WO2021120398A1

WO2021120398A1 - Automatic grinding system for car roof weld seam

Info

Publication number: WO2021120398A1
Application number: PCT/CN2020/077556
Authority: WO
Inventors: 汤旭东; 金爱龙; 潘宣军; 柏杨
Original assignee: 同高先进制造科技（太仓）有限公司
Priority date: 2019-12-20
Filing date: 2020-03-03
Publication date: 2021-06-24
Also published as: KR20210080281A; LU102257A1; LU102257B1; CN110842688A; KR102478681B1

Abstract

An automatic grinding system for a car roof weld seam, comprising an industrial robot (1), a grinding unit (2), and a grinding plate consumption monitoring unit (3). The grinding unit (2) is installed on the industrial robot (1); the grinding plate consumption monitoring unit (3) is electrically connected to the industrial robot (1); the industrial robot (1) drives the grinding unit (2) to carry out weld seam grinding; and after weld seam grinding is completed, the grinding plate consumption monitoring unit detects the grinding consumption of a grinding plate on the grinding unit (2), and is compared with initial data of the grinding plate; and if the consumption of the grinding plate exceeds a calibrated threshold, the industrial robot (1) automatically replaces the grinding plate. By means of an optimally designed floating module, constant and stable pressure and torque can be outputted, better ensuring grinding quality; a grinding plate detecting device can measure online the consumption of a grinding wheel and may automatically replace a grinding plate; in addition, a dust removing device can collect and remove grinding dust, thus ensuring the cleanliness and attractiveness of the weld seam, and the dust may also be prevented from being scattered in the air so as not to affect the human body.

Description

Automatic grinding system for roof weld

Technical field

The invention relates to a car roof polishing equipment, in particular to an automatic car roof welding seam polishing system.

Background technique

After laser welding on the body-in-white roof, a small amount of spatter will be generated during the welding process, which will cause uneven welds and slightly uneven welds after welding, which will affect the processing of the next procedure, resulting in poor weld formation. Beautiful, so the grinding treatment of the weld after welding is a necessary process. At present, the existing polishing equipment and polishing system, its polishing force, polishing speed and other process parameters are difficult to control, so the polishing quality is difficult to guarantee; secondly, in the polishing process, the real-time compensation of the polishing position cannot be realized, and the debugging requirements of the robot are required. The clamping and positioning requirements of tooling fixtures are relatively high. In addition, the dust removal hood in the existing polishing system cannot realize the self-adaptive adjustment of the Z axis according to the loss of the polishing pad, which not only affects the use frequency of the polishing pad, increases the cost, reduces the production efficiency, and it is difficult to control the dust dispersion, which causes damage to the human body. hurt.

Summary of the invention

Purpose of the invention: In order to solve the problems existing in the prior art, the purpose of the present invention is to provide an automatic roof welding seam grinding system that can detect the state of the grinding sheet in real time and can automatically replace the grinding sheet.

Technical solution: An automatic polishing system for car roof welds, including an industrial robot, a polishing unit and a polishing disc consumption monitoring unit. The polishing unit is installed on the industrial robot, and the polishing disc consumption monitoring unit is electrically connected to the industrial robot; the industrial robot drives the polishing unit Perform welding seam grinding. After the weld seam grinding is completed, the grinding disc monitoring unit detects the grinding consumption of the grinding disc on the grinding unit, and compares it with the initial data of the grinding disc. When the consumption of the grinding disc exceeds the calibrated threshold, the industrial robot Automatically replace the polishing pads.

Further, the polishing sheet consumption monitoring unit includes a photoelectric sensor, which is electrically connected to the industrial robot; each time the polishing unit completes a process, the industrial robot moves the polishing sheet close to the photoelectric sensor to detect the position of the polishing sheet, and the photoelectric sensor detects the data It is sent to the industrial robot, and the industrial robot compares it with the initial position of the polishing pad. When the position difference of the polishing pad exceeds the calibrated threshold, the industrial robot automatically replaces the polishing pad.

