Fuel gas metering device based on MEMS sensor

Abstract

The invention relates to the technical field of fuel gas metering, in particular to a fuel gas metering device based on an MEMS sensor, which comprises a metering pipeline and a sensor, the sensor is mounted on the metering pipeline, a rotating shaft is rotatably mounted on the metering pipeline, a ball is connected to the rotating shaft, the ball is slidably and hermetically connected with the metering pipeline, and the sensor is mounted on the metering pipeline. A channel is formed in the ball body, through openings communicated with the channel are formed in the positions, located on the two sides of the channel, of the ball body, the axis of the sensor and the rotating shaft are coaxially arranged, the sensor extends into the channel, a motor is installed on the metering pipeline, and the output end of the motor is connected with the rotating shaft. According to the gas metering device, the channels of different sizes are switched to be communicated with the gas pipeline, after the channels are switched, the gas flowing direction is not changed, the gas flowing speed is increased, meanwhile, the metering accuracy of the gas metering device can be guaranteed without rotating a sensor, and therefore new errors are prevented from being introduced.

Description

Technical Field

[0001] The present invention relates to the technical field of gas metering, and in particular to a gas metering device based on a MEMS sensor. Background Art

[0002] With the development of the Internet of Things, gas metering devices based on MEMS sensors have the advantages of low cost, small size, and integration. As a result, gas metering devices based on MEMS sensors have gradually replaced traditional diaphragm gas meters and become an important technical direction in the field of intelligent gas metering.

[0003] However, when the current MEMS gas metering device measures gas at a low gas flow rate, the thermal boundary layer of the MEMS thermal sensor is difficult to break through the static gas wrapping effect at low flow rates, and the heat of the MEMS thermal sensor cannot diffuse along with the airflow, resulting in reduced measurement accuracy of the gas metering device.

[0004] In order to solve the problem, the invention patent with application number CN202111665334.7 provides a small-range thermal gas mass flowmeter. This invention patent sets U-shaped tubes on both sides of the measuring pipe, closes the main pipe when the gas flow rate decreases, allows the gas to enter from the U-shaped tube, and allows the airflow to flow through the sensor. The diameter of the U-shaped tube is much smaller than the diameter of the main pipe, so that the airflow is accelerated after entering the U-shaped tube, thereby increasing the airflow speed, thereby ensuring the accuracy of the measurement. During use, the sensor usually needs to be parallel or perpendicular to the airflow, so the sensor needs to be rotated during use. The sensor rotation setting will cause mechanical wear, causing the sensor rotation mechanism to loosen, which in turn introduces new measurement errors.

[0005] Therefore, in order to improve the measurement accuracy of the gas metering device, a gas metering device based on a MEMS sensor is proposed. Summary of the Invention

[0006] The purpose of the present invention is to provide a gas metering device based on a MEMS sensor. In order to improve the accuracy of the gas metering device and avoid the introduction of new errors, the device is connected to the gas pipeline by switching channels of different sizes. After the channels are switched, the gas flow direction does not change. While increasing the gas flow rate, the accuracy of the gas metering device can be guaranteed without rotating the sensor, thereby avoiding the introduction of new errors.

[0007] To achieve the above object, the present invention provides the following technical solutions: A gas metering device based on a MEMS sensor includes a metering pipe and a sensor. The sensor is installed on the metering pipe. A rotating shaft is rotatably installed on the metering pipe. A sphere is connected to the rotating shaft. The sphere is slidingly and sealingly connected to the metering pipe. A channel is opened on the sphere. The sphere is provided with openings communicating with the channel on both sides of the channel. The axis of the sensor is coaxially arranged with the rotating shaft. The sensor extends into the interior of the channel. A motor is installed on the metering pipe, and the output end of the motor is connected to the rotating shaft.

[0008] The motor drives the sphere to rotate, so that the opening is connected to the gas pipeline, and the channel is closed, so that the gas flows along the opening. The diameter of the opening is smaller than the diameter of the channel, so that after the gas flows into the opening, the gas flow rate increases, thereby avoiding the low gas speed causing the gas metering device to reduce the measurement accuracy. After the sphere rotates, the flow direction of the airflow will not change, so there is no need to rotate the sensor, thereby avoiding the problem of the sensor becoming loose due to wear after multiple rotations, thereby affecting the measurement accuracy of the gas metering device.

