Servo liquid level meter

Abstract

The utility model relates to the technical field of liquid level measurement, and discloses a servo liquid level meter which comprises a servo mechanism, a length measuring mechanism and a liquid level sensor connected with the servo mechanism through a hub and a connecting cable, and the liquid level sensor comprises an ultrasonic sensor located on the side, close to the servo mechanism, of the liquid level sensor; the hub and the connecting cable are used for driving the liquid level sensor to move up and down; the length measuring mechanism is connected with the servo mechanism and used for measuring the length of the connecting cable; when the liquid level sensor is completely immersed in the liquid, the ultrasonic sensor detects the distance from the liquid level sensor to the liquid level, and the servo mechanism determines first liquid level data according to the distance from the liquid level sensor to the liquid level and the length of the connecting cable. When the liquid level sensor is immersed in liquid, the ultrasonic sensor is used for measuring the distance between the liquid level sensor and the liquid level, whether the liquid level changes or not is judged accordingly, real-time liquid level data are calculated, it is guaranteed that the liquid level sensor is immersed in the liquid to measure other parameters, the liquid level can be detected and measured in real time, and the implementation method is simple.

Description

Technical Field

[0001] The utility model relates to the technical field of liquid level measurement, in particular to a servo liquid level meter. Background Art

[0002] The servo level gauge is generally driven by a servo mechanism through a flexible cable wrapped around a hub to drive a liquid level sensor: such as a buoyancy-type or other type of liquid level sensing component. When the liquid level changes, the liquid level sensing information such as buoyancy or capacitance or other signals changes. The servo mechanism moves, the hub rotates, and drives the liquid level sensor up and down to reach a new signal balance point and balance on the liquid surface. The rotation of the hub causes the distance between the liquid level sensor and the servo mechanism to change. The length of the change is measured by a measuring mechanism connected to the servo mechanism. The length measuring mechanism is implemented by a rotary encoder or other physical counter.

[0003] Since the liquid level sensor of the servo level gauge can be multifunctional, in addition to sensing the liquid level, it can also integrate sensors such as temperature, density, and oil-water interface. In this way, in addition to the liquid level measurement function, the servo level gauge can also measure other physical parameters of the liquid at different heights. However, when measuring other physical parameters, the liquid level sensor must be immersed in the liquid at various heights under the action of gravity and released by the servo mechanism for measurement. When the servo level gauge measures parameters other than the liquid level, the sensor must drop below the liquid level, and the servo level gauge cannot detect the liquid level in real time. Since the servo mechanism takes a long time to drive the main liquid level sensor to drop into the liquid to measure other parameters, if the liquid level changes at this time, it is easy to cause safety accidents such as tank overflow or emptying. Therefore, if the current servo level gauge is to measure other parameters in the liquid, it cannot be used as a safety interlocked liquid level device. Utility Model Content

[0004] In view of this, the utility model provides a servo liquid level meter to solve the problem that the liquid level cannot be measured when the liquid level sensor is immersed in the liquid.

[0005] In a first aspect, the utility model provides a servo level gauge, which comprises: a servo mechanism, a length measuring mechanism, and a liquid level sensor connected to the servo mechanism through a hub and a connecting cable, wherein the liquid level sensor comprises: an ultrasonic sensor, which is located on a side of the liquid level sensor close to the servo mechanism;

[0006] The hub and connecting cable are used to drive the liquid level sensor to move up and down;

[0007] The length measuring mechanism is connected to the servo mechanism and is used to measure the length of the connecting cable from the wheel hub to the liquid level sensor;

[0008] When the liquid level sensor is completely immersed in the liquid, the ultrasonic sensor is used to detect the distance from the ultrasonic sensor to the liquid surface, and the servo mechanism determines the first liquid level data of the liquid according to the distance from the liquid level sensor to the liquid surface and the length of the connecting cable.

[0009] The servo liquid level meter provided by the utility model uses an ultrasonic sensor to measure the distance between the liquid level sensor and the liquid surface when the liquid level sensor is immersed in the liquid, thereby judging whether the liquid level has changed and calculating the real-time liquid level data, thereby ensuring that the liquid level sensor can detect and measure the liquid level in real time while measuring other parameters when immersed in the liquid, the implementation method is simple, and the equipment is easy to maintain.

