Fluid metering device

Abstract

The invention belongs to the technical field of fluid metering equipment, and discloses a fluid metering device which comprises an electric cylinder driving device used for driving a piston rod to reciprocate in a closed cylinder body; the high-pressure gas control switching valve module comprises four switching valves which are a switching valve A, a switching valve B, a switching valve C and a switching valve D respectively, and the switching valve module is used for switching between liquid suction and liquid drainage; the inlet pressure sensor and the outlet pressure sensor are used for detecting pressure changes of the liquid inlet end and the liquid outlet end. The mode that the servo motor drives the precise electric cylinder is adopted, high-precision control over reciprocating motion of the piston rod in the closed cylinder body is achieved, the fluid metering device is used for achieving volume switching of the upper metering closed cylinder body and the lower metering closed cylinder body so as to form continuous fluid output, the metering error can be controlled within 1%, and the metering precision is greatly improved. And stepless regulation of the flow in the range of 0-100% is supported, and the accuracy and flexibility of fluid metering are greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fluid metering equipment, and in particular to a fluid metering device. Background Art

[0002] The existing metering device adopts a single-stroke or double-stroke design, uses a motor to drive the piston rod to reciprocate in the metering cylinder, uses a one-way valve to achieve the suction and discharge of liquid, causes changes in the volume and pressure of the cavity, and achieves the purpose of metering.

[0003] Disadvantages or shortcomings:

[0004] 1. The existing single-stroke metering device has alternating intervals between suction and discharge, and the slow connection speed leads to large flow pulsation and unstable pressure, which in turn affects the spraying effect.

[0005] 2. The existing double-stroke metering device is driven by a screw rod, a screw rod seat and a slide rail. There is an installation error that leads to a large concentricity deviation and greater wear; and the positioning accuracy is poor, resulting in a large error in the metering output result.

[0006] 3. There are many parts, the size is large, and the maintenance is complicated and difficult. Summary of the invention

[0007] The main purpose of the present invention is to provide a fluid metering device, aiming to solve the technical problems of the existing single-stroke metering device, such as alternating intervals between suction and discharge, slow connection speed resulting in large flow pulsation, unstable pressure and thus affecting the spraying effect.

[0008] In order to achieve the above-mentioned object of the invention, the first aspect of the present invention provides a fluid metering device; comprising:

[0009] The electric cylinder driving device is used to drive the piston rod to reciprocate in the closed cylinder body;

[0010] A high-pressure gas control switching valve module, comprising four switching valves, the four switching valves being switching valve A, switching valve B, switching valve C and switching valve D, the switching valve module being used to switch between liquid suction and liquid discharge;

[0011] Inlet and outlet pressure sensors are used to detect pressure changes at the liquid inlet and outlet ends.

[0012] Furthermore, the switching valve A and the switching valve C are respectively connected to the discharge path of the fluid metering device, and the switching valve B and the switching valve D are respectively connected to the suction path of the fluid metering device;

[0013] When the high-pressure gas control switching valve module is in the self-checking process, it is determined whether there is leakage in the switching valve and the piston rod by controlling the opening and closing of the four switching valves and monitoring the pressure change within the set time;

[0014] The electric cylinder driving device is driven by a servo motor, and the servo motor is used to drive the precision electric cylinder, and the precision electric cylinder drives the piston rod to reciprocate in the closed cylinder body, and can accurately control the position of the piston rod, thereby realizing accurate control of the fluid volume;

[0015] The fluid metering device is used to realize the volume switching of the upper and lower metering closed cylinders to form a continuous fluid output, and the metering error can be controlled within 1%;

[0016] The sealed cylinder is made of corrosion-resistant material, especially ceramic material, to extend the service life of the device;

[0017] The high-pressure gas control switching valve module adopts a self-made high-pressure valve, which can withstand a pressure of at least 3000psi;

[0018] The precision electric cylinder adopts a high positioning accuracy electric cylinder with a metering error controlled within 1%, and the flow rate can be adjusted steplessly within the range of 0-100%;

[0019] The precision electric cylinder and the piston rod are integrated to ensure the concentricity of the piston rod, thereby reducing mechanical wear and improving the overall life of the device.

[0020] It also includes a throat lubricating oil cup, which is arranged on the outer wall of the closed cylinder body and is used to provide lubricating oil to the contact surface between the piston rod and the closed cylinder body, thereby reducing friction between the two, improving the reliability of the device and extending its service life.

