CN104369064A - Air bag polishing tool and system and method - Google Patents

Abstract

The application discloses an airbag polishing tool, system and method. The tool includes a motor, a reducer, a hollow rotating shaft and an airbag connected in sequence. The hollow rotating shaft has a hollow cavity, and the two ends of the hollow cavity communicate with the The airbag and a ventilation catheter, the ventilation catheter is provided with an electric proportional valve, the airbag polishing tool also includes a pressure sensor for detecting the gas pressure in the airbag, and the airbag polishing tool also includes a detection tool pressure sensor. The airbag polishing tool based on the electric proportional valve of the present invention can control the contact pressure and contact pressure of the polishing surface in real time. Cost, and the structure is relatively simple, easy to control.

Description

Airbag polishing tool, system and method

technical field

The invention relates to an airbag polishing tool, in particular to a device capable of controlling the surface polishing contact pressure by controlling the air pressure in real time.

Background technique

In recent years, the optical curved surface and mold curved surface manufacturing industry has developed very rapidly and involves a wide range of areas. As the last process in the manufacture of optical curved surfaces and mold curved surfaces, polishing plays a vital role in the final quality and service life of curved surfaces. Balloon polishing is an emerging deterministic polishing process, especially suitable for polishing free-form surfaces. The so-called certainty means that the amount of material removal in the polishing process is controllable. Airbag polishing mainly enables the airbag to be in stable contact with various curved surfaces by controlling the pressure inside the airbag during polishing. When the residence time is constant, the amount of material removal can be achieved. predictability. Balloon polishing uses an inflatable spherical flexible airbag and pastes a polishing pad on the outer surface of the airbag as a polishing tool to polish the curved surface. It can not only ensure good fit between the polishing head and the surface of the polished workpiece, but also control the polishing efficiency and the hardness of the polished workpiece by adjusting the pressure. Surface Quality.

During the polishing process, the polishing tool is polished on the surface of the polished workpiece according to a given path. When there is a shape error on the surface of the polished workpiece, a change in the curvature of the surface of the polished workpiece, or machine vibration, the polishing contact force may not meet the requirements. The contact force is an important control parameter in the polishing process. A stable polishing contact force is beneficial to reduce the surface roughness of the workpiece, improve the polishing accuracy and increase the polishing stability. Before the appearance of airbag polishing technology, the polishing tools generally used springs or other flexible materials to achieve flexible contact between the polishing tool and the polished surface, so that the contact force during the polishing process could be kept within a certain range as much as possible, but this Flexible contacts are generally difficult to achieve on-line control.

Contents of the invention

The object of the present invention is to provide an airbag polishing tool, system and method to overcome the deficiencies in the prior art.

To achieve the above object, the present invention provides the following technical solutions:

The embodiment of the present application discloses an airbag polishing tool, which includes a motor, a reducer, a hollow shaft and an airbag connected in sequence. The hollow shaft has a hollow cavity, and the two ends of the hollow cavity are respectively connected to the airbag and the airbag. A ventilation conduit, an electric proportional valve is arranged on the ventilation conduit, and the airbag polishing tool also includes a pressure sensor for detecting the gas pressure in the airbag.

Preferably, in the airbag polishing tool above, the airbag polishing tool further includes a pressure sensor for detecting the forward pressure of the tool.

Preferably, in the above-mentioned airbag polishing tool, the output end of the reducer is fixed with an upper box, and the upper box has an installation space, and a shaft coupling is arranged in the installation space, and the shaft coupling is fixed Between the output shaft of the reducer and the top end of the hollow shaft.

Preferably, in the above-mentioned airbag polishing tool, a lower box is fixed to the bottom of the upper box, the lower box is sleeved on the outside of the hollow rotating shaft, the lower box has a sealed space, The sealed space is respectively communicated with the air duct and the hollow cavity, and the upper and lower ends of the sealed space are respectively provided with a bearing, and the two bearings are sleeved on the outside of the hollow shaft.

Preferably, in the above airbag polishing tool, the top surface of the upper box is attached to the bottom surface of the lower box, and an annular upper surface is sealed between the hollow shaft and the bottom wall of the upper box. A sealing ring, an annular middle sealing ring is sealed between the contact surfaces of the upper box and the lower box, and an end cover is fixed on the bottom of the lower box, and the end cover is sleeved on the hollow rotating shaft On the outside, a lower sealing ring is sealed between the end cover and the hollow rotating shaft.

