置,包括两工业机器人、自由弯曲成形装置、绕弯成形装置、外部夹持导向装置,两地轨；自由弯曲成形装置和绕弯成形装置分别装在两工业机器人的末端,工业机器人安装在地轨上,两台工业机器人并联式排布,可分别沿地轨进行水平运动；外部夹持导向装置处于两工业机器人之间。采用两台带地轨的工业机器人,在机器人末端分别安装自由弯曲成形系统和绕弯成形系统,使得复杂空间构件的弯曲成形过程中,既可以成形连续变曲率半径特征,又可以成形小弯曲半径特征,甚至是弯扭复合特征。避免了单一成形方式频繁更换模具,实现了多特征复杂空间管件多种弯曲方式复合一体化短流程成形。(The invention discloses a parallel-connection track type intelligent robot composite bending forming processing method and device, comprising two industrial robots, a free bending forming device, a bending forming device, an external clamping guide device and two ground tracks; the free bending forming device and the bending forming device are respectively arranged at the tail ends of the two industrial robots, the industrial robots are arranged on the ground rail, and the two industrial robots are arranged in parallel and can respectively move horizontally along the ground rail; the outer clamping guide is located between the two industrial robots. Two industrial robots with ground rails are adopted, and a free bending forming system and a bending forming system are respectively arranged at the tail ends of the robots, so that the continuous variable curvature radius characteristic, the small bending radius characteristic and even the bending and twisting composite characteristic can be formed in the bending forming process of the complex space component. The method avoids the frequent replacement of the die in a single forming mode, and realizes the composite integrated short-flow forming of the multi-feature complex space pipe fitting in multiple bending modes.)

1. A parallel-rail type intelligent robot composite bending forming processing device is characterized by comprising two industrial robots (12) and (42), a free bending forming device (13), a winding forming device (41), an external clamping guide device (2) and two ground rails (11) and (43); a free bend forming device (13) and a wrap bend forming device (41) are respectively mounted on the ends of two industrial robots (12) (42), and the two industrial robots (12) (42) are mounted on two ground rails (11) (43).

2. A composite bend forming apparatus according to claim 1, wherein two industrial robots (12) (42) are arranged in parallel and are each capable of horizontal movement along a ground rail (11) (43).

3. A compound bend forming apparatus as set forth in claim 1 wherein said industrial robot (12) (42) is a tandem six axis robot.

4. The apparatus according to claim 1, wherein the ground rails (11) (43) are arranged in parallel, so that the two industrial robots (12) (42) can move horizontally to alternately perform the bending of the pipe.

5. The compound bending forming processing device according to claim 1, wherein the free bending forming device (13) comprises a cylinder seat (131), a cylinder (132), a transmission mechanism (133) and a free bending die (134), the free bending die (134) is an open-close die, the transmission mechanism (133) is driven by the movement of a piston rod of the cylinder (132) to realize the opening and closing of the free bending die (134), and the tube blank (3) can be clamped at any position by matching with the movement of a robot so that the tube blank (3) penetrates through the die; then controlling offset distances and offset angles in all directions of the free bending die (134), wherein different offset distances correspond to different bending radiuses, and different offset angles correspond to different bending planes; the size of the offset distance and the offset angle of the bending die is controlled in real time, and the axial feeding of the pipe is carried out simultaneously, so that the continuous variable-curvature space bent pipe forming is realized.

6. The composite bend forming apparatus according to claim 1, wherein the wrap-around forming apparatus (41) includes a bending mechanism (411), a clamping mechanism (412), a driving mechanism (413), a connecting mechanism (414), and a pressing mechanism (415); the bending forming device (41) is arranged at the tail end of an arm of an industrial robot (42), the industrial robot (42) drives the bending forming device (41) to move to a bending starting position, the clamping mechanism (412) clamps the tube blank (3) through the cylinder driving connecting rod group, the pressing mechanism (415) presses the tube blank (3) through the cylinder driving connecting rod group for guiding, and the clamping mechanism (412) and the bending mechanism (411) clamp the tube blank (3) to rotate together so that the tube blank (3) is fully attached to a die; meanwhile, the whole device translates along the axis direction of the tube blank (3) under the cooperation of an arm of an industrial robot (42), a part of modules in the pressing mechanism (415) which are in contact with the tube blank (3) keep relatively static with the tube blank (3) when being bent, after bending forming, the pressing mechanism (415) resets under the driving of an air cylinder when the clamping mechanism (412) and the bending mechanism (411) are opened and reset, and finally, a bending section with the same radius as that of a bending die is formed; the bending forming of different bending planes can be realized along with the movement of the arm of the industrial robot (42).

