A vacuum calibration device

Abstract

The utility model provides a kind of vacuum calibration device.The vacuum calibration device includes support frame, vacuum cavity being set on support frame, standard vacuum gauge, air extraction unit, nitrogen heater and inflation pipe.Standard vacuum gauge is communicated with vacuum cavity, for measuring actual pressure value in vacuum cavity.Air extraction unit is set on support frame, the import of air extraction unit is connected with vacuum cavity, and air extraction unit is used to extract gas in vacuum cavity.Nitrogen heater is set on support frame.Inflation pipe is set on support frame, the outlet of inflation pipe is connected with vacuum cavity or nitrogen heater by first valve, and inflation pipe is used to supplement gas to vacuum cavity, or provide nitrogen to nitrogen heater.Vacuum calibration device has multiple functions, improves the utilization of vacuum calibration device, meets the efficient use demand of modern laboratory or production line to multifunctional integrated equipment.

Description

Technical Field

[0001] This utility model relates to the field of vacuum calibration technology, and in particular to a vacuum calibration device. Background Technology

[0002] Vacuum calibration is a process of comparing the measurement results of the vacuum measuring instrument under test (such as a vacuum gauge or pressure sensor) with those of a standard vacuum gauge to determine the error, and then verifying and adjusting the vacuum measuring instrument under test based on the error. This process ensures that the measurement results of the vacuum measuring instrument under test meet the accuracy requirements of the standard or specified requirements. It is widely used in precision vacuum fields such as vacuum coating.

[0003] However, existing vacuum calibration devices have limited functionality, only capable of calibrating the vacuum measuring instruments under test, which is insufficient to meet the needs of modern laboratories or production lines for efficient use of multifunctional integrated equipment. Utility Model Content

[0004] In view of the above problems, this utility model is proposed to provide a vacuum calibration device that overcomes or at least partially solves the above problems. It can solve the problem that the vacuum calibration device has only one function, which is to calibrate the vacuum measuring instrument under test. It can meet the needs of modern laboratories or production lines for efficient use of multifunctional integrated equipment.

[0005] Specifically, this utility model provides a vacuum calibration device, including a support frame and a vacuum cavity disposed on the support frame. The vacuum calibration device further includes:

[0006] A standard vacuum gauge, which is connected to the vacuum chamber.

[0007] A vacuum pumping unit is mounted on the support frame. The inlet of the vacuum pumping unit is connected to the vacuum chamber, and the vacuum pumping unit is used to extract gas from the vacuum chamber.

[0008] A nitrogen heater, which is mounted on the support frame.

[0009] An inflation pipe is provided on the support frame. The outlet of the inflation pipe is connected to the vacuum chamber or the nitrogen heater through a first valve. The inflation pipe is used to replenish gas into the vacuum chamber or to supply nitrogen to the nitrogen heater.

[0010] Optionally, the nitrogen heater includes:

[0011] The cylinder has a nitrogen outlet and a nitrogen inlet connected to the first valve.

[0012] An electric heating element, comprising a tube body, a heating wire disposed within the tube body, and magnesium oxide powder filled within the tube body. The electric heating element is disposed within a cylindrical body.

[0013] An insulation layer is provided on the outside of the cylinder.

[0014] Optionally, the nitrogen inlet is located at one end of the cylinder, and the nitrogen outlet is located at the other end of the cylinder. Multiple baffles are provided inside the cylinder, each baffle being perpendicular to the axis of the cylinder, and the baffles are spaced apart sequentially along the length of the cylinder. In every two adjacent baffles, the gap between one baffle and the cylinder is located on one side of the cylinder, and the gap between the other baffle and the cylinder is located on the other side of the cylinder, so that the nitrogen entering the cylinder flows in a bend.

[0015] Optionally, the first valve is a four-way valve, including a first valve port communicating with the gas filling pipe, a second valve port communicating with the vacuum chamber, a third valve port communicating with the nitrogen heater, and a closed fourth valve port. The first valve port is controlled to communicate with either the second valve port or the third valve port.

[0016] A mass flow controller is installed between the outlet of the air inlet pipe and the first valve.

[0017] The inflation tube is also equipped with a second valve, which is a four-way valve including a fifth valve port, a sixth valve port, a seventh valve port, and an eighth valve port. When the fifth valve port and the sixth valve port are connected, the inflation tube is open. The seventh valve port and the eighth valve port are closed. The fifth valve port is controlled to communicate with either the sixth valve port or the seventh valve port.

[0018] Optionally, the air extraction unit includes:

[0019] A molecular pump, the inlet of which is connected to the vacuum chamber via a vacuum gate valve. The vacuum chamber, the vacuum gate valve, and the molecular pump are arranged sequentially in a vertical direction.

[0020] A vortex pump is connected to the vacuum chamber via a pipeline. Along the airflow direction within the pipeline, a vacuum butterfly valve and an internal gas cylinder valve are sequentially installed on the pipeline.

[0021] A vacuum angle valve is installed between the outlet of the molecular pump and the inlet of the vortex pump.