[0010] In an optional embodiment, when the liquid level sensor floats above the liquid surface, the length measuring mechanism measures a first length of the connecting rope, and the servo connection mechanism determines second liquid level data of the liquid based on the first length and the buoyancy of the liquid level sensor.

[0011] The servo liquid level meter provided by the utility model measures the liquid level data of the liquid in a traditional way when the liquid level sensor floats above the liquid surface. At this time, the ultrasonic sensor does not affect the measurement of the liquid level, thereby ensuring the measurement accuracy, and no other equipment needs to be added, thus saving costs.

[0012] In an optional implementation, the servo liquid level meter further includes: an alarm device, which is connected to the servo mechanism and issues an alarm when the first liquid level data exceeds a preset liquid level threshold.

[0013] The servo liquid level meter provided by the utility model has an alarm device that sends out an alarm to prompt the staff when the first liquid level data exceeds the preset liquid level threshold value, so that corresponding measures can be taken in time to avoid the danger caused by excessively high liquid level, thereby ensuring the safety of liquid storage.

[0014] In an optional embodiment, the ultrasonic sensor includes an ultrasonic transmitter and an ultrasonic receiver, and the direction in which the ultrasonic transmitter sends ultrasonic waves is opposite to the direction in which the ultrasonic receiver receives ultrasonic waves;

[0015] When the liquid level sensor is completely immersed in the liquid, the ultrasonic transmitter of the ultrasonic sensor emits ultrasonic waves perpendicular to the liquid surface.

[0016] The servo liquid level meter provided by the utility model has an ultrasonic sensor positioned so that the propagation direction of the ultrasonic wave is perpendicular to the liquid surface, thereby ensuring that the propagation distance of the ultrasonic wave is the minimum distance from the ultrasonic sensor to the liquid surface, thereby improving the measurement accuracy.

[0017] In an optional embodiment, the connecting cable is a steel wire or a coded tape.

[0018] In an optional embodiment, the ultrasonic sensor is electrically connected to the servo mechanism to feed back the measured second ultrasonic wave transmission time to the servo mechanism.

[0019] The servo liquid level meter provided by the utility model has an ultrasonic sensor electrically connected to a servo mechanism, thereby ensuring the stability of data transmission, feeding back the measured second ultrasonic transmission time to the servo mechanism, and the data processing process is concentrated in the servo mechanism, thus simplifying the structure of the liquid level sensor and ensuring the accuracy of the measurement result.

[0020] In an optional embodiment, the liquid level sensor further includes: a temperature sensor and a density sensor. When the liquid level sensor is completely immersed in the liquid, the temperature sensor detects the temperature data of the liquid, and the density sensor detects the density data of the liquid.

[0021] The servo liquid level meter provided by the utility model has a liquid level sensor integrated with temperature and density measurement functions, and has more complete functions, which is conducive to comprehensive detection of liquid status and ensures the safety of liquid in the storage tank.

[0022] In an optional embodiment, a power supply is provided inside the liquid level sensor for providing power to the ultrasonic sensor, the temperature sensor, and the density sensor, and the power supply is a disposable battery or a rechargeable battery.

[0023] The servo liquid level meter provided by the utility model is provided with a power supply inside the liquid level sensor to supply power to each sensor, thereby ensuring the stable operation of each sensor and further ensuring the accuracy of measurement of each parameter. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 It is a structural schematic diagram of a servo liquid level meter according to an embodiment of the utility model;

[0026] Figure 2 It is a structural schematic diagram of a servo liquid level meter according to an embodiment of the utility model when the liquid level sensor is located above the liquid level;

[0027] Figure 3 It is a structural schematic diagram of a liquid level sensor in a servo liquid level meter according to an embodiment of the utility model when immersed in the liquid surface;

[0028] Figure 4 It is a structural schematic diagram of another servo liquid level meter according to an embodiment of the utility model. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.