[0021] Beneficial effects:

[0022] The fluid metering device of the present invention is derived based on the content of the exclusive right 1 to obtain beneficial effects.

[0023] 1. The present invention adopts the method of servo motor driving precision electric cylinder to realize high-precision control of the reciprocating motion of the piston rod in the closed cylinder body. The fluid metering device is used to realize the volume switching of the upper and lower metering closed cylinder bodies to form a continuous fluid output, and can control the metering error within 1%, and support stepless adjustment of the flow rate in the range of 0-100%, which greatly improves the accuracy and flexibility of fluid metering. And through optimized design, the number of parts is reduced and the structure of the entire device is simplified. This not only reduces the manufacturing cost, but also makes daily maintenance simpler and faster, reducing downtime and maintenance costs.

[0024] 2. The closed cylinder body in the present invention is made of ceramic material with excellent corrosion resistance. This material not only has good corrosion resistance, but also can withstand higher pressure, thereby ensuring the long-term stable operation of the equipment in harsh environments. The switching valve uses a homemade high-pressure valve that can withstand a pressure of 3000psi. Changes in the outlet pressure will not affect the results of the quantitative output, thereby improving the stability of the metering system.

[0025] 3. The present invention detects whether there is leakage in the system by controlling the switch status of four switching valves and monitoring the pressure change within a preset time. This function helps to discover potential problems in time, prevent production interruptions due to failures, and improve the reliability and safety of the system.

[0026] 4. The precision electric cylinder and the piston rod of the present invention adopt an integrated structural design to ensure the concentricity of the piston rod and reduce mechanical wear. At the same time, by setting a throat lubricating oil cup on the outer wall of the closed cylinder body, lubricating oil is provided to the contact surface between the piston rod and the closed cylinder body, further reducing the friction coefficient and improving the reliability and service life of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a structural schematic diagram of a fluid metering device according to an embodiment of the present invention;

[0028] Figure 2 is a front view of a fluid metering device according to an embodiment of the present invention;

[0029] Figure 3 An embodiment of the present invention Figure 2 Cross-section of the middle AA;

[0030] Figure 4 This is a diagram showing the components of a high-pressure gas control switching valve module according to an embodiment of the present invention;

[0031] Figure 5 is a schematic diagram of switching valve leakage detection according to an embodiment of the present invention;

[0032] Figure 6 It is a schematic diagram of piston leakage detection according to an embodiment of the present invention.

[0033] in:

[0034] 1-Servo motor; 2-Precision electric cylinder; 3-Piston rod; 4-Enclosed cylinder body; 51-Switch valve A; 52-Switch valve B; 53-Switch valve C; 54-Switch valve D; 6-Throat lubricating oil cup; 7-Inlet pressure sensor; 8-Outlet pressure sensor.

[0035] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0036] It should be understood that the specific embodiments described herein are only used to explain the present invention, and are not used to limit the present invention.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0040] Reference Figure 1-Figure 6 An embodiment of the present invention provides a fluid metering device; comprising:

[0041] The electric cylinder driving device is used to drive the piston rod 3 to reciprocate in the closed cylinder body 4;

[0042] A high-pressure gas control switching valve module, comprising four switching valves, namely a switching valve A51, a switching valve B52, a switching valve C53 and a switching valve D54, wherein the switching valve module is used to switch between liquid suction and liquid discharge;

[0043] Inlet and outlet pressure sensors are used to detect pressure changes at the liquid inlet and outlet ends.

[0044] Among them, the inlet and outlet pressure sensors are divided into inlet pressure sensor 7 and outlet pressure sensor 8, and the inlet pressure sensor 7 is expressed as sensor 1 in the accompanying drawing, and the outlet pressure sensor 8 is expressed as sensor 2 in the accompanying drawing; they are used to monitor the pressure changes at the liquid inlet and discharge ends in real time, which helps to adjust the operating parameters in time and maintain the fluid metering accuracy.

[0045] The switching valve A51 and the switching valve C53 are respectively connected to the discharge path of the fluid metering device, and the switching valve B52 and the switching valve D54 are respectively connected to the suction path of the fluid metering device.

[0046] In this embodiment, the device uses a servo motor 1 as a power source, which drives a precision electric cylinder 2, and the precision electric cylinder 2 drives a piston rod 3 to reciprocate inside a closed cylinder body 4. The precision electric cylinder 2 has high positioning accuracy, can control the metering error within 1%, and allows the flow rate to be adjusted steplessly within the range of 0-100%.