[0009] Preferably, a closed pipe is slidably installed at the through-port, a reset spring is connected between the closed pipe and the sphere, a winding chamber connected to the through-port is opened inside the sphere, a winding piece is provided on the metering pipe, a pull rope is connected between the winding piece and the closed pipe, the winding piece is connected to the motor and the rotating shaft respectively, a plurality of guide rollers are provided inside the winding chamber, and the pull rope passes around the guide rollers and is connected to the closed pipe.

[0010] By setting a closed pipe at the opening and a winding piece on the metering pipe, the motor can rotate the power to realize the rotation of the sphere to ensure the accuracy of the gas metering device, and can also drive the winding piece to reel in the pull rope, thereby pulling the two closed pipes to cover the sensor, so that after the gas enters the opening, the gas flows along the closed pipe, avoiding the gas flow caused by the change of the width of the flow part, resulting in a decrease in air flow velocity and turbulence, which affects the accuracy of the gas metering device.

[0011] Preferably, the winding member includes a winding wheel, a push cylinder, and a power cylinder. The winding wheel is arranged on the motor output end, and the motor output end extends into the interior of the winding chamber. The motor output end is sleeved with a power cylinder, and the power cylinder slides along the axial direction of the motor output end. The power cylinder and the rotating shaft are respectively provided with power block one and power block two. The push cylinder is slidably installed on the metering pipe, and the push cylinder is threadedly connected to the motor output end, and the push cylinder is rotatably connected to the power cylinder.

[0012] By setting a reel at the output end of the motor, the pull rope 1 can be reeled in by the rotation of the motor, thereby pulling the closed pipe toward the sensor side, so as to ensure the stability of the gas flow and the accuracy of the gas metering device. When the motor is reversed, the pull rope 1 is released. At this time, the reset spring pushes the closed pipe to reset, and thus will not interfere with the normal operation of the gas metering device. During the rotation of the motor, when the power block 1 and the power block 2 are staggered, the rotation of the motor will only release or reel the pull rope 1. Therefore, during use, the closed pipe moves the set distance first, and then the ball starts to rotate. When the ball rotates to the set angle, the rotation of the motor will not drive the ball to rotate, but it will still Continuing to reel in or release the pull rope allows the gas metering device to be embedded in the side wall of the measuring pipe after the closed pipe is reset during use, thereby reducing the size of the sphere. This reduces the volume of the metering device, helps save materials, and reduces manufacturing costs. After the closed pipe is embedded in the sphere, the rotation of the motor will drive the closed pipe to move a set distance and then drive the sphere to rotate, so as not to interfere with the rotation of the sphere. After the sphere rotates to the set angle and stops rotating, the closed pipe continues to move to cover the sensor, so as to avoid the closed pipe contacting the sensor and causing damage to the sensor or the seal on the closed pipe, which affects the accuracy of the gas metering device.

[0013] Preferably, a blocking plate is hingedly mounted on the side wall of the metering pipe, the blocking plate is provided with an arc surface, the arc surface has the same diameter as the inner wall of the sphere, and a second pull rope is connected between the closed pipe and the blocking plate.

[0014] By arranging a sealing plate on the side wall of the metering pipe, and connecting a pull rope 2 between the closed pipe and the sealing plate, the closed pipe is pushed to reset by a reset spring, and the sealing plate is pulled by the pull rope 2 to make the sealing plate embedded in the through hole, thereby avoiding the problem of depression on the inner wall of the sphere, which is prone to turbulence when the gas flows through the depression and affects the metering accuracy of the gas metering device. The sealing plate is provided with an arc surface, and the arc surface is equal to the diameter of the inner wall of the sphere, so that after the sealing plate blocks the opening, the flatness of the inner wall of the sphere is guaranteed, further avoiding the occurrence of turbulence and ensuring the metering accuracy of the gas metering device.

