CN105128363B - A kind of system of the rebound phenomenon during solution composite material laying - Google Patents

Abstract

The invention relates to a system for solving the springback phenomenon in the process of laying composite materials, which is based on a torque/force sensor and a three-dimensional shape measurement system for solving the springback of prepreg tapes in the process of laying composite materials Phenomenon. The invention is based on a 6-axis robot platform, which is easy to realize the motion control of the tape laying head; a torque/force sensor is installed at the connection between the end of the robot and the tape laying head to detect the pressure of the main pressure roller of the tape laying head in real time, so as to ensure constant pressure paving as much as possible. It is used to prevent the springback phenomenon; it is equipped with a three-dimensional shape measurement system to reconstruct the contour of the workpiece, and the video detection technology is used for the quality control of the composite material laying process; the original tape laying head is equipped with an auxiliary Compaction device and auxiliary heating system. Under the heating of the auxiliary heating system, the auxiliary compaction device will re-compact the prepreg tape in the area where the springback phenomenon occurs, and minimize the probability of springback phenomenon, thereby achieving high quality and high quality. Efficient fully automatic laying.

Description

A system to solve the springback phenomenon in the process of laying up composite materials

technical field

The invention relates to a system for solving the springback phenomenon in the laying process of composite materials, which is used in the field of automatic laying of composite materials and solves the springback phenomenon generated in the laying process of prepreg tapes. Realize the fully automatic laying of composite materials in the true sense.

Background technique

Composite materials are more and more widely used in the field of aerospace, and show an irreplaceable important position.

Composite materials are represented by carbon fiber reinforced resin-based composite materials, which have outstanding advantages such as light weight, high strength, high modulus, fatigue resistance, corrosion resistance, integration of structure and function, integration of design and manufacturing, and easy forming of large components. The extensive application of advanced composite materials is an important way to improve the performance of aerospace vehicles, vehicles and weaponry, and its amount has become an important symbol of the advanced nature of aerospace vehicles.

Advanced composite materials have been widely used in the aerospace industry due to their excellent comprehensive properties, but the cost of advanced composite materials is much higher than that of metal materials, and high cost has become the main obstacle to the expansion of composite materials.

After years of hard work, a low-cost composite material technology system consisting of low-cost material technology, low-cost design and manufacturing technology, and maintenance technology has been formed. At present, the low-cost manufacturing technology of advanced composite materials mainly includes two categories: 1) RTM, VARTM and other technologies based on liquid molding; 2) fiber winding technology, pultrusion molding technology and automatic laying technology based on prepreg tape (material) forming . Among them, the automatic placement technology of composite materials is a key technology to increase the amount of composite materials, improve the level and efficiency of manufacturing technology, ensure product quality and reduce costs.

In foreign countries, automatic laying technology has been quite mature and widely used in actual production. Research on related technologies has also been carried out in China, and corresponding progress has been made, but there is still a long way from the actual engineering application, and there are indeed many problems to be solved. Among them, the springback phenomenon in the laying process of composite materials Just one aspect.

The springback phenomenon involved in the present invention mainly refers to that in the process of automatically laying curved workpieces, due to factors such as uneven pressure of the pressure rollers, the prepreg tape to be laid cannot be in contact with the mandrel or the laid surface. One layer of prepreg tapes are tightly bonded together, and finally due to the effect of tension, the prepreg tapes that have already been laid will spring up again, which is the so-called rebound phenomenon, as shown in Figure 3, where a is the core The surface of the mold or the prepreg tape that has been laid, b is the prepreg tape that produces the rebound phenomenon.

This springback is an important defect in the field of composite material laying. If it is not dealt with, it will seriously affect the quality of the final product, greatly increase the scrap rate, greatly increase the production cost, and seriously cause waste of resources. Most importantly, this Most of the workpieces produced by this method are used in the aviation field. If this potential quality defect is not detected, it will cause immeasurable losses. Therefore, it is very important to find a method to solve the springback phenomenon.

At present, the method of manual real-time monitoring and manual compaction is mainly used in China to solve the problem. It seems feasible, but in fact it is a semi-automatic laying, which violates the original intention of automatic laying, and at the same time increases the labor intensity of the staff. The most important It seriously affects the quality and efficiency of laying. Therefore, it is still of great significance to seek a method to prevent the springback phenomenon or detect whether it occurs after the springback phenomenon occurs, and to take corresponding measures to solve this phenomenon. research value.