[0022] A pressure controller is connected to a standard vacuum gauge and the vacuum butterfly valve to obtain the pressure inside the vacuum chamber and control the opening degree of the vacuum butterfly valve according to the pressure.

[0023] Optionally, the vacuum calibration device also includes:

[0024] The PLC controller is electrically connected to the molecular pump, the vortex pump, the vacuum gate valve, the inline cylinder valve, the vacuum angle valve, the pressure controller, the nitrogen heater, the first valve, and the second valve.

[0025] The control panel is electrically connected to the PLC controller.

[0026] Optionally, the support frame is a box. A handle is provided on one side of the box, and casters are provided at the bottom.

[0027] The upper end of the front surface of the housing is inclined and is provided with a first mounting hole and a second mounting hole.

[0028] The control panel is located at the first mounting hole, and the pressure controller is located at the second mounting hole.

[0029] The molecular pump and the nitrogen heater are vertically arranged and located on one side of the chamber. The vortex pump is located on the other side of the chamber. An exhaust port is provided on the side wall of the other side of the chamber, and the exhaust port of the vortex pump extends out of the chamber from the exhaust port.

[0030] The nitrogen inlet is located at the upper end of the cylinder. A first perforation and a second perforation are provided on one side wall of the housing. The inlet of the gas filling pipe passes through the first perforation and exits the housing, while the nitrogen outlet passes through the second perforation and exits the housing.

[0031] Optionally, the vacuum chamber is provided with multiple vacuum device interfaces, and at least one of the vacuum device interfaces is connected to a different vacuum device than the other vacuum device interfaces.

[0032] The vacuum equipment interface extends upwards from the housing.

[0033] Optionally, a first flange is provided at the bottom opening of the vacuum chamber.

[0034] The molecular pump is provided with a second flange at its upper end.

[0035] The vacuum gate valve is located between the first flange and the second flange.

[0036] The vacuum chamber, the vacuum gate valve, and the second flange are fixedly connected by screws passing through the first flange and the vacuum gate valve and connecting to the second flange.

[0037] In this invention, the vacuum calibration device not only verifies and adjusts the accuracy of the readings of the vacuum measuring instrument under test, but also outputs high-temperature nitrogen gas for use in scenarios requiring high-temperature nitrogen, such as condenser pump regeneration. This multi-functionality improves the utilization rate of the vacuum calibration device and meets the high-efficiency utilization needs of modern laboratories or production lines for multi-functional integrated equipment. Furthermore, the device utilizes a first valve with multiple ports to allow the vacuum chamber and nitrogen heater to share a common charging pipe, resulting in a compact internal structure and reduced space requirements. This avoids the space occupation and resource waste associated with configuring separate equipment for different functions.

[0038] The above and other objects, advantages and features of this utility model will become more apparent to those skilled in the art from the following detailed description of specific embodiments of this utility model in conjunction with the accompanying drawings. Attached Figure Description

[0039] The following sections will describe some specific embodiments of the present invention in a detailed manner by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or components. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings:

[0040] Figure 1 This is a schematic structural diagram of a vacuum calibration device according to an embodiment of the present invention;

[0041] Figure 2 yes Figure 1 Enlarged view of point A in the middle;

[0042] Figure 3 This is a schematic structural diagram of a vacuum calibration device according to an embodiment of the present invention, with some parts of the structure hidden.

[0043] Figure 4 yes Figure 3 Enlarged view of point B in the middle;

[0044] Figure 5 This is a schematic cross-sectional view of a nitrogen heater in a vacuum calibration device according to an embodiment of the present invention;

[0045] Figure 6 This is a schematic block diagram of a vacuum calibration device according to an embodiment of the present invention.

[0046] List of reference numerals in the attached diagram:

[0047] 100. Support frame; 110. Handle; 120. Roller; 130. First through hole; 140. Second through hole;

[0048] 200. Vacuum chamber;

[0049] 300. Standard vacuum gauge;

[0050] 400. Pumping unit; 410. Molecular pump; 420. Vortex pump; 421. Exhaust port; 430. Vacuum angle valve; 440. Pressure controller; 450. Vacuum butterfly valve; 460. Inline cylinder valve; 470. Vacuum gate valve;

[0051] 500. Nitrogen heater; 510. Cylinder; 511. Baffle; 520. Heating element; 530. Insulation layer;

[0052] 600. Inflation pipe; 610. First valve; 620. Second valve; 630. Mass flow controller;

[0053] 700. Control Panel;

[0054] 800. Vacuum equipment interface. Detailed Implementation

[0055] The following reference Figures 1 to 6 This description describes a vacuum calibration device according to an embodiment of the present invention. In this description, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature, that is, include one or more of that feature. In the description of the present invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified. When a feature "includes or contains" one or more of the features it encompasses, unless otherwise specifically described, this indicates that other features are not excluded and may be further included.

