阅读说明：本技术 一种柔性支撑芯棒、支撑装置及弯管机器人成形控制方法 (Flexible support core rod, support device and pipe bending robot forming control method ) 是由 郑�硕 刘春梅 郭训忠 于 2021-09-06 设计创作，主要内容包括：本发明公开了一种柔性支撑芯棒、支撑装置及弯管机器人成形控制方法,所述芯棒包括芯头、芯尾,所述芯头为橡胶材质,其在气压作用下体积会增大,其从外往内共两层,分别为疏松多孔橡胶层和原始橡胶层。通过牵引伺服电机、牵引轮、牵引线与芯棒的结构解决了机器人弯管成形过程中无法加入芯棒的问题,且芯棒的芯头采用疏松多孔橡胶层,便于芯棒抽芯与弯曲成形过程中的润滑作用；通过气压控制系统、进气线、芯棒组成的气压可控式充气芯棒结构实现了管材弯曲成形时弯曲段内部支撑力可调,可有效改善机器人弯管成形过程中管材发生截面畸变、失稳及破裂等缺陷,提高了管材的成形性能。(The invention discloses a flexible supporting core rod, a supporting device and a pipe bending robot forming control method. The problem that the core rod cannot be added in the bending forming process of the robot is solved through the structure of the traction servo motor, the traction wheel, the traction wire and the core rod, and the core head of the core rod adopts the loose porous rubber layer, so that the core rod is convenient to loose core and lubricate in the bending forming process; the air pressure controllable type inflatable core rod structure composed of the air pressure control system, the air inlet wire and the core rod realizes that the internal supporting force of the bending section is adjustable when the pipe is bent and formed, can effectively overcome the defects of cross section distortion, instability, breakage and the like of the pipe in the pipe bending and forming process of the robot, and improves the forming performance of the pipe.)

1. The flexible supporting core rod for the elbow is characterized by comprising a core head (31) and a core tail (32), wherein the core tail (32) seals a cavity in the core head, an air inlet is formed in the core tail (32), the air inlet is in airtight connection with one end of an air inlet pipe (6), the other end of the air inlet pipe (6) is connected to an air pressure control system (9), the pressure of the cavity in the core head (31) is controlled through the air pressure control system, the expansion volume of the core head (3) is further controlled, the core tail (32) is further fixedly connected with a traction wire (7), and the traction wire (7) is driven by a traction servo motor (2) to drag the core head (31) and the core tail (32) to move freely in a single direction in a pipe; the core print is made of rubber, the volume of the core print can be increased under the action of air pressure, and the core print is divided into two layers from outside to inside, namely a loose porous rubber layer and an original rubber layer.

2. The flexible supporting core rod for the elbow pipe according to claim 1, wherein the loose porous rubber layer is of a loose porous structure, and lubricating oil can be stored in the loose porous rubber layer to be directly contacted with the inner wall of the pipe, so that the internal lubrication is performed when the pipe is bent, and the position movement of the core rod is facilitated.

3. The mandrel of claim 1 wherein said primary rubber layer is a solid structure which is in direct contact with the gas.

4. The flexible support mandrel for an elbow pipe as set forth in claim 1, wherein said mandrel tail is of a metallic material.

5. The flexible supporting device for flexibly supporting the core rod is characterized by comprising a supporting base (1), a traction servo motor (2), a clamping mechanism (5), the core rod (3), an air inlet pipe (6), a traction wire (7), a guide mechanism (8) and an air pressure control system (9); the top of the supporting base is provided with a clamping mechanism (5), and the middle of the supporting base is provided with a traction servo motor (2) and a guide mechanism (8); the clamping mechanism (5) is arranged at the top of the supporting base and used for clamping the pipe; the guide mechanism comprises a driving guide wheel, a driven guide wheel and a traction wheel, wherein the driving guide wheel is connected with a traction servo motor, and a circle of semicircular groove is formed in the driving guide wheel and used for guiding the air inlet pipe; the driven guide wheel is arranged in the middle of the supporting base, is horizontally parallel to the driving guide wheel and can freely rotate, and is provided with a groove which is the same as the driving guide wheel and is used for guiding the air inlet pipe by matching with the driving guide wheel; the traction wheel is connected with the traction servo motor, coaxial with the driving guide wheel and the like in diameter, and is fixedly wound with a traction wire so as to ensure that the speeds of the traction wire and the movement wire of the air inlet pipe driven by the traction servo motor are equal; and the traction servo motor is connected with the driving guide wheel and the traction wheel through a speed reducer and is used for controlling the position of the core rod in the pipe.