[0015] Preferably, the blocking plate is provided with a straight chamfer, a slider is slidably mounted on the metering pipe, the blocking plate and the slider are hinged, and a movable gap is provided at the hinged portion.

[0016] The blocking plate is prone to tilt when hinged, which affects the flatness of the inner wall of the sphere. For this reason, the blocking plate is hinged on the slider and the blocking plate is matched with the opening through the guiding effect of the straight chamfer. By setting a movable gap, the angle of the blocking plate can be adjusted when the blocking plate is pulled horizontally by the pull rope, so that the blocking plate can be fully matched with the opening, ensuring the flatness of the inside of the sphere, thereby avoiding turbulence that affects the measurement accuracy of the gas metering device.

[0017] Preferably, a pre-tightening groove is provided on the rotating shaft, and the power block 2 is slidably installed inside the pre-tightening groove. Pre-tightening springs are installed on both sides of the power block 2 and the rotating shaft.

[0018] By making the power block 2 slidably connected to the rotating shaft, and connecting a pre-tightening spring between the power block 2 and the rotating shaft, the power block 1 and the power block 2 are in contact to push the rotating shaft to rotate, and when the ball rotates to the limit position, the ball can be squeezed by the pre-tightening spring to ensure the sealing between the ball and the metering pipe. After the ball reaches the limit position, when the power block 1 and the power block 2 are in contact, the power cylinder can still rotate with the output end of the motor, so as to avoid the motor output end being stuck or the ball being unable to rotate to the limit position, resulting in the port or channel being not coaxial with the gas pipeline, causing turbulence when the gas flows into the sensor and affecting the accuracy of the gas metering device.

[0019] Preferably, the pull rope 1 includes a winding rope and two pulling ropes, the two pulling ropes are connected to the winding rope, and the two pulling ropes are respectively connected to the two sides of the closed pipe. The connection part between the winding chamber and the opening and the connection part between the two pulling ropes and the closed pipe are in the same horizontal plane, and the winding rope is connected to the winding wheel.

[0020] By pulling the closed pipe to move with two pull ropes, the tension on the closed pipe can be balanced, thereby avoiding uneven force on the closed pipe and causing local wear of the closed pipe, which in turn causes leakage in the closed pipe and affects the accuracy of the gas metering device.

[0021] Preferably, the through opening is in a conical shape, and the closed pipe is provided with a conical chamfer with the same slope as the through opening.

[0022] By setting the opening into a conical shape, turbulence caused by sudden changes in diameter at the opening can be avoided, which affects the accuracy of the gas metering device. The maximum diameter of the opening is equal to the channel diameter, so that when the sphere switches the opening to connect with the gas pipeline, there will be no sudden change in diameter at the connection part, thereby avoiding turbulence caused by sudden changes in diameter, thereby ensuring the accuracy of the gas metering device.

[0023] Preferably, the power block 1 abuts against the rotating shaft, the power block 2 abuts against the inner wall of the power cylinder, and a guide chamfer is provided above the power block 1.

[0024] Power block one abuts against the rotating shaft, and power block two abuts against the inner wall of the power cylinder, which can play a supporting role, thereby improving the bending resistance of power block one and power block two, and improving the stability of the rotation of the rotating shaft or power cylinder, reducing the vibration of the gas metering device, and increasing the service life of the gas metering device.

[0025] Compared with the prior art, the present invention has the following beneficial effects: 1. The motor drives the sphere to rotate so that the port is connected to the gas pipeline. The diameter of the port is smaller than the diameter of the channel, so that after the gas flows into the port, the gas flow rate increases, thereby avoiding the problem that the gas metering device's measurement accuracy is reduced due to the low gas velocity. After the sphere rotates, the flow direction of the airflow does not change, so there is no need to rotate the sensor, thereby avoiding the problem that the sensor becomes loose due to wear after multiple rotations, which affects the measurement accuracy of the gas metering device.

[0026] 2. By setting a closed pipe at the opening and a reel on the metering pipe, the motor can rotate the power to realize the rotation of the sphere to ensure the accuracy of the gas metering device, and can also drive the reel to reel in the pull rope, thereby pulling the two closed pipes to cover the sensor, so that after the gas enters the opening, the gas flows along the closed pipe, avoiding the gas flow caused by the change in the width of the flow part, resulting in a decrease in air flow velocity and turbulence, which affects the accuracy of the gas metering device.