[0047] The high-pressure gas control switching valve module includes four switching valves, namely switching valve A51, switching valve B52, switching valve C53 and switching valve D54. Switching valve A51 and switching valve C53 are responsible for controlling the discharge path, while switching valve B52 and switching valve D54 are used to control the suction path. The four switching valves are composed of self-made high-pressure valves that can withstand a pressure of at least 3000psi. During the self-test process, the system is tested for leakage by controlling the switch status of the four switching valves and monitoring the pressure changes within a preset time period.

[0048] The fluid metering device of the present invention can realize the volume switching of the upper and lower metering closed cylinders 4, thereby forming a continuous fluid output, and controlling the metering error within 1%. Compared with the traditional technology, the present invention reduces the number of parts and simplifies the maintenance process, making the entire device more compact and easy to maintain.

[0049] In some embodiments, when the high-pressure gas control switching valve module is in the self-test process, the opening and closing of the four switching valves are controlled and the pressure changes are monitored within a set time to determine whether there is leakage in the switching valve and the piston rod 3. The electric cylinder driving device is driven by a servo motor 1, and the servo motor 1 is used to drive the precision electric cylinder 2. The precision electric cylinder 2 drives the piston rod 3 to reciprocate in the closed cylinder body 4, and can accurately control the position of the piston rod 3, thereby realizing accurate control of the fluid volume.

[0050] The fluid metering device is used to realize the volume switching of the upper and lower metering closed cylinders 4 to form a continuous fluid output, and can control the metering error within 1%. Compared with the prior art, the fluid metering device reduces the number of parts and simplifies the maintenance process.

[0051] In some embodiments, the sealed cylinder 4 is made of corrosion-resistant material, especially ceramic material, to extend the service life of the device.

[0052] The closed cylinder body 4 is made of ceramic material with excellent corrosion resistance. This material not only has good corrosion resistance but also can withstand higher pressure, thereby ensuring the long-term stable operation of the equipment.

[0053] The high-pressure gas control switching valve module adopts a self-made high-pressure valve and can withstand a pressure of at least 3000psi.

[0054] The precision electric cylinder 2 adopts a high positioning accuracy electric cylinder with a metering error controlled within 1%, and the flow rate can be adjusted steplessly within the range of 0-100%.

[0055] In some embodiments, the precision electric cylinder 2 and the piston rod 3 are integrated into one structure to ensure the concentricity of the movement of the piston rod 3, thereby reducing mechanical wear and improving the overall life of the device.

[0056] In order to ensure the concentricity of the piston rod 3 and reduce mechanical wear, an integrated structure is used between the precision electric cylinder 2 and the piston rod 3. In addition, a throat lubricating oil cup 6 is provided on the outer wall of the closed cylinder body 4, which provides lubricating oil to the contact surface between the piston rod 3 and the closed cylinder body 4, further reducing the friction coefficient and improving the reliability and service life of the equipment.

[0057] In some embodiments, a throat lubricating oil cup 6 is also included, which is arranged on the outer wall of the closed cylinder body 4 to provide lubricating oil to the contact surface between the piston rod 3 and the closed cylinder body 4, thereby reducing friction between the two, improving the reliability of the device and extending its service life.

[0058] In one embodiment: the self-test process of the upper feed switching valve A51

[0059] Reference Figure 5 In the process shown, make sure all other switching valves are closed before starting the self-test. Open the inlet color-changing valve to feed the material. At this time, the switching valves A51 and C should be closed, the switching valve D54 should also be closed, and the switching valve B52 should be open. In this state, the piston rod 3 is stationary in the closed cylinder body 4, and the servo motor 1 and the precision electric cylinder 2 do not move.

[0060] After the fluid enters the feed zone for a period of time, close the inlet color-changing valve to stop feeding. Then, use the inlet pressure sensor 7 to monitor the pressure change in the feed zone. If the pressure does not drop significantly within the set time period, it indicates that the switching valve A51 is normal and has no leakage. On the contrary, if the pressure drops, it indicates that the switching valve A51 is leaking and needs further inspection or replacement.

