Control method of vacuum adsorption device and vacuum adsorption device

Abstract

The invention discloses a control method of a vacuum adsorption device and the vacuum adsorption device.The vacuum adsorption device comprises a suction assembly, a main flow pipeline and a plurality of branch pipelines, a plurality of suction holes are formed in the length direction of each branch pipeline at intervals, and the control method of the vacuum adsorption device comprises the steps that S1, the suction assembly is started, and the flow q of each suction hole is determined, and the vacuum degree Pm in the main flow pipeline is detected in real time. And S2, at the same moment, the flow q of the other suction holes is adjusted according to the minimum flow qmin in all the suction holes, so that the relative deviation value between the minimum flow qmin and the flow q of all the suction holes is smaller than a first preset value. And S3, when the relative deviation value between the flow q of each suction hole and the minimum flow qmin is smaller than a first preset value and the vacuum degree Pm of the main flow pipeline is lower than a second preset value, the suction assembly stops suction, and otherwise, the step S2 is executed again. The problem that the suction holes have different adsorption forces on the to-be-machined workpiece is solved.

Description

Technical Field

[0001] The present application relates to the field of vacuum technology, and in particular to a control method for a vacuum adsorption device and a vacuum adsorption device. Background Art

[0002] When the grinding and polishing machine clamps the workpiece to be processed, it does not use a mechanical clamping mechanism, but instead adopts vacuum adsorption. That is, after the workpiece to be processed is placed on the workbench, the air under the workpiece to be processed is extracted through a vacuum adsorption device to make a certain vacuum degree under the workpiece to be processed. Due to the pressure difference formed by the atmospheric pressure above the workpiece to be processed and the vacuum below, the workpiece to be processed is clamped on the workbench under the action of atmospheric pressure, ensuring that no displacement occurs during the processing process.

[0003] Usually, a vacuum adsorption device is arranged at the bottom of a workbench, and a plurality of through holes are provided on the workbench. The vacuum adsorption device comprises a vacuum pump, a mainstream pipeline and a plurality of branch pipelines. The vacuum pump is connected to the mainstream pipeline, and the plurality of branch pipelines are connected to the mainstream pipeline. Each branch pipeline is provided with a plurality of suction holes at intervals along the length direction. The plurality of suction holes are arranged in one-to-one correspondence with the plurality of through holes. The plurality of suction holes are used to suck the workpiece to be processed respectively, thereby fixing the workpiece to be processed on the workbench.

[0004] However, in the existing vacuum adsorption device, since the distances between the suction holes on the branch pipes and the main pipes are different, the adsorption forces of the suction holes are different, which ultimately causes the workpiece to be easily deformed when adsorbed or easily displaced during processing. Summary of the invention

[0005] The main purpose of the present application is to provide a control method for a vacuum adsorption device and a vacuum adsorption device, so as to at least solve the problem in the prior art that each suction hole has different adsorption forces on the workpiece.

[0006] According to one aspect of the present application, a control method for a vacuum adsorption device is provided, wherein the vacuum adsorption device comprises a suction assembly, a mainstream pipe and a plurality of branch pipes, wherein the mainstream pipe is connected to the suction assembly, each of the branch pipes is connected to the mainstream pipe, and each of the branch pipes is provided with a plurality of suction holes spaced apart in the length direction. The control method for the vacuum adsorption device comprises:

[0007] Step S1: starting the suction component, determining the flow rate q of each suction hole and detecting the vacuum degree Pm in the mainstream pipeline in real time;

[0008] Step S2: At the same time, according to the minimum flow rate q in each of the suction holes min Adjust the flow rate q of the remaining suction holes so that the minimum flow rate q minThe relative deviation value between the flow rate q of each of the suction holes is less than a first predetermined value;

[0009] Step S3: When the flow rate q of each suction hole is equal to the minimum flow rate q min When the relative deviation value is less than the first predetermined value and the vacuum degree Pm of the mainstream pipeline is lower than the second predetermined value, the suction component stops suctioning, otherwise the step S2 is executed again.

[0010] Furthermore, the step of determining the flow rate q of each of the suction holes comprises:

[0011] Detecting the pressure value P1 outside each of the suction holes, the pressure value P0 inside the branch pipe corresponding to each of the suction holes, and the effective gas flow cross-sectional area A of each of the suction holes;

[0012] The flow rate q of each suction hole is calculated according to the pressure value P1 outside each suction hole, the pressure value P0 in the branch pipe corresponding to each suction hole, and the effective gas flow cross-sectional area A of each suction hole.