Preferably, in the above-mentioned airbag polishing tool, a connecting bracket for connecting with an external industrial robot is fixed on the side wall of the upper box, and the pressure sensor is arranged on the connecting bracket.

Preferably, in the above-mentioned airbag polishing tool, an airbag support is provided at the bottom end of the hollow rotating shaft, and the airbag support includes a hollow main body part, and a mounting part extends around the bottom end of the main body, and the hollow rotating shaft Sleeved on the outside of the main body, a hydraulic expansion sleeve is fixed between the main body and the hollow rotating shaft, and the airbag is fixed on the installation part through a locking sleeve.

The embodiment of the present application also discloses an airbag polishing system, including a controller, a DAQ data acquisition card and the above-mentioned airbag polishing tool, and the DAQ data acquisition card is connected between the controller and an electric proportional valve.

Correspondingly, the embodiment of the present application also discloses a control method of the airbag polishing system. The control method adopts a two-stage control method of pressure and pressure, including a pressure control loop and a pressure control loop, and the controller includes a pressure controller and a pressure control loop. The DAQ data acquisition card transmits the collected pressure signal to the pressure controller. The pressure controller adjusts the difference between the ideal pressure and the actual pressure, and outputs the control signal to the electric proportional valve. At the same time, the DAQ data acquisition card will collect the The pressure signal is transmitted to the pressure controller, and the pressure controller adjusts the difference between the ideal pressure and the actual pressure, and outputs the set pressure value to the pressure control loop.

Compared with the prior art, the present invention has the advantages of:

1) The present invention can be used for polishing of various optical elements and moulds, which can be free-form surfaces, planes, etc.;

2) The present invention can not only use one airbag head, but also is suitable for the use of multiple heads. Different airbag polishing tool heads can be connected through the hydraulic expansion sleeve to achieve various specific processing requirements.

3) Due to the natural flexibility of the gas, the flexibility of the airbag polishing tool after inflation makes the polishing process more stable, and the use of an electric proportional valve to control its internal pressure can make the airbag polishing tool according to the surface and processing requirements of different workpieces. Provide corresponding pressure to ensure the quality of polishing.

4) The present invention uses a two-stage control method to control air pressure and polishing pressure, and proposes a new constant pressure and variable pressure airbag polishing control method, which can ensure polishing better than the previous single control of airbag pressure or polishing pressure Smoothness and uniformity of the process.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments described in this application. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Fig. 1 shows the three-dimensional schematic diagram of the airbag polishing tool in the specific embodiment of the present invention;

Figure 2 is a sectional view of the airbag polishing tool in a specific embodiment of the present invention;

Fig. 3 shows the schematic diagram of the principle of the airbag polishing system in a specific embodiment of the present invention;

Fig. 4 is a control schematic diagram of the airbag polishing system in a specific embodiment of the present invention.

Detailed ways

The technical solutions in the embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

As shown in Figure 1 and Figure 2, the airbag polishing tool includes a motor and encoder 1, a reducer 2, a reducer interface flange 3, a coupling 4, an upper box body 5, an upper sealing ring 6, and a mechanical arm interface flange 7. Connecting bracket 8, middle sealing ring 9, upper bearing 10, lower box body 11, air duct pipe 12, hollow shaft 13, lower bearing 14, lower sealing ring 15, hydraulic expansion sleeve 16, locking sleeve 17, airbag bracket 18, air bag 19.

The motor and the encoder 1 are fixedly connected with the reducer 2, and are connected together with the upper box 4 through the reducer interface flange 3. The output shaft of the reducer 2 drives the hollow rotating shaft 13 to rotate through the coupling 4, and the hydraulic expansion sleeve 16 is set On the hollow rotating shaft 13, the airbag bracket 18 is connected with the hydraulic expansion sleeve 16, the airbag 19 is fixed on the airbag bracket 18 through the locking sleeve 17, and can rotate together with the hollow rotating shaft 13, and the lower box body 11 is connected with the upper box body 5 by screws , the upper end bearing 10 and the lower end bearing 14 are placed in the lower box body 11, and are positioned by the shaft shoulder of the hollow rotating shaft 13 for interference fit, and the gap fit between the upper sealing ring 6 and the hollow rotating shaft 13 reduces axial leakage Air does not interfere with the rotation of the shaft, and the middle sealing ring 9 is located between the upper and lower casings, adopting an interference fit to prevent air leakage, and the lower sealing ring 15 and the shaft also adopt a clearance fit. The manipulator interface flange 7 is connected with the connecting bracket 8 and fixed on the upper box body 5 for connection with the end flange of the industrial robot. The ventilation conduit 12 is connected to the ventilation hole opened on the lower box body 11 to supply air to the lower box body, and is connected to the air bag 19 through the hollow rotating shaft 13 .