[0056] Unless otherwise expressly specified and limited, the terms "set," "install," "connect," "link," "fix," and "couple" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art should be able to understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0057] Furthermore, in the description of this embodiment, "above" or "below" the second feature can include direct contact between the first and second features, or it can include contact between the first and second features through another feature between them. That is, in the description of this embodiment, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "below" of the second feature can mean the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0058] In the description of this embodiment, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0059] Figure 1 This is a schematic structural diagram of a vacuum calibration device according to an embodiment of the present invention, as shown below. Figure 1 As shown, and refer to Figures 2 to 6 This utility model provides a vacuum calibration device. The vacuum calibration device includes a support frame 100, a vacuum chamber 200 disposed on the support frame 100, a standard vacuum gauge 300, a pumping unit 400, a nitrogen heater 500, and a gas filling pipe 600. The standard vacuum gauge 300 is connected to the vacuum chamber 200 and is used to measure the actual pressure value inside the vacuum chamber 200. The pumping unit 400 is disposed on the support frame 100, and its inlet is connected to the vacuum chamber 200. The pumping unit 400 is used to extract gas from the vacuum chamber 200. The nitrogen heater 500 is disposed on the support frame 100. The gas filling pipe 600 is disposed on the support frame 100, and its outlet is connected to either the vacuum chamber 200 or the nitrogen heater 500 via a first valve 610. The gas filling pipe 600 is used to replenish gas into the vacuum chamber 200 or to supply nitrogen to the nitrogen heater 500.

[0060] In the semiconductor integrated circuit manufacturing process, such as vacuum processes like vapor phase chemical deposition, physical vapor deposition, ion implantation, and molecular beam epitaxy, condenser pumps are often used to obtain a clean vacuum. However, because a condenser pump is a vacuum pump that uses low-temperature surface condensation and adsorption of gas below 20K (1K = -272.15℃) to obtain a vacuum, and because it is a gas storage pump, the adsorbed gas cannot be discharged during operation. When the stored gas reaches saturation, its pumping rate will be greatly reduced, and the vacuum pressure will deteriorate. Therefore, the regeneration process is a means to ensure the condensation and adsorption efficiency of the condenser pump.

[0061] In this embodiment, the vacuum calibration device includes a nitrogen heater 500. One end of a first valve 610 is connected to the outlet of the filling pipe 600, and the other end is connected to either the nitrogen heater 500 or the vacuum chamber 200. The vacuum calibration device controls the flow direction of nitrogen by controlling the first valve 610. That is, when the outlet of the filling pipe 600 is connected to the vacuum chamber 200 through the first valve 610, the filling pipe 600 is used to replenish gas into the vacuum chamber 200. When the outlet of the filling pipe 600 is connected to the nitrogen heater 500 through the first valve 610, the filling pipe 600 is used to supply nitrogen to the nitrogen heater 500.

[0062] When the first valve 610 is connected to the vacuum chamber 200, nitrogen gas flows from the inlet of the filling pipe 600 through the first valve 610 into the vacuum chamber 200. Since the inlet of the pumping unit 400 is also connected to the vacuum chamber 200, the airflow within the vacuum chamber 200 can flow smoothly, thereby allowing the pressure within the vacuum chamber 200 to reach the preset vacuum value. Once the pressure within the vacuum chamber 200 stabilizes, the readings of the vacuum measuring instrument under test (such as a vacuum gauge, pressure sensor, etc.) connected to the vacuum chamber 200 to measure the pressure within the vacuum chamber 200 can be compared with those of the standard vacuum gauge 300. If they are consistent, it indicates that the vacuum calibration of the vacuum measuring instrument under test is complete.

[0063] When the first valve 610 is connected to the nitrogen heater 500, nitrogen gas flows from the inlet of the charging pipe 600 through the first valve 610 to the nitrogen heater 500. After being heated by the nitrogen heater 500, the nitrogen gas can be introduced into the condensate pump for condensate pump regeneration, thereby ensuring the pumping rate of condensate pumping. Preferably, the nitrogen gas can be heated to 850°C in the nitrogen heater 500.

[0064] The vacuum calibration device can not only verify and adjust the accuracy of the readings of the vacuum measuring instrument under test, but also output high-temperature nitrogen gas for use in scenarios requiring high-temperature nitrogen, such as condenser pump regeneration. This gives the vacuum calibration device multiple functions, improving its utilization rate and meeting the high-efficiency utilization needs of modern laboratories or production lines for multifunctional integrated equipment. Furthermore, the vacuum calibration device uses a first valve 610 with multiple ports to allow the vacuum chamber 200 and the nitrogen heater 500 to share a common charging pipe 600, resulting in a compact internal structure and reduced space requirements. This avoids the space occupation and resource waste associated with configuring separate equipment for different functions.

[0065] In some embodiments of this utility model, the vacuum measuring instrument to be tested includes vacuum measuring devices such as thermocouple vacuum gauges, ionization vacuum gauges, and capacitive thin-film vacuum gauges.

[0066] In some embodiments of this utility model, such as Figure 5 As shown, the nitrogen heater 500 includes a cylinder 510, an electric heating element 520, and an insulation layer 530.

