CN112414363A - Flexible positioning and detecting system and method for large-size easily-deformed part - Google Patents

Abstract

The application provides a flexible positioning and detecting system and method for large-size easily-deformed parts. Each group of devices are symmetrically arranged on two sides of a large-size easily-deformed part, the electric push rod device is quickly moved by using a precision guide rail along the length direction of the part, the electric push rod device can be moved to a specified position under the control of a computer, meanwhile, a push rod extends out of a specified length, and a pressure sensor ensures that the force applied by the push rod does not exceed a limit value so as to protect the part. The plane movement can ensure that the electric push rod device is quickly positioned to the maximum deformation position under the automatic control of a computer, and stably clamps parts on the basis of eliminating the elastic deformation of the parts.

Description

Flexible positioning and detecting system and method for large-size easily-deformed part

Technical Field

The invention relates to the field of three-dimensional digital measurement, in particular to a flexible positioning and detection system and method for large-size easily-deformed parts.

Background

In the machining of airplane parts, due to the influence of factors such as cutting force, uneven material removal, asymmetric structure and the like, the stress in the parts is redistributed, so that the parts are deformed differently, and particularly thin-wall slender beam parts and edge strip parts are typical. The quality control elements of the deformed parts are directly measured, so that a real and reliable measurement result cannot be obtained, and the measurement is meaningless. The accurate measurement degree can be achieved only by offsetting the deformation of the part to the maximum extent before measurement and enabling the part to recover to the original real state as far as possible and then measuring, so that whether the quality state meets the design function requirement or not is objectively evaluated.

The traditional solution method depends on manual experience and cannot be accurately controlled, namely, firstly, a wood hammer sleeved with rubber is used for slightly pushing a deformed part in the opposite direction of deformation, and a touch head of a dial indicator is used for contacting the deformed part; the part is then supported laterally with flat head threads to prevent spring back while being held in load-engaging compression against the upper surface of the part. In order to ensure the quality of the product and avoid the influence of the wooden hammer on the surface of the product, the wooden hammer needs to be repeatedly adjusted on site.

The problems of the existing detection means are poor repeated precision of force application installation and positioning and low detection efficiency. The difficulty in force application, installation and positioning is shown in large-size easily-deformed parts, and the deformation cannot be accurately and quantitatively described on the whole coordinate system of the parts by the traditional method, so that the results are different when different people operate or the same person operates for multiple times. The low detection efficiency is shown in the fact that the influence caused by manual operation is reduced to the maximum extent, repeated adjustment can be performed for multiple times in one measurement operation only until the requirements are finally met, and therefore time and labor are wasted, and efficiency is low.

Therefore, the following three main problems need to be solved in the prior art:

(1) when force is applied and positioning is carried out manually, the human error is large, and the accuracy and the reliability of a correction result are influenced;

(2) the force application and positioning are difficult to be adjusted in place at one time through manual operation, and repeated adjustment is needed for many times, so that the overall detection efficiency is low;

(3) the force application size cannot be effectively controlled during manual operation, and certain influence on the surface quality of the part can be caused.

Disclosure of Invention

In order to solve the problems, the invention provides a flexible positioning and detecting system and a flexible positioning and detecting method for large-size easily-deformed parts.

A flexible positioning and detection system for large-size easily-deformed parts comprises a plurality of groups of double-guide-rail sliding table mechanisms and an electric push rod mechanism, wherein each double-guide-rail sliding table mechanism comprises a ball screw, a smooth guide rail, a sliding table, a base, a limit stop, a coupler and a stepping motor; electric putter mechanism includes positioning baffle, electric putter, stabilize the clamp, connecting sleeve, pressure sensor, bear the support, it fixes on the slip table to bear the support, positioning baffle installs on bearing the support, the cooperation groove that bears the support is the dysmorphism groove, its shape, the size is unanimous with electric putter's the latter half's shape, in order to guarantee level and centering precision after the electric putter installation, electric putter installs at the cooperation inslot that bears the support and leans on tight positioning baffle, electric putter's outer end is only linear concertina movement and non-rotation concertina movement, inside is equipped with the outer end motion of screw mechanism drive push rod by motor drive, it compresses tightly fixedly electric putter to stabilize the clamp and install on bearing the support, connecting sleeve passes through the locating pin and installs the outermost end at electric putter, pressure sensor installs on connecting sleeve's outer terminal surface.

