Vacuum-pumping system suitable for HP-RTM process

Abstract

The utility model relates to the technical field of vacuum-pumping equipment, in particular to a vacuum-pumping system suitable for an HP-RTM (High Pressure-Resin Transfer Molding) process, which comprises a pre-vacuum-pumping module, a fine vacuum-pumping module and a sensing control module, the roots pump unit serves as fine pumping equipment to supplement pumping and maintain the vacuum degree and is matched with the two vacuum buffer tanks to achieve the high vacuum degree of the system, the air compressor supplies air to the pneumatic valve to ensure reliable sealing of the pipeline, and the stainless steel vacuum pumping pipeline, the oil mist separator and the filter reduce impurity residues and improve the filtering efficiency. The vacuumizing module is matched with a high-precision sensor to achieve low pressure and high vacuumizing speed, and system parameterization control meets the process requirements of different components. The whole equipment adopts modular design, maintenance and pipeline improvement are facilitated, pipelines are optimized, a convenient filter is installed, the vacuumizing efficiency is improved, the service life of the pipelines is prolonged, the matching degree with HP-RTM process production equipment is high, and stable high vacuum is achieved.

Description

Technical Field

[0001] The utility model relates to the technical field of vacuum equipment, in particular to a vacuum system suitable for HP-RTM process. Background Art

[0002] In the high-pressure resin transfer molding (HP-RTM) process, the vacuum system is a crucial component. The HP-RTM process is an advanced resin composite molding technology that manufactures lightweight, high-strength composite parts by injecting resin into the mold. It is widely used in aerospace, automotive, shipbuilding and other fields. In the HP-RTM process, ensuring a high vacuum environment inside the mold is crucial for the full penetration and curing of the resin, which directly affects the quality and performance of the molded parts. The HP-RTM process vacuum system has the following technical difficulties:

[0003] 1. High-efficiency vacuuming: The HP-RTM process requires a high degree of vacuum in a short time to ensure that the resin can fully penetrate every corner of the mold. Therefore, the vacuuming system needs to be highly efficient and able to extract air quickly and reliably.

[0004] 2. Stability and reliability: During the process, the vacuum system must be able to operate stably for a long time and maintain consistent performance during long-term use to ensure the stable and consistent quality of the molded parts.

[0005] 3. Material compatibility: The material of the vacuum system must be compatible with the resin used in the process to prevent material contamination or reaction from affecting the quality of the finished product.

[0006] 4. Automation and control: The vacuum system may need to be integrated with the automated control system of the molding equipment to achieve automation and precise control of the molding process, thereby improving production efficiency and product quality.

[0007] At the same time, the HP-RTM process has the following characteristics: Many impurities: impurities or corrosive substances such as unsaturated vapor of carbon fiber, resin, and solvent are contained in the process. Fast curing: a fast curing resin system is used to shorten the production cycle. Complex geometric structures: complex geometric structures and details can be manufactured. Therefore, the common vacuum pumping system on the market is no longer suitable for the HP-RTM process, and a vacuum pumping system for the HP-RTM process needs to be designed. Utility Model Content

[0008] The purpose of the utility model is to provide a vacuum pumping system suitable for HP-RTM process to solve the above problems. By improving the traditional vacuum pumping equipment, modular design, selecting Roots vacuum pump and rotary vane vacuum pump for pre-vacuuming and fine pumping, high pumping speed and high vacuum degree are achieved. Filters and oil mist separators are installed in the pipeline to reduce the residual impurities in the gas and pipeline. The air compressor cooperates with the pneumatic valve to ensure the sealing of the vacuum pumping equipment. The PLC control system is used to perform parameterized control of the equipment. The whole equipment design achieves the purposes of high vacuum, high pumping speed, stable vacuum, impurity removal and oil control, and meets the vacuum pumping requirements of HP-RTM.