[0061] In one embodiment: the self-test process of the upper discharge switching valve B52

[0062] Also refer to Figure 5 In the process shown, when preparing for self-test, the inlet color-changing valve is opened to feed the material. At this time, the switching valve C53 should be closed, the switching valve D54 should also be closed, and the switching valve B52 should be opened. The piston rod 3 remains stationary in the closed cylinder body 4.

[0063] After the fluid enters the feed zone for a period of time, close the inlet color-changing valve to stop feeding. Use the inlet pressure sensor 7 to monitor the pressure change in the feed zone. If the pressure remains stable within the set time, it indicates that the switching valve B52 is working properly. If the pressure drops, it indicates that there may be a problem with the switching valve B52 and it needs to be checked or repaired.

[0064] In one embodiment: Self-check process of lower feed switching valve C53

[0065] Continue to refer Figure 5 In the process, to test the switching valve C53, first open the inlet color-changing valve to feed, the switching valves A51 and C should be closed, the switching valve B52 is closed, and the switching valve D54 is opened. The piston rod 3 remains stationary.

[0066] After feeding for a period of time, close the inlet color-changing valve to stop feeding. Use the inlet pressure sensor 7 to monitor the pressure change. If the pressure does not drop significantly within the set time, it indicates that the switching valve C53 has no leakage. Otherwise, it is necessary to check the status of the switching valve C53.

[0067] In one embodiment: the self-test process of the lower discharge switching valve D54

[0068] Still follow Figure 5 In order to detect the switching valve D54, the inlet color-changing valve is first opened to feed the material, the switching valves B52 and D are closed, the switching valve A51 is closed, and the switching valve C53 is opened. At this time, the piston rod 3 does not move.

[0069] After feeding for a period of time, close the inlet color-changing valve to stop feeding. Use the inlet pressure sensor 7 to monitor the pressure change. If the pressure is stable within the set time, it indicates that the switching valve D54 is working properly. If the pressure drops, it means that the switching valve D54 may be leaking.

[0070] In one embodiment: Piston leakage detection

[0071] according to Figure 6 As shown in the process, piston leakage detection is divided into two stages: upstroke and downstroke.

[0072] Upper stroke piston leakage detection: Open the color-changing valve to feed, open the upper and lower feed switching valves and the upper and lower discharge switching valves at the same time, close the quick exhaust valve, and let the piston connecting rod run to the lowest position. After the set time is reached, close the color-changing valve and the upper and lower feed switching valves. Open the quick exhaust valve to release the pressure in the discharge area, open the upper feed switching valve A51 and the lower discharge switching valve D54, close the lower feed switching valve C53 and the upper discharge switching valve B52, and detect the leakage of the upper stroke piston.

[0073] Downstroke piston leakage detection: The detection method for the downstroke is similar to that for the upstroke. The leakage detection of the piston downstroke can be completed by simply adjusting the opening and closing sequence of the corresponding switching valve.

[0074] Description: Servo motor 1, as a power source, can precisely adjust the motor speed and position by precisely controlling the current input. The power of the motor is transmitted to the precision electric cylinder 2, which then drives the piston rod 3 to make reciprocating linear motion in the closed cylinder 4. The key to this structural setting is that the precision electric cylinder 2 has extremely high positioning accuracy, which can control the metering error within 1%, and at the same time supports stepless adjustment of the flow rate from zero to full load (0-100%), meeting the fluid delivery needs under different working conditions.

[0075] In order to achieve the switching of fluids during the suction and discharge processes, the device is equipped with a high-pressure gas-controlled switching valve module, which contains four switching valves (A, B, C, D). Among them, switching valves A and C are responsible for controlling the discharge path, while switching valves B and D are used to control the suction path. These four switching valves are all homemade high-pressure valves that can withstand a pressure of at least 3000psi to ensure normal operation under high-pressure environments. By precisely controlling the opening and closing states of these switching valves, it is possible to quickly switch between suction and discharge to form a continuous fluid output.

[0076] During the fluid delivery process, the change in inlet and outlet pressure is an important indicator for evaluating the operating status of the device. Therefore, the device is equipped with an inlet pressure sensor 7 (sensor 1) and an outlet pressure sensor 8 (sensor 2) for real-time monitoring of the pressure changes at the inlet and outlet ends. The data from these sensors are fed back to the control system to help the operator adjust the operating parameters in a timely manner, maintain the accuracy of fluid metering, and take quick measures in abnormal situations to prevent the expansion of faults.