A flexible positioning and detecting method for large-size easily-deformed parts comprises the following steps:

step 1, returning the sliding table and the outer end head of the electric push rod to a zero position;

step 2, the computer judges the maximum deformation position and the maximum deformation of the part according to the single-side shape data of the part measured by the three-coordinate measuring machine;

step 3, converting the parameters into the position of the sliding table along the direction of the smooth guide rail and the extension amount of the outer end head of the electric push rod by the computer;

step 4, the computer controls the motor to rotate, drives the sliding table and the outer end head of the electric push rod to move to the designated position, and locks the mechanism;

step 5, in the above steps, if the pressure sensor judges that the pressure value exceeds the threshold value, the sliding table and the electric push rod return to the safe position, and the computer is instructed to recalculate;

step 6, repeating the steps 2 to 5 until the part is stably clamped and the deformation is corrected;

and 7, starting a normal measurement process by the three-coordinate measuring machine.

The invention symmetrically arranges each group of devices at two sides of a large-size easily-deformed part, utilizes a precise guide rail along the length direction of the part to quickly move the electric push rod device, under the control of a computer, the electric push rod device can move to a specified position, meanwhile, the push rod extends out of a specified length, and the pressure sensor ensures that the force applied by the push rod does not exceed a limit value so as to protect the part. The plane movement can ensure that the electric push rod device is quickly positioned to the maximum deformation position under the automatic control of a computer, and stably clamps parts on the basis of eliminating the elastic deformation of the parts. The beneficial effects of the method mainly comprise the following three points:

(1) the computer converts the maximum deformation amount and the deformation position into the preset target point position of the device and automatically runs, and the whole automatic process is accurate and reliable;

(2) the whole system is automatically controlled by a computer to carry out iterative debugging, manual intervention is not needed, the iteration times and single time consumption are far less than those of manual operation, and the overall detection efficiency can be obviously improved.

(3) The end pressure sensor ensures that the pressure value is always within the allowable range, and the surface of the part can be effectively protected.

Drawings

FIG. 1 is a schematic view of an overall flexible positioning and detection system

FIG. 2 is a schematic view of a flexible positioning and detecting device

FIG. 3 is a schematic diagram of a single-set structure of a flexible positioning and detecting device

The numbering in the figures illustrates: 1. a flexible positioning and detection device; 2. a standard platform; 11. a double-guide-rail sliding table mechanism; 12. an electric push rod mechanism; 111. a ball screw; 112. a smooth guide rail; 113. a sliding table; 114. a base; 115. a limit stop block; 116. a coupling; 117. a stepping motor; 121. positioning a baffle plate; 122. an electric push rod; 123. stabilizing the clamp; 124. a connecting sleeve; 125. a pressure sensor; 126. a bearing support;

Detailed Description

As shown in fig. 1-3, a flexible positioning and detecting system for large-size easily deformed parts comprises a plurality of sets of double-guide-rail sliding table mechanisms 11 and electric push rod mechanisms 12, wherein each double-guide-rail sliding table mechanism 11 comprises a ball screw 111, a smooth guide rail 112, a sliding table 113, a base 114, a limit stop 115, a coupling 116 and a stepping motor 117, the base 114 is fixed on a standard platform 2, the smooth guide rail 112 is fixed on the base 114 in parallel along a central axis, the ball screw 111 is arranged symmetrically on two sides of the central axis, the ball screw 111 is arranged on the base 114 along the central axis and can rotate along the central axis, the sliding table 113 is arranged on the smooth guide rail 112 and can move along the smooth guide rail 112 in cooperation with the ball screw 111, the stepping motor 117 is arranged on the base 114 and is connected with the ball screw 111 through the coupler 116, the ball screw 111 can be driven to rotate by the rotation of the stepping motor 117, and the limit stopper 115 is fixed on the base 114 to prevent the sliding table 113 from contacting with the coupler 116; the electric push rod mechanism 12 comprises a positioning baffle 121, an electric push rod 122, a stabilizing hoop 123, a connecting sleeve 124, a pressure sensor 125 and a bearing support 126, wherein the bearing support 126 is fixed on the sliding table 113, the positioning baffle 121 is installed on the bearing support 126 through bolts, a matching groove of the bearing support 126 is a special-shaped groove, the shape and the size of the matching groove are consistent with those of the lower half part of the electric push rod 122 so as to ensure the horizontal and centering accuracy after the electric push rod 122 is installed, the electric push rod 122 is installed in the matching groove of the bearing support 126 and is tightly close to the positioning baffle 121, the outer end head of the electric push rod 122 only makes linear telescopic motion but non-rotary telescopic motion, a screw mechanism driven by a motor is arranged inside to drive the outer end head of the push rod to move, the stabilizing hoop 123 is installed on the bearing support 126 through bolts to press and fix the electric push rod 122, the connecting, a pressure sensor 125 is mounted on the outer end face of the connecting sleeve 124.