[0067] The cylinder 510 is equipped with a nitrogen outlet and a nitrogen inlet connected to the first valve 610. The nitrogen inlet is connected to the charging pipe 600 via the first valve 610 to receive ambient temperature nitrogen from a gas source. The nitrogen outlet is connected to the pipeline of equipment requiring high-temperature nitrogen, such as a condenser pump that needs regeneration, to output heated high-temperature nitrogen.

[0068] The heating element 520 includes a tube body, a heating wire disposed within the tube body, and magnesium oxide powder filled within the tube body. The heating element 520 is disposed within a cylinder 510. Preferably, the heating element 520 has a metal tube body as its outer shell, with high-resistance heating wires tightly arranged inside. The gap between the heating wires and the tube wall is filled with magnesium oxide powder, which has high thermal conductivity and high insulation properties. This allows the magnesium oxide powder to effectively conduct heat to the tube wall, while also ensuring excellent electrical insulation performance and preventing the risk of leakage. Multiple such heating elements 520 are installed inside the cylinder 510 to directly heat nitrogen gas flowing through the cylinder 510.

[0069] The insulation layer 530 is disposed on the outside of the cylinder 510. The insulation layer 530 is preferably made of materials with low thermal conductivity such as ceramic fiber and rock wool. Its function is to minimize the heat loss of the cylinder 510 to the surrounding environment, thereby significantly improving heating efficiency and reducing energy consumption, maintaining the stability of the nitrogen outlet temperature, and preventing the outer wall of the nitrogen heater 500 from overheating, thus ensuring operational safety.

[0070] In some embodiments of this utility model, such as Figure 5As shown, a nitrogen inlet is located at one end of the cylinder 510, and a nitrogen outlet is located at the other end of the cylinder 510. Multiple baffles 511 are disposed inside the cylinder 510, each baffle 511 being perpendicular to the axis of the cylinder 510, and the multiple baffles 511 are arranged sequentially at intervals along the length of the cylinder 510. In every two adjacent baffles 511, the gap formed between one baffle 511 and the cylinder 510 is on one side of the cylinder 510, and the gap formed between the other baffle 511 and the cylinder 510 is on the other side of the cylinder 510, so that the nitrogen entering the cylinder 510 flows in a bend.

[0071] In this embodiment, nitrogen gas enters the cylinder 510 from one end and exits from the other end. Multiple baffles 511, perpendicular to the axis, are sequentially spaced along the length of the cylinder 510. Because the gaps between adjacent baffles 511 and the cylinder 510 are staggered on both sides of the cylinder 510, the nitrogen gas flow cannot pass through the cylinder 510 in a straight line. Instead, it must change direction within the cylinder 510 according to the guidance of the baffles 511, forming a tortuous flow path. This prolongs the residence time of the nitrogen gas within the cylinder 510, allowing sufficient time for heat exchange with the heating element 520, thereby ensuring that the nitrogen gas is heated uniformly and sufficiently.

[0072] Moreover, the multi-partition 511 design can significantly improve heating effect and temperature stability without increasing energy consumption, thereby reducing energy consumption and making it more environmentally friendly.

[0073] In some embodiments of this utility model, multiple parallel fins are arranged between each pair of adjacent partitions 511. Each fin is perpendicular to the axis of the cylinder 510, and both ends of each fin form gaps with the sides of the cylinder 510. For example, the upper side of the first partition 511 forms a gap with the upper side of the cylinder 510, and the lower side of the second partition 511 forms a gap with the lower side of the cylinder 510. The upper and lower ends of the fins between the two partitions 511 form gaps with the cylinder 510, which ensures that nitrogen can enter between the fins and flow out from between the fins, ensuring heating effect while achieving smooth airflow.

[0074] In some embodiments of this invention, the distance between the two baffles 511 gradually increases along the airflow direction. All the baffles 511 and fins are arranged at equal intervals along the length of the cylinder 510. That is, along the airflow direction, the number of fins between the two baffles 511 gradually increases to provide sufficient heat exchange surface near the outlet, improve the heating effect of nitrogen at the outlet, avoid excessive resistance when the airflow flows in the cylinder 510, ensure smooth airflow, and ensure that the temperature of nitrogen at the outlet can reach the expected value.

[0075] In some embodiments of this utility model, such as Figure 4 and Figure 6 As shown, the first valve 610 is a four-way valve, including a first valve port connected to the gas filling pipe 600, a second valve port connected to the vacuum chamber 200, a third valve port connected to the nitrogen heater 500, and a closed fourth valve port. The first valve port is controlled to be connected to either the second or third valve port, so that the first valve 610 can select whether to inject gas flowing out of the gas filling pipe 600 into the vacuum chamber 200 or to deliver it to the nitrogen heater 500 by controlling the conduction of the first valve port to the second or third valve port.

[0076] A mass flow controller 630 is installed between the outlet of the inflation pipe 600 and the first valve 610 to monitor and precisely adjust the gas flow rate through the inflation pipe 600 in real time, ensuring the accuracy and stability of the gas flow rate.