6. The flexible support device of claim 5, wherein the air inlet tube is connected to the mandrel at one end and connected to an air pressure control system at the other end for transmitting a specified air pressure into the mandrel.

7. The flexible support device of claim 5, wherein the pulling wire is connected to the mandrel at one end and is fixedly connected to the pulling wheel at the other end for driving the mandrel to move in the tube.

8. The flexible supporting device according to claim 5, wherein the air pressure control system is connected with the mandrel through an air inlet pipe, and can provide a stable, accurate and adjustable air pressure value for the mandrel during the bending forming of the tube.

9. A method for controlling the formation of a pipe bending robot for a flexible supporting means according to any one of claims 5 to 8, comprising the steps of:

(1) selecting a bending forming pipe for a pipe bending robot, and determining the yield strength sigma of the pipe material_sThe outer diameter D and the wall thickness delta of the pipe;

(2) measuring the three-dimensional model of the pipe part to obtain the 1 st straight section L₁Angle of bending theta₁Bending radius R₁2 nd straight section L₂Angle of bending theta₂Bending radius R₂The 3 rd straight section L₃Angle of bending theta₃Bending radius R₃… …, n-th straight section L_nAngle of bending theta_nBending radius R_nLast 1 straight section L_n+1And calculating the total length S of the required tube blank as follows:

(3) adjusting the extension distance of the core rod to be longer than S, lubricating the surface of the core rod, penetrating the core rod out of the pipe, then clamping the pipe by using a clamping mechanism, and adjusting the position of the core rod in the pipe by using a traction servo motor to ensure that a core head of the core rod leaks out of the pipe and a core tail just sinks into a pipe end, thereby completing the installation of the core rod and the pipe;

(4) the traction servo motor and the air pressure control system are connected with the robot control system, so that the robot control is realized to transmit the data information in the step (1) and the step (2) to the traction servo motor and the air pressure control system in real time;

(5) during forming, the traction servo motor controls a formula according to a traction distance: s_i＝L_i+θ_iR_i(ii) a Wherein S is_iFor the ith tractionDistance in mm; l is_iIs the ith straight section with the unit of mm; theta_iIs the ith bending angle in mm; r_iIs the ith bend radius in mm; drawing the mandrel to a first curved support position, and then the air pressure control system according to an air pressure control formula:wherein, P_iThe internal supporting pressure provided by the core rod during bending forming is N/mm²；σ_sIs the material yield strength of the pipe with the unit of N/mm²(ii) a k is an empirical coefficient and takes a value of 0.6-1; r_iIs the ith bend radius in mm; d is the outer diameter of the pipe, and the unit is mm; delta is the wall thickness of the pipe, and the unit is mm; p₀The air pressure value when the core rod is inflated and expanded to just contact the inner wall of the pipe is measured in the unit of N/mm²(ii) a Providing stable and accurate internal support pressure for the core rod, starting to execute a bending forming process by the pipe bending robot, and finally reducing the air pressure to 0N/mm by the air pressure control system²Separating the core rod from the inner wall of the pipe to complete the bending formation of the first bending section;

(6) and (5) repeating the step (5) to sequentially bend and form the subsequent bent sections until all the bent sections are bent and formed, and finally forming the designed bent component.

Technical Field

The invention relates to the technical field of flexible forming processing of a robot bent pipe, in particular to a flexible supporting core rod for a bent pipe, a supporting device and a method.