[0077] In order to ensure the reliability of the system, the device is also structured with a self-checking program. During the self-checking process, the system is tested for leaks by controlling the different combinations of the four switching valves and monitoring the pressure changes within the set time. For example, when testing switching valve A51, ensure that the other switching valves are in the closed state, open only switching valve B52, and then observe the pressure changes to determine if there is a leak. Such a self-checking mechanism helps to detect potential problems early and avoid production interruptions due to failures.

[0078] In addition to the self-test of the switching valve, the device also has the function of detecting whether there is leakage in the piston rod 3. The piston leakage detection is divided into two stages: the upstroke and the downstroke. When detecting the leakage of the upstroke piston, first open the color-changing valve to feed, and at the same time open the upper and lower feed switching valves and the upper and lower discharge switching valves, close the quick exhaust valve, and let the piston connecting rod run to the lowest position. After the set time is reached, close the color-changing valve and the upper and lower feed switching valves, then open the quick exhaust valve to unload the pressure in the discharge area, and open the upper feed switching valve A51 and the lower discharge switching valve D54, and close the lower feed switching valve C53 and the upper discharge switching valve B52 to detect the leakage of the upstroke piston. The downstroke detection method is similar to this, and it can be completed by adjusting the opening and closing sequence of the corresponding switching valves.

[0079] The sealed cylinder 4 of the device is made of ceramic material with excellent corrosion resistance. This material not only has good corrosion resistance, but also can withstand high pressure, thus ensuring the long-term stable operation of the equipment. In addition, in order to further improve the reliability and service life of the device, an integrated structure is adopted between the precision electric cylinder 2 and the piston rod 3 to ensure the concentricity of the movement of the piston rod 3 and reduce mechanical wear. At the same time, a throat lubricating oil cup 6 is set on the outer wall of the sealed cylinder 4 to provide lubricating oil to the contact surface between the piston rod 3 and the sealed cylinder 4 to reduce the friction coefficient.

[0080] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A fluid metering device; characterized in that, include: An electric cylinder driving device, used to drive the piston rod (3) to perform reciprocating motion in the sealed cylinder body (4); A high-pressure gas control switching valve module, comprising four switching valves, the four switching valves being switching valve A (51), switching valve B (52), switching valve C (53) and switching valve D (54), the switching valve module being used for switching between liquid suction and liquid discharge; Inlet and outlet pressure sensors are used to detect pressure changes at the liquid inlet and outlet ends.

2. The fluid metering device according to claim 1, characterized in that: The switching valve A (51) and the switching valve C (53) are respectively connected to the discharge path of the fluid metering device, and the switching valve B (52) and the switching valve D (54) are respectively connected to the suction path of the fluid metering device.

3. The fluid metering device according to claim 1, characterized in that: When the high-pressure gas control switching valve module is in the self-checking process, it is determined whether there is leakage in the switching valve and the piston rod (3) by controlling the opening and closing of the four switching valves and monitoring the pressure change within a set time.

4. The fluid metering device according to claim 1, characterized in that: The electric cylinder driving device is driven by a servo motor (1), and the servo motor (1) is used to drive a precision electric cylinder (2). The precision electric cylinder (2) drives a piston rod (3) to perform reciprocating motion in a closed cylinder body (4).

5. The fluid metering device according to claim 1, characterized in that: The fluid metering device is used to realize volume switching of an upper and lower metering sealed cylinder (4) to form a continuous fluid output, and can control the metering error within 1%.

6. The fluid metering device according to claim 1, characterized in that: The sealed cylinder (4) is made of corrosion-resistant material, in particular ceramic material.

7. The fluid metering device according to claim 1, characterized in that: The high-pressure gas control switching valve module adopts a self-made high-pressure valve and can withstand a pressure of at least 3000psi.

8. The fluid metering device according to claim 4, characterized in that: The precision electric cylinder (2) adopts a high positioning accuracy electric cylinder whose metering error is controlled within 1%, and the flow rate can be adjusted steplessly within the range of 0-100%.

9. The fluid metering device according to claim 4, characterized in that: The precision electric cylinder (2) and the piston rod (3) are integrated into one structure, which is used to ensure the concentricity of the movement of the piston rod (3), thereby reducing mechanical wear.

10. The fluid metering device according to claim 1, characterized in that: It also includes a throat lubricating oil cup (6), which is arranged on the outer wall of the closed cylinder body (4) and is used to provide lubricating oil to the contact surface between the piston rod (3) and the closed cylinder body (4).

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