[0027] 3. By setting up the winding piece, the gas metering device can be embedded in the side wall of the measuring pipe after the closed pipe is reset during use, thereby reducing the size of the sphere, thereby reducing the volume of the metering device, helping to save materials, and reducing the manufacturing cost of the gas metering device. After the sphere rotates to the extreme angle and stops rotating, the closed pipe continues to move to cover the sensor, thereby avoiding the closed pipe contacting the sensor and causing damage to the sensor or the seal on the closed pipe due to the rotation of the sphere, thereby affecting the accuracy of the gas metering device. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 for Figure 1 Partial structural cross-sectional view; Figure 3 for Figure 2 A cross-sectional view of the structure of the power block 1 when it moves to contact the power block 2; Figure 4 for Figure 2 A cross-sectional view of the structure of the closed pipe fitting; Figure 5 for Figure 1 The structural diagram of the measuring pipeline is removed; Figure 6 for Figure 5 Cross-sectional view at AA in the middle; Figure 7 for Figure 5 Cross-sectional view at the middle BB; Figure 8 It is a structural schematic diagram of the cooperation between the slider and the blocking plate of the present invention.

[0029] In the figure: 1. Metering pipe; 2. Sensor; 3. Rotating shaft; 4. Sphere; 41. Channel; 42. Through port; 43. Winding chamber; 5. Motor; 51. Motor output end; 6. Closed pipe; 7. Return spring; 8. Winding member; 81. Winding wheel; 82. Push cylinder; 83. Power cylinder; 84. Power block 1; 85. Power block 2; 9. Pull rope 1; 91. Winding rope; 92. Pull rope; 10. Guide roller; 11. Sealing plate; 111. Arc surface; 112. Straight chamfer; 12. Pull rope 2; 13. Slider; 14. Active gap; 15. Preload groove; 16. Preload spring; 17. Conical chamfer; 18. Guide chamfer. DETAILED DESCRIPTION