7. A composite bend forming apparatus according to claim 1, wherein the external clamp guide (2) comprises a guide portion and a clamp portion, and the clamp device is released to perform a guiding function when free bend forming is performed; when the bending forming is carried out, the tube blank (3) is clamped, and the clamping effect is achieved.

8. A composite bend forming process based on the apparatus of any one of claims 1 to 7, comprising the steps of:

1) extracting geometric parameters of the formed pipe fitting, inputting the geometric parameters into a software control system, and determining a coordination and matching mode of the free bending forming system (1), the bending forming system (4) and the external clamping guide device (2) through iterative calculation for a plurality of times; a free bending apparatus (13) in a free bending system (1) corresponds to the coordinates (x) of the center position of a bending die for each feature_i，y_j，z_k) Curve of bending angle versus time (theta-t), curve of torsion angle versus timeAnd a curve (S-t) of the relation between the feeding distance of the tube blank (3) and time; the wrap-around forming device (41) in the wrap-around forming system (4) corresponds to the position coordinate (x) of the end axis of the clamping die of each characteristic_l，y_m，z_n) A curve of the relationship between the rotation angle of the bending forming device and time (alpha-t), a curve of the relationship between the bending angle of the bending die and time (beta-t), and a curve of the relationship between the axial moving distance of the bending die and time (L-t);

2) respectively transmitting the various process parameters to a robot motion control system, a bending forming device control system and an external clamping guide control system; the robot motion control system determines the spatial motion track of each robot in each stage according to the spatial coordinates and the distance-time (S-t, L-t) relation curve of each point of the bending die, and the bending forming device control system determines the bending angle and time (theta-t) of the free bending forming device (13) and the torsion angle and time of the free bending forming device (13)The torsion angle of the bending forming device (41) is determined according to various relation curves such as time (alpha-t), bending angle of the bending forming device (41) and time (beta-t)Determining a composite process curve of two bending forming modes and a switching node of the clamping/guiding action of the external clamping and guiding device (2);

3) and simultaneously starting the robot motion control system, the bending forming device control system and the external clamping guide control system, executing all the motion curves, and completing the free bending/twisting composite forming or the free bending/bending composite forming of the target pipe fitting.

9. The composite bend forming process of claim 8, comprising the steps of:

firstly, extracting geometric parameters of a formed pipe fitting, inputting the geometric parameters into a software control system, and determining the central position coordinates (x) of a bending die corresponding to each characteristic of a free bending forming device (13) through iterative computation for a plurality of times_i，y_j，z_k) Bending angle and time (theta-t), torsion angle and timeCurves of the rotation angle of the pipe blank (3) clamped by the bending forming device (41) and the time (alpha-t), the feeding distance and the time (S-t) and the like:S＝vt,A＝|z_k-z₀|， (x₀，y₀，z₀) The coordinate of the center point of the front end of the external clamping guide device (2), R is the bending radius of the pipe fitting, A is the axial distance from the center of the free bending die to the center point of the front end of the external clamping guide device (2), and v is the feeding speed of the pipe blank (3) clamped by the bending forming device (41);

secondly, the obtained process parameters are respectively transmitted to a robot motion control system and a bending forming device control system; the robot motion control system determines the spatial motion track of each stage of the robot according to the spatial coordinates of each characteristic point and the relation curve of the feeding distance of the tube blank (3) and time (S-t), and the bending forming device control system determines the bending angle and time (theta-t) of the free bending forming device (13) and the torsion angle and time of the free bending forming device (13)And various relation curves of the rotation angle and the time (alpha-t) of the bending forming device (41) and the like are used for determining a free bending/twisting composite forming process curve, and the external clamping guide device (2) plays a role in guiding;

thirdly, the pipe blank (3) is clamped by a bending forming system (4) and conveyed to an external clamping guide device (2), and the external clamping guide device (2) guides the pipe blank (3);

fourthly, the robot motion control system, the bending forming device control system and the external clamping guide control system carry out cooperative control, each motion curve obtained in the second step is executed, and free bending/twisting composite bending forming of the target pipe fitting is completed;

fifthly, after the bending forming is finished, the external clamping guide device (2) is opened;

sixthly, the winding and forming system (4) grips and places the forming component at a designated position, and then the next tube blank (3) is bent and formed.