[0009] In order to achieve the above purpose, the technical solution adopted by the utility model is as follows:

[0010] A vacuum pumping system suitable for HP-RTM process, characterized in that: the whole equipment is modularly designed and divided into a pre-vacuum pumping module, a fine vacuum pumping module and a sensor control module, and the three modules are bolted to a frame: the pre-vacuum pumping module comprises: a pre-vacuum pumping pipeline, a vacuum clamp, a vacuum electromagnetic pressure difference valve, a rotary vane vacuum pump, a vacuum bellows, a vacuum buffer tank, a vacuum pneumatic solenoid valve, a vacuum pressure sensor, and a frame; the pre-vacuum pumping pipeline is connected to the rotary vane vacuum pump and the vacuum buffer tank; a vacuum electromagnetic pressure difference valve is connected between the pre-vacuum pumping pipeline and the rotary vane vacuum pump; a vacuum bellows and a vacuum pneumatic solenoid valve are connected between the pre-vacuum pumping pipeline and the vacuum buffer tank; and the vacuum pressure sensor is installed above the vacuum buffer tank;

[0011] Further, the fine vacuum module includes: a fine vacuum pipeline, a vacuum clamp, a vacuum pneumatic solenoid valve, a vacuum resistance gauge, a muffler, a mold interface valve, a mold access pipeline, a filter, a Roots vacuum pump, a rotary vane vacuum pump, a vacuum buffer tank, an air compressor, and an oil mist separator. The fine vacuum pipeline is connected to the vacuum mold, the vacuum buffer tank, the Roots vacuum pump and the rotary vane vacuum pump. The mold access pipeline is connected to 4 mold interface valves, and then connected to a vacuum pneumatic solenoid valve with a muffler, and then through a filter. The fine vacuum pipeline has three branches, the two end branches are connected to two vacuum buffer tanks, and the middle branch is connected to a Roots vacuum pump and a rotary vane vacuum pump. A vacuum resistance gauge is installed on the fine vacuum pipeline before connecting the vacuum pump, and the oil mist separator is bolted to the frame;

[0012] Further, the sensor control module includes: a system control cabinet, a vacuum pressure sensor, and a vacuum resistance gauge;

[0013] Furthermore, the pipeline connection with the vacuum pumping pipeline and the precision pumping pipeline uses a vacuum clamp, which can quickly connect the vacuum pipeline and facilitate pipeline maintenance and pipeline redesign.

[0014] Furthermore, the pre-vacuum module is pre-vacuumed by a rotary vane vacuum pump, and the fine vacuum module is composed of a unit consisting of a rotary vane vacuum pump and a Roots vacuum pump to achieve fine vacuuming. The two-stage vacuuming achieves high pumping speed and high vacuum degree of the system, meeting the short cycle and high vacuum requirements of the HP-RTM process.

[0015] Furthermore, the pipeline interfaces of the pre-vacuum pipelines and the fine-pumping pipelines of the pre-vacuum module and the fine-pumping module are connected by vacuum pneumatic solenoid valves. The air compressor provides the air source for these valves, and the valves automatically close by spring force to ensure the system sealing and vacuum stability. The air inlet of the vacuum pump of the pre-vacuum module and the fine-pumping module adopts a vacuum solenoid pressure differential valve to effectively prevent oil return from the mechanical pump.

[0016] Furthermore, the fine pumping pipeline of the fine vacuum module is designed with a filter and a silencer, and an oil mist separator is installed in the rear section, which has the functions of removing impurities, degreasing and silencing; the filter is a homemade portable filter, and the filter element can be replaced to achieve the impurity removal requirements of carbon fiber composite materials with different components.

[0017] Furthermore, the vacuum detection of the pre-vacuum module and the fine vacuum module is respectively realized by a vacuum pressure sensor and a vacuum resistance gauge, which cooperate with the system control circuit to accurately control the vacuum degree.

[0018] Compared with the prior art, the utility model has the following beneficial effects:

[0019] 1. The utility model adopts two rotary vane vacuum pumps (one for use and one for standby) integrated with a Roots vacuum pump to improve the energy saving, high efficiency and stability of vacuum extraction.

[0020] 2. The utility model optimizes the design of the system pipeline, uses a vacuum bellows at the pipeline interface, designs a convenient filter device at the vacuum pump inlet, and connects the pipeline to the oil mist separator. The entire pipeline reduces impurity residue and improves filtering efficiency.

[0021] 3. The utility model adopts modular design, which is divided into a vacuum pumping module, a fine vacuum pumping module and a sensor control module. The pipelines are sealed and connected with vacuum clamps, which is convenient for pipeline maintenance, replacement and pipeline upgrading.