Further, the polishing unit includes a polishing module, a constant force floating module, and a dust removal module;

The polishing module includes a servo motor, a conversion mechanism, an automatic chuck and a polishing plate. The conversion mechanism is connected with the servo motor and the automatic chuck. The automatic chuck automatically tightens the polishing plate, and the servo motor controls the rotation of the polishing plate. The constant force floating module includes an equipment housing, inside the equipment housing are installed a pressure sensor, cylinder I, cylinder II, and a vertically arranged linear slide rail; the linear slide rail is provided with a sliding block, and a connecting plate is installed on the sliding block, Cylinder I is connected with the connecting plate, and the connecting plate is fixedly connected with the polishing module through the connecting parts; the connecting plate is pushed by the cylinder I and slides up and down along the linear guide rail to drive the polishing module to move up and down, and produce relative movement with the constant force floating module; II is connected with the grinding module. Cylinder II is controlled by a proportional valve to control the air supply. Through the closed loop adjustment inside the proportional valve, the output air pressure is controlled to a constant value; the pressure sensor is installed on the side of the cylinder II to detect the grinding pressure. The dust removal module includes a dust removal wind hood and a dust removal device. The casing frame of the dust removal wind hood is placed above the entire polishing sheet. Both sides of the casing are provided with dust removal suction ports. The dust removal suction ports are connected to the dust removal equipment. Brushes are installed at the bottoms of the slabs, and the dust formed after the grinding plate is polished is discharged through the dust removal suction port.

Further, the dust removal module includes an air channel switching module, the air channel switching module is provided with an air channel corresponding to the dust removal suction port, the dust removal suction port is connected to the air channel of the air channel switching module through a pipeline, and the other of the air channel switching module One end is connected with the dust removal equipment.

Further, the dust removal module further includes a cover adjustment module for adjusting the upper and lower positions of the dust removal wind cover. Specifically: The cover adjustment module includes a fixed part, a sliding part, and a cover connecting part. The fixed part is installed on the polishing unit. The fixed part is provided with a guide rail. The sliding part is movably connected to the fixed part and can be moved up and down along the guide rail. When moving, the dust removal hood is installed on the fixed part through the cover connecting part, and the sliding part is installed with a motor module, which is electrically connected to the industrial robot; the industrial robot adjusts the upper and lower positions of the dust removal hood by driving the motor module. Preferably, a proximity switch is installed on the outside of the motor module for detecting the stroke of the motor.

Further, the servo motor is electrically connected to the industrial robot. After the polishing sheet consumption monitoring unit detects the polishing sheet data, the detection value is fed back to the industrial robot, and the industrial robot adjusts the rotation speed of the servo motor in real time to maintain a constant polishing linear speed.

Further, the constant force floating module is provided with a position sensor, which is electrically connected to the industrial robot, and is used to monitor whether the up and down displacement of the polishing unit is within a safe travel range.

Further, a ruler is provided on the side of the device housing, and a pointer corresponding to it is provided on one side of the connecting plate.

Compared with the prior art, the present invention has the following significant advantages: the optimized design of the constant force floating device can realize displacement compensation for the grinding process, can output constant and stable pressure and torque, better guarantee the quality of grinding, and can Alleviate the influence of welding seam trajectory fluctuations and grinding disc consumption, and at the same time alleviate the increased grinding wheel wear caused by excessive grinding force; the additional grinding disc detection device can measure the consumption of the grinding wheel online, and can realize automatic replacement and grinding The perfect follow-up dust removal device can collect and remove the dust in the grinding process, so as to avoid spilling into the air or remaining on the weld, which not only ensures the clean and beautiful weld, but also avoids the impact of dust inhalation on the human body .

Description of the drawings

Figure 1 is the structure of the automatic polishing system for roof welds of the present invention;

Figure 2 is a schematic diagram of the structure of the polishing equipment;

Figure 3 is a schematic diagram of the structure of the constant force floating module;

Figure 4 is a schematic diagram of the structure of the polishing module.

Detailed ways

The technical solution of the present invention will be further described in detail below in conjunction with the drawings and specific embodiments.