[0030] See also Figures 1 to 8 The present invention provides a gas metering device based on a MEMS sensor, and the technical solution is as follows: A gas metering device based on a MEMS sensor includes a metering pipe 1, a sensor 2 is threadedly connected to the metering pipe 1, and the sensor 2 is a MEMS intelligent sensor. A rotating shaft 3 is rotatably installed on the metering pipe 1, and a sphere 4 is connected to the rotating shaft 3. The sphere 4 is slidingly and sealingly connected to the metering pipe 1. A channel 41 is opened on the sphere 4. The sphere 4 is provided with a through hole 42 on both sides of the channel 41 and connected to the channel 41. The channel 41 has a diameter of 100 mm, and the through hole 42 has a diameter of 10 mm. The sensor 2 is coaxially arranged with the rotating shaft 3, and the sensor 2 extends into the interior of the channel 41. A motor 5 is installed on the metering pipe 1, and the motor output end 51 is connected to the rotating shaft 3. By setting the sphere 4, the sensor 2 extends into the interior of the sphere 4. The sensor 2 is coaxially arranged with the rotating shaft 3. When the motor 5 drives the rotating shaft 3 to rotate, the rotating shaft 3 drives the sphere 4 to rotate, so that the port 42 is connected to the gas pipeline. The diameter of the port 42 is smaller than the diameter of the channel 41, so that the flow speed can be increased when the airflow flows in from the port 42, thereby ensuring the measurement accuracy of the gas metering device. In this process, the flow direction of the airflow will not change, and there is no need to rotate the sensor 2, so as to avoid mechanical wear and tear that causes the sensor 2 to loosen and the measurement accuracy of the gas metering device to decrease; a closed pipe 6 is slidably installed at the port 42, and a reset spring 7 is connected between the closed pipe 6 and the sphere 4. A winding chamber 43 connected to the port 42 is provided inside the sphere 4, and a winding piece 8 is provided on the metering pipe 1. A pull rope 9 is connected between 8 and the closed pipe 6, and a plurality of guide rollers 10 are provided inside the winding chamber 43. The pull rope 9 passes around the guide rollers 10 and is connected to the closed pipe 6. Since the through port 42 is connected with the channel 41, in order to avoid turbulence due to diameter change at the connected part, after the through port 42 is switched, the pull rope 9 is wound by the winding member 8, so that the pull rope 9 pulls the closed pipe 6, so that the two closed pipes 6 cover the sensor 2, so that after the gas enters the through port 42, the gas flows along the closed pipe 6, avoiding the gas flow caused by the change in width resulting in a decrease in air flow speed and turbulence, which affects the accuracy of the gas metering device. When normal air flow measurement is required, the pull rope 9 is released by the winding member 8. At this time, the pull rope 9 no longer pulls the closed pipe 6 The closed pipe 6 can be reset under the elastic force of the reset spring 7, so that it will not cross the inside of the channel 41 and affect the air flow inside the channel 41, thereby ensuring the accuracy of the gas metering device; the winding member 8 includes a winding wheel 81 arranged on the motor output end 51, the motor output end 51 extends into the inside of the winding chamber 43, and a power cylinder 83 is sleeved on the motor output end 51. The power cylinder 83 is connected to the motor output end 51 with a flat key, so that the power cylinder 83 can move axially at the motor output end 51, and a power block 1 84 and a power block 2 85 are respectively provided on the power cylinder 83 and the rotating shaft 3. A push cylinder 82 is slidably installed on the metering pipe 1, and the push cylinder 82 is threadedly connected to the motor output end 51, and the push cylinder 82 is rotatably connected to the power cylinder 83;During operation, the motor 5 rotates. At this time, the power block 1 84 is not in contact with the power block 2 85. At this time, the motor 5 will only drive the winding wheel 81 to rotate, thereby pulling the closed pipe 6 to move toward the sensor 2. As the motor 5 rotates, the motor output end 51 drives the push cylinder 82 to slide along the axial direction of the rotating shaft 3, thereby pushing the power cylinder 83 to move in the direction of the rotating shaft 3, thereby making the power block 1 84 contact with the power block 2 85, thereby pushing the rotating shaft 3 to rotate and realize the switching of the through port 42. After the switching of the through port 42 is completed, the motor 5 continues to rotate. At this time, the power block 1 84 is separated from the power block 2 85. At this time, the motor 5 rotates to continue to reel in the pull rope 1 9, thereby making the two closed pipes 6 fit together. And cover the sensor 2, so as to prevent the ball 4 from rotating after the closed pipe 6 contacts the sensor 2, causing damage to the sensor 2 or damage to the seal on the closed pipe 6, thereby affecting the accuracy of the gas metering device. At the beginning of the rotation of the motor 5, the power block 1 84 and the power block 2 85 are not in contact. At this time, the shaft 3 is not rotating, and the reel 81 rotates. At this time, the reel 81 first reels the rope 1 9, so that the closed pipe 6 moves a certain distance on the ball 4 before driving the shaft 3 to rotate. Therefore, the closed pipe 6 can be embedded in the measuring pipe and will not interfere with the rotation of the ball 4 when the port 42 is switched, thereby reducing the size of the ball 4, thereby reducing the volume of the metering device, which is helpful The invention saves materials and reduces the manufacturing cost of the gas metering device; a pre-tightening groove 15 is provided on the rotating shaft 3, and the power block 2 85 is slidably installed in the pre-tightening groove 15, and pre-tightening springs 16 are installed on both sides of the power block 2 85 and the rotating shaft 3; when the power block 1 84 pushes the rotating shaft 3 to rotate, when the ball 4 rotates to the limit position, the power block 1 84 squeezes the power block 2 85, so that the power block 2 85 slides along the pre-tightening groove 15, so that when the ball 4 rotates to the limit position, the pre-tightening spring 16 can squeeze the ball 4 to ensure the sealing between the ball 4 and the metering pipe 1, and after the ball 4 reaches the limit position, the power cylinder 83 can still rotate with the motor output end 51, thereby avoiding the motor output end 51 is stuck or the ball 4 cannot be rotated to the extreme position, resulting in the port 42 or the channel 41 being out of alignment with the gas pipeline, causing turbulence when the gas flows into the sensor 2, thereby affecting the accuracy of the gas metering device; the power block 1 84 is in contact with the rotating shaft 3, the power block 2 85 is in contact with the inner wall of the power cylinder 83, and a guide chamfer 18 is provided above the power block 1 84; the power block 1 84 is in contact with the rotating shaft 3, and the power block 2 85 is in contact with the inner wall of the power cylinder 83, which can play a supporting role, thereby improving the bending resistance of the power block 1 84 and the power block 2 85, and can improve the rotation stability of the rotating shaft 3 or the power cylinder 83, reduce the vibration of the gas metering device, and increase the service life of the gas metering device;The pull rope 9 includes a winding rope 91 and two pulling ropes 92, the two pulling ropes 92 are connected to the winding rope 91, the winding rope 91 is connected to the winding wheel 81, and the two pulling ropes 92 are respectively connected to the two sides of the closed pipe 6, and the connection part between the winding chamber 43 and the through-port 42 and the connection part between the two pulling ropes 92 and the closed pipe 6 are in the same horizontal plane; by making the connection part between the winding chamber 43 and the through-port 42 and the connection part between the two pulling ropes 92 and the closed pipe 6 in the same horizontal plane, the pulling force of the two pulling ropes 92 on the closed pipe 6 is parallel to the axis of the closed pipe 6, thereby reducing the friction between the closed pipe 6 and the inner wall of the through-port 42, slowing down the wear of the closed pipe 6, and This prevents local wear of the closed pipe 6 due to uneven force, thereby effectively increasing the service life of the metering device. The opening 42 is tapered, and the closed pipe 6 is provided with a tapered chamfer 17 with the same slope as the opening 42. The maximum diameter of the opening 42 is equal to the diameter of the passage 41. By making the opening 42 tapered, sudden changes in diameter at the opening 42 that could cause turbulence and affect the accuracy of the gas metering device are avoided. The maximum diameter of the opening 42 is equal to the diameter of the passage 41, so that when the sphere 4 is switched to connect the opening 42 with the gas pipeline, no sudden changes in diameter occur at the connection point, thereby avoiding turbulence caused by sudden changes in diameter and ensuring the accuracy of the gas metering device.