[0077] In some embodiments of this utility model, such as Figure 4 and Figure 6 As shown, a second valve 620 is also provided on the inflation pipe 600. The second valve 620 is a four-way valve, including a fifth valve port, a sixth valve port, a seventh valve port, and an eighth valve port. The fifth valve port is connected to an external air source, and the sixth valve port is connected to the inlet of the mass flow controller 630. When the fifth and sixth valve ports are connected, the inflation pipe 600 is open. The seventh and eighth valve ports are closed. The fifth valve port is controlled to connect to either the sixth or seventh valve port. By controlling the opening and closing of the fifth and sixth or seventh valve ports, the opening and closing of the second valve 620 on the inflation pipe 600 can be achieved.

[0078] The design of the eighth valve port allows for connection to a backup gas source, providing a reliable gas transport structure.

[0079] In this embodiment, the design of the first valve 610 and the second valve 620 working together realizes path switching and flow regulation, ensuring precise control of the airflow direction while ensuring the stability of the gas flow, and providing reliable gas transport guarantee for processes such as vacuum calibration and condenser pump regeneration.

[0080] In some embodiments of this utility model, such as Figure 3 and Figure 6 As shown, the pumping unit 400 includes a molecular pump 410, a vortex pump 420, a vacuum angle valve 430, and a pressure controller 440.

[0081] The inlet of the molecular pump 410 is connected to the vacuum chamber 200 via a vacuum gate valve 470. The vacuum chamber 200, the vacuum gate valve 470, and the molecular pump 410 are arranged sequentially in the vertical direction.

[0082] The vortex pump 420 is connected to the vacuum chamber 200 via a pipeline. Along the direction of airflow within the pipeline, a vacuum butterfly valve 450 and an internal cylinder valve 460 are sequentially installed.

[0083] Vacuum valve 430 is located between the outlet of molecular pump 410 and the inlet of vortex pump 420.

[0084] The pressure controller 440 is connected to the standard vacuum gauge 300 and the vacuum butterfly valve 450 to obtain the pressure in the vacuum chamber 200 and control the opening degree of the vacuum butterfly valve 450 according to the pressure.

[0085] In this embodiment, the molecular pump 410 is a pumping device that uses high-speed rotating blades (20,000–90,000 rpm) to directionally propel gas molecules to the exhaust port 421, thereby achieving the function of pumping gas. Internally, it typically consists of alternating rotor and stator blades. However, as a high-vacuum pump, the molecular pump 410 generally only operates within the vacuum and ultra-vacuum range (0.1 Pa–10⁻⁵ Pa and <-10⁻⁵ Pa), so it needs to be used in conjunction with a backing pump. Preferably, the backing pump is a vortex pump 420 with a working vacuum range of 1000 Pa–0.1 Pa to meet the requirements of rough vacuum calibration. The pumping unit 400 employs a two-stage pump assembly of "rough vacuum + high vacuum" to ensure rapid pumping and maintenance of high vacuum.

[0086] The inlet of the molecular pump 410 is directly connected to the vacuum chamber 200 through the vacuum gate valve 470. The vacuum chamber 200, the vacuum gate valve 470 and the molecular pump 410 are arranged vertically in sequence along the vertical direction to reduce airflow resistance by utilizing gravity, thereby obtaining a higher ultimate vacuum.

[0087] The vortex pump 420 is connected to the vacuum chamber 200 through an independent pipeline. A vacuum butterfly valve 450 and an internal cylinder valve 460 are sequentially installed along the airflow direction on this pipeline. The vacuum butterfly valve 450 is characterized by its compact structure, light weight, low flow resistance, and large flow capacity, while the internal cylinder valve 460 is characterized by its simple structure, small size, and high strength.

[0088] In some embodiments of this utility model, such as Figure 1 and Figure 6 As shown, the vacuum calibration device also includes a PLC controller and a control panel 700.

[0089] The PLC controller is electrically connected to the molecular pump 410, the vortex pump 420, the vacuum gate valve 470, the inline cylinder valve 460, the vacuum angle valve 430, the pressure controller 440, the nitrogen heater 500, the first valve 610, and the second valve 620.

[0090] The control panel 700 is electrically connected to the PLC controller.

[0091] In this embodiment, the vacuum calibration device achieves automated and precise operation through a PLC controller and a control panel 700. The PLC controller can collect system data in real time and output control commands. The control panel 700, as a human-machine interface, is electrically connected to the PLC controller and provides users with functions such as parameter setting, device start / stop, and status monitoring.

[0092] In some embodiments of this utility model, the control panel 700 is a touch screen, and the user can control the vacuum calibration device by touching the touch screen.

[0093] In some embodiments of this invention, vacuum calibration is performed in two ways: low vacuum calibration and high vacuum calibration. Low vacuum calibration has a zero-point calibration mode and a process calibration mode. High vacuum calibration has a zero-point calibration mode.