[0022] 4. The utility model adopts a high-precision vacuum gauge to detect the pre-vacuuming and fine vacuuming modules and combines a two-stage high-speed vacuuming system to achieve low pressure and high pumping speed.

[0023] 5. The utility model uses pneumatic valves between the vacuum pump and the pipeline, and the air compressor provides an air source to achieve rapid closure of the valve, thereby ensuring the sealing and vacuum stability of the entire equipment.

[0024] 6. The utility model uses a parameterized vacuum control system to adjust the vacuuming rate and vacuum time to meet the process requirements of different cycles and vacuum degrees. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is the axonometric diagram of the overall layout of the vacuum system of the utility model suitable for HP-RTM process

[0026] Figure 2 This is the front view of the overall equipment layout of the utility model

[0027] Figure 3 This is the rear view of the overall equipment layout of the utility model

[0028] Figure 4 This is the electrical schematic diagram of the utility model equipment

[0029] Markings and corresponding parts names in the attached drawings:

[0030] 1. Fine extraction pipeline; 11. Vacuum pneumatic solenoid valve; 12. Vacuum resistance gauge; 13. Muffler; 14. Mold interface valve; 15. Mold access pipeline; 16. Filter; 17. Roots vacuum pump; 2. Vacuum pressure sensor; 3. Oil mist separator; 4. Vacuum buffer tank; 5. System control cabinet; 6. Drain valve; 7. Pre-vacuum pipeline; 71. Vacuum solenoid pressure differential valve; 72. Rotary vane vacuum pump; 73. Vacuum bellows; 8. Vacuum clamp; 9. Air compressor; 10. Frame; DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0032] Reference Figure 1-4, This embodiment provides a vacuum pumping system suitable for HP-RTM process. The whole equipment is modularly designed and divided into a pre-vacuum pumping module, a fine vacuum pumping module and a sensor control module. The three modules are bolted to the frame 10: the pre-vacuum pumping module includes: a pre-vacuum pumping pipeline 7, a vacuum clamp 8, a vacuum electromagnetic pressure difference valve 71, a rotary vane vacuum pump 72, a vacuum bellows 73, a vacuum buffer tank 4, a vacuum pneumatic solenoid valve 11, a vacuum pressure sensor 2, and a frame 10. The pre-vacuum pumping pipeline 7 connects the rotary vane vacuum pump 72 and the vacuum buffer tank 4. A vacuum electromagnetic pressure difference valve 71 is connected between the pre-vacuum pumping pipeline 7 and the rotary vane vacuum pump 72. A vacuum bellows 73 and a vacuum pneumatic solenoid valve 11 are connected between the pre-vacuum pumping pipeline 7 and the vacuum buffer tank 4. The vacuum pressure sensor 2 is installed above the vacuum buffer tank 4;

[0033] The fine vacuum module includes: a fine pumping pipeline 1, a vacuum clamp 8, a vacuum pneumatic solenoid valve 11, a vacuum resistance gauge 12, a muffler 13, a mold interface valve 14, a mold access pipeline 15, a filter 16, a Roots vacuum pump 17, a rotary vane vacuum pump 72, a vacuum buffer tank 4, an air compressor 9, and an oil mist separator 3. The fine pumping pipeline 1 is connected to the vacuum mold, the vacuum buffer tank 4, the Roots vacuum pump 17 and the rotary vane vacuum pump 72. The mold access pipeline 15 is connected to four mold interface valves 14, and then connected to the vacuum pneumatic solenoid valve 11 with a muffler 13, and then through the filter 16. The fine pumping pipeline 1 has three branches, the two end branches are connected to two vacuum buffer tanks 4, and the middle branch is connected to the Roots vacuum pump 17 and the rotary vane vacuum pump 72. The fine pumping pipeline 1 is installed with a vacuum resistance gauge 12 before connecting the vacuum pump, and the oil mist separator 3 is bolted to the frame 10;

[0034] The sensor control module includes: a system control cabinet 5, a vacuum pressure sensor 2, and a vacuum resistance gauge 12;

[0035] To further optimize the solution, the pre-vacuum pipeline 7 and the fine-vacuum pipeline 1 are connected by a vacuum clamp 8, which can quickly connect the vacuum pipeline and facilitate pipeline maintenance and pipeline redesign.