[0013] Furthermore, the step of calculating the flow rate q of each of the suction holes comprises:

[0014] If P0>0.528P1, the flow rate q of each suction hole is calculated by the following formula:

[0015] q=3.9·10 -3 ·A·[(P1-P0)·P1] 1 / 2 (273 / T) 1 / 2 ,

[0016] Wherein, T is the gas temperature outside the suction hole.

[0017] Furthermore, the step of calculating the flow rate q of each of the suction holes comprises:

[0018] If P0≤0.528P1, the flow rate q of each suction hole is calculated by the following formula:

[0019] q=1.89·10 -3 ·A·P1·(273 / T) 1 / 2 ,

[0020] Wherein, T is the gas temperature outside the suction hole.

[0021] Further, according to the minimum flow rate q in each of the suction holes min The step of adjusting the flow rate q of the remaining suction holes comprises:

[0022] Reduce the effective gas flow cross-sectional area A of the suction hole.

[0023] Further, the steps after stopping the suction component from suctioning include:

[0024] Step S4: when it is detected that the vacuum degree Pm in the mainstream pipeline is greater than a second predetermined value, the steps S1, S2 and S3 are sequentially executed.

[0025] On the other hand, the present application provides a vacuum adsorption device, which is used to execute the control method of the vacuum adsorption device mentioned above, and the vacuum adsorption device includes:

[0026] Suction assembly;

[0027] a main flow conduit, the main flow conduit being in communication with the suction assembly;

[0028] A branch pipe, wherein the branch pipes include a plurality of branch pipes, each of which is connected to the main pipe, and each of which is provided with a plurality of suction holes spaced apart in the length direction;

[0029] A throttle valve, wherein the throttle valve comprises a plurality of throttle valves, and the plurality of throttle valves are arranged in a one-to-one correspondence with the plurality of suction holes;

[0030] A detection component, the detection component includes a plurality of detection components, the plurality of detection components are arranged on the throttle valve in a one-to-one correspondence, the detection component is used to detect the valve core displacement of the throttle valve, and is used to detect the pressure value P1 before the throttle valve and the pressure value P2 in the branch pipe after the throttle valve;

[0031] A controller, the controller is electrically connected to each of the detection components and each of the throttle valves, the controller is used to calculate the gas effective flow cross-sectional area A of the throttle valve according to the valve core displacement of the throttle valve detected by the detection component, and the controller is also used to control each of the throttle valves according to the gas effective flow cross-sectional area A of the throttle valve, the pressure value P1 in the branch pipe before the throttle valve, and the pressure value P2 in the branch pipe after the throttle valve, so that the relative deviation value of the flow rate between each of the throttle valves is less than the first predetermined value;

[0032] A vacuum detection component is provided in the mainstream pipeline, and the vacuum detection component is electrically connected to the controller.

[0033] Furthermore, the detection component comprises:

[0034] A pressure sensor, the pressure sensor is arranged on the throttle valve and is electrically connected to the controller, and the pressure sensor is used to detect a pressure value P1 before the throttle valve and a pressure value P2 in the branch pipe after the throttle valve;

[0035] A displacement sensor is provided on the throttle valve and is electrically connected to the controller. The displacement sensor is used to detect the displacement of the valve core of the throttle valve.

[0036] Furthermore, the vacuum adsorption device also includes a first solenoid valve, which is arranged on the mainstream pipeline, and has an open position for connecting the mainstream pipeline with the external atmosphere, and a closed position for cutting off the mainstream pipeline.

[0037] Furthermore, the suction assembly comprises:

[0038] Vacuum pump;

[0039] An air storage tank, the air storage tank being arranged between the vacuum pump and the mainstream pipeline;

[0040] a second solenoid valve, the second solenoid valve being arranged on the main flow pipeline;

[0041] A filter is arranged on the main flow pipeline and located between the second solenoid valve and the gas storage tank.