[0094] During the low vacuum calibration process, the molecular pump 410 is not in operation; only the vortex pump 420 pumps air to achieve the required rough vacuum air pressure. The vacuum gate valve 470 and the vacuum angle valve 430 are both closed, and the internal gas cylinder valve 460 is open. At this time, the vacuum measuring instrument under test, the vacuum chamber 200, and the vortex pump 420 form a sealed chamber.

[0095] In zero-point calibration mode, the PLC controller first activates the vortex pump 420. After 5 seconds, the PLC controller opens the inline cylinder valve 460, and the synchronous pressure controller 440 controls the vacuum butterfly valve 450 to gradually open from 0% to 100% to its maximum. Under normal circumstances, after approximately 30-40 seconds, the pressure in the vacuum chamber 200 drops from atmospheric pressure to 1000 Pa, and within 2 minutes, it drops below 10 Pa, reaching the coarse pumping endpoint. The PLC controller receives the pressure feedback signal from the vacuum chamber 200 and plots a pressure-time curve to determine if the vortex pump 420 is operating normally. The coarse pumping endpoint pressure value can be set via the control panel 700. When the vacuum butterfly valve 450 is 100% open, the vacuum level in the vacuum chamber 200 is the lowest pressure value that the vortex pump 420 can generate. Comparing this reading with the standard vacuum gauge 300 allows for the calibration and adjustment of the zero point of the vacuum measuring instrument under test.

[0096] After the process calibration mode is completed in zero-point calibration mode, in process calibration mode, the PLC controller controls the mass flow controller 630 to start via the control panel 700. The mass flow controller 630 precisely adjusts and stabilizes the input of a certain flow rate of gas. The first valve 610 and the second valve 620 are activated, connecting the gas charging pipe 600 and the mass flow controller 630. The preset vacuum value is input on the control panel 700, and the pressure signal from the pressure controller 440 is fed back to the PLC controller. The PLC controller continuously adjusts the opening of the vacuum butterfly valve 450 to regulate the pressure until the pressure value matches the preset value. The PLC controller then controls the butterfly valve to maintain a stable state through the pressure controller 440. The control panel 700 displays the corresponding adjustment time and the final stable opening of the vacuum butterfly valve 450. After the pressure value stabilizes, the readings of the vacuum gauge under test and the standard vacuum gauge 300 can be compared. If they are consistent, it indicates that the low vacuum calibration is complete.

[0097] In high vacuum calibration, only the zero-point calibration mode is used. In zero-point calibration mode, firstly, the vacuum butterfly valve 450 is opened to 100%, the vacuum gate valve 470 and vacuum angle valve 430 are closed, and the internal cylinder valve 460 is opened. At this time, the vortex pump 420 first operates to evacuate to a medium vacuum. Then, when the pressure value measured by the standard vacuum gauge 300 reaches 0.1 Pa, the vacuum angle valve 430 at the molecular pump 410 opens, and the vortex pump 420 evacuates the interior of the molecular pump 410. Once the vacuum value meets the minimum operating requirements of the molecular pump 410, the molecular pump 410 starts. Subsequently, the vacuum gate valve 470 is opened, and the molecular pump 410 begins evacuating to a high vacuum. Finally, after the pressure reading stabilizes, the vacuum values ​​of the tested vacuum measuring instrument and the standard vacuum gauge 300 are compared and calibrated. The further detailed steps are as follows: The PLC controller controls the vortex pump 420 to start. After 5 seconds of operation, it controls the inline cylinder valve 460 to open, and simultaneously controls the vacuum butterfly valve 450 to open from 0% to 100%. The PLC controller receives the pressure feedback signal. When the pressure value measured by the standard vacuum gauge 300 reaches 0.1 Pa, the PLC controller controls the vacuum angle valve 430 to open. At this time, the pressure value will fluctuate. When the pressure value is set to be less than 0.1 Pa, the molecular pump 410 is started. After the molecular pump 410 starts for 3 seconds, the vacuum gate valve 470 is activated. The molecular pump 410 starts to pump air to a high vacuum. The final high vacuum value is set by the control panel 700.

[0098] In some embodiments of this invention, when using the high-temperature nitrogen regeneration function, the vacuum gate valve 470, vacuum angle valve 430, and internal cylinder valve 460 are all closed, the molecular pump 410 and vortex pump 420 are not working, and the vacuum butterfly valve 450 is open to 0. In the high-temperature nitrogen supply mode, the PLC controller activates the first valve 610 and the second valve 620, connecting the charging pipe 600 and the nitrogen heater 500. The nitrogen flow rate is controlled by the mass flow controller 630, and the heating temperature is adjusted via the control panel 700. Once the set heating temperature is reached, the nitrogen supply can enter the condenser pump for condenser pump regeneration.

[0099] In some embodiments of this utility model, such as Figure 1 As shown, the support frame 100 is a housing. A handle 110 is provided on one side of the housing, and casters 120 are provided at the bottom, which allows the vacuum calibration device to be moved easily and improves the mobility of the vacuum calibration device.