As shown in Figure 1, an automatic polishing system for car roof welds includes an industrial robot 1, a polishing unit 2 and a polishing sheet consumption monitoring unit 3. The polishing unit 2 includes an "inverted L"-shaped static arm 201, and the upper end of the static arm 201 Through the robot flange 101 and the industrial robot 1, the polishing sheet consumption monitoring unit 3 is placed on the ground on the side of the industrial robot 1, and is electrically connected to the industrial robot 1; the industrial robot 1 drives the polishing unit 2 to polish the welds and complete the welding After the seam is polished, the polishing disc monitoring unit 3 detects the polishing consumption of the polishing disc on the polishing unit 2, and compares it with the initial data of the polishing disc. When the consumption of the polishing disc exceeds the calibrated threshold, the industrial robot 1 automatically replaces the polishing disc. .

The polishing sheet consumption monitoring unit 3 includes a main body support 301. The photoelectric sensor 302 is installed on the top of the main support 301. Preferably, a fork-shaped photoelectric sensor is used. The photoelectric sensor 302 is electrically connected to an industrial robot. Each time the polishing robot completes a process, the polishing wheel is placed close to the fork. The polishing consumption is detected at the center gap of the photoelectric sensor, and the detected position is compared with the initial position. When the position difference exceeds the calibrated threshold, the industrial robot automatically replaces the polishing pad.

Inside the static arm 201, a constant force floating module 6 is installed. The constant force floating module 6 mainly has two functions: 1. Realize the gravity compensation of the grinding module and balance the gravity; 2. Apply a constant grinding pressure.

As shown in Figures 2 and 3, the constant force floating module 6 includes an equipment housing 608, which is fixed on the static arm 201. One side of the equipment housing is an opening. The housing is provided with a linear slide 601 and a pressure sensor. 602. Cylinder I 603, cylinder II 604, cylinder I 603 is used to balance the gravity of the grinding unit, and cylinder II 604 is used to provide constant grinding pressure. Specifically, two linear slide rails 601 are laid symmetrically and vertically. The linear slide rail 601 is provided with a slider, and the connecting plate 605 is fixed on the slider of the linear slide rail 601. On the one hand, it is provided as a cover plate in the opening of the housing. On one side, on the other hand, the lower end of the connecting plate 605 is fixedly connected to the polishing module 4 through the connecting part 606, and the cylinder I 603 is connected to the connecting plate 605. The connecting plate 605 slides along the linear guide 601 under the push of the cylinder I 603. As a result, the polishing module 4 is driven to move up and down, and relative movement can be generated with the equipment housing 608, and the precise control of the linear trajectory of the polishing module 4 in the Z direction is realized. The cylinder II 604 installed on the cylinder connection seat is connected to the polishing module 4. The cylinder II 604 is controlled by a proportional valve to control the air supply. Through the closed loop adjustment inside the proportional valve, the output air pressure is controlled to a constant value. The pressure sensor 602 is installed in the cylinder II. 604 side, used to detect the grinding pressure.

Further, the constant force floating module 6 is also provided with a position sensor 607 for detecting that the up and down displacement of the polishing module is within the safe travel range. The position sensor includes at least an upper limit position sensor and a lower limit position sensor. The upper limit position sensor is used to detect the upper limit position of the polishing module, and the lower limit position sensor is used to detect the lower limit position of the polishing module. When the grinding module exceeds the upper and lower displacement limits, that is, when the upper and lower limit position sensors detect signals, an alarm signal will be activated and the equipment will stop. In addition, a safety position sensor can be set in the middle of the upper and lower limit position sensors to indicate that the polishing module is within the normal stroke range. Specifically, the sensor can be a contact type or a non-contact type. Contact type: Install the limit switch in the equipment shell, and install the limit stop on the fixed point of relative movement, or the opposite installation position. When the mechanical contact of the travel switch hits the stopper, the control circuit is cut off (or changed), and the operation is stopped. Non-contact type: common dry reed switch, photoelectric type, induction type, etc. can be used.

Furthermore, a ruler is engraved on the side of the equipment housing 608, and one side of the connecting plate 605 is provided with a pointer corresponding to the ruler. The range of the ruler is plus or minus 10 mm. The ruler is used to visually reflect the up and down stroke of the polishing module.

The polishing module 4 includes a servo motor 401, a conversion mechanism 402, an automatic chuck 403 and a polishing plate 404. The conversion mechanism 402 is connected to the servo motor 401 and the automatic chuck 403. The automatic chuck 403 automatically tightens the polishing plate 404, and the servo motor 401 controls the polishing plate. 404 rotation. The servo motor 401 is electrically connected to the industrial robot. After the polishing disk consumption monitoring unit detects the polishing disk data, the detected value is fed back to the industrial robot, and the industrial robot adjusts the speed of the servo motor in real time to maintain a constant polishing line speed.