[0042] Compared with the prior art, the flow rate q of each suction hole is first determined at the same time, and then the flow rate q of each suction hole is compared to find the minimum flow rate q min , then reduce the flow rate q of the remaining suction holes so that the flow rate q of each suction hole is equal to q min Close, that is, q and q min The relative deviation value should be less than or equal to the first predetermined value. At this time, the flow rate of each suction hole is almost the same, that is, the negative pressure of each suction hole is almost equal, thereby avoiding the problem of different adsorption forces of each suction hole. In addition, when the vacuum degree of the mainstream pipeline reaches or is lower than the second predetermined value, the suction component should be stopped to prevent the suction component from being over-pressured and causing damage to the suction component. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0044] Figure 1 A logic diagram of a control method for a vacuum adsorption device disclosed in the present application;

[0045] Figure 2 It is a schematic diagram of the structure of the vacuum adsorption device disclosed in this application;

[0046] Figure 3A simple schematic diagram of the vacuum adsorption device disclosed in this application;

[0047] Figure 4 It is a simple schematic diagram of a part of the structure of the vacuum adsorption device disclosed in the present application (with the throttle valve removed);

[0048] Figure 5 This is a diagram of the electrical connection relationship between the controller, throttle valve and detection assembly in this application.

[0049] The above drawings include the following reference numerals:

[0050] 10. Suction assembly; 11. Vacuum pump; 12. Air storage tank; 13. Second solenoid valve; 14. Filter; 15. First solenoid valve; 16. One-way valve; 20. Main stream pipeline; 30. Branch pipeline; 40. Throttle valve; 50. Vacuum detection assembly; 61. Pressure sensor; 62. Displacement sensor; 70. Controller; 141. First filter; 142. Second filter. DETAILED DESCRIPTION

[0051] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0052] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0053] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0054] Usually, the main pipeline 20 is arranged directly below the middle of the processing table of the machine tool, and each branch pipeline 30 extends in the radial direction of the main pipeline 20, and the workpiece to be processed is usually fixed in the middle of the processing table. As mentioned in the background technology, since the distances between each suction hole on the branch pipeline 30 and the main pipeline 20 are inconsistent, the adsorption forces of each suction hole are inconsistent. In other words, the negative pressure on the suction holes close to the main pipeline 20 is higher than the negative pressure on the suction holes far away from the main pipeline 20. At this time, the adsorption force on the middle part of the workpiece to be processed is higher than the adsorption force on the edge of the workpiece to be processed. When the adsorption force on the middle part of the workpiece to be processed is too large, it may cause the workpiece to be processed to be deformed; and when the adsorption force on the edge of the workpiece to be processed is too low, it may cause the workpiece to be processed to be displaced on the processing table when the workpiece to be processed.

[0055] To solve the above problems, see Figure 1 As shown, according to an embodiment of the present application, a control method for a vacuum adsorption device is provided, the vacuum adsorption device comprises a suction assembly 10, a mainstream pipe 20 and a plurality of branch pipes 30, the mainstream pipe 20 is connected to the suction assembly 10, each branch pipe 30 is connected to the mainstream pipe 20, and each branch pipe 30 is provided with a plurality of suction holes spaced apart in the length direction, the control method for the vacuum adsorption device comprises:

[0056] Step S1: Start the suction assembly 10, determine the flow rate q of each suction hole and detect the vacuum degree Pm in the mainstream pipeline 20 in real time. Step S2: At the same time, according to the minimum flow rate q in each suction hole min Adjust the flow rate q of the remaining suction holes so that the minimum flow rate q min The relative deviation between the flow rate q of each suction hole and the minimum flow rate q is less than the first predetermined value. Step S3: When the flow rate q of each suction hole is less than the minimum flow rate q min When the relative deviation value is less than the first predetermined value and the vacuum degree Pm of the mainstream pipeline 20 is lower than the second predetermined value, the suction component 10 stops suctioning, otherwise step S2 is executed again.

[0057] Specifically, first determine the flow rate q of each suction hole at the same time, then compare the flow rate q of each suction hole to find the minimum flow rate q min , then reduce the flow rate q of the remaining suction holes so that the flow rate q of each suction hole is equal to q min Close, that is, q and q min The relative deviation value should be less than or equal to the first predetermined value. At this time, the flow rate of each suction hole is almost the same, that is, the negative pressure of each suction hole is almost equal, thereby avoiding the problem of different adsorption forces of each suction hole. In addition, when the vacuum degree of the mainstream pipeline 20 reaches or is lower than the second predetermined value, the suction component 10 should be stopped to prevent the suction component 10 from being over-pressured and causing damage to the suction component 10.