10. The composite bending forming processing method according to claim 8, characterized by comprising the following specific steps:

firstly, extracting geometric parameters of a formed pipe fitting, inputting the geometric parameters into a software control system, carrying out sectional treatment on the pipe fitting according to the forming requirement of a target component, dividing the pipe fitting into a small relative bending radius section with a straight section, a large relative bending radius section with the straight section, a large relative bending radius section without the straight section, a continuous variable curvature bending section, and determining the position of a binding point of each different characteristic section;

secondly, for a small bending radius section with a straight section, acquiring the position coordinate (x) of the tail end axis of the clamping die corresponding to each characteristic of a bending forming device (41) in a bending forming system (4)_l，y_m，z_n) A curve (alpha-t) of the rotation angle of the winding forming device (41), a curve (beta-t) of the bending angle of the bending die and a curve (L-t) of the axial movement distance; for a large bending radius section with a straight section/a non-straight section large relative bending radius section/a continuous variable curvature bending section, obtaining the central position coordinates (x) of the bending mould of each characteristic corresponding to the free bending forming system (1)_i，y_j，z_k) Bending angle and time (theta-t), torsion angle and timeAn equal relation curve; a wrap-around forming device (41) clamps a relation curve of a rotation angle and time (alpha-t) of the tube blank (3) and a relation curve of a feeding distance and time (S-t) of the tube blank (3);

thirdly, the various process parameters are respectively transmitted to a robot motion control system, a bending forming device control system and an external clamping guide control system; the robot motion control system determines the spatial motion track of each robot in each stage according to the spatial coordinates and the distance-time (S-t, L-t) relation curve of each characteristic point, and the bending forming device control system determines the bending angle and time (theta-t) of the free bending forming device (13) and the torsion angle and time of the free bending forming device (13)An equal relation curve; the free bending/bending composite forming process curve is determined by various relation curves such as the rotation angle and the time (alpha-t) of a bending forming device (41), the bending angle and the time (beta-t) of a bending mould and the like, and an external clamping and guiding control system determines a switching node of a clamping/guiding function according to the obtained composite process curve;

fourthly, the pipe blank is clamped by a bending forming system (4) and conveyed to an external clamping guide device (2), and the external clamping guide device (2) clamps or guides the pipe blank (3);

and fifthly, cooperatively controlling the robot motion control system, the bending forming device control system and the external clamping guide control system to finally finish the free bending/twisting composite bending forming of the target pipe fitting. For a small bending radius section with a straight section, a bending forming process is adopted, an external clamping guide device (2) clamps a tube blank (3), and a bending forming device (41) bends the tube blank (3). For a large-bending radius section with a straight section/a large-relative-bending radius section without the straight section/a continuous variable-curvature bending section, a free bending forming process is adopted, an external clamping and guiding device (2) loosens a pipe blank (3) to play a guiding role, a winding forming device (41) moves to the other end of the pipe blank (3) to clamp the pipe blank (3) for feeding the pipe blank (3), and a free bending forming device (13) performs free bending forming on the pipe blank (3);

sixthly, after the bending forming is finished, the external clamping guide device (2) is opened;

seventh, the winding and bending forming system (4) further picks and places the forming member at a designated position, and then performs bending forming on the next tube blank (3).

Technical Field

The invention relates to the technical field of pipe forming processing, in particular to a compound bending forming processing method and device based on a parallel track type intelligent robot.

Background

With the increasing demand for light weight, the hollow component of the pipeline system is widely applied to equipment in the fields of aerospace, petrochemical industry, automobiles, ships and the like, the structural complexity is higher and higher, and the hollow pipe fitting with a complex three-dimensional space structure is more favorable for improving the structural compactness of the pipeline system, so that the utilization rate of the equipment space is greatly improved, and the hollow pipe fitting plays an important role in reducing the weight of the equipment.

At present, the bending forming technology of the hollow pipe fitting mainly comprises roll bending, stretch bending, bending by winding, push bending and other technologies, if the hollow pipe fitting with various complex space axes and continuously changed bending radius is bent by the traditional method, a bending forming die or different forming methods must be continuously replaced according to different bending characteristics, welding is carried out after some bending and even sectional forming is needed, and the size precision and the forming quality of a formed component cannot be guaranteed, so that the complexity, the production cost and the period of the process flow are greatly increased. The traditional bending technology has the limitation of forming, so that the integral short-flow forming of the hollow pipe fitting with the complex three-dimensional space configuration has great difficulty.

The whole mechanism of the industrial robot is similar to a human hand, and can provide higher freedom degree and more complex motion trail, so that the complex space configuration can be better adapted. The free bending forming technology, the bending forming technology and the robot technology are combined, the advantages of the two bending forming technologies are reflected, the mechanism characteristics and the control mode of the existing bending forming system are broken through, the movement interference in the forming process can be better avoided, the pipe fitting with a more complex space configuration is formed, and the complex space pipe fitting composite bending integrated short-flow forming is realized.