[0100] In some embodiments of this utility model, such as Figure 1 As shown, the upper end of the front surface of the housing is inclined to facilitate user observation and operation. The upper end of the front surface of the housing has a first mounting hole and a second mounting hole. The control panel 700 is located at the first mounting hole, and the pressure controller is located at the second mounting hole, thus centralizing the operating interface for user convenience.

[0101] like Figure 3 As shown, the molecular pump 410 and nitrogen heater 500 are vertically arranged and located on one side of the enclosure to fully utilize vertical space and reduce floor space. The vortex pump 420 is located on the other side of the enclosure. Since the molecular pump 410 and vortex pump 420 are located at opposite ends of the enclosure, the stability of the vortex pump 420 and molecular pump 410, whether operating individually or simultaneously, is ensured, reducing the impact of shaking during operation on the other device. An exhaust port is provided on the side wall of the other side of the enclosure. The exhaust port 421 of the vortex pump 420 extends out of the enclosure through the exhaust port, allowing the airflow in the vortex pump 420 to be directly discharged to the outside of the enclosure. This reduces dust ingress and facilitates the exhaust of the vortex pump 420 to the outside.

[0102] like Figure 3 and Figure 5 As shown, the nitrogen inlet is located at the upper end of the cylinder 510. A first perforation 130 and a second perforation 140 are provided on one side wall of the cylinder. The inlet of the inflation pipe 600 passes through the first perforation 130 and exits the cylinder to facilitate connection with an external gas source. The nitrogen outlet passes through the second perforation 140 and exits the cylinder to discharge nitrogen.

[0103] The interior of the enclosure is connected to the outside through the first perforation 130 and the second perforation 140, which improves the enclosure's airtightness and reduces the occurrence of dust entering the enclosure.

[0104] In some embodiments of this utility model, such as Figure 1 and Figure 2 As shown, the first perforation 130 and the second perforation 140 are spaced apart in the vertical direction, maintaining the overall neatness of the box.

[0105] In some embodiments of this utility model, such as Figure 1 and Figure 3 As shown, the vacuum chamber 200 is provided with multiple vacuum device interfaces 800. At least one vacuum device interface 800 is connected to a different vacuum device than the other vacuum device interfaces 800, so that users can calibrate, test or compare multiple vacuum devices simultaneously in a single vacuuming cycle, thereby improving calibration efficiency and calibration accuracy.

[0106] In some embodiments of this utility model, the vacuum equipment interface 800 extends upwards from the housing, facilitating the installation, disassembly, and replacement of various vacuum equipment or sensors by the user. This avoids the user having to bend over or move the housing, resulting in more ample operating space. The vacuum equipment interface 800 is concentrated at the top, preventing interference with structures such as the rollers 120, handles 110, first through-hole 130, second through-hole 140, or heat dissipation holes located on the side of the housing. It also reduces the risk of accidental collisions between the vacuum equipment interface 800 and the vacuum equipment.

[0107] In some embodiments of this utility model, such as Figure 3 As shown, a first flange is provided at the bottom opening of the vacuum chamber 200. A second flange is provided at the upper end of the molecular pump 410. The vacuum gate valve 470 is located between the first flange and the second flange. The vacuum chamber 200, the vacuum gate valve 470, and the second flange are fixedly connected by screws passing through the first flange and the vacuum gate valve 470 and connecting to the second flange.

[0108] In this embodiment, screws are sequentially passed through the first flange, the vacuum gate valve 470 flange, and finally screwed into the threaded hole of the second flange, tightly fixing the vacuum chamber 200, vacuum gate valve 470, and molecular pump 410 into a rigid, integrated structure. This improves the airtightness of the joints between the vacuum chamber 200, vacuum gate valve 470, and molecular pump 410, reducing the risk of leakage. Simultaneously, this structure not only ensures high connection strength between the vacuum chamber 200, vacuum gate valve 470, and molecular pump 410, but also facilitates disassembly and reassembly during maintenance, balancing stability and convenience.

[0109] In some embodiments of this invention, a gas pump is also provided between the nitrogen inlet and the first valve 610. The gas pump is located inside the housing to provide power for the flow of nitrogen in the filling pipe 600. Placing the gas pump inside the housing makes the internal structure of the housing more compact, further improving the space utilization of the vacuum calibration device.

[0110] In some alternative embodiments of this invention, the outlet of the vortex pump 420 is directly connected to the outside via a third valve, or connected to a nitrogen inlet. The third valve may be a four-way valve, having a ninth valve port, a tenth valve port, an eleventh valve port, and a twelfth valve port. The ninth valve port is connected to the outlet of the vortex pump 420, the tenth valve port is connected to the outside, the eleventh valve port is connected to the nitrogen inlet, and the twelfth valve port is closed.

[0111] In this embodiment, when supplying gas to the nitrogen heater 500, not only can an external gas pump be used, but the vortex pump 420 in this vacuum calibration device can also be used as the gas pump, making the use of the vacuum calibration device more flexible and convenient.

[0112] Therefore, those skilled in the art should recognize that although many exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications conforming to the principles of the present invention can be directly determined or derived from the disclosure of the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all such other variations or modifications.