Background

The robot pipe bending forming technology is an important technological innovation for reducing production cost, improving production efficiency and precision and realizing intellectualization and digitization in recent years. The technology combines the traditional bending forming technology with a six-axis series robot, an end bending actuator is additionally arranged at the tail end of a robot arm, and the whole accurate and rapid forming of bent pipes with various spatial complex axes and small/multiple bending radius configurations is realized through the multi-axis coordinated motion of the end bending actuator and the robot arm, as shown in figure 1. Compared with the traditional bending method, the robot bending forming technology has the outstanding advantages of high flexibility, high forming efficiency, low production cost, wide product adaptability, high manufacturing precision and the like, the robot bending equipment has high degree of freedom, quick response and small occupied area, the cost of numerical control machines, molds and the like is reduced, and the robot bending forming technology is particularly suitable for aviation pipeline systems with the characteristics of compact structure, integral components, light weight and the like.

Because the pipe is mostly of a hollow structure, the pipe is easy to have the defects of instability and wrinkling of the inner wall, cross section distortion, even thinning and cracking of the outer wall and the like during the bending forming process, especially when a small-bending radius or thin-wall pipe is bent, and the bending forming quality is seriously influenced. At present, the traditional numerical control bending mostly adopts a forming mode of adding a core rod to solve the defects, because the position of a bending die is fixed and the position of the core rod is also fixed or adjustable in a bending section of the bending die in the traditional numerical control bending forming process, for example, patent CN109985942 discloses a flexible core pulling device of a numerical control pipe bender, but the bending position of the numerical control pipe bender is fixed, so the core rod in the device can only adjust the position of a core rod head in a pipe fitting in the bending section of the fixed bending position, so as to solve the problems of forming defects caused by unreasonable position control of the core rod head and overlarge extension of the core rod in the traditional numerical control bending process, but compared with the traditional numerical control bending forming process, the robot bending pipe always keeps fixed and the bending position is constantly changed due to the special processing forming mode, the bending die changes along with the movement of the robot, so the added core rod also needs to move along with the movement of the bending die, and the traditional core rod structure form for numerical control bending cannot be applied to the robot elbow forming technology.

Accordingly, the prior art is deficient and needs improvement.

Disclosure of Invention

Aiming at the defects in the prior art and the forming characteristics of the robot elbow forming technology, the invention provides the flexible supporting core rod for the elbow, the supporting device and the forming control method thereof, so that the flexible supporting core rod can accurately change along with the change of the bending point position of the bending die in the elbow forming process of the elbow robot, meanwhile, the flexible supporting core rod adopts a traction inflatable rubber structure, the surface of the inflatable rubber core rod is porous, lubricating oil is conveniently stored, the adjustable supporting force in the bending section during the bending forming of the pipe is realized, the assembly, the position adjustment and the disassembly of the core rod in the pipe are convenient, and the defects of the pipe such as section distortion, instability, breakage and the like in the elbow forming process of the robot can be effectively improved.

The invention is realized by the following technical scheme:

a flexible supporting core rod for a bent pipe comprises a core head 31 and a core tail 32, wherein the core tail 32 seals a cavity in the core head, an air inlet is formed in the core tail 32 and is hermetically connected with one end of an air inlet pipe 6, the other end of the air inlet pipe 6 is connected to an air pressure control system 9, the pressure of the cavity in the core head 31 is controlled through the air pressure control system, the expansion volume of the core head 3 is further controlled, the core tail 32 is fixedly connected with a traction wire 7, and the traction wire 7 is driven by a traction servo motor 2 to drag the core head 31 and the core tail 32 to move freely in a pipe in a unidirectional mode; the core print is made of rubber, the volume of the core print can be increased under the action of air pressure, and the core print is divided into two layers from outside to inside, namely a loose porous rubber layer and an original rubber layer.

The elbow is with flexible support plug, loose porous rubber layer is loose porous structure, and its inside can save lubricating oil and directly contact with the tubular product inner wall for inside lubrication when tubular product is crooked also makes things convenient for the position of plug to move simultaneously.

The elbow is with flexible support plug, primitive rubber layer is solid construction, and it directly contacts with gas.

The elbow is with flexible support plug, the core tail is the metal material.