[0036] To further optimize the solution, the pre-vacuum module is pre-vacuumed by a rotary vane vacuum pump, and the fine vacuum module is composed of a unit consisting of a rotary vane vacuum pump 72 and a Roots vacuum pump 17 to achieve fine vacuuming. The two-stage vacuuming achieves high pumping speed and high vacuum degree of the system, meeting the short cycle and high vacuum requirements of the HP-RTM process.

[0037] To further optimize the solution, the pipeline interfaces of the pre-vacuum pipeline 7 and the fine pumping pipeline 1 of the pre-vacuum module and the fine pumping module are connected by a vacuum pneumatic solenoid valve 11, and the air compressor 9 provides the air source for these valves. The valves automatically close by spring force to ensure the sealing of the system and the stability of the vacuum degree. The air inlet of the vacuum pump of the pre-vacuum module and the fine pumping module adopts a vacuum electromagnetic pressure differential valve to effectively prevent oil return from the mechanical pump.

[0038] To further optimize the solution, the system pipeline is designed with a filter 16 and a silencer 13 at the front end, and an oil mist separator 3 is installed at the rear end, which has the functions of removing impurities, degreasing and silencing; the filter 16 is a homemade portable filter, and the filter element can be replaced to achieve the impurity removal requirements of carbon fiber composite materials with different components.

[0039] To further optimize the scheme, vacuum detection of the pre-vacuum module and the fine vacuum module is achieved by a vacuum pressure sensor (2) and a vacuum resistance gauge (12) respectively, and the vacuum degree is precisely controlled in coordination with the system control circuit.

[0040] Example 1

[0041] like Figure 4 , V1 and V2 are the inlet solenoid valves (anti-oil return valves) of the SV220B rotary vane pump. The V1 and V2 solenoid valves are opened synchronously with the vacuum pump. V3~V9 are vacuum pneumatic solenoid valves, and their functions are as follows:

[0042] V3 and V4 are valves connecting the No. 1 pump (pre-pump) and the two vacuum tanks;

[0043] V5 and V6 are valves connecting the vacuum tank and the mold respectively;

[0044] V7 is the valve connecting the Roots vane unit and the mold;

[0045] V8 is the main pipeline on-off valve;

[0046] V9 is the mold pressure relief valve;

[0047] In the automatic operation state: #1 rotary vane pump starts, V3 valve opens, when #1 vacuum tank reaches -99KPa, V3 valve closes; then V4 valve opens, when #2 vacuum tank reaches -99KPa, V4 valve closes, V3 valve continues to open, and the cycle repeats. V3 and V4 valves are not opened at the same time. When both vacuum tanks reach the set vacuum value, the pre-pumping is completed and an alarm is issued. After #1 rotary vane pump starts, the Roots rotary vane unit starts after a delay of 2-3 minutes (time adjustable) (the rotary vane pump starts first, and the Roots pump starts after a delay). When the set vacuum value is reached in both vacuum tanks, the V8 valve opens automatically, followed by the V5 valve. When the vacuum degree in tank #1 is lower than -60KPa, the V5 valve closes and the V6 valve opens. When the vacuum degree in tank #2 is lower than -80KPa, the V6 valve closes and the V7 valve opens. The V7 valve automatically closes after a delay (adjustable time). After the V7 valve closes, the V8 valve automatically closes. The V9 pressure relief valve opens after a delay (adjustable time), and closes after a delay (adjustable time). Roots pump protection function: When the V7 valve is opened, the vacuum degree is lower than 1KPa within 3 minutes (adjustable time), the control cabinet alarms and the V7 valve automatically closes. This system has a 220V air compressor 9 to provide air source for all pneumatic valves.

[0048] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0049] The embodiments described above are only descriptions of the preferred methods of the present invention, and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should fall within the protection scope determined by the claims of the present invention.