Claims

1. A vacuum calibration device, comprising a support frame and a vacuum chamber disposed on the support frame; characterized in that, Also includes: A standard vacuum gauge, which is connected to the vacuum chamber; A vacuum pumping unit is mounted on the support frame. The inlet of the vacuum pumping unit is connected to the vacuum chamber. The vacuum pumping unit is used to extract gas from the vacuum chamber. A nitrogen heater, wherein the nitrogen heater is mounted on the support frame; An inflation pipe is provided on the support frame. The outlet of the inflation pipe is connected to the vacuum chamber or the nitrogen heater through a first valve. The inflation pipe is used to replenish gas into the vacuum chamber or to supply nitrogen to the nitrogen heater.

2. The vacuum calibration device according to claim 1, characterized in that, The nitrogen heater includes: The cylinder has a nitrogen outlet and a nitrogen inlet connected to the first valve. An electric heating element, comprising a tube body, a heating wire disposed within the tube body, and magnesium oxide powder filled within the tube body; the electric heating element is disposed within a cylindrical body; An insulation layer is provided on the outside of the cylinder.

3. The vacuum calibration device according to claim 2, characterized in that, The nitrogen inlet is located at one end of the cylinder, and the nitrogen outlet is located at the other end of the cylinder. Multiple baffles are provided inside the cylinder, each baffle being perpendicular to the axis of the cylinder, and the baffles are spaced apart sequentially along the length of the cylinder. In every two adjacent baffles, the gap between one baffle and the cylinder is on one side of the cylinder, and the gap between the other baffle and the cylinder is on the other side of the cylinder, so that the nitrogen entering the cylinder flows in a curved manner.

4. The vacuum calibration device according to claim 2, characterized in that, The first valve is a four-way valve, including a first valve port connected to the gas filling pipe, a second valve port connected to the vacuum chamber, a third valve port connected to the nitrogen heater, and a closed fourth valve port; the first valve port is controlled to be connected to the second valve port or the third valve port. A mass flow controller is provided between the outlet of the air inlet pipe and the first valve; The inflation tube is also equipped with a second valve, which is a four-way valve, including a fifth valve port, a sixth valve port, a seventh valve port, and an eighth valve port; when the fifth valve port is connected to the sixth valve port, the inflation tube is connected; the seventh valve port and the eighth valve port are closed; the fifth valve port is controlled to be connected to the sixth valve port or the seventh valve port.

5. The vacuum calibration device according to claim 4, characterized in that, The air extraction unit includes: A molecular pump, the inlet of which is connected to the vacuum chamber via a vacuum gate valve; the vacuum chamber, the vacuum gate valve, and the molecular pump are arranged sequentially in a vertical direction; A vortex pump is connected to the vacuum chamber via a pipeline; along the airflow direction in the pipeline, a vacuum butterfly valve and an internal gas cylinder valve are sequentially installed on the pipeline. A vacuum angle valve is disposed between the outlet of the molecular pump and the inlet of the vortex pump; A pressure controller is connected to a standard vacuum gauge and the vacuum butterfly valve to obtain the pressure inside the vacuum chamber and control the opening degree of the vacuum butterfly valve according to the pressure.

6. The vacuum calibration device according to claim 5, characterized in that, Also includes: The PLC controller is electrically connected to the molecular pump, the vortex pump, the vacuum gate valve, the inline cylinder valve, the vacuum angle valve, the pressure controller, the nitrogen heater, the first valve, and the second valve. The control panel is electrically connected to the PLC controller.

7. The vacuum calibration device according to claim 6, characterized in that, The support frame is a box-shaped structure; a handle is provided on one side of the box-shaped structure, and rollers are provided at the bottom. The upper end of the front surface of the housing is inclined and is provided with a first mounting hole and a second mounting hole; The control panel is located at the first mounting hole, and the pressure controller is located at the second mounting hole; The molecular pump and the nitrogen heater are arranged vertically and located on one side of the chamber; the vortex pump is located on the other side of the chamber; an exhaust port is provided on the side wall of the other side of the chamber, and the exhaust port of the vortex pump extends out of the chamber from the exhaust port; The nitrogen inlet is located at the upper end of the cylinder; a first perforation and a second perforation are provided on one side wall of the housing, the inlet of the gas filling pipe passes through the first perforation and exits the housing, and the nitrogen outlet passes through the second perforation and exits the housing.

8. The vacuum calibration device according to claim 7, characterized in that, The vacuum chamber is provided with multiple vacuum equipment interfaces, and at least one of the vacuum equipment interfaces is connected to a different vacuum equipment than the other vacuum equipment interfaces. The vacuum equipment interface extends upwards from the housing.

9. The vacuum calibration device according to claim 8, characterized in that, A first flange is provided at the bottom opening of the vacuum chamber; The upper end of the molecular pump is provided with a second flange; The vacuum gate valve is located between the first flange and the second flange; The vacuum chamber, the vacuum gate valve, and the second flange are fixedly connected by screws passing through the first flange and the vacuum gate valve and connecting to the second flange.

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