The dust removal module 5 includes a dust removal wind hood 501, an air duct switching module 502, and a dust removal device. The cover frame of the dust removal hood 501 is placed above the entire polishing sheet 404. There are dust suction ports 504 on both sides of the cover. Brushes 505 are respectively installed at the bottom of the air channel switching module 502, and the air channel switching module 502 has two air channels, and the dust removal suction port 504 is connected to the corresponding air channel of the air channel switching module 502 through a pipeline (the connection relationship indicated by the curve in Figure 2) , The air duct switching module 502 is connected to the dust removal equipment through the connecting piece 503. The dust formed after the polishing sheet is polished is discharged through the dust removal suction port 504. In addition, when the grinding wheel is worn, in order to ensure the normal operation of the system, the height of the dust removal hood needs to be adjusted. Therefore, the dust removal module 5 preferably also includes a cover adjustment module for automatically adjusting the upper and lower positions of the dust removal hood. Specifically, the cover The adjustment module includes a fixed part 506, a sliding part 507 and a cover connecting part 508. The fixed part is installed on the static arm 201. The fixed part is provided with a guide rail. The sliding part is movably connected to the fixed part and can move up and down along the guide rail to remove dust. The wind hood is installed on the fixed part through the cover connecting part, and the motor module is installed on the sliding part, and the motor module is electrically connected with the industrial robot; the industrial robot adjusts the upper and lower positions of the dust removal wind hood by driving the motor module. Preferably, a proximity switch is installed on the outside of the motor for detecting the stroke of the motor.

In order to further facilitate the robot to automatically replace the polishing pads, the system is also provided with a polishing pad placement rack 7, which can be installed with multiple polishing pads.

working principle:

Before entering the polishing state, you need to calibrate the position of the unpolished polishing pad, and apply a certain air pressure to the cylinder II. At this time, the pointer on the connecting plate is aligned with the zero-scale position on the side of the floating module housing, which is the calibration state; here In the state, the robot guides the grinding head to move to the position of the fork photoelectric sensor. When the grinding disc does not touch the photoelectric sensor, the signal output by the touch sensor is always 0. When the grinding wheel touches the sensor, the output signal is 1. At this time, write down the coordinate position of the robot's six axes, namely (x, y, z, A, B, C). The industrial robot drives the grinding head to realize the automatic welding seam grinding process of the white body car roof. Every time a welding seam grinding is completed, Repeat this operation to obtain the current state (x', y', z', A', B', C'). Each recorded value only has a difference in z value. Through the formula in the robot program, that is, each time A difference value vertical Δz=z-z' is obtained. This difference value is respectively transmitted to the motor that controls the dust removal hood and the motor that controls the polishing plate. The motor that controls the dust removal hood moves the dust removal hood upwards by the same difference according to the difference. The displacement of the value value; the motor that controls the polishing plate changes its speed through the displacement difference, thereby controlling its linear speed to be constant, so that the polishing state can be controlled.

In summary, the grinding disc consumption detection station detects the position of the grinding disc (grinding disc), and the control center of the industrial robot feeds back the position difference between it and the unused grinding disc for the first time. The difference between the numerical values during grinding) is used to reflect the usage of the grinding wheel after each grinding. When the detected numerical difference is greater than the calibrated value, the grinding wheel is replaced. The constant torque and constant pressure in the grinding process of the invention can efficiently remove dust, and can also automatically adjust the rotation speed of the servo motor and the position of the dust removal hood according to the consumption of the grinding wheel after use, so as to increase the frequency of use of the grinding wheel. Under the joint work of each unit, the two-way automatic polishing of the roof weld and the automatic replacement of the polishing pad can be realized.

