CN113042572A - Modular clamping and correcting device and method for aviation stringer - Google Patents

Abstract

Translated fromChinese

本发明一种航空长桁件模块化装夹校形装置与装夹方法属于装夹技术领域，涉及一种航空长桁件模块化装夹校形装置与装夹方法，实现航空长桁件的自动装夹校形。该装置由底板、定位块、夹持块、滑台、导轨、丝杠座、丝杠、手轮、弹性软膜、型腔、磁流变液、电磁铁组成。该方法采用模块化的装夹校形装置进行装夹，并根据实际需要对模块化装置进行组合，构建组合工装。采用位置可调节结构进行调整；采用磁流变液作为施力介质，可与工件紧密贴合，增加了装夹刚度，有效的减少了零件加工中的震颤。本发明模块化的工装和可调节的设计，增加了夹具工装的通用性，可适应不同型号零件在加工制造中的装夹需求，实现了航空长桁件的自动装夹和校形。

The invention discloses a modular clamping and shape-correcting device and a clamping method for an aviation long truss, belonging to the technical field of clamping, and relates to a modular clamping and shape-correcting device and a clamping method for an aviation long truss, which realizes the automatic installation of the aviation long truss. Clip shape. The device consists of a base plate, a positioning block, a clamping block, a sliding table, a guide rail, a lead screw seat, a lead screw, a hand wheel, an elastic soft film, a cavity, a magnetorheological fluid, and an electromagnet. In the method, a modular clamping and correcting device is used for clamping, and the modular devices are combined according to actual needs to construct a combined tooling. The position-adjustable structure is used for adjustment; the magnetorheological fluid is used as the force medium, which can closely fit the workpiece, increase the stiffness of the clamping, and effectively reduce the vibration in the processing of the parts. The modularized tooling and adjustable design of the present invention increase the versatility of the fixture tooling, can adapt to the clamping requirements of different types of parts in processing and manufacturing, and realize the automatic clamping and shape correction of the aviation long truss.

Description

Modular clamping and correcting device and method for aviation stringer

Technical Field

The invention belongs to the technical field of clamping, and relates to a modular clamping and shape correcting device and a clamping method for an aviation stringer, which are used for realizing automatic clamping and shape correcting of the aviation stringer.

Background

The stringer serves as an important bearing and connecting piece and is widely applied to aviation equipment, the parts are generally made of lighter aluminum-lithium alloy or aluminum-magnesium alloy profiles serving as base materials through numerical control machining of upper and lower molded surfaces and flanges of the parts, the processing quality of the parts serving as important aviation parts directly influences the overall quality and service life of the aviation equipment, and therefore the parts have high requirements on processing precision, the parts belong to thin-wall parts and are soft in material and easy to deform, the parts serving as a core link influencing the final processing geometric precision of the parts ensure reliable clamping and shape correction in the aviation stringer numerical control processing process.

In actual production, the web of the stringer is generally clamped by a wedge block ejection mechanism, an operator needs to manually screw a wedge block screw to clamp and unload a workpiece, and after the workpiece is clamped, the deviation of the whole workpiece blank on the straightness is corrected by means of striking a table and adjusting the wedge block screw. The traditional fixture tool and the clamping method have the advantages that the production auxiliary time is long, the labor intensity of workers is high, due to manual operation, the clamping force is not controllable, an indentation is easily formed on the clamping surface of a part, the fixture tool and the part are difficult to be tightly attached, vibration is generated during machining, and the final machining precision is influenced.

In 2018, Chongqing university of science and engineering discloses a flexible clamp based on magnetorheological fluid in a patent CN 208811949U, and through the cooperation of a plurality of clamp arms, the clamp can effectively clamp a special-shaped workpiece, and has better clamping effect and stronger stability on the special-shaped workpiece, but is not suitable for clamping a long truss piece. In 2014, the limited liability company of Yutai machinery in Tianjin discloses an I-steel clamping device in a patent CN204053517U, the clamping device adopts a gear and rack transmission mechanism to apply force to a workpiece for clamping, the structure is simple, and the clamping device is only suitable for steel with good rigidity and difficult deformation.