[0058] It is worth mentioning that since the suction assembly 10 is constantly evacuating the vacuum adsorption device, as the vacuum degree changes, the flow rate at each suction hole will decrease over time. Therefore, in order to facilitate the comparison of the flow rates q and q of each suction hole, min In this embodiment, the relative deviation value is used for comparison, q and q min The relative deviation value is calculated by the following formula: relative deviation value = (qq min ) / q min , the size of the first predetermined value is usually set to 5% or less, so that the negative pressure applied by each suction hole to the workpiece is more uniform. In some specific embodiments, the second predetermined value is 850mbar, that is, when the vacuum degree Pm of the mainstream pipeline 20 is lower than or equal to 850mbar, the vacuum degree of the vacuum adsorption device meets the working requirements. In fact, during the operation of the vacuum adsorption device, the Pm of the vacuum adsorption device cannot be too low. Too low a vacuum degree will cause the negative pressure applied by the suction hole to the workpiece to be processed to be too large, which may cause the workpiece to be processed to deform. On the other hand, too low a vacuum degree will cause the pressure of the suction component 10 to be too high, causing damage to the suction component 10.

[0059] Further, the step of determining the flow rate q of each suction hole includes: detecting the pressure value P1 outside each suction hole, the pressure value P0 in the branch pipe 30 corresponding to each suction hole, and the gas effective flow cross-sectional area A of each suction hole. According to the pressure value P1 outside each suction hole, the pressure value P0 in the branch pipe 30 corresponding to each suction hole, and the gas effective flow cross-sectional area A of each suction hole, the flow rate q of each suction hole is calculated.

[0060] In practice, the flow rate q of each suction hole is determined by the steps of detection and calculation. In this embodiment, the pressure value P1 outside each suction hole, the pressure value P0 in the branch pipe 30 corresponding to each suction hole, and the effective gas flow cross-sectional area A of each suction hole need to be detected first, and then the flow rate q of each suction hole is calculated by P1, P0 and A. In this embodiment, the effective gas flow cross-sectional area of ​​the suction hole refers to the area of ​​the effective cross section for gas flow in the suction hole.

[0061] Further, the step of calculating the flow rate q of each suction hole includes: if P0>0.528P1, the flow rate q of each suction hole is calculated by the following formula: q=3.9·10 -3 ·A·[(P1-P0)·P1] 1 / 2 (273 / T) 1 / 2 , where T is the gas temperature outside the suction hole. In addition, the step of calculating the flow rate q of each suction hole includes: if P0≤0.528P1, the flow rate q of each suction hole is calculated by the following formula: q=1.89·10 -3·A·P1·(273 / T) 1 / 2 , where T is the gas temperature outside the suction hole.

[0062] When P0>0.528P1, the relative flow rate of the suction hole is small, that is, the flow state of the airflow in the corresponding suction hole is in a subsonic flow state, and the pressure problem caused by the pressure difference between the pressure value P1 outside the suction hole and the pressure value P0 in the branch pipe 30 corresponding to the suction hole needs to be considered; and when P0≤0.528P1, the relative flow rate of the suction hole is large, that is, the flow state of the airflow in the corresponding suction hole is in a supercritical flow state, and the difference between P1 and P0 is small, and P1 can be approximately regarded as a fixed multiple of P0, thereby simplifying the calculation method.

[0063] Furthermore, according to the minimum flow rate q in each suction hole min The step of adjusting the flow rate q of the remaining suction holes includes: reducing the effective gas flow cross-sectional area A of the suction holes.

[0064] According to the above formula, it can be found that the actual flow rate at the suction hole is only related to the pressure value P1 outside the suction hole, the pressure value P0 in the branch pipe 30 corresponding to the suction hole, the gas temperature T outside the suction hole and the effective gas flow cross-sectional area A of the suction hole. It is difficult to change P1 and P0. At the same time, the gas temperature T outside each suction hole is the same. Therefore, the flow rate of the suction hole can be changed by changing the size of the effective gas flow cross-sectional area A of the suction hole.

[0065] In this embodiment, in order to prevent the poor air tightness of the mainstream pipe 20 or the branch pipe 30, which causes the vacuum degree of the entire vacuum adsorption device to drop after a certain period of time, the steps after stopping the suction component 10 in this embodiment include: Step S4: when it is detected that the vacuum degree Pm in the mainstream pipe 20 is greater than the second predetermined value, step S1, step S2 and step S3 are executed in sequence.

[0066] That is to say, if the mainstream pipe 20 or the branch pipe 30 or other components leak, the vacuum degree in the vacuum adsorption device cannot be maintained below the second predetermined value after the suction component 10 stops for a certain period of time. At this time, the vacuum adsorption device executes steps 1, 2 and 3 again until the vacuum degree Pm is equal to or less than the second predetermined value again, and the suction component 10 stops working.