[0031] A slide groove is provided on the metering pipe 1, and both ends of the slide groove are closed. The slider 13 is slidably installed on the metering pipe 1 by connecting with the slide groove. The sealing plate 11 is hinged to the slider 13, and a pull rope 2 12 is connected between the closed pipe 6 and the sealing plate 11; when the closed pipe 6 moves toward the direction of the sensor 2, the pull rope 2 12 is released. At this time, the pull rope 2 12 will not pull the sealing plate 11. At this time, the movement of the closed pipe 6 squeezes the sealing plate 11, causing the slider 13 to move. When the sealing plate 11 moves out of the opening 42, the slider 13 moves to the extreme position of the slide groove and cannot move further. At this time, the movement of the closed pipe 6 will push the sealing plate 11 to rotate, so that the sealing plate 11 will not interfere with the movement of the closed pipe 6. When the closed pipe 6 is reset by the elastic force of the reset spring 7, the closed pipe 6 pulls the sealing plate 11 to rotate , and then pull the sealing plate 11 to slide, so that the arc surface 111 is completely matched with the inside of the sphere 4, thereby ensuring the flatness of the inner wall of the sphere 4, thereby avoiding the problem that the inner wall of the sphere 4 is concave, and turbulence is easily generated when the gas flows through the concave, thereby affecting the measurement accuracy of the gas metering device; a straight chamfer 112 is provided on the sealing plate 11, and a movable gap 14 is provided at the hinge part of the slider 13 and the sealing plate 11; the sealing plate 11 is matched with the through port 42 through the guiding effect of the straight chamfer 112, and through the setting of the movable gap 14, when the rope pulls the sealing plate 11 for translation, the angle of the sealing plate 11 can be adjusted, so that the sealing plate 11 can be completely matched with the through port 42, thereby ensuring the flatness of the inside of the sphere 4, thereby avoiding turbulence that affects the measurement accuracy of the gas metering device.