Disclosure of Invention

The invention mainly solves the technical problems of overcoming the defects of the method and inventing a modularized clamping and correcting device and a clamping method for an aviation stringer aiming at the clamping problem of the aviation stringer in numerical control processing. The device takes magnetorheological fluid as a force application medium, flexibly fills a clamping gap by utilizing the excellent flow characteristic of the magnetorheological fluid, realizes the tight fit of the magnetorheological fluid and the clamping surface of a part, converts the magnetorheological fluid into a solid-like form by applying a magnetic field, forms a particle chain along the direction of the magnetic field to extrude a workpiece, realizes the automatic clamping of the part, and applies larger clamping force to the local deformation area of the part by changing the size of the magnetic field, thereby realizing the shape correction of the part.

The technical scheme adopted by the invention is that the aviation stringer modularization clamping and correcting device is characterized by comprising abase plate 1, apositioning block 2, aclamping block 3, a sliding table 4, aguide rail 5, alead screw seat 6, alead screw 7, ahand wheel 8, an elasticsoft film 9, acavity 10,magnetorheological fluid 11 and an electromagnet 12; thebottom plate 1 plays a role in supporting the whole device, and bolt holes are arranged in four corner areas of thebottom plate 1 and are fixedly connected with a machine tool workbench; thepositioning block 2 is fixed on thebottom plate 1 through a bolt, and is attached to a web plate of the aviation stringer and the inner surface of a flange to be processed during clamping, so that the part is positioned; theclamping block 3 is arranged on the sliding table 4 and is opposite to thepositioning block 2, clamping force is applied to the other side of the part web plate, and thepart 13 is clamped. Theguide rail 5 is arranged on thebottom plate 1, and the sliding table 4 and theguide rail 5 form a linear motion pair to limit theclamping block 3; thelead screw seat 6 is fixed on thebottom plate 1, thelead screw 7 is arranged in thelead screw seat 6, and thehand wheel 8 is fixedly connected with one end of thelead screw 7; according to different thicknesses of webs of clamped parts, the positions of theclamping blocks 3 are adjusted by rotating thehand wheel 8 to rotate thelead screw 7.

Thepositioning block 2 and theclamping block 3 are internally provided with electromagnets 12, the two electromagnets 12 are oppositely arranged, and a power supply is turned on during processing, so that a large magnetic field vertically penetrating through the thin-wall part 13 can be obtained. The elasticsoft film 9 is used as a clamping surface of theclamping block 3 and can be flexibly attached to the surface of a web plate of thepart 13, thecavity 10 behind the elasticsoft film 9 is used for storing themagnetorheological fluid 11, after a magnetic field is applied, themagnetorheological fluid 11 is excited and solidified into a chain along the direction of the magnetic field under the action of the magnetic field, and the web plate of thepart 13 is extruded.

In order to reduce the loss of the magnetic field intensity generated by the electromagnet and enable the magnetorheological fluid to obtain a stronger magnetic field, thebottom plate 1 and the sliding table 4 are designed to be used as magnetic yokes, Q235 steel with higher relative permeability is used, the magnetic resistance is smaller, magnetic induction lines form a loop through the magnetic yokes, and the magnetic leakage is less. The iron core of the electromagnet 12 is made of electrical pure iron DT4C, and the electromagnet is good in electromagnetic performance, stable in magnetism and free of magnetic aging; thepositioning block 2 and theclamping block 3 are made of Q235 steel, and the horizontal penetration of a magnetic field is facilitated.

A clamping method for an aviation stringer modularization device is characterized in that a modularization clamping and shape correcting device is adopted for clamping, and modularization devices are combined according to actual needs to construct a combined tool; adjusting by adopting a position adjustable structure; magnetorheological fluid is used as a force application medium and can be tightly attached to a workpiece, so that the clamping rigidity is increased, and the vibration in part processing is effectively reduced; the specific clamping process comprises the following steps:

firstly, placing a plurality of groups of modularized clamping and shape correcting devices on a machine tool workbench, arranging and installing the devices in an array manner, and fixing each device with the workbench through bolts; according to the type of the part to be processed, thelead screw 7 of each modular device is rotated through thehand wheel 8, theclamping block 3 is driven to move along theguide rail 5 and adjusted to a proper position, and therefore when the part is installed, the elasticsoft film 9 can be tightly attached to a web plate of thepart 13 along the shape; then, setting the initial current according to the clamping force required by part processing to ensure that the magnetorheological fluid can provide enough extrusion force to clamp the web of the part under the excitation curing action of the transverse magnetic field provided by the electromagnet, and stably clamping the part; the specific steps of part clamping are as follows:

after the preparation work is finished, thepart 13 is put in from one end of the combined tool, so that the inner surface of the flange to be processed of thepart 13 and a web plate on one side are tightly attached to thepositioning block 4, and the elasticsoft film 9 is tightly attached to the web plate on the other side of thepart 13 along with the shape;

turning on a power switch of the electromagnet, and generating a transverse magnetic field by the electromagnet 12 arranged in a contra-polar manner in thepositioning block 2 and theclamping block 3 to enable themagnetorheological fluid 11 in thecavity 10 to extrude the part under the excitation curing action of the magnetic field, so that the aim of clamping the part is fulfilled;

step three, after each module clamps the part, the overall straightness of the part is measured by striking a meter, the current of the clamping module corresponding to the area is correspondingly increased for the position where the local straightness of the part does not reach the standard, so as to increase the clamping force of theclamping block 3 on thepart 13 to correct the deformation of thepart 13 in the area, and after the overall straightness of the workpiece obtained by measuring the striking a meter meets the clamping requirement, the clamping is completed;

after the clamping is finished, machining thepart 13; after the processing is finished, the power supply of the electromagnet 12 is turned off, the transverse magnetic field generated by the electromagnet disappears, themagnetorheological fluid 11 is recovered to be in a liquid state, the clamping force is removed, and the part is taken down from the end part of the combined tool.

The fixture tool has the advantages that the modularized tool and the position adjustable design are adopted, the universality of the fixture tool is improved, and the fixture tool can meet the clamping requirements of parts of different models in machining and manufacturing. Magnetorheological fluid is used as a force application medium, and can be tightly attached to a part, so that the clamping rigidity is increased, and the vibration in part processing is effectively reduced. Through the adjustment electric current size, change magnetic field intensity, and then can adjust clamping force, realize that the clamping is automatic and clamping force is controllable, solved the problem that intensity of labour is high, production auxiliary time is long and the part damage that artifical clamping exists. The electricity is used as the drive, the demand on other power sources is avoided, the adaptability of the clamping module to the application environment is improved, and the machining efficiency and the quality of parts are improved.

Drawings

Fig. 1 is a schematic structural view of a modular clamping and correcting device. The device comprises abase plate 1, apositioning block 2, aclamping block 3, a sliding table 4, aguide rail 5, ascrew rod seat 6, ascrew rod 7 and ahand wheel 8.

Fig. 2-internal structure view of the modular clamping and shape correcting device. The device comprises a positioning block, a clamping block, an elastic soft film, a cavity, a magnetorheological fluid, a magnetic fluid, a mold cavity, a magnetic fluid, an electromagnet and a part, wherein the positioning block is 2, the clamping block is 3, the elastic soft film is 9, the mold cavity is 10, the magnetorheological fluid is 11.

Fig. 3-schematic view of the combined tool for machining parts. Module I-1, module II-2, module III-3, module IV-4, 13-part.

Detailed Description

The detailed description of the embodiments of the invention is provided with the accompanying drawings and technical solutions.

The carbonyl iron powder magnetorheological fluid in the embodiment is prepared from 40 volume percent of carbonyl iron powder and 60 volume percent of silicone oil, and the density is 3.55 g/ml. The long purlin piece of aviation of treating processing is aluminium magnesium alloy material, and web thickness is about 1mm, and length size is 1200 mm. Firstly, 4 groups of the modularized assembling clampshape correcting device 1, 2, 3 and 4 modules I, II and IV are placed on a machine tool workbench and arranged in an array manner to form a tool for processing parts, as shown in figure 3. Each module is fixedly connected with a machine tool workbench through a bolt.