When the motor rotates, it drives the reducer 2 to rotate, and the reducer 2 drives the hollow rotating shaft 13 to rotate through the coupling 4. The above-mentioned hydraulic expansion sleeve 16 is tightly hugged to the hollow rotating shaft 13 during work, and the airbag bracket 18 is fastened, because the airbag 19 The locking sleeve 17 is connected with the air bag bracket, so the air bag 19 also rotates synchronously with the hollow rotating shaft 13 .

When processing workpieces, the air source is connected to the ventilation duct 12 through the electric proportional valve, and supplies air (or exhaust) to the lower box 11 to control the air pressure inside it. Through, the gas in the air bag 19 communicates with the gas in the lower box, and the air pressure is the same, so as to achieve the purpose of controlling the air pressure in the air bag 19. When a higher (or lower) pressure needs to be provided, the electric proportional valve can be controlled to set a higher (or lower) air pressure value, and the air duct 12 is now used as an air supply pipe (or exhaust pipe) to supply air to the interior of the polishing tool (or exhaust).

Referring to FIG. 3 , the airbag polishing system includes a controller 20 , a DAQ data acquisition card 21 , an electric proportional servo valve 22 , a pressure sensor 23 and a gas pressure sensor 24 . The controller 20 includes a hardware system and a software system of the controller. The hardware system is the control device, and the software system is the control algorithm. Data reception and transmission depend on the control device, and data processing and calculation depend on the software device. The air inlet of the electric proportional valve 22 is connected to an air source, and its air outlet is connected to the air hole on the lower box body 11 of the airbag polishing tool. The gas pressure sensor 24 is connected in the lower box body 11 to measure the gas pressure in the box body and the air bag in real time. A pressure sensor 23 is installed on the interface flange 7 of the mechanical arm to measure the positive pressure of the tool system. The data acquisition card 21 collects the signals in the pressure sensor 23 and the pressure sensor 24 as the feedback signal of the control system. At the same time, the data acquisition card 21 outputs a voltage value to the electric proportional servo valve 22, and the output air pressure of the electric proportional servo valve 22 is proportional to the input signal. The data acquisition card 21 and the control device communicate with each other through the PCI local bus, and the control device can save the data collected by the data acquisition card 21 and transmit commands to the data acquisition card 21 at the same time.

The control device may include a microprocessor (MCU), and the MCU may include a central processing unit (Central Processing Unit, CPU), a read-only memory module (read-only memory, ROM), a random access memory module (random access memory, RAM), Timing module, digital-to-analog conversion module (A/D converter), and complex input/output ports. Of course, the control device can also use other forms of integrated circuits, such as Application Specific Integrated Circuit (ASIC) or Field Programmable Gate Array (Field Programmable Gate Array, FPGA). Preferably, the control device is preferably a computer with a display device.

Referring to Fig. 4, the example of the present invention adopts a two-stage control method of pressure and pressure, including a pressure control loop and a pressure control loop. The controller includes a pressure controller and a pressure controller. The data acquisition card 21 transmits the collected pressure signal to the pressure controller. The pressure controller adjusts the difference between the ideal pressure and the actual pressure, and outputs a control signal to the electric proportional valve. At the same time, the data acquisition card 21 transmits the collected pressure signal to the pressure controller, and the pressure controller adjusts the difference between the ideal pressure and the actual pressure, and outputs the set pressure value to the pressure control loop.