The flexible supporting device based on any flexible supporting core rod comprises a supporting base 1, a traction servo motor 2, a clamping mechanism 5, a core rod 3, an air inlet pipe 6, a traction wire 7, a guide mechanism 8 and an air pressure control system 9; the top of the supporting base is provided with a clamping mechanism 5, and the middle part of the supporting base is provided with a traction servo motor 2 and a guide mechanism 8.

In the flexible supporting device, the clamping mechanism 5 is mounted at the top of the supporting base and used for clamping the pipe.

The flexible supporting device is characterized in that the guide mechanism comprises a driving guide wheel, a driven guide wheel and a traction wheel, the driving guide wheel is connected with a traction servo motor, and a circle of semicircular groove is formed in the driving guide wheel and used for guiding the air inlet pipe; the driven guide wheel is arranged in the middle of the supporting base, is horizontally parallel to the driving guide wheel and can freely rotate, and is provided with a groove which is the same as the driving guide wheel and is used for guiding the air inlet pipe by matching with the driving guide wheel; the traction wheel is connected with the traction servo motor, coaxial with the driving guide wheel and the like in diameter, and is fixedly wound with a traction wire so as to ensure that the speeds of the traction wire and the movement wire of the air inlet pipe driven by the traction servo motor are equal.

And the flexible supporting device is characterized in that the traction servo motor is connected with the driving guide wheel and the traction wheel through a speed reducer and is used for controlling the position of the core rod in the pipe.

One end of the air inlet pipe is connected with the core rod, and the other end of the air inlet pipe is connected with the air pressure control system and used for transmitting specified air pressure to the core rod.

One end of the traction wire is connected with the core rod, and the other end of the traction wire is fixedly connected to the traction wheel and used for driving the core rod to move in the pipe.

The flexible supporting device is characterized in that the air pressure control system is connected with the core rod through an air inlet pipe, and a stable, accurate and adjustable air pressure value can be provided for the core rod when the pipe is bent.

The pipe bending robot forming control method of any flexible supporting device comprises the following steps:

(1) selecting a bending forming pipe for a pipe bending robot, and determining the yield strength sigma of the pipe material_sThe outer diameter D and the wall thickness delta of the pipe;

(2) measuring the three-dimensional model of the pipe part to obtain the 1 st straight section L₁Angle of bending theta₁Bending radius R₁2 nd straight section L₂Angle of bending theta₂Bending radius R₂The 3 rd straight section L₃Angle of bending theta₃Bending radius R₃… …, n-th straight section L_nAngle of bending theta_nBending radius R_nLast 1 straight section L_n+1And calculating the total length S of the required tube blank as follows:

(3) adjusting the extension distance of the core rod to be longer than S, lubricating the surface of the core rod, penetrating the core rod out of the pipe, then clamping the pipe by using a clamping mechanism, and adjusting the position of the core rod in the pipe by using a traction servo motor to ensure that a core head of the core rod leaks out of the pipe and a core tail just sinks into a pipe end, thereby completing the installation of the core rod and the pipe;

(4) the traction servo motor and the air pressure control system are connected with the robot control system, so that the robot control is realized to transmit the data information in the step (1) and the step (2) to the traction servo motor and the air pressure control system in real time;

(5) during forming, the traction servo motor controls a formula according to a traction distance: s_i＝L_i+θ_iR_i(ii) a Wherein S is_iIs the ith traction distance in mm; l is_iIs the ith straight section with the unit of mm; theta_iIs the ith bending angle in mm; r_iIs the ith bend radius in mm; drawing the mandrel to a first curved support position, and then the air pressure control system according to an air pressure control formula:wherein, P_iThe internal supporting pressure provided by the core rod during bending forming is N/mm²；σ_sIs the material yield strength of the pipe with the unit of N/mm²(ii) a k is an empirical coefficient and takes a value of 0.6-1; r_iIs the ith bend radius in mm; d is the outer diameter of the pipe, and the unit is mm; delta is the wall thickness of the pipe, and the unit is mm; p₀The air pressure value when the core rod is inflated and expanded to just contact the inner wall of the pipe is measured in the unit of N/mm²(ii) a Providing stable and accurate internal support pressure for the core rod, starting to execute a bending forming process by the pipe bending robot, and finally reducing the air pressure to 0N/mm by the air pressure control system²Separating the core rod from the inner wall of the pipe to complete the bending formation of the first bending section;

(6) and (5) repeating the step (5) to sequentially bend and form the subsequent bent sections until all the bent sections are bent and formed, and finally forming the designed bent component.