[0032] Working principle: when the gas flow is small, the motor 5 rotates forward, and the motor output end 51 drives the winding wheel 81 to rotate, and drives the push cylinder 82 to move toward the sphere 4. At this time, the winding wheel 81 reels the pull rope 1 9, so that the pull rope 92 pulls the closed pipe 6 to move toward the sensor 2. When the closed pipe 6 moves, the pull rope 2 12 is released, and the closed pipe 6 squeezes the blocking plate 11, so that the blocking plate 11 slides first and then rotates, so that the blocking plate 11 does not interfere with the movement of the closed pipe 6. When pushing and moving, the push cylinder 82 pushes the power cylinder 83 to move. When the power block 1 84 moves to fit with the power block 2 85, the power block 1 84 squeezes the power block 2 85, thereby pushing the rotating shaft 3 to rotate, so that the rotation drives the sphere 4 to rotate, from The through port 42 is connected to the gas pipeline. When the sphere 4 rotates 90°, the rotation of the sphere 4 is restricted. At this time, the power block 1 84 squeezes the power block 2 85, so that the power block 2 85 slides along the preload groove 15 and compresses the preload spring 16. At this time, the power cylinder 83 can still rotate. With the movement of the push cylinder 82, the power block 1 84 moves to above the power block 2 85. At this time, the power block 1 84 no longer squeezes the power block 2 85, so as not to interfere with the rotation of the motor output end 51. At this time, the winding wheel 81 continues to rotate and continues to wind up the pull rope 1 9, so that the two closed pipes 6 fit together to cover the sensor 2. At this time, the airflow enters the closed pipe 6 along the through port 42, thereby increasing the airflow velocity and ensuring the measurement accuracy of the metering device.

[0033] When the gas flow increases again, the motor 5 reverses and the pull rope 1 9 is released. At this time, the pull rope 1 9 no longer pulls the closed pipe 6. The closed pipe 6 is reset under the elastic force of the reset spring 7, and the motor output end 51 drives the push cylinder 82 to move toward the motor 5. At this time, the power block 1 84 moves downward. When the power block 1 84 is fitted with the power block 2 85, the power block 1 84 squeezes the power block 2 85, thereby pushing the rotating shaft 3 to rotate, and the rotation drives the ball 4 to rotate, so that the channel 41 is connected to the gas pipeline. When the ball 4 rotates 90°, the rotation of the ball 4 is restricted. At this time, the power block 1 84 squeezes the power block 2 85, so that the power block 2 85 slides along the pre-tightening groove 15 and compresses the pre-tightening spring 16. At this time, the power cylinder 83 can still rotate, and as the push cylinder 82 moves , power block 1 84 moves to the bottom of power block 2 85. At this time, power block 1 84 no longer squeezes power block 2 85, so as not to interfere with the rotation of the motor output end 51. At this time, the reel 81 continues to rotate and continuously releases the pull rope 1 9, so that the two closed pipes 6 are embedded in the measuring pipe. At this time, the airflow enters the gas pipe along the channel 41, thereby ensuring the gas supply. During the movement of the closed pipe 6, the closed pipe 6 pulls the sealing plate 11 through the pull rope 2 12, so that the sealing plate 11 rotates first, and then pulls the sealing plate 11 to slide, so that the arc surface 111 is completely matched with the inside of the sphere 4, thereby ensuring the flatness of the inner wall of the sphere 4, thereby avoiding the inner wall of the sphere 4 from being concave, thereby avoiding the problem that the gas flowing through the concave is prone to turbulence and affecting the measurement accuracy of the gas metering device.

[0034] A specific embodiment of the present invention has been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the embodiment described above. It will be apparent to those skilled in the art that various changes, modifications, substitutions, and variations to these embodiments without departing from the principles and concepts of the present invention should still fall within the scope of protection of the present invention.