A flexible positioning and detecting method for large-size easily-deformed parts comprises the following steps:

step 1, returning the sliding table 113 and the outer end of the electric push rod 122 to the zero point position;

step 2, the computer judges the maximum deformation position and the maximum deformation of the part according to the single-side shape data of the part measured by the three-coordinate measuring machine;

step 3, converting the parameters into the position of the sliding table 113 along the smooth guide rail 112 and the extension of the outer end of the electric push rod 122 by the computer;

step 4, the computer controls the motor to rotate, drives the sliding table 113 and the outer end of the electric push rod 122 to move to the designated position, and locks the mechanism;

step 5 in the above steps, if the pressure sensor 125 determines that the pressure value exceeds the threshold value, the sliding table 113 and the electric push rod 122 are retracted to the safe position, and the computer is instructed to recalculate;

step 6, repeating the steps 2 to 5 until the part is stably clamped and the deformation is corrected;

and 7, starting a normal measurement process by the three-coordinate measuring machine.

Claims (4)

1. A flexible positioning and detection system for large-size easily-deformed parts is characterized by comprising a plurality of groups of double-guide-rail sliding table mechanisms and electric push rod mechanisms, wherein the double-guide-rail sliding table mechanisms are longitudinally arranged along a standard platform and comprise ball screws, smooth guide rails, sliding tables, a base, limit stops, a coupler and a stepping motor; electric putter mechanism includes positioning baffle, electric putter, stabilize the clamp, connecting sleeve, pressure sensor, bear the support, it fixes on the slip table to bear the support, positioning baffle installs on bearing the support, electric putter installs in the cooperation inslot that bears the support and leans on positioning baffle, it compresses tightly fixedly electric putter to stabilize the clamp and install on bearing the support, connecting sleeve passes through the locating pin and installs the outermost end at electric putter, pressure sensor installs on connecting sleeve's outer terminal surface.

2. The system for flexibly positioning and detecting the large-size easily-deformed part as claimed in claim 1, wherein the outer end of the electric push rod only performs linear telescopic motion rather than rotary telescopic motion, and a screw mechanism driven by a motor is arranged inside the electric push rod to drive the outer end of the push rod to move.

3. The system as claimed in claim 1, wherein the engaging groove of the supporting seat is a shaped groove, the shape and size of which are consistent with those of the lower half portion of the electric push rod, so as to ensure the horizontal and centering accuracy of the electric push rod after installation.

4. A flexible positioning and detecting method for large-size easily-deformed parts is characterized by comprising the following steps:

step 1, returning the sliding table and the outer end head of the electric push rod to a zero position;

step 2, the computer judges the maximum deformation position and the maximum deformation of the part according to the single-side shape data of the part measured by the three-coordinate measuring machine;

step 3, converting the parameters into the position of the sliding table along the direction of the smooth guide rail and the extension amount of the outer end head of the electric push rod by the computer;

step 4, the computer controls the motor to rotate, drives the sliding table and the outer end head of the electric push rod to move to the designated position, and locks the mechanism;

step 5, in the above steps, if the pressure sensor judges that the pressure value exceeds the threshold value, the sliding table and the electric push rod return to the safe position, and the computer is instructed to recalculate;

step 6, repeating the steps 2 to 5 until the part is stably clamped and the deformation is corrected;

and 7, starting a normal measurement process by the three-coordinate measuring machine.

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