Thebottom plate 1, thepositioning block 2, theclamping block 3 and the sliding table 4 are made of Q235 steel. The iron core of the electromagnet 12 is made of electrical pure iron DT 4C.

The modularized clamping and shape correcting device designed by the invention consists of abottom plate 1, apositioning block 2, aclamping block 3, a sliding table 4, aguide rail 5, ascrew rod seat 6, ascrew rod 7, ahand wheel 8, an elasticsoft film 9, acavity 10, 11 magnetorheological fluid and an electromagnet 12, and is shown in the figure 1 and the figure 2. The four corners of thebottom plate 1 are provided with bolt holes which are fixedly connected with a machine tool workbench through bolts. Thepositioning block 2 is fixed on thebottom plate 1 through bolts, and is attached to the inner surface of a flange of a part to be processed with a web plate of the aviation stringer during clamping, so that the part is positioned. Theclamping block 3 is arranged on the sliding table 4 and is opposite to thepositioning block 2, and clamping force is applied to the other side of the part web plate to clamp the part. The sliding table 4 and theguide rail 5 form a linear motion pair to adjust and limit theclamping block 3. Thelead screw seat 6 is fixed on thebottom plate 1, thelead screw 7 is installed in thelead screw seat 6, and thehand wheel 8 is fixedly connected with one end of thelead screw 7. According to different thicknesses of webs of the clamped parts, the positions of theclamping blocks 3 are adjusted by rotating thehand wheel 8 to rotate thelead screw 7, so that the elasticsoft film 9 can be tightly attached to the webs of the parts along with the shape when the parts are loaded.

Thepositioning block 2 and theclamping block 3 are internally provided with electromagnets 12, the two electromagnets 12 are oppositely arranged, and a power supply is turned on during processing, so that a large magnetic field vertically penetrating through the thin-wall part 13 can be obtained. The elasticsoft film 9 is used as a clamping surface of theclamping block 3 and can be flexibly attached to the surface of a web plate of thepart 13, thecavity 10 behind the elasticsoft film 9 is used for storing themagnetorheological fluid 11, after a magnetic field is applied, themagnetorheological fluid 11 is excited and solidified into a chain along the direction of the magnetic field under the action of the magnetic field, and the web plate of thepart 13 is extruded.

The clamping and correcting method comprises the following specific steps:

step one, a part is put into the combined tool from one end of the combined tool, so that the inner surface of the flange to be processed of the part and a web plate on one side are tightly attached to thepositioning block 4, and the elasticsoft film 9 is tightly attached to the web plate on the other side of the part along with the shape.

And step two, turning on a power switch of the electromagnet and clamping thepart 13.

Step three, measuring the integral straightness of the workpiece by a meter, and entering step five if the straightness meets the requirement; and if the local straightness does not meet the requirement, entering the step four.

And step four, correspondingly increasing the current of the clamping module corresponding to the area to increase the clamping force of theclamping block 3 on thepart 13 to correct the local deformation of the part, and entering step three.

And step five, after clamping and correcting are completed, machining the part.

And step six, after the machining is finished, closing a power supply of the electromagnet, and taking down the part from the end part of the combined tool.

The modular clamping and shape correcting device and method for the aviation stringer realize automatic clamping and shape correction of the aviation stringer, and improve the processing efficiency and quality of parts.

Claims (2)

1. A modularization clamping and shape correcting device for an aviation stringer is characterized by comprising a bottom plate (1), a positioning block (2), a clamping block (3), a sliding table (4), a guide rail (5), a lead screw seat (6), a lead screw (7), a hand wheel (8), an elastic soft film (9), a cavity (10), magnetorheological fluid (11) and an electromagnet (12); the bottom plate (1) is provided with bolt holes in four corner areas to be connected and fixed with a machine tool workbench; the positioning block (2) is fixed on the bottom plate (1) through a bolt, and is attached to a web plate of the aviation long truss piece and the inner surface of a flange to be processed during clamping to position the part (13); the clamping block (3) is arranged on the sliding table (4) and is opposite to the positioning block (2), and clamping force is applied to the other side of the web plate of the part (13) to clamp the part (13); the guide rail (5) is arranged on the bottom plate (1), and the sliding table (4) and the guide rail (5) form a linear motion pair to limit the clamping block (3); the screw seat (6) is fixed on the bottom plate (1), the screw (7) is installed in the screw seat (6), and the hand wheel (8) is fixedly connected with one end of the screw (7); according to different thicknesses of webs of the clamped parts, the positions of the clamping blocks (3) are adjusted by rotating a hand wheel (8) to rotate a lead screw (7);