Claims

1. A gas metering device based on a MEMS sensor, characterized in that: The invention comprises a metering pipe (1) and a sensor (2), wherein the sensor (2) is mounted on the metering pipe (1), a rotating shaft (3) is rotatably mounted on the metering pipe (1), a sphere (4) is connected to the rotating shaft (3), the sphere (4) is slidingly and sealingly connected to the metering pipe (1), a channel (41) is opened on the sphere (4), and the sphere (4) is provided with openings (42) communicating with the channel (41) on both sides of the channel (41), the axis of the sensor (2) is coaxially arranged with the rotating shaft (3), the sensor (2) extends into the interior of the channel (41), a motor (5) is mounted on the metering pipe (1), and the output end (51) of the motor is connected to the rotating shaft (3).

2. A gas metering device based on a MEMS sensor according to claim 1, characterized in that: A closed pipe (6) is slidably installed at the opening (42), a return spring (7) is connected between the closed pipe (6) and the sphere (4), a winding chamber (43) communicating with the opening (42) is provided inside the sphere (4), a winding member (8) is provided on the metering pipe (1), a pull rope (9) is connected between the winding member (8) and the closed pipe (6), the winding member (8) is respectively connected to the motor (5) and the rotating shaft (3), a plurality of guide rollers (10) are provided inside the winding chamber (43), and the pull rope (9) is connected to the closed pipe (6) by passing around the guide rollers (10).

3. A gas metering device based on a MEMS sensor according to claim 2, characterized in that: The winding member (8) includes a winding wheel (81), a push cylinder (82), and a power cylinder (83). The winding wheel (81) is arranged on the motor output end (51), and the motor output end (51) extends into the interior of the winding chamber (43). The motor output end (51) is sleeved with a power cylinder (83), and the power cylinder (83) slides along the axial direction of the motor output end (51). The power cylinder (83) and the rotating shaft (3) are respectively provided with a power block 1 (84) and a power block 2 (85). The push cylinder (82) is slidably installed on the metering pipe (1), and the push cylinder (82) is threadedly connected to the motor output end (51), and the push cylinder (82) and the power cylinder (83) are rotatably connected.

4. A gas metering device based on a MEMS sensor according to claim 3, characterized in that: A blocking plate (11) is hingedly mounted on the side wall of the metering pipe (1), and a curved surface (111) is provided on the blocking plate (11). The curved surface (111) has a diameter equal to that of the inner wall of the sphere (4). A second pull rope (12) is connected between the closed pipe (6) and the blocking plate (11).

5. A gas metering device based on a MEMS sensor according to claim 4, characterized in that: The blocking plate (11) is provided with a straight chamfer (112), a slider (13) is slidably mounted on the metering pipe (1), the blocking plate (11) and the slider (13) are hinged, and a movable gap (14) is provided at the hinged portion.

6. A gas metering device based on a MEMS sensor according to claim 3, characterized in that: A preload groove (15) is provided on the rotating shaft (3), and the power block 2 (85) is slidably mounted inside the preload groove (15). Preload springs (16) are mounted on both sides of the power block 2 (85) and the rotating shaft (3).

7. A gas metering device based on a MEMS sensor according to claim 3, characterized in that: The pull rope 1 (9) includes a reeling rope (91) and two pulling ropes (92), the two pulling ropes (92) are connected to the reeling rope (91), and the two pulling ropes (92) are respectively connected to the two sides of the closed pipe (6), the connection part between the reeling chamber (43) and the opening (42) and the connection part between the two pulling ropes (92) and the closed pipe (6) are in the same horizontal plane, and the reeling rope (91) is connected to the reeling wheel (81).

8. A gas metering device based on a MEMS sensor according to claim 2, characterized in that: The through opening (42) is conical in shape, and the closed pipe (6) is provided with a conical chamfer (17) with the same slope as the through opening (42). The maximum diameter of the through opening (42) is equal to the diameter of the channel (41).

9. A gas metering device based on a MEMS sensor according to claim 3, characterized in that: The power block 1 (84) is in contact with the rotating shaft (3), the power block 2 (85) is in contact with the inner wall of the power cylinder (83), and a guide chamfer (18) is provided above the power block 1 (84).

Images