[0030] Now the safety management department has a clear requirement that the liquid level gauge for monitoring storage tanks must measure the liquid level in real time. Therefore, the existing multi-functional servo liquid level cannot be used as a liquid level gauge for safety interlocking, but can only be used as a metering device. This limits the scope of use of the multi-functional liquid level gauge. If users want to achieve liquid level safety monitoring and automatic metering of storage tanks, they must install two liquid level gauges, one of which (servo liquid level gauge, radar liquid level gauge or other form of liquid level gauge) is used for safety monitoring, and the other multi-functional servo liquid level gauge is used for automatic metering of storage tanks. This brings users disadvantages such as increased investment, complex installation, and increased equipment maintenance.

[0031] The utility model provides a servo level meter, which measures the distance from a liquid level sensor immersed in liquid to the liquid surface by an ultrasonic sensor to measure real-time liquid level data so as to achieve the effect of still being able to measure liquid level data when immersed in liquid.

[0032] According to an embodiment of the utility model, a servo level meter is provided, such as Figure 1 As shown, the servo level meter includes: a servo mechanism 1, a length measuring mechanism 2, a liquid level sensor 5 connected to the servo mechanism through a hub 3 and a connecting cable 4, and the liquid level sensor 5 includes: an ultrasonic sensor 51, which is located on a side of the liquid level sensor close to the servo mechanism.

[0033] Specifically, the liquid level sensor 5 can also be called a liquid level sensor or a multifunctional float. The liquid level sensor 5 of this embodiment is an original intelligent float with an ultrasonic sensor 51 added. The original intelligent float has built-in temperature sensor 52, density sensor 53, oil-water interface sensor, etc., which are used to measure relevant parameters of the liquid. This is only used as an example, but not limited to this.

[0034] The hub 3 and the connecting cable 4 are used to drive the liquid level sensor 5 to move up and down.

[0035] Specifically, the main function of the hub 3 is to rotate according to the control instruction of the servo mechanism 1, thereby retracting or releasing the connecting cable 4, so that the connecting cable 4 drives the liquid level sensor 5 to move up and down, and measures the relevant parameters of the liquid according to actual needs. Some parameters require the liquid level sensor 5 to be immersed in different positions inside the liquid for measurement, and some parameters can be measured above the liquid surface, so the hub 3 and the connecting cable 4 are required to drive the liquid level sensor 5 to move up and down to achieve the purpose of measuring various parameters.

[0036] The length measuring mechanism 2 is connected to the servo mechanism 1 and is used to measure the length of the connecting cable 4 from the hub 3 to the liquid level sensor 5 .

[0037] Specifically, the length measuring mechanism 2 is used to measure the length of the connecting cable 4 from the hub 3 to the liquid level sensor 5, and then transmit the measured length of the connecting cable 4 to the servo mechanism 1 for other data calculation. Optionally, the length measuring mechanism 2 can measure the length of the connecting cable 4 according to the rotation angle of the hub 3, which is only an example, but not limited to this.

[0038] When the liquid level sensor 5 is completely immersed in the liquid, the ultrasonic sensor 51 is used to detect the distance from the ultrasonic sensor 5 to the liquid surface, and the servo mechanism 1 determines the first liquid level data of the liquid according to the distance from the liquid level sensor 5 to the liquid surface and the length of the connecting cable 4 .

[0039] Specifically, the principle of the ultrasonic sensor 51 is to measure the propagation time difference between the transmitted and received ultrasonic waves in the propagation medium, and to calculate the distance from the ultrasonic sensor 51 to the target object in combination with the propagation speed of the ultrasonic wave in the propagation medium. Here, the distance from the ultrasonic sensor 51 to the liquid surface is measured, so that the liquid level sensor 5 can still measure the liquid level in real time when it is immersed in the liquid.

[0040] The servo liquid level meter provided in this embodiment uses an ultrasonic sensor 51 to measure the distance between the liquid level sensor 5 and the liquid surface when the liquid level sensor 5 is immersed in the liquid, thereby determining whether the liquid level has changed and calculating real-time liquid level data, thereby ensuring that the liquid level sensor 5 can detect and measure the liquid level in real time while measuring other parameters while being immersed in the liquid. The implementation method is simple and the equipment is easy to maintain.