Disclosure of Invention

The invention provides a compound bending forming processing method and a forming device based on a parallel track type intelligent robot aiming at the defects of the prior art and the characteristic of high degree of freedom of an industrial robot. Therefore, the frequent replacement of the die by a single forming mode is effectively avoided, and the short-flow forming of the multi-feature complex space pipe fitting by combining multiple bending modes is realized.

The technical scheme adopted by the invention is as follows:

a parallel-rail type intelligent robot composite bending forming processing device comprises industrial robots (12) and (42), a free bending forming device (13), a bending forming device (41), an external clamping guide device (2) and ground rails (11) and (43); the free bending forming device (13) and the bending forming device (41) are respectively arranged at the tail ends of the industrial robots (12) and (42), the industrial robots (12) and (42) are arranged on the ground rails (11) and (43), and the two industrial robots (12) and (42) are arranged in parallel and can respectively move horizontally along the ground rails (11) and (43); the outer clamping guide (2) is located between two industrial robots (12) (42).

In the composite bending forming apparatus, the industrial robots (12) and (42) are tandem six-axis robots.

According to the composite bending forming processing device, the ground rails (11) and (43) are arranged in parallel, so that the two industrial robots (12) and (42) can horizontally move to alternately complete the bending forming of the pipe fittings.

The free bending forming device (13) comprises a cylinder seat (131), a cylinder (132), a transmission mechanism (133) and a free bending die (134), wherein the free bending die (134) is an open-close die, the transmission mechanism (133) is driven by the motion of a piston rod of the cylinder (132) to realize the opening and closing of the free bending die (134), and the free bending die can be matched with the motion of a robot to clamp a tube blank (3) at any position so that the tube blank (3) penetrates through the die; then controlling offset distances and offset angles in all directions of the free bending die (134), wherein different offset distances correspond to different bending radiuses, and different offset angles correspond to different bending planes; the size of the offset distance and the offset angle of the bending die is controlled in real time, and the axial feeding of the pipe is carried out simultaneously, so that the continuous variable-curvature space bent pipe forming is realized.

The compound bending forming device comprises a bending mechanism (411), a clamping mechanism (412), a driving mechanism (413), a connecting mechanism (414) and a pressing mechanism (415), wherein the bending forming device (41) comprises a bending mechanism (411); the bending forming device (41) is arranged at the tail end of an arm of an industrial robot (42), the industrial robot (42) drives the bending forming device (41) to move to a bending starting position, the clamping mechanism (412) clamps the tube blank (3) through the cylinder driving connecting rod group, the pressing mechanism (415) presses the tube blank (3) through the cylinder driving connecting rod group for guiding, and the clamping mechanism (412) and the bending mechanism (411) clamp the tube blank (3) to rotate together so that the tube blank (3) is fully attached to a die; meanwhile, the whole device translates along the axis direction of the tube blank (3) under the cooperation of an arm of an industrial robot (42), a part of modules in the pressing mechanism (415) which are in contact with the tube blank (3) keep relatively static with the tube blank (3) when being bent, after bending forming, the pressing mechanism (415) resets under the driving of an air cylinder when the clamping mechanism (412) and the bending mechanism (411) are opened and reset, and finally, a bending section with the same radius as that of a bending die is formed; the bending forming of different bending planes can be realized along with the movement of the arm of the industrial robot (42).

The external clamping guide device (2) comprises a guide part and a clamping part, and when free bending forming is performed, the clamping device is released to play a role in guiding; when the bending forming is carried out, the tube blank (3) is clamped, and the clamping effect is achieved.

A composite bending forming processing method based on any device comprises the following steps:

1) extracting geometric parameters of the formed pipe fitting, inputting the geometric parameters into a software control system, and determining a coordination and matching mode of the free bending forming system (1), the bending forming system (4) and the external clamping guide device (2) through iterative calculation for a plurality of times; a free bending apparatus (13) in a free bending system (1) corresponds to the coordinates (x) of the center position of a bending die for each feature_i，y_j，z_k) Curve of bending angle versus time (theta-t), torsion angle versus timeIs curve lineAnd a curve (S-t) of the relation between the feeding distance of the tube blank (3) and time; the wrap-around forming device (41) in the wrap-around forming system (4) corresponds to the position coordinate (x) of the end axis of the clamping die of each characteristic_l，y_m，z_n) A curve of the relationship between the rotation angle of the bending forming device and time (alpha-t), a curve of the relationship between the bending angle of the bending die and time (beta-t), and a curve of the relationship between the axial moving distance of the bending die and time (L-t);