Compared with the prior art, the invention has the following beneficial effects: the invention provides a flexible core rod supporting device for a pipe bending robot and a forming control method thereof, which solve the problem that a core rod cannot be added in the pipe bending forming process of the robot by the structure of a traction servo motor, a traction wheel, a traction wire and the core rod, and facilitate the core rod core pulling and lubricating action in the bending forming process by adopting a loose porous rubber layer for a core head of the core rod; the air pressure controllable type inflatable mandrel structure composed of the air pressure control system, the air inlet line and the mandrel realizes that the internal supporting force of a bending section is adjustable when a pipe is bent and formed, can effectively overcome the defects of cross section distortion, instability, breakage and the like of the pipe in the bending and forming process of the robot, improves the forming performance of the pipe, is more favorable for the installation and debugging of the mandrel, is convenient for core pulling after bending and forming, and further expands the application range of the bending and forming technology of the robot.

Drawings

FIG. 1 is a schematic diagram of a robotic elbow forming technique of the background art;

FIG. 2 is a partial cross-sectional view of a flexible mandrel device for a pipe bending robot;

FIG. 3 is a schematic view of a flexible mandrel device for a pipe bending robot;

FIG. 4 is a schematic view of a flexible mandrel;

FIG. 5 is a schematic representation of a three-dimensional model of a curved shaped part;

FIG. 6 is a schematic view of the flexible mandrel assembly position prior to forming;

in the figure: 1. the device comprises a supporting base, 2, a traction servo motor, 3, a core rod, 31, a core head, 311, a loose porous rubber layer, 312, an original rubber layer, 32, a core tail, 4, a pipe, 5, a clamping mechanism, 6, an air inlet pipe, 7, a traction wire, 8, a guide mechanism, 81, a driven guide wheel, 82, a driving guide wheel, 83, a traction wheel and 9, an air pressure control system, wherein the supporting base is fixedly connected with the core rod;

Detailed Description

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

As shown in fig. 2-6, a flexible supporting core rod device for a pipe bending robot is disclosed, which comprises a supporting base 1, a traction servo motor 2, a clamping mechanism 5, a core rod 3, an air inlet pipe 6, a traction wire 7, a guiding mechanism 8 and an air pressure control system 9. The top of the supporting base 1 is provided with a clamping mechanism 5, and the middle part of the supporting base is provided with a traction servo motor 2 and a guide mechanism 8.

The clamping mechanism 5 is arranged at the top of the supporting base 1 and used for clamping the pipe 4.

The guide mechanism 8 comprises a driving guide wheel 82, a driven guide wheel 81 and a traction wheel 83, wherein the driving guide wheel 82 is connected with the traction servo motor 2, and a circle of semicircular groove is formed in the driving guide wheel 82 and used for guiding the air inlet pipe 6; the driven guide wheel 81 is arranged in the middle of the support base 1, is horizontally parallel to the driving guide wheel 82, can freely rotate, is provided with a groove the same as the driving guide wheel 82, and is used for guiding the air inlet pipe 6 by matching with the driving guide wheel 82; the traction wheel 83 is connected with the traction servo motor 2, coaxial with the driving guide wheel 82 and the like in diameter, and is fixed with and wound with a traction wire 7, so that the speeds of the traction wire 7 and the movement line of the air inlet pipe 6 driven by the traction servo motor 2 are equal.

The traction servo motor 2 is connected with a driving guide wheel 82 and a traction wheel 83 through a speed reducer and is used for controlling the position of the core rod 3 in the pipe 4.

One end of the air inlet pipe 6 is connected with the core rod 3, and the other end of the air inlet pipe is connected with the air pressure control system 9 and used for transmitting specified air pressure to the core rod 3.

One end of the traction wire 7 is connected with the core rod 3, and the other end is fixedly connected with the traction wheel 83 and used for pulling the core rod 3 to move in the pipe 4 in a single direction.