[0041] In an optional embodiment, if Figure 2 As shown, when the liquid level sensor 5 floats above the liquid surface, the length measuring mechanism 2 measures the first length of the connecting rope 4, and the servo connection mechanism determines the second liquid level data of the liquid according to the first length and the buoyancy of the liquid level sensor 5.

[0042] Specifically, the liquid level sensor 5 mainly performs liquid level measurement based on the principle of buoyancy balance. The specific measurement process is prior art and will not be described in detail here.

[0043] The servo liquid level meter provided in this embodiment measures the liquid level data of the liquid in a traditional manner when the liquid level sensor 5 floats above the liquid surface. At this time, the ultrasonic sensor 51 does not affect the measurement of the liquid level, thereby ensuring the measurement accuracy and saving costs without adding other equipment.

[0044] In an optional embodiment, if Figure 3 As shown, when the liquid level sensor 5 is completely immersed in the liquid, the ultrasonic sensor 51 detects the real-time distance from the liquid surface according to the propagation speed of the ultrasonic wave in the liquid and the first ultrasonic wave transmission time.

[0045] D=V×t / 2

[0046] Wherein, D represents the real-time distance from the ultrasonic sensor 51 to the liquid surface, V represents the propagation speed of the ultrasonic wave in the liquid, and t represents the second ultrasonic wave transmission time. The propagation speed is calculated based on the first length, the second length, the third length, and the second ultrasonic wave transmission time:

[0047] V=2(H2-H1-hc) / t

[0048] Wherein, H1 represents the first length, H2 represents the second length, hc represents the third length, and t represents the second ultrasonic transmission time.

[0049] The second length is the length of the connecting rope 4 measured by the length measuring mechanism 2 when the liquid level sensor 5 is completely immersed in the liquid. The third length is the distance from the ultrasonic sensor 51 to the liquid surface when the liquid level sensor 5 floats above the liquid surface. The second ultrasonic transmission time is the time from the ultrasonic sensor 51 emitting the ultrasonic wave to receiving the returned ultrasonic wave when the length of the connecting rope 4 is the second length.

[0050] Specifically, when the servo level meter works normally, the liquid level sensor 5 is located above the liquid surface to measure the liquid level data. When it is necessary to measure other physical parameters of the liquid such as temperature and density, the liquid level sensor 5 is immersed in the liquid at various height positions for measurement under the action of its own gravity and the release of the hub 3 and the connecting cable 4. It is assumed that the liquid level data of the liquid remains unchanged during the process of the liquid level sensor 5 descending to the target position. Therefore, the propagation distance of the ultrasonic wave can be determined by using the changing length of the connecting cable 4 and the distance from the ultrasonic sensor 51 to the liquid surface when the liquid level sensor 5 floats above the liquid surface, and then the propagation distance of the ultrasonic wave and the second ultrasonic wave transmission time are used to correct the propagation speed of the ultrasonic sensor 51 in the liquid.

[0051] It should be noted that the third length is the distance from the ultrasonic sensor 51 to the liquid surface when the liquid level sensor 5 floats above the liquid surface. It can be measured and calculated using the buoyancy of the liquid level sensor and its overall height. This is only an example, but not limited to this. The specific measurement and calculation process will not be repeated here.

[0052] After calculating the propagation speed of ultrasound in the liquid, when measuring other physical parameters of the liquid, the ultrasonic sensor 51 can be used to measure the time difference between transmitting and receiving ultrasound in real time, and then the distance from the liquid level sensor 5 to the liquid surface can be calculated using the time difference of the ultrasound and the propagation speed of the ultrasound.

[0053] The servo mechanism 1 obtains the first liquid level data of the liquid according to the real-time distance from the liquid level sensor 5 to the liquid surface and the second liquid level data.

[0054] The servo liquid level meter provided in this embodiment corrects the transmission speed of ultrasonic waves in the liquid by changing the length of the connecting rope 4 when the liquid level sensor 5 is immersed in the liquid and when the liquid level sensor 5 floats above the liquid surface, thereby reducing the measurement error caused by inaccurate liquid density, making the distance measured by the ultrasonic sensor 51 more accurate, and ultimately achieving high-precision measurement of liquid level data.