2) and respectively transmitting the various process parameters to a robot motion control system, a bending forming device control system and an external clamping guide control system. The robot motion control system determines the spatial motion track of each robot in each stage according to the spatial coordinates and the distance-time (S-t, L-t) relation curve of each point of the bending die, and the bending forming device control system determines the bending angle and time (theta-t) of the free bending forming device (13) and the torsion angle and time of the free bending forming device (13)Determining composite process curves of two bending forming modes and a switching node of the clamping/guiding action of the external clamping and guiding device (2) by various relation curves of the torsion angle and the time (alpha-t) of the bending forming device (41), the bending angle and the time (beta-t) of the bending forming device (41) and the like;

3) and simultaneously starting the robot motion control system, the bending forming device control system and the external clamping guide control system, executing all the motion curves, and completing the free bending/twisting composite forming or the free bending/bending composite forming of the target pipe fitting.

The composite bending forming processing method comprises the following specific steps:

firstly, extracting geometric parameters of a formed pipe fitting, inputting the geometric parameters into a software control system, and determining the central position coordinates (x) of a bending die corresponding to each characteristic of a free bending forming device (13) through iterative computation for a plurality of times_i，y_j，z_k) Bending angle and time (theta-t), torsion angle and timeCurves of the rotation angle of the pipe blank (3) clamped by the bending forming device (41) and the time (alpha-t), the feeding distance and the time (S-t) and the like:S＝vt,A＝|z_k-z₀|， (x₀，y₀，z₀) The coordinate of the center point of the front end of the external clamping guide device (2), R is the bending radius of the pipe fitting, A is the axial distance from the center of the free bending die to the center point of the front end of the external clamping guide device (2), and v is the feeding speed of the pipe blank (3) clamped by the bending forming device (41);

secondly, the obtained process parameters are respectively transmitted to a robot motion control system and a bending forming device control system; the robot motion control system determines the spatial motion track of each stage of the robot according to the spatial coordinates of each characteristic point and the relation curve of the feeding distance of the tube blank (3) and time (S-t), and the bending forming device control system determines the bending angle and time (theta-t) of the free bending forming device (13) and the torsion angle and time of the free bending forming device (13)And various relation curves of the rotation angle and the time (alpha-t) of the bending forming device (41) and the like are used for determining a free bending/twisting composite forming process curve, and the external clamping guide device (2) plays a role in guiding;

thirdly, the pipe blank (3) is clamped by a bending forming system (4) and conveyed to an external clamping guide device (2), and the external clamping guide device (2) guides the pipe blank (3);

fourthly, the robot motion control system, the bending forming device control system and the external clamping guide control system carry out cooperative control, each motion curve obtained in the second step is executed, and free bending/twisting composite bending forming of the target pipe fitting is completed;

fifthly, after the bending forming is finished, the external clamping guide device (2) is opened;

sixthly, the winding and forming system (4) grips and places the forming component at a designated position, and then the next tube blank (3) is bent and formed.

The composite bending forming processing method comprises the following specific steps:

firstly, extracting geometric parameters of a formed pipe fitting, inputting the geometric parameters into a software control system, carrying out sectional treatment on the pipe fitting according to the forming requirement of a target component, dividing the pipe fitting into a small relative bending radius section with a straight section, a large relative bending radius section with the straight section, a large relative bending radius section without the straight section, a continuous variable curvature bending section, and determining the position of a binding point of each different characteristic section;

secondly, for a small bending radius section with a straight section, acquiring the position coordinate (x) of the tail end axis of the clamping die corresponding to each characteristic of a bending forming device (41) in a bending forming system (4)_l，y_m，z_n) A curve (alpha-t) of the variation of the rotation angle of the wrap-around bending forming device (41), a curve (beta-t) of the variation of the bending angle of the bending die, and a curve (L-t) of the axial movement distance. For a large bending radius section with a straight section/a non-straight section large relative bending radius section/a continuous variable curvature bending section, obtaining the central position coordinates (x) of the bending mould of each characteristic corresponding to the free bending forming system (1)_i，y_j，z_k) Bending angle and time (theta-t), torsion angle and timeAn equal relation curve; a wrap-around forming device (41) clamps a relation curve of a rotation angle and time (alpha-t) of the tube blank (3) and a relation curve of a feeding distance and time (S-t) of the tube blank (3);

thirdly, the various process parameters are respectively transmitted to a robot motion control system, a bending forming device control system and an external clamping guide control systemAnd (5) manufacturing a system. The robot motion control system determines the spatial motion track of each robot in each stage according to the spatial coordinates and the distance-time (S-t, L-t) relation curve of each characteristic point, and the bending forming device control system determines the bending angle and time (theta-t) of the free bending forming device (13) and the torsion angle and time of the free bending forming device (13)An equal relation curve; the free bending/bending composite forming process curve is determined by various relation curves such as the rotation angle and the time (alpha-t) of a bending forming device (41), the bending angle and the time (beta-t) of a bending mould and the like, and an external clamping and guiding control system determines a switching node of a clamping/guiding function according to the obtained composite process curve;