The air pressure control system 9 is connected with the core rod 3 through the air inlet pipe 6, and can provide a stable, accurate and adjustable air pressure value for the core rod 3 when the pipe 4 is bent.

The core rod 3 comprises a core head 31 and a core tail 32, the core head 31 and the core tail 32 are connected with an air inlet pipe 6 and a traction wire 7, and the core rod can move in a single direction in the pipe 4 under the driving of a traction servo motor 2.

The core print 31 is made of rubber, the volume of the core print can be increased under the action of air pressure, and the core print has two layers from outside to inside, namely a loose porous rubber layer 311 and an original rubber layer 312.

The loose porous rubber layer 311 is of a loose porous structure, lubricating oil can be stored in the loose porous rubber layer and directly contacts with the inner wall of the pipe 4, the loose porous rubber layer is used for internal lubrication when the pipe 4 is bent, and meanwhile, the position of the core rod 3 is convenient to move.

The primary rubber layer 312 is a solid structure that is in direct contact with the gas and is used to provide internal support for the robotic elbow forming.

The core tail 32 is made of metal, is provided with connecting interfaces with the core head 31, the air inlet pipe 6 and the traction wire 7, and is provided with a sealing ring at each interface to ensure the air tightness of the core rod 3.

The invention relates to a forming control method of the flexible support core rod, which is characterized by comprising the following steps:

(1) selecting a bending forming pipe 4 for a pipe bending robot, and determining the yield strength sigma of the material of the pipe 4_sThe outer diameter D of the pipe 4 and the wall thickness delta of the pipe 4;

(2) measuring the three-dimensional model of the pipe 4 part, as shown in FIG. 5, to obtain the 1 st straight section L₁Angle of bending theta₁Bending radius R₁2 nd straight section L₂Angle of bending theta₂Bending radius R₂The 3 rd straight section L₃Angle of bending theta₃Bending radius R₃Last 1 straight section L₄And calculating the total length S of the required tube blank as follows:

(3) adjusting the extending distance of the core rod 3 to be longer than S, lubricating the surface of the core rod 3, penetrating the core rod 3 out of the pipe 4, clamping the pipe 4 by using a clamping mechanism 5, and adjusting the position of the core rod 3 in the pipe 4 by using a traction servo motor 2 to enable a core head 31 of the core rod 3 to be exposed out of the pipe and a core tail 32 to just sink into the pipe end, as shown in fig. 6, completing the installation of the core rod 3 and the pipe 4.

(4) The traction servo motor 2 and the air pressure control system 9 are connected with the robot control system, so that the robot control can transmit the data information in the step (1) and the step (2) to the traction servo motor 2 and the air pressure control system 9 in real time.

(5) During forming, the traction servo motor 2 controls the formula according to the traction distance: s_i＝L_i+θ_iR_i(wherein, S_iIs the ith traction distance in mm; l is_iIs the ith straight section with the unit of mm; theta_iIs the ith bending angle in mm; r_iIs the ith bend radius in mm; ) Pulling the mandrel 3 to the first bending support position, and then the pneumatic control system 9 according to the pneumatic control formula:(wherein, P_iThe internal supporting pressure provided by the core rod during bending forming is N/mm²；σ_sIs the material yield strength of the pipe with the unit of N/mm²(ii) a k is an empirical coefficient and takes a value of 0.6-1; r_iIs the ith bend radius in mm; d is the outer diameter of the pipe, and the unit is mm; delta is the wall thickness of the pipe, and the unit is mm; p₀The air pressure value when the core rod is inflated and expanded to just contact the inner wall of the pipe is measured in the unit of N/mm²(ii) a ) Providing stable and accurate internal supporting pressure for the core rod 3, starting to execute a bending forming process by the pipe bending robot, and finally reducing the air pressure to 0N/mm by the air pressure control system²And separating the core rod 3 from the inner wall of the pipe 4 to finish the bending forming of the first bending section.

(6) And (5) repeating the step (5) to sequentially carry out bending forming on the subsequent second and third bent sections, and finally forming the designed bent component.

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.