[0055] In an optional embodiment, the calculation formula for the servo mechanism 1 to obtain the first liquid level data of the liquid according to the real-time distance from the liquid level sensor 5 to the liquid surface and the second liquid level data is:

[0056] Ht=(D-(H2-H1-hc))+H

[0057] Wherein, Ht represents the first liquid level data of the liquid, and H represents the second liquid level data of the liquid.

[0058] Specifically, (H2-H1-hc) represents the initial distance from the liquid level sensor 5 to the liquid surface when the liquid level sensor 5 is just immersed in the target position in the liquid. The real-time distance from the liquid level sensor 5 to the liquid surface is subtracted from the initial distance to obtain the change in liquid level. The real-time first liquid level data can be obtained by adding the change in liquid level to the initial second liquid level data. When the liquid level sensor 5 is stationary in the liquid, if the first liquid level data changes, the ultrasonic sensor 51 can be used to accurately determine and timely monitor the change in liquid level.

[0059] The servo liquid level meter provided in this embodiment uses an ultrasonic sensor 51 to measure the real-time distance between the liquid level sensor 5 and the liquid surface, and calculates the first liquid level data of the liquid in combination with the second liquid level data of the liquid. The calculation method is simple and convenient, and has a high accuracy rate.

[0060] In an optional embodiment, if Figure 4 As shown, the servo level meter further includes: an alarm device 6, which is connected to the servo mechanism 1 and issues an alarm when the first liquid level data exceeds a preset liquid level threshold.

[0061] Specifically, the alarm device 6 may be a buzzer or a warning light, or may be displayed on the control interface of the servo level meter in the form of an information prompt, which is only taken as an example but not limited thereto.

[0062] In the servo level meter provided in this embodiment, when the first liquid level data exceeds the preset liquid level threshold, the alarm device 6 sends out an alarm to prompt the staff to take corresponding measures in time to avoid the danger of excessively high liquid level, thereby ensuring the safety of liquid storage.

[0063] In an optional implementation, the ultrasonic sensor 51 includes an ultrasonic transmitter and an ultrasonic receiver, and the direction in which the ultrasonic transmitter sends ultrasonic waves is opposite to the direction in which the ultrasonic receiver receives ultrasonic waves.

[0064] When the liquid level sensor 5 is completely immersed in the liquid, the ultrasonic wave emitted by the ultrasonic transmitter of the ultrasonic sensor 51 is perpendicular to the liquid surface.

[0065] Specifically, the ultrasonic sensor 51 can be embedded in the position where the liquid level sensor 5 is connected to the connecting cable 4, and a hole can be used to ensure that the ultrasonic sensor 51 transmits and receives ultrasonic waves only in the liquid and is not blocked or affected by other objects. The directions in which the transmitter and receiver of the ultrasonic sensor 51 receive ultrasound should be perpendicular to the liquid surface to ensure the accuracy of the measurement.

[0066] In the servo liquid level meter provided in this embodiment, the ultrasonic sensor 51 is positioned so that the propagation direction of the ultrasonic wave is perpendicular to the liquid surface, ensuring that the propagation distance of the ultrasonic wave is the minimum distance from the ultrasonic sensor 51 to the liquid surface, thereby improving the accuracy of the measurement.

[0067] In an optional embodiment, the connecting rope 4 is a steel wire or a coding tape. Alternatively, the connecting rope 4 can also be other flexible cables, which is only used as an example, but not limited thereto.

[0068] In an optional implementation, the ultrasonic sensor 51 is electrically connected to the servo mechanism 1 to feed back the measured second ultrasonic wave transmission time to the servo mechanism 1 .

[0069] Specifically, the ultrasonic sensor 51 and the servo mechanism 1 may be connected by other communication methods as long as data transmission can be achieved. Here, electrical connection is taken as an example. This implementation method is simple and efficient, and the data transmission is stable.