Claims

1. A vacuum pumping system suitable for HP-RTM process, characterized by: The whole equipment is modularly designed and is divided into a pre-vacuum module, a fine vacuum module and a sensor control module. The three modules are bolted to the frame (10): The pre-vacuum module comprises: a pre-vacuum pipeline (7), a vacuum clamp (8), a vacuum electromagnetic pressure differential valve (71), a rotary vane vacuum pump (72), a vacuum bellows (73), a vacuum buffer tank (4), a vacuum pneumatic electromagnetic valve (11), a vacuum pressure sensor (2), and a frame (10); the pre-vacuum pipeline (7) is connected to the rotary vane vacuum pump (72) and the vacuum buffer tank (4); a vacuum electromagnetic pressure differential valve (71) is connected between the pre-vacuum pipeline (7) and the rotary vane vacuum pump (72); a vacuum bellows (73) and a vacuum pneumatic electromagnetic valve (11) are connected between the pre-vacuum pipeline (7) and the vacuum buffer tank (4); and the vacuum pressure sensor (2) is installed above the vacuum buffer tank (4); The fine vacuum module comprises: a fine vacuum pipeline (1), a vacuum clamp (8), a vacuum pneumatic solenoid valve (11), a vacuum resistance gauge (12), a muffler (13), a mold interface valve (14), a mold access pipeline (15), a filter (16), a Roots vacuum pump (17), a rotary vane vacuum pump (72), a vacuum buffer tank (4), an air compressor (9), and an oil mist separator (3). The fine vacuum pipeline (1) is connected to the vacuum mold, the vacuum buffer tank (4), the Roots vacuum pump (17) and the rotary vane vacuum pump ( 72), the mold access pipeline (15) is connected to four mold interface valves (14), then connected to a vacuum pneumatic solenoid valve (11) with a muffler (13), and then through a filter (16), the fine pumping pipeline (1) has three branches, the two end branches are connected to two vacuum buffer tanks (4), the middle branch is connected to a Roots vacuum pump (17) and a rotary vane vacuum pump (72), the fine pumping pipeline (1) is installed with a vacuum resistance gauge (12) before connecting to the vacuum pump, and the oil mist separator (3) is bolted to the frame (10); The sensor control module comprises: a system control cabinet (5), a vacuum pressure sensor (2), and a vacuum resistance gauge (12).

2. A vacuum pumping system suitable for HP-RTM process according to claim 1, characterized in that: The pipeline connection between the pre-vacuuming pipeline (7) and the fine-vacuuming pipeline (1) uses a vacuum clamp (8), which can quickly connect the vacuum pipeline, making it easy to repair and redesign the pipeline.

3. A vacuum pumping system suitable for HP-RTM process according to claim 1, characterized in that: The pre-vacuuming module is pre-vacuumed by a rotary vane vacuum pump (72), and the fine vacuuming module is composed of a unit consisting of a rotary vane vacuum pump (72) and a Roots vacuum pump (17) to achieve fine vacuuming. The two-stage vacuuming achieves high system pumping speed and high vacuum degree, thus meeting the short cycle and high vacuum requirements of the HP-RTM process.

4. A vacuum pumping system suitable for HP-RTM process according to claim 1, characterized in that: The pipeline interfaces of the pre-vacuuming pipeline (7) and the fine pumping pipeline (1) of the pre-vacuuming module and the fine pumping module are connected by vacuum pneumatic solenoid valves (11). The air compressor (9) provides an air source for these valves. The valves automatically close by relying on spring force to ensure the sealing of the system and the stability of the vacuum degree. The vacuum pump air inlet of the pre-vacuuming module and the fine pumping module adopts a vacuum solenoid pressure differential valve to effectively prevent oil return from the mechanical pump.

5. A vacuum pumping system suitable for HP-RTM process according to claim 1, characterized in that: The fine extraction pipeline (1) of the fine extraction vacuum module is provided with a designed filter (16) and a silencer (13), and an oil mist separator (3) is installed at the rear section, which has the functions of removing impurities, removing oil and silencing; the filter (16) is a homemade portable filter, and the filter element can be replaced to achieve the impurity removal requirements of carbon fiber composite materials with different components.

6. A vacuum pumping system suitable for HP-RTM process according to claim 1, characterized in that: The vacuum detection of the pre-vacuuming module and the fine vacuuming module is respectively achieved by a vacuum pressure sensor (2) and a vacuum resistance gauge (12), and the vacuum degree is precisely regulated in coordination with the system control circuit.

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