Claims

An automatic polishing system for car roof welds, which is characterized in that it includes an industrial robot, a polishing unit, and a polishing sheet consumption monitoring unit. The polishing unit is installed on the industrial robot, and the polishing sheet consumption monitoring unit is electrically connected to the industrial robot; the industrial robot drives the polishing The unit performs welding seam grinding. After the welding seam is finished, the grinding disc monitoring unit detects the grinding consumption of the grinding disc on the grinding unit, and compares it with the initial data of the grinding disc. When the consumption of the grinding disc exceeds the calibrated threshold, the industrial The robot automatically replaces the polishing pads.
The automatic roof welding seam polishing system of claim 1, wherein the polishing sheet consumption monitoring unit includes a photoelectric sensor, which is electrically connected to an industrial robot; each time the polishing unit completes a process, the industrial robot will polish The wafer is close to the photoelectric sensor to detect the position of the polishing plate. The photoelectric sensor sends the detection data to the industrial robot. The industrial robot compares it with the initial position of the polishing plate. When the position difference of the polishing plate exceeds the calibrated threshold, the industrial robot automatically replaces the polishing plate. sheet.
The automatic polishing system for car roof welds according to claim 1 or 2, wherein the polishing unit includes a polishing module, a constant force floating module, and a dust removal module;

The polishing module includes a servo motor, a conversion mechanism, an automatic chuck and a polishing plate, the conversion mechanism is connected with the servo motor and the automatic chuck, the automatic chuck automatically tightens the polishing plate, and the servo motor controls the rotation of the polishing plate;

The constant force floating module includes an equipment housing, inside the equipment housing are installed a pressure sensor, cylinder I, cylinder II, and a vertically arranged linear slide rail; the linear slide rail is provided with a sliding block, and a connecting plate is installed on the sliding block, Cylinder I is connected to the connecting plate, and the connecting plate is fixedly connected to the polishing module through the connecting parts; the connecting plate is pushed by the cylinder I and slides up and down along the linear guide to drive the polishing module to move up and down; the cylinder II is connected to the polishing module, and the cylinder II is connected by The proportional valve controls the air supply, and the output air pressure is controlled to a constant value through the closed loop adjustment inside the proportional valve; the pressure sensor is installed on the side of the cylinder II to detect the grinding pressure;

The dust removal module includes a dust removal wind hood and a dust removal device. The casing frame of the dust removal wind hood is placed above the entire polishing sheet. Both sides of the casing are provided with dust removal suction ports. The dust removal suction ports are connected to the dust removal equipment. Brushes are installed at the bottoms of the slabs, and the dust formed after the grinding plate is polished is discharged through the dust removal suction port.
The automatic polishing system for car roof welds according to claim 3, wherein the dust removal module includes an air channel switching module, the air channel switching module is provided with an air channel corresponding to the dust removal suction port, and the dust removal suction port passes through the pipeline It is connected to the air duct of the air duct switching module, and the other end of the air duct switching module is connected to the dust removal equipment.
The automatic polishing system for the roof weld seam according to claim 3, wherein the dust removal module further comprises a cover adjustment module for adjusting the upper and lower positions of the dust removal wind hood.
The automatic polishing system for car roof welds according to claim 5, wherein the cover adjustment module includes a fixed part, a sliding part and a cover connecting part, the fixed part is installed on the polishing unit, and the fixed part is provided with The guide rail, the sliding part and the fixed part are movably connected and can move up and down along the guide rail. The dust removal hood is installed on the fixed part through the cover connecting part. The sliding part is equipped with a motor module, which is electrically connected to the industrial robot; industrial robot Adjust the up and down position of the dust removal hood by driving the motor module.
The automatic roof welding seam grinding system according to claim 6, wherein a proximity switch is installed on the outer side of the motor module for detecting the stroke of the motor.
The automatic polishing system for roof welds according to claim 3, characterized in that: the servo motor is electrically connected to the industrial robot, and the polishing sheet consumption monitoring unit detects the polishing sheet data, and then feeds back the detection value to the industrial robot, the industrial robot Adjust the speed of the servo motor in real time to maintain a constant polishing line speed.
The automatic polishing system for car roof welds according to claim 1, characterized in that: the constant force floating module is provided with a position sensor for detecting the displacement of the connecting plate relative to the equipment housing, the position sensor and the industrial robot electric connection.
The automatic polishing system for car roof welds according to claim 1, characterized in that: a ruler is provided on the side of the equipment housing, and a pointer corresponding to it is provided on one side of the connecting plate.