[0070] In the servo level meter provided in this embodiment, the ultrasonic sensor 51 is electrically connected to the servo mechanism 1, which ensures the stability of data transmission, feeds back the measured second ultrasonic transmission time to the servo mechanism 1, and the data processing process is concentrated in the servo mechanism 1, which simplifies the structure of the liquid level sensor 5 and ensures the accuracy of the measurement result.

[0071] In an optional embodiment, if Figure 4 As shown, the liquid level sensor 5 further includes: a temperature sensor 52 and a density sensor 53. When the liquid level sensor 5 is completely immersed in the liquid, the temperature sensor 52 detects the temperature data of the liquid, and the density sensor 53 detects the density data of the liquid.

[0072] Specifically, the liquid level sensor 5 also includes an oil-water interface sensor, etc. The liquid level sensor 5 integrating sensors for detecting different parameters is selected according to actual needs. This is only used as an example, but not limited to this.

[0073] The servo liquid level meter provided in this embodiment has a liquid level sensor 5 that integrates temperature and density measurement functions, and has more complete functions, which is conducive to comprehensive detection of liquid status and ensuring the safety of liquid in the storage tank.

[0074] In an optional embodiment, a power supply 54 is provided inside the liquid level sensor 5 for providing power to the ultrasonic sensor 51, the temperature sensor 52, and the density sensor 53. The power supply 54 is a disposable battery or a rechargeable battery.

[0075] Specifically, when the power supply 54 is a rechargeable battery, it can be connected to an external power source through the connecting cable 4, or the power supply 54 of the servo mechanism 1 can be used to charge the rechargeable battery. A power management module for the rechargeable battery can also be added to the servo mechanism 1. This is only an example, but not limited to this.

[0076] The servo liquid level meter provided in this embodiment is provided with a power supply 54 inside the liquid level sensor 5 to supply power to each sensor, thereby ensuring the stable operation of each sensor and further ensuring the accuracy of the measurement of each parameter.

[0077] Although the embodiments of the present invention are described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A servo level meter, comprising: A servo mechanism, a length measuring mechanism, and a liquid level sensor connected to the servo mechanism through a hub and a connecting cable, wherein the liquid level sensor comprises: an ultrasonic sensor, the ultrasonic sensor being located on a side of the liquid level sensor close to the servo mechanism; The hub and the connecting cable are used to drive the liquid level sensor to move up and down; The length measuring mechanism is connected to the servo mechanism and is used to measure the length of the connecting cable from the hub to the liquid level sensor; When the liquid level sensor is completely immersed in the liquid, the ultrasonic sensor is used to detect the distance from the ultrasonic sensor to the liquid surface, and the servo mechanism determines the first liquid level data of the liquid according to the distance from the liquid level sensor to the liquid surface and the length of the connecting cable.

2. The servo level meter according to claim 1, characterized in that: The servo liquid level meter also includes: an alarm device, which is connected to the servo mechanism and issues an alarm when the first liquid level data exceeds a preset liquid level threshold.

3. The servo level meter according to claim 1, characterized in that: The ultrasonic sensor comprises an ultrasonic transmitter and an ultrasonic receiver, wherein the direction in which the ultrasonic transmitter transmits ultrasonic waves is opposite to the direction in which the ultrasonic receiver receives ultrasonic waves; When the liquid level sensor is completely immersed in the liquid, the ultrasonic wave emitted by the ultrasonic transmitter of the ultrasonic sensor is perpendicular to the liquid surface.

4. The servo level meter according to claim 1, characterized in that: The connecting rope is a steel wire or a coding tape.

5. The servo level meter according to claim 3, characterized in that: The ultrasonic sensor is electrically connected to the servo mechanism to feed back the measured second ultrasonic wave transmission time to the servo mechanism.

6. The servo level meter according to claim 1, characterized in that: The liquid level sensor further comprises: a temperature sensor and a density sensor. When the liquid level sensor is completely immersed in liquid, the temperature sensor detects temperature data of the liquid, and the density sensor detects density data of the liquid.

7. The servo level meter according to claim 1, characterized in that: A power supply is provided inside the liquid level sensor for providing power to the ultrasonic sensor, the temperature sensor and the density sensor. The power supply is a disposable battery or a rechargeable battery.

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