[0067] On the other hand, the present application also provides a vacuum adsorption device, as shown in the attached Figures 2 to 5 As shown, the vacuum adsorption device is used to execute the above-mentioned control method of the vacuum adsorption device, and the vacuum adsorption device includes a suction component 10, a mainstream pipeline 20, a branch pipeline 30, a throttle valve 40, a detection component, a controller 70 and a vacuum degree detection component 50.

[0068] The main pipeline 20 is connected to the suction assembly 10, the branch pipeline 30 includes a plurality of branch pipelines 30, each branch pipeline 30 is connected to the main pipeline 20, and each branch pipeline 30 is provided with a plurality of suction holes spaced apart in the length direction, and the throttle valve 40 includes a plurality of throttle valves 40, and the plurality of throttle valves 40 are arranged one-to-one correspondingly on the plurality of suction holes. The detection assembly includes a plurality of detection assemblies, and the plurality of detection assemblies are arranged one-to-one correspondingly on the throttle valve 40, and the detection assembly is used to detect the valve core displacement of the throttle valve 40, and to detect the pressure value P1 before the throttle valve 40 and the pressure value P2 in the branch pipeline 30 after the throttle valve 40. The controller 70 is electrically connected to each detection component and each throttle valve 40. The controller 70 is used to calculate the gas effective flow cross-sectional area A of the throttle valve 40 based on the valve core displacement of the throttle valve 40 detected by the detection component. The controller 70 is also used to control each throttle valve 40 based on the gas effective flow cross-sectional area A of the throttle valve 40, the pressure value P1 in the branch pipe 30 before the throttle valve 40, and the pressure value P2 in the branch pipe 30 after the throttle valve 40, so that the flow difference between each throttle valve 40 is less than a first predetermined value. The vacuum detection component 50 is arranged in the mainstream pipe 20, and the vacuum detection component 50 is electrically connected to the controller 70.

[0069] Specifically, when executing step S1, the suction component 10 is first started by the controller 70, and the suction component 10 sucks the main pipeline 20, so that the suction holes on the branch pipeline 30 are in working state. Since a throttle valve 40 is provided on each suction hole, and the throttle valve 40 is connected to the through hole on the workbench, the throttle valve 40 can be used to adjust the gas flow of each suction hole. Then step S2 is executed, that is, the detection component provided on the throttle valve 40 monitors the pressure value P1 between the throttle valve 40 and the through hole on the workbench, the pressure value P2 in the branch pipeline 30 after the throttle valve 40, and the valve core displacement of the throttle valve 40 at this time. Afterwards, the detection component transmits P1, P0 and the valve core displacement of the throttle valve 40 at this time to the controller 70 through an electrical signal. The controller 70 first calculates the gas effective flow cross-sectional area A of the throttle valve 40 through the valve core displacement of each throttle valve 40 at this time, and then calculates the flow rate q of each throttle valve 40 at this time according to the relationship between P1, P0 and A, and compares and obtains the minimum flow rate q of each throttle valve 40 min , at the same time, for min Each throttle valve 40 is used to adjust the flow rate, that is, to control the throttle valve 40 to move the valve core, so that the flow rate q of the throttle valve 40 is equal to q minThe difference between is less than or equal to the first predetermined value. Since each throttle valve 40 is arranged on each suction hole in a one-to-one correspondence, the flow rate flowing into the throttle valve 40 is the same as the flow rate flowing out of the suction hole, so that the flow rates of each suction hole are almost the same, that is, the adsorption force of each suction hole is almost the same. Then, step S3 is executed. Since the vacuum detection component 50 constantly detects the vacuum degree Pm in the mainstream pipeline 20 and sends the vacuum degree Pm in the mainstream pipeline 20 to the controller 70 through an electrical signal, when Pm is less than or equal to the second predetermined value, the controller 70 controls the suction component 10 to stop working, and when Pm is greater than the second predetermined value, step S2 is executed again. After the suction component 10 stops working, if the vacuum degree Pm in the vacuum adsorption device is higher than the second predetermined value again due to airtightness problems, the controller 70 controls the vacuum adsorption device again, and executes steps S1, S2 and S3 in sequence, that is, executes step S4.

[0070] It can be understood that the flow rate of the throttle valve is related to the size of P1, P0 and A. Therefore, in this embodiment, the minimum flow rate q is found. min , so that the flow of each throttle valve is adjusted to the minimum flow q min , which is an executable method, that is, according to the minimum flow q min It is relatively easy to change the effective gas flow cross-sectional area A of each throttle valve 40, thereby reducing the flow rate of the throttle 40. max To adjust, since the adjustment range of A is limited and P1 and P0 are difficult to change, if the maximum flow q max To adjust the flow of each throttle, this is a difficult method to implement.