Contents of the invention

The present invention mainly solves the technical problems existing in the prior art; it provides a fully automatic detection, analysis, and processing of the whole process, which basically does not require human participation, greatly reduces the cost of manpower and material resources, and significantly improves the laying quality and laying quality. A system that solves the rebound phenomenon in the process of laying composite materials.

Above-mentioned technical problem of the present invention is mainly solved by following technical scheme:

A system for solving the rebound phenomenon in the process of laying composite materials, characterized in that it includes a 6-axis robot, a tape laying head arranged on the 6-axis robot, a workpiece arranged under the tape laying head, a solid auxiliary compaction device and an auxiliary heating system; a three-dimensional shape measurement system is arranged above the workpiece;

Both the auxiliary compacting device and the auxiliary heating system are connected to the tape laying head and move together with the tape laying head. The auxiliary compacting device includes a cylinder with only one degree of freedom of up and down movement and an auxiliary pressure roller connected to the cylinder drive rod , the horizontal distance between the axis of the auxiliary pressure roller and the axis of the main pressure roller of the tape laying head should be greater than the product of the sum of the reaction time of the system and the time required for the rebound phenomenon to occur and the laying speed, that is, assuming that the distance is d, The laying speed is v, the time elapsed from the laying of the prepreg tape on the workpiece to the rebound phenomenon is t1, and the response time of the system is t2, then d>v*(t1+t2);

The auxiliary heating system is located between the main pressure roller and the auxiliary pressure roller, and is used to heat the prepreg tape under the auxiliary pressure roller. The tape is softened and the viscosity is enhanced, which is convenient for the auxiliary compaction device to re-compact the prepreg tape in the area where the rebound phenomenon occurs;

The 6-axis robot, the auxiliary compacting device and the auxiliary heating system are all connected to a controller;

The system also includes a force/torque sensor, installed at the connection between the end of the six-axis robot and the tape laying head, for real-time detection of the pressure between the main pressure roller and the workpiece during the laying process, so as to control the constant pressure laying and prevent springback At the same time, the three-dimensional shape measurement system performs three-dimensional shape measurement to detect whether springback has occurred, and then the controller starts the auxiliary compaction device and auxiliary heating system to solve the springback.

In the above-mentioned system for solving the rebound phenomenon in the process of laying composite materials, the three-dimensional shape measurement system is used for real-time feedback on the contour of the workpiece, and then the main controller sends signals to control the auxiliary heating system and auxiliary compaction The work of the device, the three-dimensional contour measurement system includes a sensor that constitutes a workpiece contour detection unit, and the sensor is a 3-dimensional laser range finder or a femtosecond laser-based 3-dimensional range finder or a two-dimensional grating or a binocular camera.

Therefore, the present invention has the following advantages: 1. Firstly, the constant tension laying is guaranteed by the feedback of the torque/force sensor, and the generation of springback phenomenon is prevented from the root cause, and then the small amplitude rebound that may still occur is eliminated by the auxiliary compacting device. Eliminate the spring phenomenon, which can basically completely solve the spring back phenomenon, thus ensuring the quality of the final product; 2. Since the whole process is completely automatic detection, analysis, and processing, basically no human participation is required, which greatly reduces the cost of manpower and material resources, and significantly The laying quality and laying efficiency are improved.

Description of drawings

Figure 1 is a schematic diagram of the structure of the entire system.

Fig. 2 is a three-dimensional structure diagram of the tape laying head in the present invention, which is used to illustrate the auxiliary compacting device.

Fig. 3 is a schematic diagram of the rebound phenomenon in the present invention.

Figure 4 is a schematic diagram of the re-compaction of the rebound area in the present invention.

detailed description

The technical solutions of the present invention will be further specifically described below through the embodiments and in conjunction with the accompanying drawings.

Example:

FIG. 1 is a schematic diagram of the overall structure of the entire system of the present invention. The torque/force sensor located at the connection between the end of the six-axis robot and the tape laying head detects the laying pressure of the main pressure roller in real time; the three-dimensional shape measurement system 106 gives real-time feedback to the contour of the workpiece 105, and then sends a signal control through the main controller as shown in Figure 4 The operation of the auxiliary heating system 104 and the auxiliary compaction device 103 is shown.

First, the tape laying head 102 is laid according to a predetermined trajectory driven by the six-axis robot 101. At the same time, the torque/force sensor connected to the end of the robot and the laying head detects the pressure of the main laying roller on the laying head in real time. And transmit the signal to the control system. After receiving the signal, the control system compares it with the pre-set pressure to judge whether there is a relatively large deviation, decide whether to adjust the pressure, and transmit the feedback signal to the cylinder. By adjusting the cylinder To adjust the pressure of the pressure roller, try to ensure a constant pressure during the laying process, that is, to ensure a good compaction effect, and prevent the springback phenomenon in principle.