fourthly, the pipe blank is clamped by a bending forming system (4) and conveyed to an external clamping guide device (2), and the external clamping guide device (2) clamps or guides the pipe blank (3);

and fifthly, cooperatively controlling the robot motion control system, the bending forming device control system and the external clamping guide control system to finally finish the free bending/twisting composite bending forming of the target pipe fitting. For a small bending radius section with a straight section, a bending forming process is adopted, an external clamping guide device (2) clamps a tube blank (3), and a bending forming device (41) bends the tube blank (3). For a large-bending radius section with a straight section/a large-relative-bending radius section without the straight section/a continuous variable-curvature bending section, a free bending forming process is adopted, an external clamping and guiding device (2) loosens a pipe blank (3) to play a guiding role, a winding forming device (41) moves to the other end of the pipe blank (3) to clamp the pipe blank (3) for feeding the pipe blank (3), and a free bending forming device (13) performs free bending forming on the pipe blank (3);

sixthly, after the bending forming is finished, the external clamping guide device (2) is opened;

seventh, the winding and bending forming system (4) further picks and places the forming member at a designated position, and then performs bending forming on the next tube blank (3).

The composite bending forming processing method is characterized in that when R/D is less than or equal to 2.5, the bending radius is small, when R/D is greater than or equal to 2.5, the bending radius is large, wherein R is the bending radius, and D is the outer diameter of a pipe blank.

The invention has the beneficial effects that: 1) the invention provides a new flexible forming method and a device for the production and the manufacture of a complex three-dimensional space configuration pipe fitting; 2) the invention is beneficial to optimizing the forming process of the spatial complex pipe fitting, fully exerts the advantages of each bending forming process, realizes the forming of the small bending radius section and the forming of the multi-characteristic continuous variable curvature section;

3) compared with the traditional machine tool control, the control method has higher degree of freedom and flexibility, and can effectively avoid the interference between the pipe fitting and the mechanism for the complex space member; 4) the invention is beneficial to reducing the production period, avoiding frequent replacement of the forming die and realizing the composite integrated flexible forming of a plurality of bending modes; 5) the invention has obvious economic benefit and realizes automatic intelligent operation, including loading and unloading and bending forming of the robot.

Drawings

FIG. 1 is a flow chart of a compound bending forming method based on a parallel track type intelligent robot;

FIG. 2 is a composite bend forming system based on a parallel rail-mounted intelligent robot;

FIG. 3 is a schematic diagram of the free bend forming stage of the free bend/twist composite forming;

FIG. 4 is a schematic representation of the post-twist free-form bending phase of the free-form bend/twist composite forming;

FIG. 5 is a schematic view of a free bend forming stage of free bend/wrap composite forming;

FIG. 6 is a schematic view of a wrap forming stage of the free-form/wrap composite forming;

FIG. 7 is a schematic view of a freeform bend forming apparatus;

FIG. 8 is a schematic view of a wrap-around forming apparatus;

FIG. 9 is a schematic view of a pipe clamping process in the wrap-around forming apparatus;

FIG. 10 is a schematic view of a process for bending a tube in a wrap-forming apparatus;

in the figure: 1. the bending forming device comprises a free bending forming system, 11 ground rails, 12 industrial robots, 13 free bending forming devices, 131 cylinder bases, 132 cylinders, 133 transmission mechanisms, 134 free bending dies, 2 external clamping guide devices, 3 tube blanks, 4 bending forming systems, 41 bending forming devices, 411 bending mechanisms, 412 clamping mechanisms, 413 driving mechanisms, 414 connecting mechanisms, 415 material pressing mechanisms, 42 industrial robots and 43 ground rails;

Detailed Description

The present invention will be described in detail with reference to specific examples.

Example 1

FIG. 3 is a schematic diagram of a free bend forming stage of the free bend/twist composite forming, and FIG. 4 is a schematic diagram of a post-twist bending stage of the free bend/twist composite forming. The free bending forming device 13 and the bending forming device 41 are respectively arranged at the tail ends of the industrial robots 12 and 42, the industrial robots 12 and 42 are arranged on the ground rails, and the two robots are arranged in parallel and can move along the ground rails 11 and 43; the external gripping guide 2 is located between the two robots. The free bending forming system 1 and the bending forming system 4 are respectively arranged at two sides of the external clamping guide device 2 and respectively comprise a robot motion control system and a bending die control system. The position and the posture of the free bending forming device 13 are controlled by a robot to realize the space bending forming with different curvatures, the external clamping and guiding device 2 guides the free bending forming device, the winding and forming device 41 clamps the other end of the tube blank 3 to feed and twist the tube blank 3, and the free bending/twisting composite bending forming of the complex space tube fitting is realized.