[0071] In addition, the detection component includes a pressure sensor 61 and a displacement sensor 62. The pressure sensor 61 is arranged on the throttle valve 40, and the pressure sensor 61 is electrically connected to the controller 70. The pressure sensor 61 is used to detect the pressure value P1 before the throttle valve 40 and the pressure value P2 in the branch pipe 30 after the throttle valve 40. The displacement sensor 62 is arranged on the throttle valve 40, and the displacement sensor 62 is electrically connected to the controller 70. The displacement sensor 62 is used to detect the valve core displacement of the throttle valve 40.

[0072] Specifically, the throttle valve 40 is provided with a first pressure sensor and a second pressure sensor, the first pressure sensor is used to detect the pressure value P1 before the throttle valve, and transmit the pressure value P1 to the controller 70 through an electrical signal, and the second pressure sensor is used to detect the pressure value P2 in the branch pipe 30 after the throttle valve 40, and transmit the pressure value P2 to the controller 70 through an electrical signal. In the actual structure, since it is difficult to directly detect the gas flow cross-sectional area A of the throttle valve 40, it is necessary to detect the valve core displacement of the throttle valve 40 through the displacement sensor 62, and use the valve core displacement of the throttle valve 40 to calculate the gas flow cross-sectional area A of the throttle valve. When the valve core displacement of the throttle valve 40 is transmitted to the controller through the battery number, the controller calculates the effective gas flow cross-sectional area A of the throttle valve 40 through the valve core displacement of the throttle valve 40 according to the stored calculation program and the information of the throttle. After calculating the effective flow cross-sectional area A of the throttle valve 40, the controller 70 calculates the flow q of the throttle valve 40 according to the pressure value P1, the pressure value P2 and the effective flow cross-sectional area A. The controller 70 can calculate the flow q of each throttle valve 40 at the same time through the above steps, and compare the flow q of each throttle valve 40, and finally obtain the minimum flow q at the same time. min , and then the controller 70 adjusts the flow of the throttle valve 40 by changing the displacement of the valve core of other throttle valves 40, and finally makes the flow of each throttle valve 40 almost the same. It is worth mentioning that when the controller 70 actually adjusts the flow of the throttle valve 40, it takes a certain execution time, that is, it takes a certain time for the valve core of the throttle valve 40 to change its position, but because the time is short, the q in the process of changing the valve core position can usually be ignored. min The effect of the change on adjusting the flow of other throttle valves 40 is that when the vacuum degree is low, the minimum q min will tend to a specific value, that is, at this time q min Can be regarded as a fixed value.

[0073] As attached Figure 2 As shown, the vacuum adsorption device further includes a first solenoid valve 15 , which is disposed on the mainstream pipeline 20 . The first solenoid valve 15 has an open position for connecting the mainstream pipeline 20 with the external atmosphere, and a closed position for cutting off the mainstream pipeline 20 .

[0074] That is to say, when the vacuum adsorption device is working, the first electromagnetic valve 15 needs to be switched from the open position to the closed position first, so as to prevent the mainstream pipeline 20 from being directly connected to the external atmosphere, so as to facilitate the suction component 10 to vacuum the mainstream pipeline 20. When it is necessary to adjust the position of the workpiece to be processed on the workbench or to remove the workpiece to be processed, the first electromagnetic valve 15 needs to be switched from the closed position to the open position, and the external gas flows into the mainstream pipeline 20 through the throttle valve 40, so that the pressure at each suction hole is almost the same as the external pressure, so as to loosen the workpiece to be processed. In this embodiment, the external gas is the atmosphere; in some other embodiments, the mainstream pipeline 20 can also be connected to a high-pressure gas tank, and the first electromagnetic valve 15 is arranged between the high-pressure gas tank and the mainstream pipeline, that is, when the first electromagnetic valve 15 is in the open position, the compressed gas in the high-pressure gas tank can enter the mainstream pipeline 20, which can also loosen the workpiece to be processed. The high-pressure gas introduced can be, for example, nitrogen, to avoid a large amount of water stains in the air, so that the vacuum adsorption device is affected by water stains.