At the same time, the three-dimensional shape measurement system 106 is used to detect the surface contour of the workpiece in real time, generate contour data and send it to the control system, compare and analyze it with the previously set contour, and accurately determine the area where the rebound phenomenon occurs, and then A command is issued to control the downward movement of the auxiliary compacting device 103, and at the same time, a command is issued to the auxiliary heating system 104 to heat the rebound area to soften the composite material in this area, which is convenient for the auxiliary compacting device to compact it. After the springback phenomenon is resolved, the auxiliary compacting device 103 is controlled to move upward, as shown in FIG. 4 , wherein 100 is the main roller; and then the normal laying motion is performed.

The axis of the pressing roller of the auxiliary compacting device 103 and the distance of the projection of the axis of the main pressing roller 100 on the horizontal plane d>v*(t1+t2), where v is the laying speed, and t1 is the response time of the system. If the system The response speed of t1 is fast enough to ignore t1, and t2 is the time required for the rebound phenomenon of the prepreg tape that has been laid on the mandrel; in this way, it can be guaranteed that the rebound that has been detected by the auxiliary compacting device 103 The prepreg tape in the region is completely compacted; the auxiliary heating system 104 uses high-temperature gas as a heat source, which can quickly heat the prepreg tape in the region where the springback phenomenon occurs, softening it and increasing its viscosity, thereby ensuring that the auxiliary compaction device 103 Under the action, there is an ideal compaction effect, which can completely eliminate the springback phenomenon in theory.

The present invention preferably uses a 3-dimensional laser rangefinder to directly obtain the 3-dimensional contour data of the workpiece, and proceed to the next step based on the data.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which the present invention belongs can make various modifications or supplements to the described specific embodiments or adopt similar methods to replace them, but they will not deviate from the spirit of the present invention or go beyond the definition of the appended claims range.

Claims (2)

1. A system for solving the rebound phenomenon in the process of laying composite materials, characterized in that it comprises a six-axis robot (101), a tape laying head (102) arranged on the six axis robot (101), a tape laying head arranged on The workpiece (105) below (102), an auxiliary compaction device (103) and an auxiliary heating system (104) for secondary compaction; a three-dimensional shape measurement system is provided above the workpiece (105) (106); Both the auxiliary compacting device (103) and the auxiliary heating system (104) are connected to the tape laying head (102) and move together with the tape laying head, and the auxiliary compacting device (103) includes a degree of freedom that only moves up and down The cylinder and the auxiliary pressure roller connected to the cylinder drive rod, the horizontal distance between the axis of the auxiliary pressure roller and the axis of the main pressure roller of the tape laying head (102) should be greater than the sum of the reaction time of the system and the time required for the rebound phenomenon to occur The product of the laying speed and the laying speed, that is, define the distance as d, the laying speed as v, the time elapsed from the laying of the prepreg tape on the workpiece to the rebound phenomenon is t1, and the response time of the system is t2, then d>v*(t1+t2); The auxiliary heating system (104) is located between the main pressing roller and the auxiliary pressing roller, and is used to heat the prepreg tape under the auxiliary pressing roller. The prepreg tape is softened and the viscosity is enhanced, which is convenient for the auxiliary compaction device to re-compact the prepreg tape in the area where the rebound phenomenon occurs; The six-axis robot (101), the auxiliary compacting device (103) and the auxiliary heating system (104) are all connected to a controller (107); The system also includes a force/torque sensor, installed at the connection between the end of the six-axis robot and the tape laying head, for real-time detection of the pressure between the main pressure roller and the workpiece during the laying process, so as to control the constant pressure laying and prevent springback At the same time, the three-dimensional shape measurement system (106) performs three-dimensional shape measurement to detect whether the rebound phenomenon occurs, and then starts the auxiliary compaction device (103) and auxiliary heating system (104) through the controller. To solve the rebound. 2. A kind of system according to claim 1 that solves the springback phenomenon in the process of laying composite materials, characterized in that, the three-dimensional shape measurement system (106) is used for real-time feedback to the workpiece profile, and then by The main controller sends signals to control the auxiliary heating system (104) and the auxiliary compaction device (103). or femtosecond laser-based 3D rangefinder or 2D grating or binocular camera.