electromagnets (12) are arranged in the positioning block (2) and the clamping block (3) respectively, and the two electromagnets (12) are arranged in an antipodal mode; during processing, a power supply is turned on, and a large magnetic field which vertically penetrates through the thin-wall part (12) can be obtained; the elastic soft film (9) is used as a clamping surface of the clamping block (3) and can be flexibly attached to the surface of a web plate of the part (13), a cavity (10) behind the elastic soft film (9) is used for storing magnetorheological fluid (11), after a magnetic field is applied, the magnetorheological fluid (11) is excited and solidified into a chain along the direction of the magnetic field under the action of the magnetic field, and the web plate of the part (13) is extruded;

in order to reduce the loss of the magnetic field intensity generated by the electromagnet and enable the magnetorheological fluid to obtain a stronger magnetic field, the bottom plate (1) and the sliding table (4) are designed to be used as magnetic yokes, Q235 steel with higher relative permeability is used, the magnetic resistance is smaller, magnetic induction lines form a loop through the magnetic yokes, and the magnetic leakage is less; the iron core of the electromagnet (12) is made of electrical pure iron DT4C, and the electromagnet is good in electromagnetic performance, stable in magnetism and free of magnetic aging; the positioning block (2) and the clamping block (3) are made of Q235 steel, and the horizontal penetration of a magnetic field is facilitated.

2. A modular clamping method for an aviation stringer is characterized in that a modular clamping and correcting device is adopted for clamping, and the modular device is combined according to actual needs to construct a combined tool; adjusting by adopting a position adjustable structure; magnetorheological fluid is used as a force application medium and can be tightly attached to a workpiece, so that the clamping rigidity is increased, and the vibration in part processing is effectively reduced; the specific clamping process comprises the following steps:

firstly, arranging and installing a plurality of groups of clamping and shape correcting devices on a machine tool workbench in an array manner, and fixing the clamping and shape correcting devices with the workbench through bolts; according to the type of the part to be processed, rotating a lead screw (7) by rotating each set of hand wheels (8) to drive a clamping block (3) to move along a guide rail (5) and adjust to a proper position; so as to ensure that the elastic soft film (9) can be tightly attached to the web plate of the part (13) along with the shape when the part is loaded; setting the initial current according to the clamping force required by part processing to ensure that the magnetorheological fluid (11) can provide enough extrusion force to clamp the web of the part under the excitation curing action of the transverse magnetic field provided by the electromagnet, and stably clamping the part; the specific steps of part clamping are as follows:

after the preparation work is finished, a part (13) is put into the combined tool from one end of the combined tool, so that the inner surface of the flange to be processed of the part and a web plate on one side are tightly attached to the positioning block (4), and the elastic soft film (9) is tightly attached to the web plate on the other side of the part (13) along the shape;

secondly, a power switch of the electromagnet is turned on, the electromagnet arranged in a contra-polar mode in the positioning block (2) and the clamping block (3) generates a transverse magnetic field, and the magnetorheological fluid (11) in the cavity (10) extrudes the part under the excitation curing action of the magnetic field, so that the purpose of clamping the part is achieved;

thirdly, after each module clamps the part, the overall straightness of the part is measured by a meter to reflect the overall deformation condition of the part, and the current of the clamping module corresponding to the area is correspondingly increased for the position of the part with local straightness not reaching the standard so as to increase the clamping force of the clamping block (3) on the part to correct the deformation of the part in the area;

after the clamping is finished, machining the part (13); after the processing is finished, the power supply of the electromagnet is turned off, the transverse magnetic field generated by the electromagnet disappears, the magnetorheological fluid is recovered to be in a liquid state, the clamping force is removed, and the part is taken down from the end part of the combined tool.

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