The free bending forming device (13) comprises a cylinder seat 131, a cylinder 132, a transmission mechanism 133 and a free bending die (134), the free bending die (134) is an open-close die, the transmission mechanism (133) is driven by the movement of a piston rod of the cylinder (132) to open and close the free bending die (134), and the free bending die can clamp the tube blank (3) at any position by matching with the movement of a robot, so that the tube blank (3) penetrates through the die. And then controlling offset distances and offset angles in all directions of the free bending die (134), wherein different offset distances correspond to different bending radii, and different offset angles correspond to different bending planes. The size of the offset distance and the offset angle of the bending die is controlled in real time, and the axial feeding of the pipe is carried out simultaneously, so that the continuous variable-curvature space bent pipe forming is realized.

The bending forming device (41) comprises a bending mechanism (411), a clamping mechanism (412), a driving mechanism (413), a connecting mechanism (414) and a pressing mechanism (415). The whole device is installed at the tail end of an arm of an industrial robot (42), the industrial robot (42) drives a bending forming device (41) to move to a bending starting position, a clamping mechanism (412) clamps a tube blank (3) through a cylinder driving connecting rod group, a pressing mechanism (415) presses the tube blank (3) through the cylinder driving connecting rod group for guiding, and the clamping mechanism (412) and a bending mechanism (411) clamp the tube blank (3) to rotate together, so that the tube blank (3) is fully attached to a die. Meanwhile, the whole device translates along the axis direction of the tube blank (3) under the cooperation of an arm of an industrial robot (42), a part of a module in the pressing mechanism (415) which is in contact with the tube blank (3) keeps relatively static with the tube blank (3) when being bent, after bending forming, the clamping mechanism (412) and the bending mechanism (411) are opened and reset, the pressing mechanism (415) is reset under the driving of an air cylinder, and finally, a bending section with the same radius as that of a bending die is formed. The bending forming of different bending planes can be realized along with the movement of an arm of an industrial robot (42), a plurality of sets of dies are required to be arranged for different bending radiuses, a clamping straight section is inevitably present, and bent pipes with complex characteristic spaces such as continuous variable curvature and the like cannot be formed, but because the forming process is under a multi-constraint condition, a bending section with small relative bending radius (R/D is less than or equal to 2.5) can be formed, and the special advantage is provided for the forming of the bending section with small relative bending radius.

In this embodiment, the specific steps are:

firstly, extracting the geometric parameters of the formed pipe fitting, inputting the geometric parameters into a software control system, and determining the coordinates (x) of the central position of the bending die corresponding to each characteristic of the free bending forming device 13 through iterative computation for a plurality of times_i，y_j，z_k) Bending angle and time (theta-t), torsion angle and timeCurves of the relationship between the rotation angle and the time (alpha-t) and the relationship between the feed distance and the time (S-t) of the pipe blank 3 held by the wrap-around forming device 41S＝vt，A＝|z_k-z₀| ((x₀，y₀，z₀) Is the coordinate of the center point of the front end of the external clamping guide device 2, R is the bending radius of the pipe fitting, A is the axial distance from the center of the free bending die to the center point of the front end of the external clamping guide device 2, v is the feeding speed of the pipe blank 3 clamped by the bending forming device 41)

Secondly, the obtained process parameters are respectively transmitted to a robot motion control system and a bending forming device control system. The robot motion control system determines the space motion track of each stage of the robot according to the space coordinate of each characteristic point and the relation curve of the feeding distance of the tube blank 3 and the time (S-t), and the bending forming device control system determines the bending angle and the time (theta-t) of the free bending forming device 13 and the torsion angle and the time of the free bending forming device 13 according to the bending angle and the time (theta-t) of the free bending forming device 13And various relation curves of the rotation angle and the time (alpha-t) of the wrap-around bending forming device 41 and the like are used for determining a free bending/twisting composite forming process curve, and the external clamping guide device 2 plays a guiding role at the moment.

Thirdly, the pipe blank 3 is clamped by the bending forming system 4 and conveyed to the external clamping guide device 2, and the external clamping guide device 2 guides the pipe blank 3.

And fourthly, cooperatively controlling the robot motion control system, the bending forming device control system and the external clamping guide control system, executing each motion curve obtained in the second step, and finishing free bending/twisting composite bending forming of the target pipe fitting.