[0075] Furthermore, the suction assembly 10 includes a vacuum pump 11, an air storage tank 12, a second solenoid valve 13 and a filter 14. The air storage tank 12 is arranged between the vacuum pump 11 and the mainstream pipeline 20, the second solenoid valve 13 is arranged on the mainstream pipeline 20, and the filter 14 is arranged on the mainstream pipeline 20 and located between the second solenoid valve 13 and the air storage tank 12.

[0076] In actual operation, the second solenoid valve 13 is first closed, that is, at this time, the mainstream pipeline 20 and the gas tank 12 are not connected, and then the vacuum pump 11 is started, and the vacuum pump 11 evacuates the gas tank 12. When the vacuum degree in the gas tank 12 reaches a predetermined value, the second solenoid valve 13 is opened, and the gas tank 12 evacuates the mainstream pipeline 20. When the value of the vacuum degree Pm detected by the vacuum degree detection component 50 is less than or equal to the second predetermined value, the vacuum pump 11 stops working. In this embodiment, the function of the gas tank 12 is to maintain the vacuum degree in the mainstream pipeline 20 for a long time. The filter 14 includes a first filter 141 and a second filter 142. The first filter 141 is arranged between the first solenoid valve 15 and the gas tank 12, and the second filter 142 is arranged between the first filter 141 and the gas tank 12. The first filter 141 is used to filter impurities and foreign matter, and the second filter 142 is used to filter water stains, thereby preventing impurities, foreign matter or water stains from entering the vacuum pump 11 and causing damage to the vacuum pump 11. A pressure sensor 61 is provided on the gas tank 12 for observing the vacuum degree in the gas tank 12. In this embodiment, the vacuum degree detection component 50 includes the pressure sensor 61. In addition, a one-way valve 16 is provided between the vacuum pump 11 and the gas tank 12 to prevent the gas in the vacuum pump 11 from flowing back into the gas tank 12 during or after vacuuming; of course, the one-way valve 16 can also be replaced by a solenoid valve, and after the vacuum degree Pm of the mainstream pipeline 20 is less than or equal to the second predetermined value, the one-way valve 16 is closed, causing the gas in the vacuum pump 11 to flow back into the gas tank 12.

[0077] To summarize, the vacuum adsorption device and the control method of the vacuum adsorption device provided in the present application change the flow rate of each suction hole by utilizing, for example, a throttle valve, so that the flow rate of each suction hole is almost the same, thereby making the negative pressure at each suction hole the same, thereby preventing the workpiece to be processed from being fixed on the processing table due to uneven force, resulting in deformation of the workpiece to be processed or displacement of the workpiece to be processed during the processing process.

[0078] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0079] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0080] The above are only preferred embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A control method for a vacuum adsorption device, the vacuum adsorption device comprising a suction assembly (10), a main flow pipe (20) and a plurality of branch flow pipes (30), the main flow pipe (20) being in communication with the suction assembly (10), each of the branch flow pipes (30) being in communication with the main flow pipe (20), each of the branch flow pipes (30) being provided with a plurality of suction holes spaced apart in a length direction, characterized in that: The control method of the vacuum adsorption device comprises: Step S1: starting the suction component (10), determining the flow rate q of each suction hole and detecting the vacuum degree Pm in the main flow pipe (20) in real time; Step S2: At the same time, according to the minimum flow rate q in each of the suction holes min Adjust the flow rate q of the remaining suction holes so that the minimum flow rate q min The relative deviation value between the flow rate q of each of the suction holes is less than a first predetermined value; Step S3: When the flow rate q of each suction hole is equal to the minimum flow rate q min When the relative deviation value is smaller than the first predetermined value and the vacuum degree Pm of the mainstream pipeline (20) is lower than the second predetermined value, the suction component (10) stops suctioning, otherwise the step S2 is executed again.

2. The control method of the vacuum adsorption device according to claim 1, characterized in that: The step of determining the flow rate q of each of the suction holes comprises: Detecting a pressure value P1 outside each of the suction holes, a pressure value P0 inside the branch pipe (30) corresponding to each of the suction holes, and an effective gas flow cross-sectional area A of each of the suction holes; The flow rate q of each suction hole is calculated according to the pressure value P1 outside each suction hole, the pressure value P0 inside the branch pipe (30) corresponding to each suction hole, and the effective gas flow cross-sectional area A of each suction hole.

3. The control method of the vacuum adsorption device according to claim 2, characterized in that: The step of calculating the flow rate q of each of the suction holes comprises: If P0>0.528P1, the flow rate q of each suction hole is calculated by the following formula: q=3.9·10 -3 ·A·[(P1-P0)·P1] 1 / 2 ·(273 / T) 1 / 2 , Wherein, T is the gas temperature outside the suction hole.