When polishing, in order to obtain a better polishing effect, on the one hand, it is necessary to make the airbag moderately soft and hard, and on the other hand, it is necessary to maintain an appropriate positive pressure. For example, when polishing a convex surface, the air bag contacts the workpiece, and its contact area is relatively small. In this way, it is necessary to reduce the pressure in the air bag and increase the polishing contact area while keeping the polishing pressure constant; The contact area of the workpiece is relatively large. At this time, the pressure of the air bag can be increased to reduce the contact area under the condition of ensuring constant pressure. Therefore, the two-stage control method in this case can better ensure the stability and uniformity of the polishing process than the single control of the air bag pressure or the polishing pressure.

In summary, the airbag polishing tool based on the electric proportional valve of the present invention can control the contact pressure and contact pressure of the polishing surface in real time. The airbag polishing tool can meet the requirements of different processing surfaces for different processing pressures, and can improve processing accuracy and simplify The polishing process reduces the processing cost, and the structure is relatively simple and easy to control.

It should be noted that in this article, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is a relationship between these entities or operations. There is no such actual relationship or order between them. Furthermore, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes elements not expressly listed. other elements of or also include elements inherent in such a process, method, article, or device. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element.

The above description is only the specific implementation of the present application. It should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present application, some improvements and modifications can also be made. It should be regarded as the protection scope of this application.

Claims (9)

1. An airbag polishing tool, characterized in that, comprises a motor, a speed reducer, a hollow rotating shaft and an airbag connected in sequence, the hollow rotating shaft has a hollow cavity, and the two ends of the hollow cavity are respectively communicated with the airbag and the airbag A ventilation conduit, an electric proportional valve is arranged on the ventilation conduit, and the airbag polishing tool also includes a pressure sensor for detecting the gas pressure in the airbag. 2. The airbag polishing tool according to claim 1, wherein the airbag polishing tool further comprises a pressure sensor for detecting the forward pressure of the tool. 3. The airbag polishing tool according to claim 2, characterized in that: the output end of the reducer is fixed with an upper box body, the upper box body has an installation space, and a shaft coupling is arranged in the installation space, The coupling is fixed between the output shaft of the reducer and the top end of the hollow shaft. 4. The airbag polishing tool according to claim 3, characterized in that: the bottom end of the upper box is fixed with a lower box, and the lower box is sleeved on the outside of the hollow rotating shaft, and the lower box The body has a sealed space, and the sealed space communicates with the ventilation duct and the hollow cavity respectively, and a bearing is provided at the upper and lower ends of the sealed space, and the two bearings are sleeved on the outside of the hollow rotating shaft. 5. The airbag polishing tool according to claim 4, characterized in that: the top surface of the upper box is attached to the bottom surface of the lower box, and the distance between the hollow shaft and the bottom wall of the upper box is An annular upper sealing ring is sealed between the upper box and the contact surface of the lower box, and an annular middle sealing ring is sealed between the contact surfaces of the upper box and the lower box. The bottom of the lower box is fixed with an end cover, which is sleeved On the outer side of the hollow rotating shaft, a lower sealing ring is sealed between the end cover and the hollow rotating shaft. 6. The airbag polishing tool according to claim 3, characterized in that: a connecting bracket for connecting with an external industrial robot is fixed on the side wall of the upper box, and the pressure sensor is arranged on the connecting bracket . 7. The airbag polishing tool according to claim 1, characterized in that: the bottom end of the hollow rotating shaft is also provided with an airbag bracket, the airbag bracket includes a hollow main body, and the bottom end of the main body extends around a mounting part, the hollow rotating shaft is sleeved on the outside of the main body, a hydraulic expansion sleeve is fixed between the main body and the hollow rotating shaft, and the airbag is fixed on the mounting part through a locking sleeve. 8. An airbag polishing system, characterized in that, comprises a controller, a DAQ data acquisition card and the airbag polishing tool described in any one of claims 1 to 7, and the DAQ data acquisition card is connected to the controller and the electrical scale between the valves. 9. The control method of the airbag polishing system according to claim 8, characterized in that: the control method adopts a two-stage control method of pressure and pressure, including a pressure control loop and a pressure control loop, and the controller includes a pressure controller and a pressure controller , the DAQ data acquisition card transmits the collected pressure signal to the pressure controller, the pressure controller adjusts the difference between the ideal pressure and the actual pressure, and outputs the control signal to the electric proportional valve. The pressure signal is sent to the pressure controller, and the pressure controller adjusts the difference between the ideal pressure and the actual pressure, and outputs the set pressure value to the pressure control loop.