Fifthly, after the bending forming is finished, the external clamping guide device 2 is opened;

sixthly, the wrap-around forming system 4 again picks up the forming member and places it at a designated position, followed by bending forming of the next tube blank 3.

Example 2

FIG. 5 is a schematic view of a free bending stage of free bending/bending composite forming, and FIG. 6 is a schematic view of a bending stage of free bending/bending composite forming. The free bending forming device 13 and the bending forming device 41 are respectively arranged at the tail ends of the industrial robots 12 and 42, the industrial robots 12 and 42 are arranged on the ground rails 11 and 43, and the two robots are arranged in parallel and can move along the ground rails 11 and 43; the external gripping guide 2 is located between the two robots. When the pipe fitting is bent and formed, the free bending forming system 1 and the bending forming system 4 are sequentially bent and formed according to the characteristics of each bent part, and a bending forming process is adopted for a small bending radius section with a straight section; and finally, adopting a free bending forming process for the large-bending radius section with the straight section/the large-relative-bending radius section without the straight section/the continuous variable-curvature bending section to realize free bending/bending composite bending forming of the pipe fitting with the complex space structure.

In this embodiment, the specific steps are:

firstly, extracting geometric parameters of a formed pipe fitting, inputting the geometric parameters into a software control system, carrying out segmentation processing on the pipe fitting according to the forming requirement of a target component, dividing the pipe fitting into a small relative bending radius section with a straight section, a large relative bending radius section with the straight section, a large relative bending radius section without the straight section and a continuous variable curvature bending section, and determining the positions of binding points of different characteristic sections.

Second, for a small bending radius section with a straight section, the coordinates (x) of the axial center position of the end of the clamping die corresponding to each feature of the wrap-around forming device 41 in the wrap-around forming system 4 are obtained_l，y_m，z_n) The curve of the rotational angle (alpha-t), the curve of the bending angle (beta-t) and the curve of the axial displacement distance (L-t) of the bending die are set around the bending forming device 41. For the large bending radius section with straight section/the large relative bending radius section without straight section/the continuous variable curvature bending section, the central position coordinate (x) of the bending mould of each characteristic corresponding to the free bending forming system 1 is obtained_i，y_j，z_k) Bending angle and time (theta-t), torsion angle and timeAn equal relation curve; the curve of the rotation angle of the hollow tube 3 with respect to time (α -t) and the curve of the feeding distance of the hollow tube 3 with respect to time (S-t) are held by the wrap-around forming device 41.

Thirdly, the various process parameters are respectively transmitted to a robot motion control system, a bending forming device control system and an external clamping and guiding control system. The robot motion control system determines the spatial motion track of each robot in each stage according to the spatial coordinates and the distance-time (S-t, L-t) relation curve of each characteristic point, and the bending forming device control system determines the bending angle and time (theta-t) of the free bending forming device 13 and the torsion angle and time of the free bending forming device 13 according to the bending angle and time (theta-t) of the free bending forming device 13An equal relation curve; the free bending/bending composite forming process curve is determined by various relation curves such as the rotation angle and time (alpha-t) of the bending forming device 41, the bending angle and time (beta-t) of the bending die and the like, and the external clamping and guiding control system determines a switching node of the clamping/guiding function according to the obtained composite process curve.

Fourthly, the pipe blank 3 is clamped by the bending forming system 4 and conveyed to the external clamping guide device 2, and the external clamping guide device 2 clamps or guides the pipe blank 3.

And fifthly, cooperatively controlling the robot motion control system, the bending forming device control system and the external clamping guide control system to finally finish the free bending/twisting composite bending forming of the target pipe fitting. For the small bending radius section with the straight section, a bending forming process is adopted, the external clamping guide device 2 clamps the tube blank 3, and the bending forming device 41 bends the tube blank 3. For a large bending radius section with a straight section/a large opposite bending radius section without a straight section/a continuous variable curvature bending section, a free bending forming process is adopted, the external clamping and guiding device 2 loosens the tube blank 3 to play a guiding role, the round bending forming device 41 moves to the other end of the tube blank 3 to clamp the tube blank 3, feeding of the tube blank 3 is carried out, and the free bending forming device 13 carries out free bending forming on the tube blank 3.

Sixthly, after the bending forming is finished, the external clamping guide device 2 is opened;

seventh, the wrap-around forming system 4 again grips the forming member to place it at a designated position, followed by the bending forming of the next tube blank 3.

It will be understood that modifications and variations can be made by persons skilled in the art in light of the above teachings and all such modifications and variations are intended to be included within the scope of the invention as defined in the appended claims.