4. The control method of the vacuum adsorption device according to claim 2, characterized in that: The step of calculating the flow rate q of each of the suction holes comprises: If P0≤0.528P1, the flow rate q of each suction hole is calculated by the following formula: q=1.89·10 -3 ·A·P1·(273 / T) 1 / 2 , Wherein, T is the gas temperature outside the suction hole.

5. The control method of the vacuum adsorption device according to any one of claims 1 to 4, characterized in that: According to the minimum flow rate q in each of the suction holes min The step of adjusting the flow rate q of the remaining suction holes comprises: Reduce the effective gas flow cross-sectional area A of the suction hole.

6. The control method of the vacuum adsorption device according to any one of claims 1 to 4, characterized in that: The steps after stopping the suction assembly (10) from suctioning include: Step S4: when it is detected that the vacuum degree Pm in the mainstream pipeline (20) is greater than a second predetermined value, the steps S1, S2 and S3 are sequentially executed.

7. A vacuum adsorption device, characterized in that: The vacuum adsorption device is used to execute the control method of the vacuum adsorption device according to any one of claims 1 to 6, and the vacuum adsorption device comprises: A suction assembly (10); A main flow pipeline (20), the main flow pipeline (20) being in communication with the suction assembly (10); A branch pipe (30), the branch pipe (30) comprising a plurality of branches, each branch pipe (30) being in communication with the main pipe (20), and each branch pipe (30) being provided with a plurality of suction holes spaced apart in a length direction; A throttle valve (40), the throttle valve (40) comprising a plurality of throttle valves (40), the plurality of throttle valves (40) being arranged in a one-to-one correspondence at the plurality of suction holes; a detection component, the detection component comprising a plurality of detection components, the plurality of detection components being arranged on the throttle valve (40) in a one-to-one correspondence, the detection component being used to detect the displacement of the valve core of the throttle valve (40), and being used to detect a pressure value P1 before the throttle valve (40) and a pressure value P2 in the branch pipe (30) after the throttle valve (40); a controller (70), the controller (70) being electrically connected to each of the detection components and each of the throttle valves (40), the controller (70) being used to calculate the effective gas flow cross-sectional area A of the throttle valve (40) according to the valve core displacement of the throttle valve (40) detected by the detection component, and the controller (70) being further used to control each of the throttle valves (40) according to the effective gas flow cross-sectional area A of the throttle valve (40), the pressure value P1 in the branch pipe (30) before the throttle valve (40), and the pressure value P2 in the branch pipe (30) after the throttle valve (40), so that the relative deviation value of the flow rate between each of the throttle valves (40) is less than the first predetermined value; A vacuum degree detection component (50), wherein the vacuum degree detection component (50) is disposed in the mainstream pipeline (20), and the vacuum degree detection component (50) is electrically connected to the controller (70).

8. The vacuum adsorption device according to claim 7, characterized in that: The detection component comprises: a pressure sensor (61), the pressure sensor (61) being arranged on the throttle valve (40), and the pressure sensor (61) being electrically connected to the controller (70), and the pressure sensor (61) being used to detect a pressure value P1 before the throttle valve (40) and a pressure value P2 in the branch pipe (30) after the throttle valve (40); A displacement sensor (62), wherein the displacement sensor (62) is disposed on the throttle valve (40), and the displacement sensor (62) is electrically connected to the controller (70), and the displacement sensor (62) is used to detect the displacement of the valve core of the throttle valve (40).

9. The vacuum adsorption device according to claim 7, characterized in that: The vacuum adsorption device further comprises a first solenoid valve (15), wherein the first solenoid valve (15) is arranged on the main flow pipeline (20), and the first solenoid valve (15) has an open position for connecting the main flow pipeline (20) with the external atmosphere, and a closed position for cutting off the main flow pipeline (20).

10. The vacuum adsorption device according to claim 7, characterized in that: The suction assembly (10) comprises: Vacuum pump (11); An air storage tank (12), wherein the air storage tank (12) is arranged between the vacuum pump (11) and the main flow pipeline (20); a second solenoid valve (13), the second solenoid valve (13) being arranged on the main flow pipeline (20); A filter (14), wherein the filter (14) is arranged on the main flow pipeline (20) and is located between the second solenoid valve (13) and the gas storage tank (12).

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